Comments on: A ValueChangeListener Question and Answer http://blogs.steeplesoft.com/2008/02/a-valuechangelistener-question-and-answer/ Mon, 06 Feb 2012 08:22:23 +0000 hourly 1 By: Gary Thttp://blogs.steeplesoft.com/2008/02/a-valuechangelistener-question-and-answer/comment-page-1/#comment-8235 Gary T Fri, 22 Feb 2008 16:29:28 +0000 http://blogs.steeplesoft.com/a-valuechangelistener-question-and-answer/#comment-8235 I really enjoyed this JUG topic. Myself coming from a Struts Framework environment to JSF/Facelets, I had to endure a learning curve. The more comfortable I become, the more that I like JSF/Facelets. This dialog and example code has helped me under stand how the “binding” with the component works.I'm still confused on which is "best", but for now I will continue using the method attribute approach until an issue arises that would behoove creating a class that implements ValueChangeListener.Sorry about my lack of communication skills, when I get nervous, I start speaking Gar-bonics. Anyone that has worked me knows what I mean! :razz:Great JUG, guys! I really enjoyed this JUG topic. Myself coming from a Struts Framework environment to JSF/Facelets, I had to endure a learning curve. The more comfortable I become, the more that I like JSF/Facelets.
This dialog and example code has helped me under stand how the “binding” with the component works.

I’m still confused on which is “best”, but for now I will continue using the method attribute approach until an issue arises that would behoove creating a class that implements ValueChangeListener.

Sorry about my lack of communication skills, when I get nervous, I start speaking Gar-bonics. Anyone that has worked me knows what I mean! :razz:

Great JUG, guys!

]]> By: jasonhttp://blogs.steeplesoft.com/2008/02/a-valuechangelistener-question-and-answer/comment-page-1/#comment-8234 jason Thu, 21 Feb 2008 22:37:06 +0000 http://blogs.steeplesoft.com/a-valuechangelistener-question-and-answer/#comment-8234 Fadi, here is what the javadocs say:<div style="margin-left: 3em">When the validate() method of this UIInput detects that a value change has actually occurred, and that all validations have been successfully passed, it will queue a ValueChangeEvent. Later on, the broadcast() method will ensure that this event is broadcast to all interested listeners. This event will be delivered by default in the Process Validators phase, but can be delivered instead during Apply Request Values if the immediate property is set to true.</div>Typically, I've seen VCLs used to change something on the UI, i.e., the user selects a new state so the list of cities is updated to show only those in the currently selected state. With such an operation, the app usually is not ready to update the model yet, which happens when an action (i.e., a h:commandButton click) occurs. I think if you're handling VCLs in the UPDATE_MODEL_VALUES phase, you might be going about it in a slightly incorrect, and apparently painful manner. :) You have my email if you'd like to send code and discuss it in more detail. Feel free. Or not. :) Fadi, here is what the javadocs say:

When the validate() method of this UIInput detects that a value change has actually occurred, and that all validations have been successfully passed, it will queue a ValueChangeEvent. Later on, the broadcast() method will ensure that this event is broadcast to all interested listeners. This event will be delivered by default in the Process Validators phase, but can be delivered instead during Apply Request Values if the immediate property is set to true.

Typically, I’ve seen VCLs used to change something on the UI, i.e., the user selects a new state so the list of cities is updated to show only those in the currently selected state. With such an operation, the app usually is not ready to update the model yet, which happens when an action (i.e., a h:commandButton click) occurs. I think if you’re handling VCLs in the UPDATE_MODEL_VALUES phase, you might be going about it in a slightly incorrect, and apparently painful manner. :) You have my email if you’d like to send code and discuss it in more detail. Feel free. Or not. :)

]]> By: Fadi Shttp://blogs.steeplesoft.com/2008/02/a-valuechangelistener-question-and-answer/comment-page-1/#comment-8229 Fadi S Wed, 20 Feb 2008 19:01:41 +0000 http://blogs.steeplesoft.com/a-valuechangelistener-question-and-answer/#comment-8229 Typo: "so my question is, when isn’t value change listener execution defaulted to Update Model Phase in JSF ??"I meant: Why isn’t value change listener execution defaulted to Update Model Phase in JSF ?? Typo:
“so my question is, when isn’t value change listener execution defaulted to Update Model Phase in JSF ??”

I meant: Why isn’t value change listener execution defaulted to Update Model Phase in JSF ??

]]> By: Fadi Shttp://blogs.steeplesoft.com/2008/02/a-valuechangelistener-question-and-answer/comment-page-1/#comment-8228 Fadi S Wed, 20 Feb 2008 04:04:11 +0000 http://blogs.steeplesoft.com/a-valuechangelistener-question-and-answer/#comment-8228 Comment on : "There’s no way to tell for sure, so the onus for controlling the timing of the event falls on the page author, and rightly so, I think."Using JSF before,i found my self having to check for the current phase, and if it is not the Update Model phase, i had to re-queue the event to execute in the Update Model Phase (almost every time) , so my question is, when isn't value change listener execution defaulted to Update Model Phase in JSF ?? Comment on :
“There’s no way to tell for sure, so the onus for controlling the timing of the event falls on the page author, and rightly so, I think.”

Using JSF before,i found my self having to check for the current phase, and if it is not the Update Model phase, i had to re-queue the event to execute in the Update Model Phase (almost every time) , so my question is, when isn’t value change listener execution defaulted to Update Model Phase in JSF ??

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