[T4.1.3] Tip for using using directlink and updatecomponents in a for loop

[Jim Roycroft]

I spent three hours on this silly thing so I hope this post will help you
avoid that!

I was testing this out with two iterations of the loop, and that's what
caused me grief. As soon as I switched to four iterations, I figured out
what was happening:

I have a SimplePage.html which includes this:

< span jwcid="@For" source="ognl:wordList" value="ognl:word"
index="ognl:objectIndex" >
   < a href="#" jwcid="@DirectLink" updateComponents="componentWrapper"
listener="listener:showTheWord" parameters="ognl:word">Show the word 
   < p>
      < span jwcid="[EMAIL PROTECTED]">
         < div jwcid="showWordComponent"/>
      < /span>
   < /p>
   < /span>
< /span>


I look at the generated page source and the clientId's within the
@DirectLink links don't look right:

< span id="For">
< a id="DirectLink"
href="/playing/SimplePage,$DirectLink.direct?sp=Sfirst&amp;updateParts=componentWrapper"
onclick="return tapestry.linkOnClick(this.href,'DirectLink', false)">Show
the word 
< p>
   < span id="componentWrapper">
Word:
   < /span>
< /p>
< /span>
< a id="DirectLink_0"
href="/playing/SimplePage,$DirectLink.direct?sp=Ssecond&amp;updateParts=componentWrapper"
onclick="return tapestry.linkOnClick(this.href,'DirectLink_0', false)">Show
the word 
< p>
   < span id="componentWrapper_0"> 
Word:
   < /span>
< /p> 

Look at the second link... it still shows 'updateParts=componentWrapper'
when it should be 'updateParts=componentWrapper_0'.

The solution to this is trivial (once you know what's going on!). Simply
move the directlink code below the component in question, so we have:

< span jwcid="@For" source="ognl:wordList" value="ognl:word"
index="ognl:objectIndex" >
   < p>
      < span jwcid="[EMAIL PROTECTED]">
         < div jwcid="showWordComponent"/>
      < /span>
   < /p>
   < a href="#" jwcid="@DirectLink" updateComponents="componentWrapper"
listener="listener:showTheWord" parameters="ognl:word">Show the word 
   < /span>
< /span>

Now the links will be correct. The reason this happens is that the
@DirectLink component will ask for the componentWrapper clientId on the
first round, and it will default to the componentId because the clientId has
not been set yet because componentWrapper has not been rendered. The second
time around, the @DirectLink will still have the wrong value because it
renders before the componentWrapper.

I hope all that was clear.... if not, please ask questions and I'll be happy
to re-write and re-word it.

Jim

-- 
View this message in context: 
http://www.nabble.com/-T4.1.3--Tip-for-using-using-directlink-and-updatecomponents-in-a-for-loop-tf4674929.html#a13356699
Sent from the Tapestry - User mailing list archive at Nabble.com.


---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]