Why is angular.js not smart enough to compile DOM when adding dynamic elements?

问题

I really like how AngularJS enables custom tags/elements by allowing you to declare directives inside your app, however, when I append a custom tag dynamically, nothing happens:

angular.module('myApp', []).directive('test', (($compile) ->
   restrict: 'E'
   link: (scope, element, attributes) ->
     $(element).html('<h1>this is a test!</h1>')
))

$('body').append('<test></test>')

How can I build an instance of my custom tag dynamically?

回答1:

Why are you calling jquery outside of angular? Normally you would do something from inside an angular directive for instance and that would have access to $compile. If you absolutely need access outside you can create an injector. (PLUNKER)

angular.module('myApp', []).directive('test', function($compile) {
  return {
    restrict: 'E',
    link: function(scope, element, attributes) {
      $(element).html('<h1>this is a test!</h1>')
    }
  }
});

///////////////////////////////////////////////////////////////////////////////
// called outside angular, you can create an injector that knows about
// certain modules
///////////////////////////////////////////////////////////////////////////////
$(function() {
  // myApp for test directive to work, ng for $compile
  var $injector = angular.injector(['ng', 'myApp']);
  $injector.invoke(function($rootScope, $compile) {
    $('body').prepend($compile('<test>Inside injector</test>')($rootScope));
  });
});

来源：https://stackoverflow.com/questions/17073721/why-is-angular-js-not-smart-enough-to-compile-dom-when-adding-dynamic-elements