<my-dir ng-show="isVisible()"></my-dir>
isVisible will call isVisible in the controller.
What if I want it to call isVisible inside the my-dir directive instead?
Note: my-dir in my application is a tree control that recursively calls itself using $compile so there may be many of them nested inside each other. Using a singleton service may not work because of asynchronicity.
EDIT: in retrospect I the correct answer was to create a filter for my directive. What can I say, Angular is a different way of doing things.
If you're using a directive you have full control of the element. Just do this: <my-dir check-visible="true"></my-dir>
Then in the directive's link function you can just go: if(attrs.checkVisible) isVisible();
Then you can show or hide the element however you like.
Related
I have two scenarios:
A function defined in a controller is called from a directive (see plunk).
The directive includes a '&' scope restriction to relate the controller and directive functions. If you click on the text, the element click event is triggered in the directive and the controller function is called. $scope.$apply() is used to notify AngularJS of the click event and refresh the value of var on the screen.
A function defined in a directive is called from a controller (see plunk).
The directive doesn't have any scope restriction, meaning that $scope in the controller and scope in the directive are shared. I defined func1() in the directive that can be called from the controller (try clicking on the text), however it seems intrusive as the controller needs to know the name of the function.
Is there a way to define func1() in such a way that the function name is declared in the directive div, similar to scenario 1?
Both options are possible and acceptable depending on how you are building the component.
Option 1 - Controllers should register listeners/callbacks and set attributes on directives (when using isolated scope - which i recommend). Controllers should not call a directives function but instead should change an attribute that has been bound on the directive. The directive if setup correctly should be watching this attribute and update accordingly.
Directives should not know who their controllers are in my opinion, it promotes decoupled code. Instead, controllers should be setting callback functions that directives can invoke at the appropriate time (i.e. letting the controller know something was clicked, selected, deleted, swiped, etc...)
Option 2 - Is acceptable to me when you are building a web component that provides the structure and behavioral logic but does not define the actual individual components UI (not including a possible skeleton UI). For example a list directive. The individual list may not be defined in the directive but "plugged in" for each context or use, giving us a more modular and reusable component. It does require us to know some things about the directive. It also requires that we modify the transclusion function to use the directives scope on the transcluded content instead of the original controllers scope. For an example you can checkout a list component I made as an example to this point.
http://github.com/Spidy88/ng-web-components
A snippet of text from this html page. The sf-list directive is an isolated scope directive that defines a lists behavior. However we can still define what each individual list item looks like with modified transclusion. It relies on us to call selectItem though in order to trigger selection behavior on the list.
<sf-list items="ctrl.emails" listener="ctrl.adapter">
<div class="list-item email" ng-click="selectItem(item)" ng-repeat="item in items track by item.id">
<div class="from">{{ item.from }}:</div>
<div class="subject">{{ item.subject }}</div>
</div>
</sf-list>
I'm trying to chain two nested directives that both use isolated scopes.
<div ng-controller="myController">
<my-dir on-done="done()">
<my-dir2 on-done="done()">
</my-dir2>
</my-dir>
</div>
I would like the second directive (my-dir2) to call the done() function of the first directive (my-dir) which in turn would call the controller one.
Unfortunately I don't know how to make the second directive access the callback of the first directive (so far the second directive is looking inside the high level controller, bypassing the first directive).
I think one could possibly make use of "require" but I can't since the two directives are not related (I want to use my-dir2 inside other directives not only my-dir).
To make it clear : I don't want to use require because it means that there would be a dependency of myDir on myDir2. My point is : I want to be able to reuse myDir2 inside others directives. So I don't want myDir2 to be based on myDir but I do want to inform the upper directive (myDir) when something is done (like in a callback in js).
I have made a plunker : as you can see in the javascript console, my-dir2 is calling directly the done function from the high level controller.
Does anyone has a clean way to deal with that kind of situation ?
