WW1.x also sets the parameters from the request on the action. They can be overridden with the param tag but not removed. In WW1.4 there is also a marker interface NoParameters that an action can implement to avoid having parameters set on it automatically by the ParametersActionFactory. This could for example be used in situations like this one (I have not studied Fred's example in detail, but that's how I understand it). The param tag parameters would be the only parameters to the action in that case.
Of course if you want to reuse the same action sometimes with parameters set, and sometimes not, then the NoParameters interface is more trouble than having an extra attribute on the action tag. But you can always get the parameters from the request that you are interested in from the action context in the action. Cheers, Dick Zetterberg [EMAIL PROTECTED] ----- Original Message ----- From: "Jason Carreira" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, November 24, 2003 9:32 PM Subject: RE: [OS-webwork] Why ActionTag is dangerous... > I think it's a good idea to have a flag on the ActionTag for whether it > should include the request parameters or not... Please add this as a > Jira issue. > > What did WW 1.x do? > > Jason > > > -----Original Message----- > > From: Fred Lamuette [mailto:[EMAIL PROTECTED] > > Sent: Monday, November 24, 2003 12:47 PM > > To: [EMAIL PROTECTED] > > Subject: [OS-webwork] Why ActionTag is dangerous... > > > > > > I've created a component that renders a configurable tabs bar. > > > > >#bodytag(Action "name='tabs'" "id=tabs") > > > #param("tabsId" "$tabsId") > > > #param("activeTab" "$activeTab") > > >#end > > > > > >#bodytag(Push "value=#tabs") > > ><div class="tabs" align="left"> > > > <table cellpadding="3" cellspacing="0" border="0"> > > > <tr> > > > #foreach($tabItem in $tabs) > > > #if($tabItem.selected) > > > <th title="$!tabItem.title">$tabItem.label</th> > > > #else > > > <td title="$!tabItem.title"><a > > href="#bodytag(URL > > "value='$tabItem.url'") #if($tabItem.paramName) > > #param>>("$tabItem.paramName" "$paramValue") #end #end > > ">$tabItem.label</td> > > > #end > > > #end > > > </tr> > > > </table> > > ></div> > > >#end > > > > I call it from a velicity view > > > > > #bodytag(Component "template=tabs.vm") > > > #param( "tabsId" "issue") > > > #param( "activeTab" "owner") > > > #param( "paramValue" "id" true) > > > #end > > > #bodytag(Form ...) > > > #tag(Hidden "name='id'" "value=id") > > > ... > > > #end > > Everything is ok. Except one thing. I put this component at > > the top of a form and here is the chronology that leads to > > the problem : > > > > 1/ I'm creating a new entity (hidden field id=null) by > > fulfilling my form 2/ I submit it 3/ ParametersInterceptor > > populates my action, actually my model class. 4/ After > > validating everything, I store the model class in the db and > > chains to the velocity view that shows again the fulfilled > > form with a message "creation successful" 5/ In this page, > > the hidden field id is still null !! Whereas after leaving > > the action, everything was ok and the id was generated and > > stored in the db. > > > > Why? > > Because of the tabs action that is called just before > > populating the form and that implicitly calls the > > ParametersInterceptor (its necessary because fields from tabs > > action (tabsId, activeTab) must be populated this way). > > Instead of using a list of two parameters (those from the > > declared #param within of the component ->tabsId and > > activeTab ) to populate the tabs action, the > > ParametersInterceptor uses moreover the input parameters from > > the form -> id, name, ...), so the field id of my model class > > is reset to null !!!!! > > > > Ok, that was a tedious example that just illustrates that > > using ActionTag can be very vicious. I was very surprised > > that action tag creates an extra context with the previous > > parameters and not only those provided by the param > > directive. Maybe because I'm not a WebWork man, I'm just > > switching from struts to WW2, but I think it can be very > > dangerous and can raise surprising and long-time-to-debug bugs. > > > > Here is my proposal. Add just a parameter to indicate to > > include or not the parameters from the current context, with > > a default behavior. It's just a simple swith to add in the > > createExtraContext() method, to add or not the > > ActionContext.getContext().getParameters(). > > > > #bodytag(Action "name='tabs'" "id=tabs" > > "includeCurrentContext=false") // Maybe a little bit too long > > as an attribute name > > #param("tabsId" "$tabsId") > > #param("activeTab" "$activeTab") > > #end > > > > What is your feedback, guys ? > > ------------------------------------------------------- This SF.net email is sponsored by: SF.net Giveback Program. Does SourceForge.net help you be more productive? Does it help you create better code? SHARE THE LOVE, and help us help YOU! Click Here: http://sourceforge.net/donate/ _______________________________________________ Opensymphony-webwork mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/opensymphony-webwork
