How to achieve that "ui-sref" be conditionally executed?

angular-ui-router, angularjs, javascript

Solution

This answer inspired me to create a directive that allows me to interrupt the chain of events that end up changing state. For convenience and other uses also prevents the execution of ng-click on the same element.

javascript

module.directive('eatClickIf', ['$parse', '$rootScope',
  function($parse, $rootScope) {
    return {
      // this ensure eatClickIf be compiled before ngClick
      priority: 100,
      restrict: 'A',
      compile: function($element, attr) {
        var fn = $parse(attr.eatClickIf);
        return {
          pre: function link(scope, element) {
            var eventName = 'click';
            element.on(eventName, function(event) {
              var callback = function() {
                if (fn(scope, {$event: event})) {
                  // prevents ng-click to be executed
                  event.stopImmediatePropagation();
                  // prevents href 
                  event.preventDefault();
                  return false;
                }
              };
              if ($rootScope.$$phase) {
                scope.$evalAsync(callback);
              } else {
                scope.$apply(callback);
              }
            });
          },
          post: function() {}
        }
      }
    }
  }
]);

html

<li ui-sref-active="active">
      <a ui-sref="somestate" eat-click-if="!model.isValid()">Go Somestate</a>
</li>

PLUNKER

Problem

I want to validate certain condition before the browser follow the link dynamically created by ui-router. I was looking into `$rootscope.$on('$stateChangeStart', ..)` but I have no access to the `controller.$scope` from there. I also need to use this in several places in the application and would be cumbersome. Keep in mind that `ui-sref` is linked to `ui-sref-active` (work together), so i can't remove `ui-sref` and, by say, to use `$state.$go('some-state')` inside a function called with `ng-click`. The condition should be evaluated inside a `$scope function` and on `on-click event` (before-transition with the ability to cancel it) I need something like this: ``` <li ui-sref-active="active"> <a ui-sref="somestate" ui-sref-if="model.validate()">Go Somestate</a> </li> ``` I tried: ``` <li ui-sref-active="active"> <a ui-sref="somestate" ng-click="$event.preventDefault()">Go Somestate</a> </li> <li ui-sref-active="active"> <a ui-sref="somestate" ng-click="$event.stopImmediatePropagation()">Go Somestate</a> </li> ``` And ``` <li ui-sref-active="active"> <a ui-sref="somestate"> <span ng-click="$event.stopPropagation();">Go Somestate</span> </a> </li> ``` Even ``` <li ui-sref-active="active"> <a ui-sref="somestate" onclick="return false;">Go Somestate</a> </li> ``` But does not work. SANDBOX

Original source

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