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javascript - Add ng-click dynamically in directive link function

I'm trying to create a directive that would allow an element to be defined as clickable or not, and would be defined like this:

<page is-clickable="true">
    transcluded elements...
</page>

I want the resulting HTML to be:

<page is-clickable="true" ng-click="onHandleClick()">
    transcluded elements...
</page>

My directive implementation looks like this:

app.directive('page', function() {
    return {
        restrict: 'E',
        template: '<div ng-transclude></div>',
        transclude: true,
        link: function(scope, element, attrs) {
            var isClickable = angular.isDefined(attrs.isClickable) && scope.$eval(attrs.isClickable) === true ? true : false;

            if (isClickable) {
                attrs.$set('ngClick', 'onHandleClick()');
            }

            scope.onHandleClick = function() {
                console.log('onHandleClick');
            };
        }
    };
});

I can see that after adding the new attribute, Angular does not know about the ng-click, so it is not firing. I tried adding a $compile after the attribute is set, but it causes an infinite link/compile loop.

I know I can just check inside the onHandleClick() function if the isClickable value is true, but I'm curious how one would go about doing this with dynamically adding an ng-click event because I may need to do with this with multiple other ng-* directives and I don't want to add unnecessary overhead. Any ideas?

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1 Reply

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by (71.8m points)

Better Solution (New):

After reading through the Angular docs I came across this:

You can specify template as a string representing the template or as a function which takes two arguments tElement and tAttrs (described in the compile function api below) and returns a string value representing the template.

So my new directive looks like this: (I believe this is the appropriate "Angular" way to go about this type of thing)

app.directive('page', function() {
    return {
        restrict: 'E',
        replace: true,
        template: function(tElement, tAttrs) {
            var isClickable = angular.isDefined(tAttrs.isClickable) && eval(tAttrs.isClickable) === true ? true : false;

            var clickAttr = isClickable ? 'ng-click="onHandleClick()"' : '';

            return '<div ' + clickAttr + ' ng-transclude></div>';
        },
        transclude: true,
        link: function(scope, element, attrs) {
            scope.onHandleClick = function() {
                console.log('onHandleClick');
            };
        }
    };
});

Notice the new template function. Now I am manipulating the template inside that function before it is compiled.

Alternative solution (Old):

Added replace: true to get rid of the infinite loop issue when recompiling the directive. And then in the link function I just recompile the element after adding the new attribute. One thing to note though, because I had an ng-transclude directive on my element, I needed to remove that so it doesn't try to transclude anything on the second compile, because there is nothing to transclude.

This is what my directive looks like now:

app.directive('page', function() {
    return {
        restrict: 'E',
        replace: true,
        template: '<div ng-transclude></div>',
        transclude: true,
        link: function(scope, element, attrs) {
            var isClickable = angular.isDefined(attrs.isClickable) && scope.$eval(attrs.isClickable) === true ? true : false;

            if (isClickable) {
                attrs.$set('ngClick', 'onHandleClick()');
                element.removeAttr('ng-transclude');
                $compile(element)(scope);
            }

            scope.onHandleClick = function() {
                console.log('onHandleClick');
            };
        }
    };
});

I don't think that recompiling the template a second time is ideal though, so I feel that there is still a way to do this before the template is compiled the first time.


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