[gatein-commits] gatein SVN: r2652 - in portal/trunk/docs/reference-guide/en: images and 5 other directories.

Author: thomas.heute(a)jboss.com Date: 2010-04-15 06:43:53 -0400 (Thu, 15 Apr 2010) New Revision: 2652 Added: portal/trunk/docs/reference-guide/en/images/Advanced/ portal/trunk/docs/reference-guide/en/images/Advanced/Foundations/ portal/trunk/docs/reference-guide/en/modules/Advanced/ portal/trunk/docs/reference-guide/en/modules/Advanced/Foundations.xml Removed: portal/trunk/docs/reference-guide/en/images/PortalDevelopment/Foundations/ portal/trunk/docs/reference-guide/en/modules/PortalDevelopment/Foundations.xml Modified: portal/trunk/docs/reference-guide/en/master.xml portal/trunk/docs/reference-guide/en/modules/PortalDevelopment.xml Log: Moved Foundation chapter in a new "Advanced" section Copied: portal/trunk/docs/reference-guide/en/images/Advanced/Foundations (from rev 2648, portal/trunk/docs/reference-guide/en/images/PortalDevelopment/Foundations) Modified: portal/trunk/docs/reference-guide/en/master.xml =================================================================== --- portal/trunk/docs/reference-guide/en/master.xml 2010-04-15 10:32:55 UTC (rev 2651) +++ portal/trunk/docs/reference-guide/en/master.xml 2010-04-15 10:43:53 UTC (rev 2652) @@ -89,4 +89,5 @@ <xi:include href="modules/GadgetDevelopment.xml" xmlns:xi="http://www.w3.org/2001/XInclude" /> <xi:include href="modules/AuthenticationAndIdentity.xml" xmlns:xi="http://www.w3.org/2001/XInclude" /> <xi:include href="modules/WSRP.xml" xmlns:xi="http://www.w3.org/2001/XInclude" /> + <xi:include href="modules/Advanced.xml" xmlns:xi="http://www.w3.org/2001/XInclude" /> </book> Copied: portal/trunk/docs/reference-guide/en/modules/Advanced/Foundations.xml (from rev 2648, portal/trunk/docs/reference-guide/en/modules/PortalDevelopment/Foundations.xml) =================================================================== --- portal/trunk/docs/reference-guide/en/modules/Advanced/Foundations.xml (rev 0) +++ portal/trunk/docs/reference-guide/en/modules/Advanced/Foundations.xml 2010-04-15 10:43:53 UTC (rev 2652) @@ -0,0 +1,733 @@ +<?xml version='1.0' encoding='utf-8' ?> +<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [ +<!ENTITY % BOOK_ENTITIES SYSTEM "../../Reference_Guide.ent"> +%BOOK_ENTITIES; +]> +<section id="sect-Reference_Guide-Foundations"> + + <title>Foundations</title> + <section id="sect-Reference_Guide-Foundations-Kernel"> + <title>GateIn Kernel</title> + <para> + &PRODUCT; is built as a set of services on top of a dependency injection kernel. The kernel provides configuration, lifecycle handling, component scopes, and some core services. + </para> + <para> + Service components exist in two scopes. First scope is represented by <emphasis role="bold">RootContainer</emphasis> - it contains services that exist independently of any portal, and can be + accessed by all portals. + </para> + <para> + Second scope is portal-private in the form of <emphasis role="bold">PortalContainer</emphasis>. Each portal lives in an instance of PortalContainer. + This scope contains services that are common for a set of portals, and services which should not be shared by all portals. + </para> + <para> + <mediaobject> + <imageobject role="html"> + <imagedata fileref="images/Advanced/Foundations/PortalContainers.png" format="PNG" align="center" scale="100" /> + </imageobject> + <imageobject role="fo"> + <imagedata fileref="images/Advanced/Foundations/PortalContainers.png" format="PNG" align="center" contentwidth="150mm" /> + </imageobject> + </mediaobject> + </para> + <para> + Whenever a specific service is looked up through PortalContainer, and the service is not available, the lookup is + delegated further up to RootContainer. We can therefore have default instance of a certain component in + RootContainer, and portal specific instances in some or all PortalContainers, that override the default + instance. + </para> + <para> + Whenever your portal application has to be integrated more closely with GateIn services, the way to do it is by + looking up these services through PortalContainer. Be careful though - only officially documented services + should be accessed this way, and used according to documentation, as most of the services are an implementation + detail of GateIn, and subject to change without notice. + </para> + </section> + + <section id="sect-Reference_Guide-Foundations-Configuring_services"> + <title>Configuring services</title> + + <para>GateIn Kernel uses dependency injection to create services based on <emphasis role="bold">configuration.xml</emphasis> configuration files. + The location of the configuration files determines if services are placed into RootContainer scope, or into PortalContainer scope. + All configuration.xml files located at <emphasis role="bold">conf/configuration.xml</emphasis> in the classpath (any directory, or any jar in the classpath) will have their + services configured at RootContainer scope. + All configuration.xml files located at <emphasis role="bold">conf/portal/configuration.xml</emphasis> in the classpath will have their services configured at PortalContainer scope. + Additionally, <emphasis role="bold">portal extensions</emphasis> can contain configuration in <emphasis role="bold">WEB-INF/conf/configuration.xml</emphasis>, and will also have their services configured at PortalContainer scope. + </para> + <note> + <para>Portal extensions are described later on.</para> + </note> + + </section> + + <section id="sect-Reference_Guide-Foundations-Configuration_syntax"> + <title>Configuration syntax</title> + + <section id="sect-Reference_Guide-Foundations-Configuration_syntax-Component"> + <title>Components</title> + <para>A service component is defined in <emphasis role="bold">configuration.xml</emphasis> by using <emphasis role="bold">&lt;component&gt;</emphasis> element.</para> + <para>There is only one required information when defining a service - the service implementation class, specified using <emphasis role="bold">&lt;type&gt;</emphasis></para> + <para>Every component has a <emphasis role="bold">&lt;key&gt;</emphasis> that identifies it. If not explicitly set, a key defaults to the value of &lt;type&gt;. + If key can be loaded as a class, a Class object is used as a key, otherwise a String is used.</para> + <para>The usual approach is to specify an interface as a key.</para> + + <example> + <title>Example of service component configuration:</title> + <programlisting role="XML"><![CDATA[ +<?xml version="1.0" encoding="ISO-8859-1"?> +<configuration + xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" + xsi:schemaLocation="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd + http://www.exoplaform.org/xml/ns/kernel_1_0.xsd" + xmlns="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd"> + <component> + <key>org.exoplatform.services.database.HibernateService</key> + <type>org.exoplatform.services.database.impl.HibernateServiceImpl</type> + + ... + + </component> +</configuration> + ]]></programlisting> + </example> + </section> + <section id="sect-Reference_Guide-Foundations-Configuration_syntax-External_plugins"> + <title>External Plugins</title> + <para>GateIn Kernel supports non-component objects that can be configured, instantiated, and injected into registered components, using method calls. + The mechanism is called 'plugins', and allows portal extensions to add additional configurations to core services.</para> + <para>External plugin is defined by using <emphasis role="bold">&lt;external-component-plugins&gt;</emphasis> wrapper element which contains one or more + <emphasis role="bold">&lt;component-plugin&gt;</emphasis> definitions. &lt;external-component-plugins&gt; uses <emphasis role="bold">&lt;target-component&gt;</emphasis> to specify a target service component that will receive injected objects.</para> + <para>Every &lt;component-plugin&gt; defines an implementation type, and a method on target component + to use for injection (<emphasis role="bold">&lt;set-method&gt;</emphasis>). </para> + <para>A plugin implementation class has to implement <emphasis role="bold">org.exoplatform.container.component. ComponentPlugin</emphasis> interface.</para> + <para>In the following example <emphasis role="bold">PortalContainerDefinitionPlugin</emphasis> implements ComponentPlugin:</para> + <example> + <title>PortalContainerDefinitionPlugin</title> + <programlisting role="XML"><![CDATA[ +<?xml version="1.0" encoding="UTF-8"?> +<configuration + xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" + xsi:schemaLocation="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd + http://www.exoplaform.org/xml/ns/kernel_1_0.xsd" + xmlns="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd"> + + <external-component-plugins> + <target-component>org.exoplatform.container.definition.PortalContainerConfig</target-component> + <component-plugin> + <!