IE placeholder input event fix suppresses an extra event with interpolation

[jbedard]

109e5d1 introduced an issue which suppresses an extra input event when a placeholder changes due to interpolation and the input has a value. I believe the extra input event does not fire if the input has a value which causes the next real input event to be ignored. I haven't tested <IE11

See http://plnkr.co/edit/qZSjmzuQfzTbkI9eprcR?p=preview

The 2 inputs using interpolation in the placeholder suppress an extra input event on initialization and again each time the interpolation value changes.

Another issue not solved by 109e5d1 is shown in the last 2 inputs of the plunker. I'm not sure if that should be fixed within angular but it would be nice now that some of the placeholder issues are. Here is the fix I've been using, with 109e5d1 I just had to switch ignoreNextInput to false since angular handles that initial input event now. This doesn't handle the extra input event when the placeholder changes but that would be easy to add.

//input events order for inputs with placeholders in IE - the focus/blur input event only occurs if the input has no value
//  creation: input
//  focus:    focusin focus input
//  blur:     focusout input blur
var ignoreNextInput = !!$attrs.placeholder;

$element.on("focusin focusout", function(e) {
    ignoreNextInput = !!(!this.value && this.placeholder);
});

$element.on("input", function(e) {
    if (ignoreNextInput) {
        e.stopImmediatePropagation(); //(stopImmediate is used so the ng-model listener never receives it)
        ignoreNextInput = false;
    }
});

[tbosch]

@caitp Could you take on this one, as it is a regression?

[caitp]

There isn't much to do about it, you have to make a choice about whether you want IE to dirty models unnecessarily, or whether you want interpolation to work correctly --- there isn't really anything in between. I spent too much time on that problem, there is no reliable way to work around the browser bug other than just ignoring the input event in the case of the empty string.

So if this is causing a problem for people then just revert it (at which point the IE people will complain again) -- given that nobody has ever complained about this until now, for months and months, I think it's better to keep it as-is