如何控制角度指令的初始化？

Question

I have a directive that is used as a form control. This directive is hidden in a modal dialog and is shown when the user clicks a button to show the form. Since this directive connects to some web services, I don't want it to initialize unless the user clicks the button and the form displays (to prevent unnecessary web service calls). So, what I'm looking for is a good way for the parent controller to trigger the directive to execute some init code. Here is an example:

App.controller('parentCtrl', ['$scope', function($scope) {
  $scope.onButtonClick = function onButtonClick() {
    // tell directive to init somehow
  };
}]);

App.directive('myDirective', function() {
return {
  restrict: 'E',
  scope: {},
  controller: function($scope, myService) {
    function init() {
      myService.getData().then(function(value) { //do init stuff });
    }
  }
});

Assume the template for parentCtrl contains a tag .

Answer 1

Tagging your element in an ng-if will prevent the directive from initializing before it's needed. ( scope.loadModal should be false by default)

<my-directive ng-if='loadModal'></mydirective>

Note: Setting scope.loadModal = false after showing the directive once will unload the directive from your DOM. Setting it back to true would reload the directive resulting in another http request.