Loop Index in Ui:repeat

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Sometimes it’s useful to know what the invariant value is for your loop within a facelets loop. I use ui:repeat a lot, but have seen some problems with it in the past. If you want to get the loop index for your ui:repeat, you may be disappointed. Basically, it requires that you use a different looping mechanism. A nice alternative is the a4j:repeat, which offers the same functionality, plus more awesomeness…

Enough talk, let’s fight:

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<a4j:repeat var="email" id="repeatid" rowKeyVar="idx"
         value="#{collection}">
   #{idx},
</a4j:repeat>

If you loop four times, you should get 1,2,3,4,.

Another point of interest on these loops:

If you have jsf components within this a4j:repeat and need to know their exact id, the id on the loop will help this id be more predictable and readable. For instance, in this situation:

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<h:form id="formid">
   <ui:repeat id="repeatid">
      <h:inputText id="textid" />
   </ui:repeat>
</h:form>

The id of the h:inputText component would be formid:repeatid:textid. This is nice to know if you’re trying to select dom elements by id in javascript.

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