AngularJS directive scope and $compile - issue with variable not displaying any value

Question

AngularJS directive scope and $compile - issue with variable not displaying any value

Encountering a small challenge with Angular that is puzzling me. I have a feeling it may be related to scope, but I'm not entirely certain.

Here is the snippet of my HTML:

<i class="icon-question-sign" popover data-placement="top" data-trigger="hover" data-title="Top 10 clients" data-content-compile="<ul><li ng-repeat='client in user.clients | limitTo: 10'>{{client}}</li></ul>"></i>

This is how my directive looks:

app.directive('popover', function($timeout, $compile) {
var linker = function (scope, element, attrs) {
    $timeout(function() {
        var content = $compile(element.data('content-compile'))(scope);
        element.popover({
            'html': true,
            'content': content
        });
    }, 200);
}

return {
    restrict: 'A',
    link: linker
}

});

The outcome correctly repeats the li's for the appropriate length of {{user.clients}}, but fails to render {{client}}. Strangely, it appears empty even though it holds a string value and works when directly added to the HTML without going through the directive. Here is how it currently displays in the DOM:

<ul class="ng-scope"><!-- ngRepeat: client in user.clients | limitTo: 10 --><li ng-repeat="client in user.clients | limitTo: 10" class="ng-scope"></li><li ng-repeat="client in user.clients | limitTo: 10" class="ng-scope"></li><li ng-repeat="client in user.clients | limitTo: 10" class="ng-scope"></li><li ng-repeat="client in user.clients | limitTo: 10" class="ng-scope"></li><li ng-repeat="client in user.clients | limitTo: 10" class="ng-scope"></li><li ng-repeat="client in user.clients | limitTo: 10" class="ng-scope"></li><li ng-repeat="client in user.clients | limitTo: 10" class="ng-scope"></li><li ng-repeat="client in user.clients | limitTo: 10" class="ng-scope"></li><li ng-repeat="client in user.clients | limitTo: 10" class="ng-scope"></li><li ng-repeat="client in user.clients | limitTo: 10" class="ng-scope"></li></ul>

If I substitute {{client}} with something like {{user.email}}, it displays correctly.

I'm unsure of what the issue might be - perhaps I'm overlooking something obvious!

javascript angularjs

Answer 1

Answer №1

The solution to the issue lies in its root cause: {{client}} in data-content-compile is compiled before the directive triggers, causing client to be undefined in the controller context. The current string passed into $compile looks like this:

<ul><li ng-repeat='client in user.clients | limitTo: 10'></li></ul>

To avoid this situation, the template needs to be passed into the directive in a different manner. Here are some possible approaches:

Store the template as a string in the controller (although not the most elegant solution).
Store the template in a separate file and retrieve it from $templateCache.

I have provided an example using the second approach in this demo:

<div ng-controller="ctrl">
    <script type="text/ng-template" id="client.html">
        <div><ul><li ng-repeat='client in user.clients'>{{client.name}}</li></ul></div>
    </script>
    <i
        popover
        class="glyphicon glyphicon-user"
        data-placement="bottom"
        data-trigger="hover"
        data-title="Top 10 clients"
        data-content-template="client.html"
    ></i>
</div>

angular.module("app", [])
.controller("ctrl", function($scope, User) {
    $scope.user = User;
})
.directive("popover", function($compile, $timeout, $templateCache) {
    return function(scope, el, attr) {
        $timeout(function() {
            el
            .popover({
                html: true,
                content: $compile($templateCache.get(attr.contentTemplate))(scope)
            })
            .popover("show")
        });    
    };
})
.value("User", {
    clients: [
        { name: "John", age: 22},
        { name: "Ann", age: 13},
        { name: "Maria", age: 62},
        { name: "Ivan", age: 44}
    ]
});

Answer 2

The solution to the issue lies in its root cause: {{client}} in data-content-compile is compiled before the directive triggers, causing client to be undefined in the controller context. The current string passed into $compile looks like this:

<ul><li ng-repeat='client in user.clients | limitTo: 10'></li></ul>

To avoid this situation, the template needs to be passed into the directive in a different manner. Here are some possible approaches:

Store the template as a string in the controller (although not the most elegant solution).
Store the template in a separate file and retrieve it from $templateCache.

I have provided an example using the second approach in this demo:

<div ng-controller="ctrl">
    <script type="text/ng-template" id="client.html">
        <div><ul><li ng-repeat='client in user.clients'>{{client.name}}</li></ul></div>
    </script>
    <i
        popover
        class="glyphicon glyphicon-user"
        data-placement="bottom"
        data-trigger="hover"
        data-title="Top 10 clients"
        data-content-template="client.html"
    ></i>
</div>

angular.module("app", [])
.controller("ctrl", function($scope, User) {
    $scope.user = User;
})
.directive("popover", function($compile, $timeout, $templateCache) {
    return function(scope, el, attr) {
        $timeout(function() {
            el
            .popover({
                html: true,
                content: $compile($templateCache.get(attr.contentTemplate))(scope)
            })
            .popover("show")
        });    
    };
})
.value("User", {
    clients: [
        { name: "John", age: 22},
        { name: "Ann", age: 13},
        { name: "Maria", age: 62},
        { name: "Ivan", age: 44}
    ]
});

Answer 3

Answer №2

It turns out that the solution to my issue was simpler than I had anticipated. I made a slight adjustment to my directive as follows:

// popover
app.directive('popover', function($timeout, $compile) {
    var linker = function (scope, element, attrs) {
        var content = $compile(element.data('content-compile'))(scope);
        $timeout(function() {
            element.popover({
                'html': true,
                'content': content
            });
        }, 800); // Doubled the $timeout duration here
    }

    return {
        restrict: 'A',
        link: linker
    }

});

The key change I made was increasing the $timeout duration and moving the compiled variable outside of it to ensure it is compiled before being called. This tweak seems to have resolved the issue in testing.

While this solution worked for me, it may not be applicable in all cases. If you encounter a similar problem, consider this solution cautiously.

Answer 4

It turns out that the solution to my issue was simpler than I had anticipated. I made a slight adjustment to my directive as follows:

// popover
app.directive('popover', function($timeout, $compile) {
    var linker = function (scope, element, attrs) {
        var content = $compile(element.data('content-compile'))(scope);
        $timeout(function() {
            element.popover({
                'html': true,
                'content': content
            });
        }, 800); // Doubled the $timeout duration here
    }

    return {
        restrict: 'A',
        link: linker
    }

});

The key change I made was increasing the $timeout duration and moving the compiled variable outside of it to ensure it is compiled before being called. This tweak seems to have resolved the issue in testing.

While this solution worked for me, it may not be applicable in all cases. If you encounter a similar problem, consider this solution cautiously.

AngularJS directive scope and $compile - issue with variable not displaying any value

Answer №1

Answer №2

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