-- The name of the plugin --> + <name>Add PortalContainer Definitions</name> + + <!-- The name of the method to call on the PortalContainerConfig + in order to register the PortalContainerDefinitions --> + <set-method>registerPlugin</set-method> + + <!-- The fully qualified name of the PortalContainerDefinitionPlugin --> + <type>org.exoplatform.container.definition.PortalContainerDefinitionPlugin</type> + + ... + + </component-plugin> + </external-component-plugins> +</configuration> + ]]></programlisting> + </example> + </section> + + <section id="sect-Reference_Guide-Foundations-Configuration_syntax-Includes"> + <title>Includes, and special URLs</title> + <para>It is possible to break <emphasis role="bold">configuration.xml</emphasis> file into many smaller files, that are then included into a 'master' configuration file. + The included files are complete configuration xml documents by themselves - they are not fragments of text.</para> + <para>An example configuration.xml that 'outsources' its content into several files:</para> + <programlisting role="XML"><![CDATA[ +<configuration xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" + xsi:schemaLocation="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd + http://www.exoplaform.org/xml/ns/kernel_1_0.xsd" + xmlns="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd"> + + <import>war:/conf/sample-ext/jcr/jcr-configuration.xml</import> + <import>war:/conf/sample-ext/portal/portal-configuration.xml</import> + +</configuration> + ]]></programlisting> + + <para>We see a special URL being used to reference another configuration file. + URL schema <emphasis role="bold">'war:'</emphasis> means, that the path that follows is resolved relative to current PortalContainer's servlet context resource path, starting at <emphasis role="bold">WEB-INF</emphasis> as a root.</para> + <note> + <para>Current PortalContainer is really a newly created PortalContainer, as war: URLs only make sense for PortalContainer scoped configuration.</para> + </note> + <para>Also, thanks to extension mechanism, the servlet context used for resource loading is a <emphasis role="bold">unified servlet context</emphasis> (as explaned in a later section).</para> + <para>To have include path resolved relative to current classpath (context classloader), use <emphasis role="bold">'jar:'</emphasis> URL schema.</para> + </section> + + <section id="sect-Reference_Guide-Foundations-Configuration_syntax-Special_vars"> + <title>Special variables</title> + <para>Configuration files may contain a <emphasis role="bold">special variable</emphasis> reference <emphasis>${container.name.suffix}</emphasis>. This variable resolves to the name of the current portal container, prefixed by underscore (_). + This facilitates reuse of configuration files in situations where portal specific unique names need to be assigned to some resources + (i.e. JNDI names, Database / DataSource names, JCR repository names, etc ...).</para> + <para>This variable is only defined when there is a current PortalContainer available - only for PortalContainer scoped services.</para> + <para>A good example for this is <emphasis role="bold">HibernateService</emphasis>:</para> + <example id="sect-Reference_Guide-Foundations-Configuration_syntax-Special_vars-Example"> + <title>HibernateService using variables</title> + <programlisting role="XML"><![CDATA[ +<?xml version="1.0" encoding="ISO-8859-1"?> +<configuration + xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" + xsi:schemaLocation="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd + http://www.exoplaform.org/xml/ns/kernel_1_0.xsd" + xmlns="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd"> + + <component> + <key>org.exoplatform.services.database.HibernateService</key> + <jmx-name>database:type=HibernateService</jmx-name> + <type>org.exoplatform.services.database.impl.HibernateServiceImpl</type> + <init-params> + <properties-param> + <name>hibernate.properties</name> + <description>Default Hibernate Service</description> + <property name="hibernate.show_sql" value="false" /> + <property name="hibernate.cglib.use_reflection_optimizer" value="true" /> + <property name="hibernate.connection.url" + value="jdbc:hsqldb:file:../temp/data/exodb${container.name.suffix}" /> + <property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver" /> + <property name="hibernate.connection.autocommit" value="true" /> + <property name="hibernate.connection.username" value="sa" /> + <property name="hibernate.connection.password" value="" /> + <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect" /> + <property name="hibernate.c3p0.min_size" value="5" /> + <property name="hibernate.c3p0.max_size" value="20" /> + <property name="hibernate.c3p0.timeout" value="1800" /> + <property name="hibernate.c3p0.max_statements" value="50" /> + </properties-param> + </init-params> + </component> +</configuration> + ]]></programlisting> + </example> + + </section> + </section> + + + <section id="sect-Reference_Guide-Foundations-Init_params"> + <title>InitParams configuration object</title> + + <para> + <literal>InitParams</literal> is a configuration object that is essentially a map of key-value pairs, + where key is always a <literal>String</literal>, and value can be any type that can be described + using kernel configuration xml. + </para> + + <para> + Service components that form the &PRODUCT; insfrastructure use <literal>InitParams</literal> object to configure themselves. + A component can have one instance of InitParams injected at most. If the service component's constructor takes InitParams + as any of the parameters it will automatically be injected at component instantiation time. The xml configuration + for a service component that expects InitParams object must include &lt;init-params&gt; element (even if an empty one). + </para> + + <para> + Let's use an example to see how the kernel xml configuration syntax looks for creating <literal>InitParams</literal> instances. + </para> + + <example> + <title>InitParams - properties-param</title> + <programlisting role="XML"><![CDATA[ +<component> + <key>org.exoplatform.services.naming.InitialContextInitializer</key> + <type>org.exoplatform.services.naming.InitialContextInitializer</type> + <init-params> + <properties-param> + <name>default-properties</name> + <description>Default initial context properties</description> + <property name="java.naming.factory.initial" + value="org.exoplatform.services.naming.SimpleContextFactory" /> + </properties-param> + </init-params> +</component> + ]]></programlisting> + </example> + + <para> + InitParams object description begins with &lt;init-params&gt; element. It can have zero or more children elements + each of which is one of &lt;value-param&gt;, &lt;values-param&gt;, &lt;properties-param&gt;, or &lt;object-param&gt;. + Each of these child elements takes a &lt;name&gt; that serves as a map entry key, and an optional &lt;description&gt;. + It also takes a type-specific value specification. + </para> + + <para> + For &lt;properties-param&gt; the value specification is in the form of one or more &lt;property&gt; elements, + each of which specifies two strings - a property name, and a property value. Each &lt;properties-params&gt; + defines one <literal>java.util.Properties</literal> instance. Also see + <xref linkend="sect-Reference_Guide-Foundations-Configuration_syntax-Special_vars-Example"/> for an example. + </para> + + <example> + <title>InitParams - value-param</title> + <programlisting role="XML"><![CDATA[ +<component> + <key>org.exoplatform.services.transaction.TransactionService</key> + <type>org.exoplatform.services.transaction.impl.jotm.TransactionServiceJotmImpl</type> + <init-params> + <value-param> + <name>timeout</name> + <value>5</value> + </value-param> + </init-params> +</component> + ]]></programlisting> + </example> + + <para> + For &lt;value-param&gt; the value specification is in the form of &lt;value&gt; element, which defines + one <literal>String</literal> instance. + </para> + + <example> + <title>InitParams - values-param</title> + <programlisting role="XML"><![CDATA[ +<component> + <key>org.exoplatform.services.resources.ResourceBundleService</key> + <type>org.exoplatform.services.resources.impl.SimpleResourceBundleService</type> + <init-params> + <values-param> + <name>classpath.resources</name> + <description>The resources that start with the following package name should be load from file system</description> + <value>locale.portlet</value> + </values-param> + + <values-param> + <name>init.resources</name> + <description>Store the following resources into the db for the first launch </description> + <value>locale.test.resources.test</value> + </values-param> + + <values-param> + <name>portal.resource.names</name> + <description>The properties files of the portal , those file will be merged + into one ResourceBundle properties </description> + <value>local.portal.portal</value> + <value>local.portal.custom</value> + </values-param> + </init-params> +</component> + ]]></programlisting> + </example> + + <para> + For &lt;values-param&gt; the value specification is in the form of one or more &lt;value&gt; elements, + each of which represents one <literal>String</literal> instance, where all the <literal>String</literal> values + are then collected into a <literal>java.util.List</literal> instance. + </para> + + <example> + <title>InitParams - object-param</title> + <programlisting role="XML"><![CDATA[ +<component> + <key>org.exoplatform.services.cache.CacheService</key> + <jmx-name>cache:type=CacheService</jmx-name> + <type>org.exoplatform.services.cache.impl.CacheServiceImpl</type> + <init-params> + <object-param> + <name>cache.config.default</name> + <description>The default cache configuration</description> + <object type="org.exoplatform.services.cache.ExoCacheConfig"> + <field name="name"> + <string>default</string> + </field> + <field name="maxSize"> + <int>300</int> + </field> + <field name="liveTime"> + <long>300</long> + </field> + <field name="distributed"> + <boolean>false</boolean> + </field> + <field name="implementation"> + <string>org.exoplatform.services.cache.concurrent.ConcurrentFIFOExoCache</string> + </field> + </object> + </object-param> + </init-params> +</component> + ]]></programlisting> + </example> + + <para> + For &lt;object-param&gt; in our case, the value specification comes in a form of &lt;object&gt; element, which is + used for POJO style object specification (you specify an implementation class - &lt;type&gt;, and property values - &lt;field&gt;). + </para> + + <para> + Also see <xref linkend="sect-Reference_Guide-Foundations-Configuring_portal_Container_declaration_example" /> + for an example of specifying a field of <literal>Collection</literal> type. + </para> + + <para> + The <literal>InitParams</literal> structure - the names and types of entries is specific for each service, + as it is the code inside service components's class that decides what entry names to look up and what types + it expects to find. + </para> + </section> + + + <section id="sect-Reference_Guide-Foundations-Configuring_portal"> + <title>Configuring a portal container</title> + + <para> + A <emphasis role="bold">portal container</emphasis> is defined by several attributes. + </para> + + <para> + First, there is a <emphasis role="bold">portal container name</emphasis>, which is always equal to URL context to which the current portal is bound. + </para> + + <para> + Second, there is a <emphasis role="bold">REST context name</emphasis>, which is used for REST access to portal application - every portal has + exactly one (unique) REST context name. + </para> + + <para> + Then, there is a <emphasis role="bold">realm name</emphasis> which is the name of security realm used for authentication when users log into the + portal. + </para> + + <para> + Finally, there is a list of <emphasis role="bold">Dependencies</emphasis> - other web applications, whose resources are visible to current + portal (via extension mechanism described later), and are searched in the specified order. + </para> + + <example id="sect-Reference_Guide-Foundations-Configuring_portal_Container_declaration_example"> + <title>Portal container declaration example</title> + <programlisting role="XML"><![CDATA[ +<?xml version="1.0" encoding="UTF-8"?> +<configuration + xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" + xsi:schemaLocation="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd + http://www.exoplaform.org/xml/ns/kernel_1_0.xsd" + xmlns="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd"> + + <external-component-plugins> + <!-- The full qualified name of the PortalContainerConfig --> + <target-component>org.exoplatform.container.definition.PortalContainerConfig</target-component> + + <component-plugin> + <!-- The name of the plugin --> + <name>Add PortalContainer Definitions</name> + + <!-- The name of the method to call on the PortalContainerConfig + in order to register the PortalContainerDefinitions --> + <set-method>registerPlugin</set-method> + + <!-- The full qualified name of the PortalContainerDefinitionPlugin --> + <type>org.exoplatform.container.definition.PortalContainerDefinitionPlugin</type> + + <init-params> + <object-param> + <name>portal</name> + <object type="org.exoplatform.container.definition.PortalContainerDefinition"> + <!-- The name of the portal container --> + <field name="name"><string>portal</string></field> + + <!-- The name of the context name of the rest web application --> + <field name="restContextName"><string>rest</string></field> + + <!-- The name of the realm --> + <field name="realmName"><string>exo-domain</string></field> + + <!-- All the dependencies of the portal container ordered by loading priority --> + <field name="dependencies"> + <collection type="java.util.ArrayList"> + <value> + <string>eXoResources</string> + </value> + <value> + <string>portal</string> + </value> + <value> + <string>dashboard</string> + </value> + <value> + <string>exoadmin</string> + </value> + <value> + <string>eXoGadgets</string> + </value> + <value> + <string>eXoGadgetServer</string> + </value> + <value> + <string>rest</string> + </value> + <value> + <string>web</string> + </value> + <value> + <string>wsrp-producer</string> + </value> + <!-- The sample-ext has been added at the end of the dependency list + in order to have the highest priority --> + <value> + <string>sample-ext</string> + </value> + </collection> + </field> + </object> + </object-param> + </init-params> + </component-plugin> + </external-component-plugins> +</configuration> + ]]> +</programlisting> + </example> + + + <note> + <para>Dependencies are part of the extension mechanism.</para> + </note> + + <para> + Every <emphasis role="bold">portal container</emphasis> is represented by a <emphasis role="bold">PortalContainer instance</emphasis>, which contains: + <itemizedlist> + <listitem> + <para>associated <emphasis role="bold">ExoContainerContext</emphasis>, which contains information about the portal</para> + </listitem> + <listitem> + <para><emphasis role="bold">unified servlet context</emphasis>, for web-archive-relative resource loading</para> + </listitem> + <listitem> + <para><emphasis role="bold">unified classloader</emphasis>, for classpath based resource loading</para> + </listitem> + <listitem> + <para>methods for retrieving services</para> + </listitem> + </itemizedlist> + </para> + + <para> + <emphasis role="bold">Unified servlet context</emphasis>, and <emphasis role="bold">unified classloader</emphasis> are part of the <emphasis role="bold">extension mechanism</emphasis> (explained in next section), + and provide standard API (ServletContext, ClassLoader) with specific resource loading behavior - visibility into associated web application archives, + configured with Dependencies property of PortalContainerDefinition. Resources from other web applications are queried in the order specified by Dependencies. + The later entries in the list override the previous ones. + </para> + </section> + + <section id="sect-Reference_Guide-Foundations-Extension_mechanism"> + <title>GateIn Extension Mechanism, and Portal Extensions</title> + + <para> + <emphasis role="bold">Extension mechanism</emphasis> is a functionality that makes it possible to override portal resources in an almost + plug-and-play fashion - just drop in a .war archive with the resources, and configure its position on the portal's + classpath. + This way any customizations of the portal don't have to involve unpacking and repacking the original portal + .war archives. Instead, you create your own .war archive with changed resources, that override the resources in + the original archive. + </para> + + <para> + A web archive packaged in a way to be used through extension mechanism is called <emphasis role="bold">portal extension</emphasis>. + </para> + <para> + There are two steps necessary to create a portal extension. + </para> + <para> + First, declare <emphasis role="bold">PortalConfigOwner</emphasis> servlet context listener in web.xml of your web application. + </para> + <example><title>Example of a portal extension called sample-ext:</title> + + <programlisting role="XML"><![CDATA[ +<?xml version="1.0" encoding="ISO-8859-1" ?> +<!DOCTYPE web-app PUBLIC -//Sun Microsystems, Inc.//DTD Web Application 2.3//EN + http://java.sun.com/dtd/web-app_2_3.dtd> +<web-app> + + <display-name>sample-ext</display-name> + + <listener> + <listener-class>org.exoplatform.container.web.PortalContainerConfigOwner</listener-class> + </listener> + + ... + +</web-app> + ]]></programlisting> + </example> + <para> + Then, add the servlet context name of this web application in proper place in the list of Dependencies of the PortalContainerDefinition + of all the portal containers that you want to have access to its resources. + </para> + <para> + After this step your web archive will be on portal's unified classpath, and unified servlet context resource path. + The later in the Dependencies list your application is, the higher priority it has when resources are loaded by portal. + </para> + + <note> + <para>See 'Configuring a portal' section for example of PortalContainerDefinition, that has sample-ext at the end of its list of Dependencies.