[jsr-314-open] View and custom scoped eager managed beans?
by David Geary
The javadocs for the @ManagedBean annotation states:
If the value of the eager() attribute is true, the runtime must instantiate
this class when the application starts. In this case, managed-bean-scope is
ignored if its value is "none", "request", or "session", or is unspecified.
In these cases, the value of managed-bean-scope is assumed to be
"application". Otherwise, any value of managed-bean-scope supported by the
implementation is allowed. Once instantiated, the bean must be placed in the
proper managed-bean-scope. This instantiation and storing of the instance
must happen before any requests are serviced. If eager is unspecified or
false, the default "lazy" instantiation and scoped storage of the managed
bean happens.
I'm wondering about the scope of an eager managed bean. The preceeding
paragraph indicates that it's okay to specify view or custom scopes, but not
none, request, or session for an eager managed bean--is that correct, or was
that paragraph written before view and custom scopes were conceived?
Thanks,
david
15 years
[jsr-314-open] @CustomScoped value attribute
by David Geary
The javadocs for @CustomScoped indicate that the value of the value
attribute must evaluate to a String:
When this annotation, along with ManagedBean is found on a class, the
runtime must act as if a <managed-bean-scope<VALUE<managed-bean-scope>
element was declared for the corresponding managed bean, where VALUE is the
value of the value() attribute, which must be an EL expression that
evaluates to a String.
I thought it was supposed to evaluate to a map.
david
15 years
[jsr-314-open] Adding handling of CDATA blocks in ResponseWriter
by Jim Driscoll
Greetings EG memebers.
I have an implementation problem, and the cleanest, most effective
solution is a change in the API, so I'm sending you this email.
The problem:
The current javax.faces.context.ResponseWriter class is aware of XML
structure, in that it has methods for writing things like Elements,
Comments, and Attributes. However, CDATA blocks are currently not
handled by the API defined there.
The RI previous to this release got around this problem by overloading
the startElement and endElement method semantics - if you passed a tag
name of "CDATA", then it would start a CDATA block.
Since nothing in the public API used CDATA, this worked fine.
Now, for PartialRequests, CDATA blocks are used by the API.
You cannot embed CDATA blocks within CDATA blocks, so both the API and
the Impl need to be aware of when CDATA blocks happen, and they need to
coordinate their actions.
This means that we need to update ResponseWriter to be aware of CDATA
blocks.
There are two ways we can go about doing this:
1) Standardize the existing behavior of the implementation, so that
startElement("CDATA", component) and endElement("CDATA") start and end
CDATA blocks.
or
2) Add two new menthods, startCDATA() and endCDATA() to ResponseWriter.
I marginally favor the first approach, mostly since it's not a common
need, it's less work, and it doesn't add two new methods that almost
noone will use. It's also the way that the RI currently uses, which
hasn't seemed to cause any issues. (It also requires less RI work, so
that may be biasing me, though that's almost never a reason to chose a
public API.)
Ryan somewhat favors the second approach, since it's cleaner,
architecturally, to separate out the start and stop of the cdata.
But in the end, we're open to which ever way the consensus of the EG goes.
Please reply by COB Monday on this issue, if you have an opinion. We
need to wrap this up quickly, we're under a great deal of time pressure.
Jim
15 years, 1 month
Re: [jsr-314-open] [Fwd: [NEW] <f:ajax> and <f:validateBean> - consistent wrapping solution needed?]
by Andy Schwartz
Gang -
Need to bring this up one more time... Last week we found that our choice of implementations for "wrapping" f:ajax/f:validateBean has implications for delta state saving, so wanted to describe the problem here and see whether we can agree to a solution.
Some quick background on the delta state saving strategy - I'll defer to Ed and Ryan on the API specifics and also on current status with respect to 20 specification. The solution that Ryan has been working on is very similar to the Trinidad approach that we've discussed in the past. Roughly speaking, we're looking at:
1. Facelets tag handlers are applied and we build up the component tree.
2. Once a component has been "populated" (attributes set, attached objects attached), we lock the component state down.
3. From that point on through state saving, we keep track of modifications (attributes modified, atached objects added/removed).
4. At state saving, if nothing has changed (the most common case by far), we have no state to save - our saved state is null.
5. If the component has been modified, we save state. The amount of state that we save for the modified component is implementation specific. The goal is to only save the deltas, though there may be cases where we may save the full state for a specific component instance.
6. At restore time, we first build up the component tree by applying the Facelets tag handlers.
7. Components which did not save any state are fully initialized - don't need to restore any state.
8. Components which did save state restore it over the initialized component instance.
That's it in a nutshell. The end result is that the total size of saved state per component/page is reduced significantly. One really nice part of this solution is that this is all completely transparent to the application developer - ie. the page author does not need to make any changes to take advantage of this optimization.
So, what does this have to do with f:ajax/f:validateBean? The issue has to do with the timing of our current implementations.
