Isolate scope not working without templateUrl/template

[llafuente]

Affect all versions, I can't find any issue related.

Test: http://plnkr.co/edit/x51ohRcoM8uCuaHpIloB?p=preview
To toogle the error go to script, un/comment line 34

The following directive, do not create a isolated scope

.directive('isolateEmpty', function() {
  return {
    restrict: 'EA',
    scope: {},
    link: function($scope, element, attrs) {}
  };
})

But this one will create the scope as expected.

.directive('isolateEmpty', function() {
  return {
    restrict: 'EA',
    scope: {},
    templateUrl: "xxx.html",
    link: function($scope, element, attrs) {}
  };
})

I try to test the other scope combo (true/false) but i'm not sure if it's working... Can't find a proper test...

[gkalpak]

I am not sure why this happens, but it seems to be by design. It was a breaking change back in v1.2.0 (it is mentioned in the changelog).

As per this comment:

We only pass the isolate scope, if the isolate directive has a template, otherwise the child elements do not belong to the isolate directive.

Like I said, I don't know why this is so (it seems counter-intuitive), but it is like that since (almost) forever. Anyone knows (or can find out) what was the reasoning behind this change ?

[gkalpak]

BTW, you can achieve what you want (but in a more verbose way) by using transclusion and "manually" managing the transclusion scope:

.directive('isolateEmpty', function isolateEmptyDirective() {
  return {
    scope: {},
    template: '',
    transclude: true,
    link: function isolateEmptyPostLink(scope, elem, attrs, _, transclude) {
      ...
      transclude(scope, function isolateEmptyCloneAttachFn(clone) {
        elem.append(clone);
      });
    }
  };
}

Demo plnkr

[Narretz]

Afaik, isolated scopes were intended for "component" directives, i.e. those that bring their own template. Although I've sometimes wanted to use the element children as an ad-hoc template so to say. It works with transclude, so maybe that's the way to go.

[gkalpak]

Indeed it doesn't sound like a good practice to rely on a component-directive's internals from the HTML (i.e. have child DOM elements that assume certain things about a directive on their parent) - if the contents are specific to a component, they belond in it's template.

In that respect, it does sounds reasonable.

[Narretz]

Let's clarify that in the docs sometime ..