[SalesForce] How to pass parameter(indexVar of iteration) from lightning component to javascript controller

This has a similar solution to this issue:

How to remove items from a dynamic list in Lightning component?

It doesn't feel clean, but this will return both the value and the input that called it:

Component

<div class="slds-form-element__control">
    <ui:inputPhone class="slds-input" placeholder="{!Phone}" change='c.save'>
    </ui:inputPhone>
    <span id="{!'thisInput'+i}"></span>
</div>

Controller

save: function(cmp, evt){
  var targetCmp = evt.getSource();
  var val = targetCmp.get('v.value');
  var inputId = targetCmp.getElement().nextSibling.nextSibling.id;

  console.log(value);
  console.log(inputId);
}

If you're wondering why the double "nextSibling", it's because the ui:input renders something like:

<!--render facet: 0000:00;a-->

following the element.

I do hope there is a better way to do this.

<aura:iteration items="{!v.records}" var="row" indexVar="rowCnt">
    {!row}
</aura:iteration>

will do the trick. Getting the value dynamically would look like this, {!v.records[rowCnt]} but it doesn't work in lightning.

Failed to save undefined: expecting a positive integer, found 'rowCnt'

You only are allowed to use static integers like: {!v.records[0]}

In case you need the index in your controller, you could use a regular html element like a div and pass the Index with a data-* attribute, unfortunately this won't work with any lightning component, only pure html.

<div onclick="{!c.doStuff}" data-index="{!rowCnt}">

doStuff : function(cmp, evt, helper) {
    var index = evt.currentTarget.dataset.index;
}