Order of execution of directive functions in AngularJS

Question

What is the order of execution of directive functions? The documentation doesn't seem to address this.

Ex

1. template / templateUrl (is evaluated)
2. controllerFn
3. compileFn
4. linkFn

Answer

From answer below: http://plnkr.co/edit/79iyKSbfxgkzk2Pivuak (plunker shows nested and sibling directives)

1. Template is parsed
2. compile() (changes made to the template within compile are proliferated down to linking functions)
3. controller()
4. preLink()
5. postLink()

Solution 1

Pre-linking function: Executed before the child elements are linked. Not safe to do DOM transformation since the compiler linking function will fail to locate the correct elements for linking.

Post-linking function: Executed after the child elements are linked. It is safe to do DOM transformation in the post-linking function.

Above excerpt is taken from the official docs on directives.

So, to answer your question, Post-linking/Link function is when/where you can safely operate on element.children().

Solution 2

on related note, here my understanding of exec order across the DOM.

Here is a demo (open browser JS console)

Given this DOM using directive foo:

  <div id="1" foo>
    one
    <div id="1_1" foo>one.one</div>
  </div>

  <div id="2" foo>two</div>

...AngularJS will traverse the DOM - twice - in depth-first order:

1st pass foo.compile()

1) compile: 1

2) compile: 1_1

3) compile: 2

2nd pass: foo.controller() traversing down; foo.link() while backtracking

controller: 1

controller: 1_1

link: 1_1

link: 1

controller: 2

link: 2

Comments

[Jakob Jingleheimer]

So: controller, compile, pre-link, template, post-link ?

[tamakisquare]

@jacob - Yes in the sense that element.children() are only made available for you to access within postLinkFn. One caveat is that your question is about the order of execution of directive functions and the template you have been referring to is simply not a function.

[Mark Rajcok]

@jacob, no, compile comes before controller (but I assume you know that, and you probably just typed your comment wrong). I will add that in the compile function you can change the template. However, any changes made there will affect all DOM clones (e.g., for a directive like ng-repeat, making changes to tElement in the compile function will affect each cloned instance). So in summary: template DOM (tElement) can be changed in compile, and instance DOM (iElement) in post-link.

[Jakob Jingleheimer]

@tamakisquare: oh well yes, template is not really a function. I couldn't think of another term that covered them all (template is a property that gets passed to a function, and compile, etc are methods/functions).

[Jakob Jingleheimer]

@MarkRajcok, oops, yes ^^,

[gregtzar]

Why was this answer marked correct? This answer addresses the question "which function is safe to operate on the DOM?" but not the question "what is the order of execution for controller, compile, and linking functions?"

[Clement]

Nice, I've forked your plunker to also log the preLink phase. plnkr.co/edit/79iyKSbfxgkzk2Pivuak Looks like the preLink phase happens directly after the controller is instantiated

[Jagan]

perfect - short and sweet example