</para> + </note> + + </section> + + + <section id="sect-Reference_Guide-Foundations-Multiple_portals"> + <title>Running Multiple Portals</title> + + <para> + It is possible to run several independent portal containers - each bound to a different URL context - within + the same JVM instance. This kind of setup is very efficient from administration and resource consumption + aspect. The most elegant way to <emphasis role="bold">reuse</emphasis> configuration for different coexisting portals is by way of extension + mechanism - by <emphasis role="bold">inheriting</emphasis> resources and configuration from existing web archives, and just <emphasis role="bold">adding</emphasis> extra resources to it, + and <emphasis role="bold">overriding</emphasis> those that need to be changed by including modified copies. + </para> + + <para> + In order for a portal application to correctly function when deployed in multiple portals, the application may + have to dynamically query the information about the current portal container. The application should not make + any assumptions about the name, and other information of the current portal, as there are now multiple different portals in play. + </para> + + <para> + At any point during request processing, or lifecycle event processing, your application can retrieve this + information through <emphasis role="bold">org.exoplatform.container. ExoContainerContext</emphasis>. + Sometimes your application needs to make sure that the proper <emphasis role="bold">PortalContainer</emphasis> + - the source of <emphasis role="bold">ExoContainerContext</emphasis> - is associated with the current call. + </para> + + <para> + If you ship servlets or servlet filters as part of your portal application, and if you need to access portal + specific resources at any time during the processing of the servlet or filter request, then you need to make + sure the servlet/filter is associated with the current container. + </para> + <para> + The proper way to do that is to make your servlet extend <emphasis role="bold">org.exoplatform.container.web. AbstractHttpServlet</emphasis> + class. + This will not only properly initialize current <emphasis role="bold">PortalContainer</emphasis> for you, but will also set the current thread's + context classloader to one that looks for resources in associated web applications in the order specified by + <emphasis role="bold">Dependencies</emphasis> configuration (as explained in Extension mechanism section). + </para> + <para> + Similarly for filters, make sure your filter class extends <emphasis role="bold">org.exoplatform.container.web. AbstractFilter</emphasis>. + Both <emphasis role="bold">AbstractHttpServlet</emphasis>, and <emphasis role="bold">AbstractFilter</emphasis> have a method <emphasis role="bold">getContainer()</emphasis>, + which returns the current <emphasis role="bold">PortalContainer</emphasis>. + + If your servlet handles the requests by implementing a <emphasis role="bold">service()</emphasis> method, you need to rename that method to match + the following signature:</para> + <programlisting role="JAVA"><![CDATA[ +/** + * Use this method instead of Servlet.service() + */ +protected void onService(ExoContainer container, HttpServletRequest req, + HttpServletResponse res) throws ServletException, IOException; + ]]></programlisting> + <note> + <para> + The reason is that AbstractHttpServlet implements service() to perform its interception, and you don't want to + overwrite (by overriding) this functionality. + </para> + </note> + <para> + You may also need to access portal information within your <emphasis role="bold">HttpSessionListener</emphasis>. Again, make sure to extend the + provided abstract class - <emphasis role="bold">org.exoplatform.container.web. AbstractHttpSessionListener</emphasis>. + Also, modify your method signatures as follows:</para> + <programlisting role="JAVA"><![CDATA[ +/** + * Use this method instead of HttpSessionListener.sessionCreated() + */ +protected void onSessionCreated(ExoContainer container, HttpSessionEvent event); + +/** + * Use this method instead of HttpSessionListener.sessionDestroyed() + */ +protected void onSessionDestroyed(ExoContainer container, HttpSessionEvent event); + ]]></programlisting> + <para> + There is another method you have to implement in this case:</para> + <programlisting role="JAVA"><![CDATA[ +/** + * Method should return true if unified servlet context, + * and unified classloader should be made available + */ +protected boolean requirePortalEnvironment(); + ]]></programlisting> + <para> + If this method returns true, current thread's context classloader is set up according to <emphasis role="bold">Dependencies</emphasis> + configuration, and availability of the associated web applications. If it returns false, the standard + application separation rules are used for resource loading (effectively turning off the + extension mechanism). This method exists on <emphasis role="bold">AbstractHttpServlet</emphasis> and <emphasis role="bold">AbstractFilter</emphasis> as well, where there is a + default implementation that automatically returns true, when it detects there is a current PortalContainer + present, otherwise it returns false. + + </para> + + <para> + We still have to explain how to properly perform <emphasis role="bold">ServletContextListener</emphasis> based initialization, when you need + access to current PortalContainer. + </para> + + <para> + GateIn has no direct control over the deployment of application archives (.war, .ear files) - it is the + application server that performs the deployment. For <emphasis role="bold">extension mechanism</emphasis> to work properly, the applications, + associated with the portal via <emphasis role="bold">Dependencies</emphasis> configuration, have to be deployed before the portal, that depends + on them, is initialized. On the other hand, these applications may require an already initialized PortalContainer + to properly initialize themselves - we have a recursive dependency problem. To resolve this problem, a + mechanism of <emphasis role="bold">initialization tasks</emphasis>, and <emphasis role="bold">task queues</emphasis>, was put in place. Web applications that depend on current + PortalContainer for their initialization have to avoid performing their initialization directly in some + ServletContextListener executed during their deployment (before any PortalContainer was initialized). Instead, + a web application should package its initialization logic into an init task of appropriate type, and only use + ServletContextListener to insert the init task instance into the proper init tasks queue. + </para> + + <para>An example of this is Gadgets application which registers Google gadgets with the current PortalContainer: + </para> + + <programlisting role="JAVA"><![CDATA[ +public class GadgetRegister implements ServletContextListener +{ + public void contextInitialized(ServletContextEvent event) + { + // Create a new post-init task + final PortalContainerPostInitTask task = new PortalContainerPostInitTask() { + + public void execute(ServletContext context, PortalContainer portalContainer) + { + try + { + SourceStorage sourceStorage = + (SourceStorage) portalContainer.getComponentInstanceOfType(SourceStorage.class); + ... + } + catch (RuntimeException e) + { + throw e; + } + catch (Exception e) + { + throw new RuntimeException("Initialization failed: ", e); + } + } + }; + + // Add post-init task for execution on all the portal containers + // that depend on the given ServletContext according to + // PortalContainerDefinitions (via Dependencies configuration) + PortalContainer.addInitTask(event.getServletContext(), task); + } +} + ]]></programlisting> + + <para> + The above example uses <emphasis role="bold">PortalContainerPostInitTask</emphasis>, which gets executed after the portal container has been + initialized. In some situations you may want to execute initialization after portal container was instantiated, + but before it was initialized - use <emphasis role="bold">PortalContainerPreInitTask</emphasis> in that case. Or, you may want to execute + initialization after all the post-init tasks have been executed - use <emphasis role="bold">PortalContainerPostCreateTask</emphasis> in that case. + </para> + + <para> + One more area that may need your attention are <emphasis role="bold">LoginModules</emphasis>. If you use custom LoginModules, that require + current ExoContainer, make sure they extend <emphasis role="bold">org.exoplatform.services.security.jaas.AbstractLoginModule</emphasis> for + proper initialization. AbstractLoginModule also takes care of the basic configuration - it recognizes two + initialization options - <emphasis role="bold">portalContainerName</emphasis>, and <emphasis role="bold">realmName</emphasis> whose values you can access via protected fields of + the same name. + </para> + + </section> + +</section> Deleted: portal/trunk/docs/reference-guide/en/modules/PortalDevelopment/Foundations.xml =================================================================== --- portal/trunk/docs/reference-guide/en/modules/PortalDevelopment/Foundations.xml 2010-04-15 10:32:55 UTC (rev 2651) +++ portal/trunk/docs/reference-guide/en/modules/PortalDevelopment/Foundations.xml 2010-04-15 10:43:53 UTC (rev 2652) @@ -1,733 +0,0 @@ -<?xml version='1.0' encoding='utf-8' ?