In the f:ajax implementation, we apply "inherited" AjaxBehavior instances at tag handler execution time. So, by the time that we reach #2 above, components that are wrapped inside of an f:ajax tag have the appropriate AjaxBehavior instances attached.
With our current f:validateBean implementation, we do not apply "inherited" validators until the encode phase, which, of course, is after we've locked down the component state (ie. after #2). As a result, these validators are treated as component modifications/deltas - and as such impact the amount of state that we save.
In order to avoid this penalty, I would like to propose that we standardize on a tag handler-time solution for both f:ajax and f:validateBean - ie. I would like to see f:validateBean migrated over to a strategy that matches our current f:ajax behavior. My guess is that the implementation changes should not be all that challenging, though I have only taken a superficial look at the f:validateBean wiring. The spec changes should be minimal.
Are people okay with this proposal - ie. okay with standardizing on the f:ajax wrapping behavior? Seems to me that this was the EG's preference back when we discussed f:ajax wrapping behavior last year, so hope that this is acceptable now.
Dan -
I think that you are most familiar with the current f:validateBean implementation. Assuming that you are okay with the proposal, would you be willing to take a look at what we do for f:ajax and maybe sync up with Ryan to discuss what it would take to convert this over to the f:ajax strategy? The f:ajax approach is fairly simple:
- When we encounter f:ajax, we create an AjaxBehavior and push it onto a stack.
- When we encounter a ClientBehaviorHolder component that can accept the AjaxBehavior instance, we create/configure a new AjaxBehavior instance and attach it to the ClientBehaviorHolder
- When we reach the end of the f:ajax tag, we pop the AjaxBehavior stack.
Note that for creating/configuring the AjaxBehavior instances, we use the technique that you hinted at in a previous email - ie. we use the intial AjaxBehavior instance as a template and save/restore its state to configure new instances.
I am actually out of the office this week - just checking email intermittently. I'll do my best to help/answer questions on this, though there may be some gaps between my access to email.
Andy
-------- Original Message -------- Message-ID: <49B67A17.8070609(a)oracle.com>
Date: Tue, 10 Mar 2009 10:32:55 -0400
From: Andy Schwartz <andy.schwartz(a)oracle.com>
User-Agent: Thunderbird 2.0.0.19 (Windows/20081209)
MIME-Version: 1.0
To: JSR 314 Open Mailing list <JSR-314-OPEN(a)JCP.ORG>
Subject: [jsr-314-open] [NEW] <f:ajax> and <f:validateBean> - consistent wrapping solution needed?
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
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Gang -
In JSF 2.0 we are introducing two core tags that wrap/enhance component
subtrees: f:ajax and f:validateBean.
f:ajax is used to enable Ajax behavior for a subtree, eg:
> <h:panelGroup>
> <!-- Turn on Ajax for the two input texts -->
> <f:ajax event="valueChange">
> <h:inputText value="foo"/>
> <h:inputText value="bar"/>
> </f:ajax>
> </h:panelGroup>
f:validateBean is used to enable bean validation for a subtree, eg:
> <h:panelGroup>
> <!-- Turn on bean validation for the two input texts -->
> <f:validateBean validationGroups="Group1, Group2"/>
> <h:inputText value="foo"/>
> <h:inputText value="bar"/>
> </f:validateBean>
> </h:panelGroup>
Of course, both tags can also be used in their nested form to enable
Ajax/bean validation on a single component.
We currently use different implementation strategies for the "wrapping"
behavior.
f:ajax uses a handler execution-time solution. AjaxHandler maintains a
stack that keeps track of the current nested state of <f:ajax> tags.
Before apply child handlers, AjaxHandler pushes the current Ajax-related
info onto this stack. When child/descendent handlers are applied,
ComponentTagHandlerDelegateImpl checks this stack to get at the current
Ajax-related state and performs the necessary work to wire up an
AjaxBehavior to the component. Finally, after child handlers have been
processed, AjaxHandler pops the stack, and we're done.
The end result of the f:ajax solution is that once handlers have
finished executing, we have a fully configured component tree. No
further processing is necessary to apply "inherited" Ajax behavior.
f:validateBean uses a solution which is split between tag/handler
execution-time, validation-time and render-time.
BeanValidatorHandler/ValidatorTagHandlerDelegateImpl set up well known
properties on the parent component's attribute map (eg.
BeanValidator.VALIDATION_GROUPS_KEY,
UIInput.DEFAULT_VALIDATOR_IDS_KEY). These are used during later
lifecycle phases (eg. BeanValidator.validate(), UIInput.encodeEnd()) to
determine which inherited validators to apply and how these validators
should be configured (eg. what validation groups to use).
The end result of the f:validateBean solution is that the handlers only
do part of the job - we need to do additional work during later
lifecycle phases to take advantage of the information that has been
stored away by the handlers.
While these two different strategies may at first seem like
implementation details, and thus not especially significant, the choice
of implementation does have impact on both our API and on spec'ed
behavior (or, on behavior that should be defined by the spec).
