When does transclusion take place in the compilation/linking process of a directive's setup?

Question

I'm writing a custom directive that uses transclusion. I need to make modifications to the transcluded DOM content AFTER the transclusion has taken place....would I want to do that in the post-link or in the controller or ... the link...? I don't know where transclusion falls in the order of those things happening, so I don't know how to ensure my JS is executed after the transclusion has taken place.

Answer 1

The transclusion takes place during the compilation phase. Angular's $compile service goes over the DOM, and if a directive has transclusion enabled, Angular extracts the contents of the element (if transclude: true, or the element itself - for transclude: 'element'), compiles them, and makes the compiled content available in the transclusion function, bound to the transclusion scope.

So, the order of execution would be:

1. Angular transcludes the contents and compiles it: compile functions of the transcluded content directives execute
2. compile function of the directive executes - returns pre- and post-link functions
3. controller function of the directive executes
4. pre-link function of the directive executes
5. post-link function of the directive executes.

You may decide to execute the transclude function in the post-link function. As soon as you do,

6. controller, pre-, and post-link functions of the transcluded content directives execute

transclude function is available at step #3-#5, and when invoked, it provides a fresh copy of the transcluded element to the cloneAttachFn, which you provide as a parameter to the transclude function:

link: function(scope, element, attrs, ctrls, transclude){
    transclude(scope, function cloneAttachFn(clone){
      // you can do DOM manipulation of the clone instance here
    });
}

Note, that the DOM manipulation in the cloneAttachFn would apply to an instance of the transcluded DOM - not to the pre-compiled DOM template.