[Jakarta Tapestry Wiki] Updated: Gotchas

[ta...@jakarta.apache.org]

   Date: 2004-10-28T12:12:40
   Editor: JamieOrchardHays <ja...@dang.com>
   Wiki: Jakarta Tapestry Wiki
   Page: Gotchas
   URL: http://wiki.apache.org/jakarta-tapestry/Gotchas

   no comment

Change Log:

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@@ -10,7 +10,7 @@
 users of the application.
 As mentioned in the previous gotcha implement PageRenderListener and then initialize your properties in pageBeginRender() to any client-specific value.
 
-= form parameter direction =
+= Form Parameter Direction =
 If the "form" direction is specified for a component parameter, that component must implement the IFormComponent interface, directly or indirectly (through inheritance).
 If there is a component which wraps a form components and is, itself, embedded in a form but does not implement the IFormComponent interface, then the 
 parameter directions for any inherited-bindings should be of direction "in", rather than "form" 
@@ -20,3 +20,15 @@
 MyComponent, in turn, uses an inherited-binding to bind textFieldValue to the "value" parameter of the TextField component.
 Even though the parameter "value" is direction "form", the "textFieldValue" parameter should
 be direction "in".
+
+
+= Form and Submit Listeners: Order Matters =
+In 3.0, it matters ''where'' you place your Submit components in your html template. Why? Because 
+components are processed in order during the rewind. This means that if you have a Submit button
+placed on a Form before some other component whose value is needed, the field's new value will not be included 
+because the Submit listener is called first. If your listener is on the Submit component, then make sure the 
+component is placed last in the Form. Also, it is important to remember that a listener placed on the Form 
+component is ''always'' called. This can getcha (get you) when, for example, you have a Cancel button with a 
+listener but put your default Form listener in the Form component. '''Both''' listeners will be called!
+Either use listeners on your Submit components only, or use them to set flags that are read by the Form 
+listener. 

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