> -<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [ -<!ENTITY % BOOK_ENTITIES SYSTEM "../../Reference_Guide.ent"> -%BOOK_ENTITIES; -]> -<section id="sect-Reference_Guide-Foundations"> - - <title>Foundations</title> - <section id="sect-Reference_Guide-Foundations-Kernel"> - <title>GateIn Kernel</title> - <para> - &PRODUCT; is built as a set of services on top of a dependency injection kernel. The kernel provides configuration, lifecycle handling, component scopes, and some core services. - </para> - <para> - Service components exist in two scopes. First scope is represented by <emphasis role="bold">RootContainer</emphasis> - it contains services that exist independently of any portal, and can be - accessed by all portals. - </para> - <para> - Second scope is portal-private in the form of <emphasis role="bold">PortalContainer</emphasis>. Each portal lives in an instance of PortalContainer. - This scope contains services that are common for a set of portals, and services which should not be shared by all portals. - </para> - <para> - <mediaobject> - <imageobject role="html"> - <imagedata fileref="images/PortalDevelopment/Foundations/PortalContainers.png" format="PNG" align="center" scale="100" /> - </imageobject> - <imageobject role="fo"> - <imagedata fileref="images/PortalDevelopment/Foundations/PortalContainers.png" format="PNG" align="center" contentwidth="150mm" /> - </imageobject> - </mediaobject> - </para> - <para> - Whenever a specific service is looked up through PortalContainer, and the service is not available, the lookup is - delegated further up to RootContainer. We can therefore have default instance of a certain component in - RootContainer, and portal specific instances in some or all PortalContainers, that override the default - instance. - </para> - <para> - Whenever your portal application has to be integrated more closely with GateIn services, the way to do it is by - looking up these services through PortalContainer. Be careful though - only officially documented services - should be accessed this way, and used according to documentation, as most of the services are an implementation - detail of GateIn, and subject to change without notice. - </para> - </section> - - <section id="sect-Reference_Guide-Foundations-Configuring_services"> - <title>Configuring services</title> - - <para>GateIn Kernel uses dependency injection to create services based on <emphasis role="bold">configuration.xml</emphasis> configuration files. - The location of the configuration files determines if services are placed into RootContainer scope, or into PortalContainer scope. - All configuration.xml files located at <emphasis role="bold">conf/configuration.xml</emphasis> in the classpath (any directory, or any jar in the classpath) will have their - services configured at RootContainer scope. - All configuration.xml files located at <emphasis role="bold">conf/portal/configuration.xml</emphasis> in the classpath will have their services configured at PortalContainer scope. - Additionally, <emphasis role="bold">portal extensions</emphasis> can contain configuration in <emphasis role="bold">WEB-INF/conf/configuration.xml</emphasis>, and will also have their services configured at PortalContainer scope. - </para> - <note> - <para>Portal extensions are described later on.</para> - </note> - - </section> - - <section id="sect-Reference_Guide-Foundations-Configuration_syntax"> - <title>Configuration syntax</title> - - <section id="sect-Reference_Guide-Foundations-Configuration_syntax-Component"> - <title>Components</title> - <para>A service component is defined in <emphasis role="bold">configuration.xml</emphasis> by using <emphasis role="bold">&lt;component&gt;</emphasis> element.</para> - <para>There is only one required information when defining a service - the service implementation class, specified using <emphasis role="bold">&lt;type&gt;</emphasis></para> - <para>Every component has a <emphasis role="bold">&lt;key&gt;</emphasis> that identifies it. If not explicitly set, a key defaults to the value of &lt;type&gt;. - If key can be loaded as a class, a Class object is used as a key, otherwise a String is used.</para> - <para>The usual approach is to specify an interface as a key.</para> - - <example> - <title>Example of service component configuration:</title> - <programlisting role="XML"><![CDATA[ -<?xml version="1.0" encoding="ISO-8859-1"?> -<configuration - xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" - xsi:schemaLocation="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd - http://www.exoplaform.org/xml/ns/kernel_1_0.xsd" - xmlns="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd"> - <component> - <key>org.exoplatform.services.database.HibernateService</key> - <type>org.exoplatform.services.database.impl.HibernateServiceImpl</type> - - ... - - </component> -</configuration> - ]]></programlisting> - </example> - </section> - <section id="sect-Reference_Guide-Foundations-Configuration_syntax-External_plugins"> - <title>External Plugins</title> - <para>GateIn Kernel supports non-component objects that can be configured, instantiated, and injected into registered components, using method calls. - The mechanism is called 'plugins', and allows portal extensions to add additional configurations to core services.</para> - <para>External plugin is defined by using <emphasis role="bold">&lt;external-component-plugins&gt;</emphasis> wrapper element which contains one or more - <emphasis role="bold">&lt;component-plugin&gt;</emphasis> definitions. &lt;external-component-plugins&gt; uses <emphasis role="bold">&lt;target-component&gt;</emphasis> to specify a target service component that will receive injected objects.</para> - <para>Every &lt;component-plugin&gt; defines an implementation type, and a method on target component - to use for injection (<emphasis role="bold">&lt;set-method&gt;</emphasis>). </para> - <para>A plugin implementation class has to implement <emphasis role="bold">org.exoplatform.container.component. ComponentPlugin</emphasis> interface.</para> - <para>In the following example <emphasis role="bold">PortalContainerDefinitionPlugin</emphasis> implements ComponentPlugin:</para> - <example> - <title>PortalContainerDefinitionPlugin</title> - <programlisting role="XML"><![CDATA[ -<?xml version="1.0" encoding="UTF-8"?> -<configuration - xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" - xsi:schemaLocation="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd - http://www.exoplaform.org/xml/ns/kernel_1_0.xsd" - xmlns="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd"> - - <external-component-plugins> - <target-component>org.exoplatform.container.definition.PortalContainerConfig</target-component> - <component-plugin> - <!-- The name of the plugin --> - <name>Add PortalContainer Definitions</name> - - <!-- The name of the method to call on the PortalContainerConfig - in order to register the PortalContainerDefinitions --> - <set-method>registerPlugin</set-method> - - <!-- The fully qualified name of the PortalContainerDefinitionPlugin --> - <type>org.exoplatform.container.definition.PortalContainerDefinitionPlugin</type> - - ... - - </component-plugin> - </external-component-plugins> -</configuration> - ]]></programlisting> - </example> - </section> - - <section id="sect-Reference_Guide-Foundations-Configuration_syntax-Includes"> - <title>Includes, and special URLs</title> - <para>It is possible to break <emphasis role="bold">configuration.xml</emphasis> file into many smaller files, that are then included into a 'master' configuration file. - The included files are complete configuration xml documents by themselves - they are not fragments of text.