[windup-dev] Rules API
Lincoln Baxter, III
lincolnbaxter at gmail.com
Mon May 5 11:28:26 EDT 2014
Sorry, in my above example I said the converter is responsible for storing
the value, which is not the case. The GraphBinding would be responsible for
that.
On Mon, May 5, 2014 at 11:27 AM, Lincoln Baxter, III <
lincolnbaxter at gmail.com> wrote:
> Sure, take this example:
>
> .addRule()
>> .when(Selection.exists(XMLFile.class, "xmls")
>> .with(Element.DOCTYPE, "
>> http://maven.apache.org/POM/4.0.0")
>> )
>> .perform(Iteration.over(XMLFile.class, "xmls", "pom"
>> ).as(MavenPomFile.class)
>> .perform(
>>
>> Graph.replace(Selection.current(XMLFile.class))
>>
>> .with(Selection.current(MavenPomFile.class))
>> )
>> )
>
>
> Now consider what would happen if we were to parameterize the DOCTYPE
> statement:
>
>
> .addRule()
>> .when(Selection.exists(XMLFile.class, "xmls")
>> .with(Element.DOCTYPE, "http://
>> {domain}/POM/4.0.0")
>> )
>
>
> What if we want to match some domains and not others? Well, we'll need to
> configure the parameter:
>
>> .addRule()
>> .when(Selection.exists(XMLFile.class, "xmls")
>> .with(Element.DOCTYPE, "http://
>> {domain}/POM/4.0.0")
>> )
>> .where("domain").matches("(maven.apache.org|
>> jboss.org/maven|example\\.(com|org|net)<http://jboss.org/maven%7Cexample%5C%5C.(com%7Corg%7Cnet)>)").convertedBy(new
>> URLDomainConverter()).bindsTo(new GraphBinding("xml>domain"))
>
>
> This would both ensure that the parameter matches only what was contained
> in the regular expression, but also adds a converter which stores the value
> in the graph (somehow) as a URLDomain (which just for example's sake is a
> @VertexFrame annotated interface.) Keep in mind that this is just a
> hypothetical example.
>
> The full battery of parameter configuration options are:
>
>> .where(String param)
>> .matches(String regex)
>> .constrainedBy(Constraint constraint)
>> .convertedBy(Converter converter)
>> .validatedBy(Validator validator)
>> .bindsTo(Binding binding)
>> .configuredBy(ParameterConfigurator configurator) // can do any of the
>> above
>
>
> ~Lincoln
>
>
>
>
> On Mon, May 5, 2014 at 11:05 AM, Jess Sightler <jsightle at redhat.com>wrote:
>
>> Could you explain the "where" clause in more detail here? I have seen
>> this a few times in your examples, but I'm not entirely clear on what it is
>> doing. :)
>>
>>
>>
>> On 05/05/2014 10:33 AM, Lincoln Baxter, III wrote:
>>
>> .addRule()
>> .when() // if
>> .perform() // then
>> .otherwise() // else
>> .where("paramName1").configuredBy(...).where("paramName2") // configure
>> parameters
>>
>>
>> On Mon, May 5, 2014 at 10:23 AM, Lincoln Baxter, III <
>> lincolnbaxter at gmail.com> wrote:
>>
>>> 1) The (when, perform) structure would be basic for all rules?
>>>
>>> Yes, there are actually a few more structures:
>>>
>>> .addRule()
>>> .when() // if
>>> .perform() // then
>>> .otherwise() // else
>>>
>>>
>>> 2) This seems like it will build object tree, which will then be
>>> processed, right? No space for custom code?
>>>
>>> You can already do exactly what you just suggested :) Custom code is no
>>> problem, it just accepts an object like any normal Java code - it's just
>>> Java.
>>>
>>>
>>> 3) Isn't that a fluent API overuse? How about something like:
>>>
>>> I don't know what you are referring to here as overuse, but yes, I am
>>> exaggerating the use of the fluent API to make a point. The rules could be
>>> completely un-fluent and still use these same APIs. I'm not sure I see the
>>> point/difference of the sample you've shown.
>>>
>>> 4) .withDoctype("http://maven.apache.org/POM/4.0.0") ?
>>> doctype is a property... Better .with(PropNames.DOCTYPE,
>>> "http://maven.apache.org/POM/4.0.0") ?
>>>
>>> I agree, some kind of more general structure here would probably be
>>> better.
>>>
>>>
>>> 5) Could the variable be filled outside .when () ? But perhaps just a
>>> matter of taste.
>>>
>>> Absolutely you could - and yes, it's all a matter of taste :)
>>>
>>>
>>> On Fri, May 2, 2014 at 7:26 PM, Ondrej Zizka <ozizka at redhat.com> wrote:
>>>
>>>> Hi,
>>>>
>>>> WRT rules API, as proposed at
>>>>
>>>> https://github.com/windup/windup/blob/master/engine/config/api/src/main/java/org/jboss/windup/addon/config/example/MavenExampleConfigurationProvider.java#L22
>>>>
>>>> It's nice, with some comments.
>>>>
>>>> I know it was typed in a hurry, but anyway:
>>>>
>>>> 1) The (when, perform) structure would be basic for all rules?
>>>>
>>>> 2) This seems like it will build object tree, which will then be
>>>> processed, right? No space for custom code?
>>>>
>>>> 3) Isn't that a fluent API overuse? How about something like:
>>>>
>>>> new ConfigBuilder( ... ){{
>>>> addRule( new MavenPomRule( this, ... ){
>>>> boolean when( ) { return Selection.exists(XMLFile.class,
>>>> "xmls").with("doctype", DOCTYPE_POM); }
>>>> void perform( MavenPomInfo mpi ){ ... }
>>>> }
>>>> );
>>>> }}.run();
>>>>
>>>> It's verbose now but with Java 8 lambdas, it would be less.
>>>>
>>>> While it's a bit more verbose, it would have obvious benefits of better
>>>> debuggability, and would better leverage Java's features like
>>>> inheritance (imagine AbstractXmlFileRule and it's subclasses for
>>>> whatever one would want to do with a XML file, having few of its
>>>> properties passed as parameters.
>>>>
>>>> Btw this code above is inspired by Wicket and GWT.
>>>>
>>>> 4) .withDoctype("http://maven.apache.org/POM/4.0.0") ?
>>>> doctype is a property... Better .with(PropNames.DOCTYPE,
>>>> "http://maven.apache.org/POM/4.0.0") ?
>>>>
>>>> 5) Could the variable be filled outside .when () ? But perhaps just a
>>>> matter of taste.
>>>>
>>>> More later when we have some more examples.
>>>>
>>>> Nice!
>>>> Ondra
>>>> _______________________________________________
>>>> windup-dev mailing list
>>>> windup-dev at lists.jboss.org
>>>> https://lists.jboss.org/mailman/listinfo/windup-dev
>>>>
>>>
>>>
>>>
>>> --
>>> Lincoln Baxter, III
>>> http://ocpsoft.org
>>> "Simpler is better."
>>>
>>
>>
>>
>> --
>> Lincoln Baxter, III
>> http://ocpsoft.org
>> "Simpler is better."
>>
>>
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>> windup-dev mailing listwindup-dev at lists.jboss.orghttps://lists.jboss.org/mailman/listinfo/windup-dev
>>
>>
>>
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>
>
>
> --
> Lincoln Baxter, III
> http://ocpsoft.org
> "Simpler is better."
>
--
Lincoln Baxter, III
http://ocpsoft.org
"Simpler is better."
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