(ANGULAR VERSION: 1.3.8)
I am getting an exception on a call within my directive's controller 'randomly'. The exception happens when the directive's controller gets called BEFORE the parent's controller and the parent controller scope variable used in the directive's controller is not yet initialized. However, on the 'random' occasion that my parent controller does get called BEFORE my directive's controller, and thus scope var is initialized, the call works and no exception is thrown. I have two questions (I have sample code below.):
Why is there 'randomness' in the sequence of calls between the directives's controller and the parent controller? I.e., why does one get called before/after the other?
I am able to eliminate the random sequence by a slight change in the HTML and by using ng-repeat on an array of length 1 in my html as opposed to passing in a single object to my directive. The directive code remains the same.
NOTE: The parent controller has a service to an ajax call injected (o_conversationService). The $scope.thread variable mentioned below relies on data returned from the ajax call. Perhaps, the randomness is rooted on the ajax callback timing although I'm not clear how. Regardless, this doesn't explain why the minor change in HTML removes the problem.
Below are two HTML snippets (the first working randomly and the second reliably) both using the same directive code:
HTML RANDOM (NOT)WORKING SCENARIO: With this HTML, the cfThread directive's controller gets called BEFORE parent controller and an exception is thrown because '$scope.thread' is null (see directive controller code below):
HTML snippet (directive name: 'cf-thread'):
<cf-thread thread = "o_conversationService.o_thread"></cf-thread>
HTML WORKING SCENARIO: With this HTML, the cfThreads directive controller gets called AFTER the parent's controller so '$scope.thread' is properly initialized (see directive controller code below):
HTML snippet (directive name: 'cf-thread'):
<cf-thread ng-repeat="threadObject in o_conversationService.o_threadCollection.objectDict" thread="threadObject"></cf-thread>
DIRECTIVE JS (Exception!!! marked below. Exception because $scope.thread is null):
threadDirectiveModule.directive('cfThread', ['$sce', function ($sce) {
return {
restrict: 'AEC',
scope: {
thread: '='
},
templateUrl: 'partials/directives/thread.html',
controller: function ($scope) {
//EXCEPTION!!! $scope.thread is null if parent controller
//wasn't called first.
var unsafeDirectLink = cf.Utilities.createExternalDirectLink($scope.thread.dataJSON.source.type,
$scope.thread.dataJSON.source.user_id,
$scope.thread.dataJSON.source.root_id)
if (cf.Utilities.isDefined(unsafeDirectLink)) {
$scope.thread.safeDirectLink = $sce.trustAsHtml(unsafeDirectLink);
}
else {
$scope.thread.safeDirectLink = null;
}
}
};
}]);
FINAL NOTE: In the non-working HTML scenario, I can always add a $watch to '$scope.thread' in the directive's controller. Needless to say, although it works, I would like to avoid it if not necessary, as seen the the working HTML scenario.
I appreciate your thoughts and patience!
Related
I have a controller name as string and I want to get constructor of it.
My current method is using $controller as below:
$scope.myControllerConstructor= $controller( "myControllerName" , {$scope: $scope.$new()}).constructor;
Later on, I use this constructor in the html like this:
<div ng-controller="myControllerConstructor">
The issue is my controller runs two time, one time when I get the constructor (which is wrong) and one time when my html gets compiled (which is correct)
The question is how to get the controller constructor without running it?
Update about use-case: In our application we have many pages with 60% similarities and 40% different activities. I created a directive for those pages and other developers in the team are using my directive to create their page.
The directive accepts a template and a controller (I get them as string) and later on I include the provided template and controller as below:
<div ng-include="myTemplate" ng-controller="myControllerConstructor"></div>
Please take a look at this jsfiddle for a simple example of issue.
The structure of your code looks ok but the issue is $controller( "myControllerName" , {$scope: $scope.$new()}) already instantiate the controller with the given scope for you.