In terms of API, for f:validateBean the choice of implementation leaks
through a bit into the API in the form of the property keys that are
used to communicate between the handler implementations and the
component/validator implementations.
In terms of behavior, the different implementation strategies and up
with subtly different results which may cause confusion.
For example, in the following f:ajax case:
> <h:panelGroup>
>
> <!-- Turn Ajax on for this one -->
> <f:ajax event="valueChange">
> <h:inputText value="foo"/>
> </f:ajax>
>
> <!-- But not for this one -->
> <h:inputText value="bar"/>
>
> </h:panelGroup>
This should work as expected. That is, Ajax should be enabled for the
"foo" inputText, but not for the "bar" input text.
In a similar f:validateBean case:
> <h:panelGroup>
>
> <!-- Turn bean validation on for this one -->
> <f:validateBean validationGroups="Group1, Group2"/>
> <h:inputText value="foor"/>
> </f:validateBean>
>
> <!-- But not for this one -->
> <h:inputText value="bar"/>
>
> </h:panelGroup>
Unless I am missing something in the spec/implementation, I believe that
the validation-related properties are going to end up being attached to
the parent panelGroup when the BeanValidatorHandler is applied. Which,
if I understand this correctly, means that the validation will be
applied to both the "foo" and the "bar" inputText. If this is the case,
this is definitely not the desired behavior.
I suspect that similar problems would arise when we've got multiple
<f:validateBean> under a single parent, eg:
> <h:panelGroup>
>
> <!-- Turn on Group1 validation for this one -->
> <f:validateBean validationGroups="Group1"/>
> <h:inputText value="foo"/>
> </f:validateBean>
>
> <!-- Turn on Group2 validation for this one -->
> <f:validateBean validationGroups="Group2"/>
> <h:inputText value="bar"/>
> <f:validateBean/>
>
> </h:panelGroup>
Though I haven't had a chance to test this out - just based on code
inspection seems like this would be a problem. (Though our <f:ajax>
implementation strategy handles this case just fine.)
Since there may be other subtle inconsistencies, it would make sense to
try to unify our implementation strategies across these two core tags.
Of course, I am biased towards the <f:ajax> approach. Seems to have
better behavior in terms of targeting only the wrapped subtrees, has
less exposure in the public API, and also just seems cleaner to me to
produce a fully configured component tree as a result of handler execution.
Looking at the code, I didn't notice anything that would make it
difficult to re-factor the <f:validateBean> code to use a handler-time
strategy like <f:ajax>. I think our users would benefit from the
consistency. Any thoughts on whether we should/can go this route? Did
I miss anything in the <f:validteBean> behavior that would prevent us
from using a handler-time solution?
Andy
15 years, 1 month
[jsr-314-open] default converter for java.util.Date type
by Dan Allen
Issue 494 (
https://javaserverfaces-spec-public.dev.java.net/issues/show_bug.cgi?id=494)
seemed to have fallen off the map, but since I just implemented a solution
in Seam, I have decided to bring it back up. It's really inconvenient not to
have at least a default converter for the type java.util.Date. While
certainly dates inputs are something which vary widely, it's tedious in the
early stages of an application to have to plug a DataTimeConverter on every
input that accepts a date.
The solution is as simple as registering DateTimeConverter with the class
java.util.Date and accepting the defaults. The developer can simply specify
a nested <f:convertDateTime> to override. The main limitation is that there
is no way to know if the developer intends to capture a date or date + time
since the type java.util.Date doesn't provide this information. Thus, we
capture date and let the user specify a converter otherwise.
-Dan
--
Dan Allen
Senior Software Engineer, Red Hat | Author of Seam in Action
http://mojavelinux.com
http://mojavelinux.com/seaminaction
NOTE: While I make a strong effort to keep up with my email on a daily
basis, personal or other work matters can sometimes keep me away
from my email. If you contact me, but don't hear back for more than a week,
it is very likely that I am excessively backlogged or the message was
caught in the spam filters. Please don't hesitate to resend a message if
you feel that it did not reach my attention.
15 years, 1 month
Re: [jsr-314-open] support for html entities
by Ed Burns
>>>>> On Fri, 27 Mar 2009 17:29:24 -0700, Alexandr Smirnov <asmirnov(a)EXADEL.COM> said:
AS> It is possible. I've done that one time for Facelets ( even with
AS> properly source encoding support ). The issue still exists in the
AS> Facelets BugZilla : https://facelets.dev.java.net/issues/show_bug.cgi?id=111
AS> As I see in the JSF 2.0 code there is same SAXCompiler as Facelets uses,
AS> therefore I can convert my old patch to the current implementation.
THat would be great, thanks.
Ed
--
| ed.burns(a)sun.com | office: 408 884 9519 OR x31640
| homepage: | http://ridingthecrest.com/
15 years, 1 month