</para> - <para>An example configuration.xml that 'outsources' its content into several files:</para> - <programlisting role="XML"><![CDATA[ -<configuration xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" - xsi:schemaLocation="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd - http://www.exoplaform.org/xml/ns/kernel_1_0.xsd" - xmlns="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd"> - - <import>war:/conf/sample-ext/jcr/jcr-configuration.xml</import> - <import>war:/conf/sample-ext/portal/portal-configuration.xml</import> - -</configuration> - ]]></programlisting> - - <para>We see a special URL being used to reference another configuration file. - URL schema <emphasis role="bold">'war:'</emphasis> means, that the path that follows is resolved relative to current PortalContainer's servlet context resource path, starting at <emphasis role="bold">WEB-INF</emphasis> as a root.</para> - <note> - <para>Current PortalContainer is really a newly created PortalContainer, as war: URLs only make sense for PortalContainer scoped configuration.</para> - </note> - <para>Also, thanks to extension mechanism, the servlet context used for resource loading is a <emphasis role="bold">unified servlet context</emphasis> (as explaned in a later section).</para> - <para>To have include path resolved relative to current classpath (context classloader), use <emphasis role="bold">'jar:'</emphasis> URL schema.</para> - </section> - - <section id="sect-Reference_Guide-Foundations-Configuration_syntax-Special_vars"> - <title>Special variables</title> - <para>Configuration files may contain a <emphasis role="bold">special variable</emphasis> reference <emphasis>${container.name.suffix}</emphasis>. This variable resolves to the name of the current portal container, prefixed by underscore (_). - This facilitates reuse of configuration files in situations where portal specific unique names need to be assigned to some resources - (i.e. JNDI names, Database / DataSource names, JCR repository names, etc ...).</para> - <para>This variable is only defined when there is a current PortalContainer available - only for PortalContainer scoped services.</para> - <para>A good example for this is <emphasis role="bold">HibernateService</emphasis>:</para> - <example id="sect-Reference_Guide-Foundations-Configuration_syntax-Special_vars-Example"> - <title>HibernateService using variables</title> - <programlisting role="XML"><![CDATA[ -<?xml version="1.0" encoding="ISO-8859-1"?> -<configuration - xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" - xsi:schemaLocation="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd - http://www.exoplaform.org/xml/ns/kernel_1_0.xsd" - xmlns="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd"> - - <component> - <key>org.exoplatform.services.database.HibernateService</key> - <jmx-name>database:type=HibernateService</jmx-name> - <type>org.exoplatform.services.database.impl.HibernateServiceImpl</type> - <init-params> - <properties-param> - <name>hibernate.properties</name> - <description>Default Hibernate Service</description> - <property name="hibernate.show_sql" value="false" /> - <property name="hibernate.cglib.use_reflection_optimizer" value="true" /> - <property name="hibernate.connection.url" - value="jdbc:hsqldb:file:../temp/data/exodb${container.name.suffix}" /> - <property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver" /> - <property name="hibernate.connection.autocommit" value="true" /> - <property name="hibernate.connection.username" value="sa" /> - <property name="hibernate.connection.password" value="" /> - <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect" /> - <property name="hibernate.c3p0.min_size" value="5" /> - <property name="hibernate.c3p0.max_size" value="20" /> - <property name="hibernate.c3p0.timeout" value="1800" /> - <property name="hibernate.c3p0.max_statements" value="50" /> - </properties-param> - </init-params> - </component> -</configuration> - ]]></programlisting> - </example> - - </section> - </section> - - - <section id="sect-Reference_Guide-Foundations-Init_params"> - <title>InitParams configuration object</title> - - <para> - <literal>InitParams</literal> is a configuration object that is essentially a map of key-value pairs, - where key is always a <literal>String</literal>, and value can be any type that can be described - using kernel configuration xml. - </para> - - <para> - Service components that form the &PRODUCT; insfrastructure use <literal>InitParams</literal> object to configure themselves. - A component can have one instance of InitParams injected at most. If the service component's constructor takes InitParams - as any of the parameters it will automatically be injected at component instantiation time. The xml configuration - for a service component that expects InitParams object must include &lt;init-params&gt; element (even if an empty one). - </para> - - <para> - Let's use an example to see how the kernel xml configuration syntax looks for creating <literal>InitParams</literal> instances. - </para> - - <example> - <title>InitParams - properties-param</title> - <programlisting role="XML"><![CDATA[ -<component> - <key>org.exoplatform.services.naming.InitialContextInitializer</key> - <type>org.exoplatform.services.naming.InitialContextInitializer</type> - <init-params> - <properties-param> - <name>default-properties</name> - <description>Default initial context properties</description> - <property name="java.naming.factory.initial" - value="org.exoplatform.services.naming.SimpleContextFactory" /> - </properties-param> - </init-params> -</component> - ]]></programlisting> - </example> - - <para> - InitParams object description begins with &lt;init-params&gt; element. It can have zero or more children elements - each of which is one of &lt;value-param&gt;, &lt;values-param&gt;, &lt;properties-param&gt;, or &lt;object-param&gt;. - Each of these child elements takes a &lt;name&gt; that serves as a map entry key, and an optional &lt;description&gt;. - It also takes a type-specific value specification. - </para> - - <para> - For &lt;properties-param&gt; the value specification is in the form of one or more &lt;property&gt; elements, - each of which specifies two strings - a property name, and a property value. Each &lt;properties-params&gt; - defines one <literal>java.util.Properties</literal> instance. Also see - <xref linkend="sect-Reference_Guide-Foundations-Configuration_syntax-Special_vars-Example"/> for an example. - </para> - - <example> - <title>InitParams - value-param</title> - <programlisting role="XML"><![CDATA[ -<component> - <key>org.exoplatform.services.transaction.TransactionService</key> - <type>org.exoplatform.services.transaction.impl.jotm.TransactionServiceJotmImpl</type> - <init-params> - <value-param> - <name>timeout</name> - <value>5</value> - </value-param> - </init-params> -</component> - ]]></programlisting> - </example> - - <para> - For &lt;value-param&gt; the value specification is in the form of &lt;value&gt; element, which defines - one <literal>String</literal> instance. - </para> - - <example> - <title>InitParams - values-param</title> - <programlisting role="XML"><![CDATA[ -<component> - <key>org.exoplatform.services.resources.ResourceBundleService</key> - <type>org.exoplatform.services.resources.impl.SimpleResourceBundleService</type> - <init-params> - <values-param> - <name>classpath.resources</name> - <description>The resources that start with the following package name should be load from file system</description> - <value>locale.portlet</value> - </values-param> - - <values-param> - <name>init.resources</name> - <description>Store the following resources into the db for the first launch </description> - <value>locale.test.resources.test</value> - </values-param> - - <values-param> - <name>portal.resource.names</name> - <description>The properties files of the portal , those file will be merged - into one ResourceBundle properties </description> - <value>local.portal.portal</value> - <value>local.portal.custom</value> - </values-param> - </init-params> -</component> - ]]></programlisting> - </example> - - <para> - For &lt;values-param&gt; the value specification is in the form of one or more &lt;value&gt; elements, - each of which represents one <literal>String</literal> instance, where all the <literal>String</literal> values - are then collected into a <literal>java.util.List</literal> instance. - </para> - - <example> - <title>InitParams - object-param</title> - <programlisting role="XML"><![CDATA[ -<component> - <key>org.exoplatform.services.cache.CacheService</key> - <jmx-name>cache:type=CacheService</jmx-name> - <type>org.exoplatform.services.cache.impl.CacheServiceImpl</type> - <init-params> - <object-param> - <name>cache.config.default</name> - <description>The default cache configuration</description> - <object type="org.exoplatform.services.cache.ExoCacheConfig"> - <field name="name"> - <string>default</string> - </field> - <field name="maxSize"> - <int>300</int> - </field> - <field name="liveTime"> - <long>300</long> - </field> - <field name="distributed"> - <boolean>false</boolean> - </field> - <field name="implementation"> - <string>org.exoplatform.services.cache.concurrent.ConcurrentFIFOExoCache</string> - </field> - </object> - </object-param> - </init-params> -</component> - ]]></programlisting> - </example> - - <para> - For &lt;object-param&gt; in our case, the value specification comes in a form of &lt;object&gt; element, which is - used for POJO style object specification (you specify an implementation class - &lt;type&gt;, and property values - &lt;field&gt;). - </para> - - <para> - Also see <xref linkend="sect-Reference_Guide-Foundations-Configuring_portal_Container_declaration_example" /> - for an example of specifying a field of <literal>Collection</literal> type. - </para> - - <para> - The <literal>InitParams</literal> structure - the names and types of entries is specific for each service, - as it is the code inside service components's class that decides what entry names to look up and what types - it expects to find. - </para> - </section> - - - <section id="sect-Reference_Guide-Foundations-Configuring_portal"> - <title>Configuring a portal container</title> - - <para> - A <emphasis role="bold">portal container</emphasis> is defined by several attributes. - </para> - - <para> - First, there is a <emphasis role="bold">portal container name</emphasis>, which is always equal to URL context to which the current portal is bound. - </para> - - <para> - Second, there is a <emphasis role="bold">REST context name</emphasis>, which is used for REST access to portal application - every portal has - exactly one (unique) REST context name. - </para> - - <para> - Then, there is a <emphasis role="bold">realm name</emphasis> which is the name of security realm used for authentication when users log into the - portal. - </para> - - <para> - Finally, there is a list of <emphasis role="bold">Dependencies</emphasis> - other web applications, whose resources are visible to current - portal (via extension mechanism described later), and are searched in the specified order. - </para> - - <example id="sect-Reference_Guide-Foundations-Configuring_portal_Container_declaration_example"> - <title>Portal container declaration example</title> - <programlisting role="XML"><![CDATA[ -<?xml version="1.0" encoding="UTF-8"?> -<configuration - xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" - xsi:schemaLocation="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd - http://www.exoplaform.org/xml/ns/kernel_1_0.xsd" - xmlns="http://www.exoplaform.org/xml/ns/kernel_1_0.xsd"> - - <external-component-plugins> - <!-- The full qualified name of the PortalContainerConfig --> - <target-component>org.exoplatform.container.definition.PortalContainerConfig</target-component> - - <component-plugin> - <!-- The name of the plugin --> - <name>Add PortalContainer Definitions</name> - - <!-- The name of the method to call on the PortalContainerConfig - in order to register the PortalContainerDefinitions --> - <set-method>registerPlugin</set-method> - - <!-- The full qualified name of the PortalContainerDefinitionPlugin --> - <type>org.exoplatform.container.definition.PortalContainerDefinitionPlugin</type> - - <init-params> - <object-param> - <name>portal</name> - <object type="org.exoplatform.container.definition.PortalContainerDefinition"> - <!-- The name of the portal container --> - <field name="name"><string>portal</string></field> - - <!-- The name of the context name of the rest web application --> - <field name="restContextName"><string>rest</string></field> - - <!-- The name of the realm --> - <field name="realmName"><string>exo-domain</string></field> - - <!-- All the dependencies of the portal container ordered by loading priority --> - <field name="dependencies"> - <collection type="java.util.ArrayList"> - <value> - <string>eXoResources</string> - </value> - <value> - <string>portal</string> - </value> - <value> - <string>dashboard</string> - </value> - <value> - <string>exoadmin</string> - </value> - <value> - <string>eXoGadgets</string> - </value> - <value> - <string>eXoGadgetServer</string> - </value> - <value> - <string>rest</string> - </value> - <value> - <string>web</string> - </value> - <value> - <string>wsrp-producer</string> - </value> - <!-- The sample-ext has been added at the end of the dependency list - in order to have the highest priority --> - <value> - <string>sample-ext</string> - </value> - </collection> - </field> - </object> - </object-param> - </init-params> - </component-plugin> - </external-component-plugins> -</configuration> - ]]> -</programlisting> - </example> - - - <note> - <para>Dependencies are part of the extension mechanism.</para> - </note> - - <para> - Every <emphasis role="bold">portal container</emphasis> is represented by a <emphasis role="bold">PortalContainer instance</emphasis>, which contains: - <itemizedlist> - <listitem> - <para>associated <emphasis role="bold">ExoContainerContext</emphasis>, which contains information about the portal</para> - </listitem> - <listitem> - <para><emphasis role="bold">unified servlet context</emphasis>, for web-archive-relative resource loading</para> - </listitem> - <listitem> - <para><emphasis role="bold">unified classloader</emphasis>, for classpath based resource loading</para> - </listitem> - <listitem> - <para>methods for retrieving services</para> - </listitem> - </itemizedlist> - </para> - - <para> - <emphasis role="bold">Unified servlet context</emphasis>, and <emphasis role="bold">unified classloader</emphasis> are part of the <emphasis role="bold">extension mechanism</emphasis> (explained in next section), - and provide standard API (ServletContext, ClassLoader) with specific resource loading behavior - visibility into associated web application archives, - configured with Dependencies property of PortalContainerDefinition. Resources from other web applications are queried in the order specified by Dependencies. - The later entries in the list override the previous ones. - </para> - </section> - - <section id="sect-Reference_Guide-Foundations-Extension_mechanism"> - <title>GateIn Extension Mechanism, and Portal Extensions</title> - - <para> - <emphasis role="bold">Extension mechanism</emphasis> is a functionality that makes it possible to override portal resources in an almost - plug-and-play fashion - just drop in a .war archive with the resources, and configure its position on the portal's - classpath. - This way any customizations of the portal don't have to involve unpacking and repacking the original portal - .war archives. Instead, you create your own .war archive with changed resources, that override the resources in - the original archive. - </para> - - <para> - A web archive packaged in a way to be used through extension mechanism is called <emphasis role="bold">portal extension</emphasis>. - </para> - <para> - There are two steps necessary to create a portal extension. - </para> - <para> - First, declare <emphasis role="bold">PortalConfigOwner</emphasis> servlet context listener in web.xml of your web application. - </para> - <example><title>Example of a portal extension called sample-ext:</title> - - <programlisting role="XML"><![CDATA[ -<?xml version="1.0" encoding="ISO-8859-1" ?> -<!DOCTYPE web-app PUBLIC -//Sun Microsystems, Inc.//DTD Web Application 2.3//EN - http://java.sun.com/dtd/web-app_2_3.dtd> -<web-app> - - <display-name>sample-ext</display-name> - - <listener> - <listener-class>org.exoplatform.container.web.PortalContainerConfigOwner</listener-class> - </listener> - - ... - -</web-app> - ]]></programlisting> - </example> - <para> - Then, add the servlet context name of this web application in proper place in the list of Dependencies of the PortalContainerDefinition - of all the portal containers that you want to have access to its resources. - </para> - <para> - After this step your web archive will be on portal's unified classpath, and unified servlet context resource path. - The later in the Dependencies list your application is, the higher priority it has when resources are loaded by portal. - </para> - - <note> - <para>See 'Configuring a portal' section for example of PortalContainerDefinition, that has sample-ext at the end of its list of Dependencies.