It is true that you can access the controller constructor with .constructor but it is too late as you already created an instance of the controller.
ng-controller does the exact same thing as $controller( "myControllerName" , {$scope: $scope.$new()})
When a Controller is attached to the DOM via the ng-controller
directive, AngularJS will instantiate a new Controller object, using
the specified Controller's constructor function. A new child scope
will be created and made available as an injectable parameter to the
Controller's constructor function as $scope.
To solve this issue you should pass the controller constructor function to pageDirectiveTemplate instead of the controller name.
The working fiddle
There is a different way we can achieve this. In directive, while using isolated scope (like you are doing here in fiddle), you could have a property controller that has value "#" and have another name property having the value of "myController" or whatever your controller name you are passing as.
So, your directive could look something like this:
app.directive('pageDirective', function() {
return {
restrict: "A",
templateUrl: "pageDirectiveTemplate",
scope: {
myTemplate: "#"
},
controller: "#",
name: "myController"
}
});
Notice that, only change in HTML would be to have the directive as an attribute instead of an element. So,
<div page-directive my-template="templateA" my-controller="controllerA">
</div>
<div page-directive my-template="templateA" my-controller="controllerB">
</div>
This would give you exactly what you are looking for. Now you can have same template pointing different controllers and vice-versa.
working fiddle | Note that it works for two different controllers having same template. Also, check the console to see how it logs only once from each controller.
I have an angular directive, which can take a parent controller function as attribute. During DOM manipulation, this angular directive is cloned, compiled and placed into the beginning part of the DOM. As a result, the passed in parent controller function does not work anymore, since there is no parent controller anymore. How could I solve this? Could I pass the parent controller function from the original to the clone when I'm compiling it? I have tried this, but it is not working:
$timeout(function () {
$scope.test ="passed content";
var compiledClonedDirective = $compile(clonedDirective)($scope);
divInTheBeginningPartOfTheDOM.prepend(clonedDirective);});
function getBack() {
console.log($scope.test);
}
This getBack() function is used in the cloned directive. When it is activated, it logs undefined. Any hints?
One solution was to copy the parent controller function to rootScope, and then call it from the rootScope in the cloned and replaced directive (directive's controller). But I would like to avoid using rootScope if possible.
I'm trying to come up with some code which allows me to run a function in the controller but only once the whole dom is setup and ready (including the directives link function run etc.).
I'm currently communicating between ctrl/service and the directive via $rootScope broadcasts. The first broadcast at the time of the controller loading is not being picked up by the directive. The reason is of course that the controller loads before the directive link function runs. I've read a few similar questions on SO where people recommended on using $timeout for these calls. This unfortunately doesn't always work and I don't want to clutter my ctrl/services with lots of $timeout calls. Therefore I'm looking for another solution to my problem.
Communication pattern is as follows:
1.) Controller tells Service to prepare some data (via function call in service)
2.) Service tells directive to display data (via broadcast)
3.) Directive displays data ...or not in my case :(
EDIT:
As timing is essential in my app, I'm basically looking for a way to initiate a function in the controller as soon as all angular components have finished loading. That function in the controller will display content by assigning a value to a scope variable. At the same time it will start taking the time. I can of course only start doing that once the directives are loaded, otherwise the tmining is wrong or the directive is not yet ready to display content etc.
I've read through a blog post by Ben Nadel, which basically shows how directives are loaded. I was hoping to setup an outer directive which loads last so I can trigger the finished loading from there. Unfortunately that doesn't work as soon as any of the inner directives use a templateUrl.
http://www.bennadel.com/blog/2603-directive-controller-and-link-timing-in-angularjs.htm
Using $timeout would be terrible. Don't do that. You can't define how long a server call is going to take.
I would recommend using this pattern:
Have the controller use a service to load some data, and have the
promise in the controller assign the return data to a scope variable.
Pass that scope variable into your directive.
Setup a watch in the directive link function, when it loads it will go from undefined to desired value. Done!
