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:

<a4j:repeat var="email" id="repeatid" rowKeyVar="idx"

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:

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

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.