How to pass in templateUrl via scope variable in attribute

Question

I'm trying to pass in the url for the template via a scope variable. The scope will not change so the template doesn't need to update based on it, but currently the scope variable is always undefined.

<div cell-item template="{{col.CellTemplate}}"></div>

Ideally the directive would be:

.directive("cellItem", ["$compile", '$http', '$templateCache', '$parse', function ($compile, $http, $templateCache, $parse) {
        return {
            scope: {
                template: '@template'
            },
            templateUrl: template // or {{template}} - either way
        };
    }])

This doesn't work however. I've tried a lot of different permutations in accomplishing the same concept, and this seems the closest, however it still doesn't work.

.directive("cellItem", ["$compile", '$http', '$templateCache', '$parse', function ($compile, $http, $templateCache, $parse) {
        return {
            scope: {
                template: '@template'
            },
            link: function (scope, element, attrs) {
                var templateUrl = $parse(attrs.template)(scope);
                $http.get(templateUrl, { cache: $templateCache }).success(function (tplContent) {
                    element.replaceWith($compile(tplContent)(scope));
                });
            }
        };
    }])

I've also tried using ng-include, but that also doesn't evaluate scope variables before compiling. The CellTemplate value is coming from a database call so is completely unknown before evaluation. Any suggestions for getting this working would be greatly appreciated!

Edit: I'm using angular 1.0.8 and am not able to upgrade to a newer version.

Answer 1

You are not far off at all.

You don't need to use an isolated scope for the directive. You can pass the templateUrl like this:

<div cell-item template="col.CellTemplate"></div>

Then add a watch to detect when the template value changes:

.directive("cellItem", ["$compile", '$http', '$templateCache', '$parse', function ($compile, $http, $templateCache, $parse) {
        return {
            restrict: 'A',
            link: function(scope , element, attrs) {

              scope.$watch(attrs.template, function (value) {
                if (value) {
                  loadTemplate(value);
                }
              });

              function loadTemplate(template) {
                  $http.get(template, { cache: $templateCache })
                    .success(function(templateContent) {
                      element.replaceWith($compile(templateContent)(scope));                
                    });    
              }
            } 
        }
    }]);

Here is a working Plunker: http://plnkr.co/edit/n20Sxq?p=preview

Answer 2

If you don't want to deal with the linking logic yourself, or you want the isolate scope, I think this is simpler:

.directive("cellItem", ["$compile", '$http', '$templateCache', '$parse', function ($compile, $http, $templateCache, $parse) {
        return {
            scope: {
                template: '@template'
            },
            template: "<div ng-include='template'></div>"
        };
    }])

or:

template:"<ng-include src='template'></ng-include>"

Answer 3

It's an old post but I thought its useful if anyone lands in here for the answer.

You can try the templateUrl function as @caub mentioned in a comment. Same can also be used for components.

.directive("cellItem", ["$compile", '$http', '$templateCache', '$parse', function ($compile, $http, $templateCache, $parse) {
    return {
        templateUrl: function(element, attrs) {
           return attrs.template || 'someDefaultFallback.html';
        }
    };
}]);

We don't need any of the injected dependencies here. Hope this helps someone.