// in your controller
YourService.all().then(function(data) {
$scope.data = data;
});
// in your view
<some-directive your-data="data"></some-directive>
// in your directive
angular.module('blah.directives').directive('someDirective', function() {
return {
scope: {
yourData: '='
},
link: function(scope, element, attrs) {
var watcher = scope.$watch('yourData', function() {
if(scope.yourData === undefined) return;
// at this point your data will be loaded, do work
// optionally kill watcher at this point if it's not going to update again
watcher();
});
}
}
});
I have to access variable defined in directive and access it in the controller using angularjs
directive :
app.directive('htmlData', function ($compile) {
return {
link: function($scope, element, attrs) {
$(element).on('click', function() {
$scope.html = $compile(element)($scope).html();
});
return $scope.html;
}
};
});
and use $scope.html in controller.
Since you are not creating an isolate scope (or a new scope) in your directive, the directive and the controller associated with the HTML where the directive is used are both using/sharing the same scope. $scope in the linking function and the $scope injected into the controller are the same. If you add a property to the scope in your linking function, the controller will be able to see it, and vice versa.
As you set the variable in the $scope, all you got to do is to bind to it normally. In your case, osmehting like:
<div html-data>{{html}}</div>
Maybe you're not seeing the update because it lacks a $scope.$apply().
Anyway, let me say that I see two problems on you code. First of, you could use ng-click directive to attach click events to your HTML.
Secondly, why would you recompile your HTML every time? There is almost no need for that. You may have a big problem, because after first compilation, your template is going to be lost, so recompiling will render it useless.
If you need to get the element, you can inject $element.
I've been using directives in AngularJS which build a HTML element with data fetched from the $scope of the controller. I have my controller set a $scope.ready=true variable when it has fetched it's JSON data from the server. This way the directive won't have to build the page over and over each time data is fetched.
Here is the order of events that occur:
The controller page loads a route and fires the controller function.
The page scans the directives and this particular directive is fired.
The directive builds the element and evaluates its expressions and goes forward, but when the directive link function is fired, it waits for the controller to be "ready".
When ready, an inner function is fired which then continues building the partial.
This works, but the code is messy. My question is that is there an easier way to do this? Can I abstract my code so that it gets fired after my controller fires an event? Instead of having to make this onReady inner method.
Here's what it looks like (its works, but it's messy hard to test):
angular.module('App', []).directive('someDirective',function() {
return {
link : function($scope, element, attrs) {
var onReady = function() {
//now lets do the normal stuff
};
var readyKey = 'ready';
if($scope[readyKey] != true) {
$scope.$watch(readyKey, function() {
if($scope[readyKey] == true) {
onReady();
}
});
}
else {
onReady();
}
}
};
});
You could use $scope.$emit in your controller and $rootScope.on("bradcastEventName",...); in your directive. The good point is that directive is decoupled and you can pull it out from project any time. You can reuse same pattern for all directives and other "running" components of your app to respond to this event.
There are two issues that I have discovered:
Having any XHR requests fire in the background will not prevent the template from loading.
There is a difference between having the data be applied to the $scope variable and actually having that data be applied to the bindings of the page (when the $scope is digested). So if you set your data to the scope and then fire an event to inform the partial that the scope is ready then this won't ensure that the data binding for that partial is ready.
So to get around this, then the best solution is to:
Use this plugin to manage the event handling between the controller and any directives below:
https://github.com/yearofmoo/AngularJS-Scope.onReady
Do not put any data into your directive template HTML that you expect the JavaScript function to pickup and use. So if for example you have a link that looks like this:
<a data-user-id="{{ user_id }}" href="/path/to/:user_id/page">My Page</a>
Then the problem is that the directive will have to prepare the :user_id value from the data-user-id attribute, get the href value and replace the data. This means that the directive will have to continuously check the data-user-id attribute to see if it's there (by checking the attrs hash every few moments).
Instead, place a different scope variable directly into the URL
My Page
And then place this in your directive:
$scope.whenReady(function() {
$scope.directive_user_id = $scope.user_id;
});