</para> - </note> - - </section> - - - <section id="sect-Reference_Guide-Foundations-Multiple_portals"> - <title>Running Multiple Portals</title> - - <para> - It is possible to run several independent portal containers - each bound to a different URL context - within - the same JVM instance. This kind of setup is very efficient from administration and resource consumption - aspect. The most elegant way to <emphasis role="bold">reuse</emphasis> configuration for different coexisting portals is by way of extension - mechanism - by <emphasis role="bold">inheriting</emphasis> resources and configuration from existing web archives, and just <emphasis role="bold">adding</emphasis> extra resources to it, - and <emphasis role="bold">overriding</emphasis> those that need to be changed by including modified copies. - </para> - - <para> - In order for a portal application to correctly function when deployed in multiple portals, the application may - have to dynamically query the information about the current portal container. The application should not make - any assumptions about the name, and other information of the current portal, as there are now multiple different portals in play. - </para> - - <para> - At any point during request processing, or lifecycle event processing, your application can retrieve this - information through <emphasis role="bold">org.exoplatform.container. ExoContainerContext</emphasis>. - Sometimes your application needs to make sure that the proper <emphasis role="bold">PortalContainer</emphasis> - - the source of <emphasis role="bold">ExoContainerContext</emphasis> - is associated with the current call. - </para> - - <para> - If you ship servlets or servlet filters as part of your portal application, and if you need to access portal - specific resources at any time during the processing of the servlet or filter request, then you need to make - sure the servlet/filter is associated with the current container. - </para> - <para> - The proper way to do that is to make your servlet extend <emphasis role="bold">org.exoplatform.container.web. AbstractHttpServlet</emphasis> - class. - This will not only properly initialize current <emphasis role="bold">PortalContainer</emphasis> for you, but will also set the current thread's - context classloader to one that looks for resources in associated web applications in the order specified by - <emphasis role="bold">Dependencies</emphasis> configuration (as explained in Extension mechanism section). - </para> - <para> - Similarly for filters, make sure your filter class extends <emphasis role="bold">org.exoplatform.container.web. AbstractFilter</emphasis>. - Both <emphasis role="bold">AbstractHttpServlet</emphasis>, and <emphasis role="bold">AbstractFilter</emphasis> have a method <emphasis role="bold">getContainer()</emphasis>, - which returns the current <emphasis role="bold">PortalContainer</emphasis>. - - If your servlet handles the requests by implementing a <emphasis role="bold">service()</emphasis> method, you need to rename that method to match - the following signature:</para> - <programlisting role="JAVA"><![CDATA[ -/** - * Use this method instead of Servlet.service() - */ -protected void onService(ExoContainer container, HttpServletRequest req, - HttpServletResponse res) throws ServletException, IOException; - ]]></programlisting> - <note> - <para> - The reason is that AbstractHttpServlet implements service() to perform its interception, and you don't want to - overwrite (by overriding) this functionality. - </para> - </note> - <para> - You may also need to access portal information within your <emphasis role="bold">HttpSessionListener</emphasis>. Again, make sure to extend the - provided abstract class - <emphasis role="bold">org.exoplatform.container.web. AbstractHttpSessionListener</emphasis>. - Also, modify your method signatures as follows:</para> - <programlisting role="JAVA"><![CDATA[ -/** - * Use this method instead of HttpSessionListener.sessionCreated() - */ -protected void onSessionCreated(ExoContainer container, HttpSessionEvent event); - -/** - * Use this method instead of HttpSessionListener.sessionDestroyed() - */ -protected void onSessionDestroyed(ExoContainer container, HttpSessionEvent event); - ]]></programlisting> - <para> - There is another method you have to implement in this case:</para> - <programlisting role="JAVA"><![CDATA[ -/** - * Method should return true if unified servlet context, - * and unified classloader should be made available - */ -protected boolean requirePortalEnvironment(); - ]]></programlisting> - <para> - If this method returns true, current thread's context classloader is set up according to <emphasis role="bold">Dependencies</emphasis> - configuration, and availability of the associated web applications. If it returns false, the standard - application separation rules are used for resource loading (effectively turning off the - extension mechanism). This method exists on <emphasis role="bold">AbstractHttpServlet</emphasis> and <emphasis role="bold">AbstractFilter</emphasis> as well, where there is a - default implementation that automatically returns true, when it detects there is a current PortalContainer - present, otherwise it returns false. - - </para> - - <para> - We still have to explain how to properly perform <emphasis role="bold">ServletContextListener</emphasis> based initialization, when you need - access to current PortalContainer. - </para> - - <para> - GateIn has no direct control over the deployment of application archives (.war, .ear files) - it is the - application server that performs the deployment. For <emphasis role="bold">extension mechanism</emphasis> to work properly, the applications, - associated with the portal via <emphasis role="bold">Dependencies</emphasis> configuration, have to be deployed before the portal, that depends - on them, is initialized. On the other hand, these applications may require an already initialized PortalContainer - to properly initialize themselves - we have a recursive dependency problem. To resolve this problem, a - mechanism of <emphasis role="bold">initialization tasks</emphasis>, and <emphasis role="bold">task queues</emphasis>, was put in place. Web applications that depend on current - PortalContainer for their initialization have to avoid performing their initialization directly in some - ServletContextListener executed during their deployment (before any PortalContainer was initialized). Instead, - a web application should package its initialization logic into an init task of appropriate type, and only use - ServletContextListener to insert the init task instance into the proper init tasks queue. - </para> - - <para>An example of this is Gadgets application which registers Google gadgets with the current PortalContainer: - </para> - - <programlisting role="JAVA"><![CDATA[ -public class GadgetRegister implements ServletContextListener -{ - public void contextInitialized(ServletContextEvent event) - { - // Create a new post-init task - final PortalContainerPostInitTask task = new PortalContainerPostInitTask() { - - public void execute(ServletContext context, PortalContainer portalContainer) - { - try - { - SourceStorage sourceStorage = - (SourceStorage) portalContainer.getComponentInstanceOfType(SourceStorage.class); - ... - } - catch (RuntimeException e) - { - throw e; - } - catch (Exception e) - { - throw new RuntimeException("Initialization failed: ", e); - } - } - }; - - // Add post-init task for execution on all the portal containers - // that depend on the given ServletContext according to - // PortalContainerDefinitions (via Dependencies configuration) - PortalContainer.addInitTask(event.getServletContext(), task); - } -} - ]]></programlisting> - - <para> - The above example uses <emphasis role="bold">PortalContainerPostInitTask</emphasis>, which gets executed after the portal container has been - initialized. In some situations you may want to execute initialization after portal container was instantiated, - but before it was initialized - use <emphasis role="bold">PortalContainerPreInitTask</emphasis> in that case. Or, you may want to execute - initialization after all the post-init tasks have been executed - use <emphasis role="bold">PortalContainerPostCreateTask</emphasis> in that case. - </para> - - <para> - One more area that may need your attention are <emphasis role="bold">LoginModules</emphasis>. If you use custom LoginModules, that require - current ExoContainer, make sure they extend <emphasis role="bold">org.exoplatform.services.security.jaas.AbstractLoginModule</emphasis> for - proper initialization. AbstractLoginModule also takes care of the basic configuration - it recognizes two - initialization options - <emphasis role="bold">portalContainerName</emphasis>, and <emphasis role="bold">realmName</emphasis> whose values you can access via protected fields of - the same name. - </para> - - </section> - -</section> Modified: portal/trunk/docs/reference-guide/en/modules/PortalDevelopment.xml =================================================================== --- portal/trunk/docs/reference-guide/en/modules/PortalDevelopment.xml 2010-04-15 10:32:55 UTC (rev 2651) +++ portal/trunk/docs/reference-guide/en/modules/PortalDevelopment.xml 2010-04-15 10:43:53 UTC (rev 2652) @@ -5,7 +5,6 @@ ]> <chapter id="chap-Reference_Guide-Development"> <title>Portal Development</title> - <xi:include href="PortalDevelopment/Foundations.xml" xmlns:xi="http://www.w3.org/2001/XInclude" /> <xi:include href="PortalDevelopment/Skinning.xml" xmlns:xi="http://www.w3.org/2001/XInclude" /> <xi:include href="PortalDevelopment/PortalLifecycle.xml" xmlns:xi="http://www.w3.org/2001/XInclude" /> <xi:include href="PortalDevelopment/DefaultPortalConfiguration.xml" xmlns:xi="http://www.w3.org/2001/XInclude" />