Thanks
Update:
to be able write directives that are independent of each other you need to use events:
use $emit('myEvent', 'myData') to fire an event that will be handled by scopes that are upward in the hierarchy.
use $broadcast('myEvent', 'myData') to fire an event that will be handled by scopes that are downward in the hierarchy.
to handle the event that was fired by $emit or $broadcast use $on('myEvent', function(event, data){\\your code})
P.S.: in your case the $emit won't work because both directives scopes are on the same level in the hierarchy so you will need to use $rootScope.$broadcast('myEvent' \*, myData*\); I've updated my plunker to reflect the needed changes http://plnkr.co/edit/eTkO6sk6hpuYPnCjlSKn?p=info
The following will make inner directive dependent on the outer directive:
basically to be able to call a function in the first directive you need to do some changes:
add require = '^myDir' to myDir2
remove the onDone from myDir2 and keep the isolated scope
scope:{}
add controller parameter to link function in myDir2 link:
function(scope,element,attrs,controller)
in myDir1 controller change the definition of the done function
from $scope.done to this.done
call controller.done() in myDir2
here is a plunker with the needed changes http://plnkr.co/edit/eTkO6sk6hpuYPnCjlSKn
I think you can do something like these:
angular.element('my-dir').controller('myDir').done();
give a try!
I have a controller that has an object on its scope: $scope.objToTrack.
I have a directive that is inside a nested view that $watches for changes to that object.
It has isolate scope, but objToTrack is set as = so that it can be watched.
When I click the directive, it calls an expression that is a method on the controller which changes objToTrack.
Here's a plunker to illustrate my setup.
The problem is that objToTrack $watch callback isn't fired, although the object is changed.
If you switch between Test1 and Test2 states, changes made to objToTrack are visible. It's just that I don't understand why it doesn't work right away on click.
Thanks.
To answer question...if you bind your own event handlers to an element, and change angular scope within that event handler you need to call $apply so angular is made aware of the change and can run a digest
Example You have:
element.on('click',function(){
scope.onClick({number:RNG.int(200,300)});
});
Would need to be changed to:
element.on('click',function(){
scope.$apply(function(){
scope.onClick({number:RNG.int(200,300)});
});
});
It is a lot simpler if you use event directives already provided by angular. In this case you are writing considerable amount of extra code vs using ng-click. It also makes testing a lot easier when you stay within angular as much as possible
Also, if you want to pass an object into your directive you should not use curly braces.
In html, use obj-to-track="objToTrack", instead of obj-to-track="{{objToTrack}}".
Like this:
<div simple-directive obj-to-track="objToTrack" class="directive"></div>
And in directive.js: use '=' for bi-directional binding of the objToTrack.
Like this:
scope:{
objToTrack:'='
}
In your "test*.html" files, replace "on-click" by "ng-click".
"on-click" doesn't look in your current controller, "ng-click" does.
I have a directive and I want to change the ng-model value given with this directive...
I'm setting scope: {ngModel: '='} and I'm changing the ngModel value (on click event) inside my directive but I can't see changes on my external/original object.
This plunker shows the problem...
There are a few things wrong here, all of them common mistakes.
Event handlers registered through jQuery using $(...).on(...) will be executed outside of angular context, so angular will not know when things have updated. To address this, you must wrap the contents in a scope.$apply call like so
$('#aaa').on('click', function() {
_scope.$apply(function(){
_scope.ngModel = 'Other Value';
updateTemplate();
});
});
This will update the binding to the input with ng-model. In fact you can avoid having to do this by using the ng-click directive.
With angular, you do not need to update templates like this yourself using .html(...). Binding is one of the major features of the framework. Instead of having the update function, you can use interpolation by putting an expression inside of {{ ... }} and your DOM will be updated when your model is. For example when defining the directive you can use
template: '<div id="aaa">{{ngModel}}</div>'
to set your template and {{ngModel}} will show the current value of ngModel.
ngModel is not just any attribute, it is a powerful directive. If you need your own directive to be able to declare the current model valid or invalid, or to interact with forms then you should use this through the require property on your controller (see here).
If you don't need those features then you should be calling your attribute something different to avoid conflict.
I have updated the plunker to include these points.
I'm new to Angular JS. In my plunkr, I have a typeahead that works when I have the typeahead in the html markup. However, when I dynamically generate the html inside my directive, the typeahead no longer works.
Code Here:
http://plnkr.co/edit/KdrxptYAnpTmKa7ZuKkM?p=preview
and to take it one step further, when I pass in a function, it still does not work:
http://plnkr.co/edit/jqN913hJxuVSFAZxAQt7?p=preview
It is not a trivial problem you are trying to solve here, I'm afraid. Basically you are bumping into the scoping issue. The typeahead directive evaluates it expression (city for city in cities($viewValue) here) in the scope of the DOM element on which it is placed. The way you written your wrapper directive makes it so the expression is evaluated in the directive's scope which is isolated and doesn't "see" your controllers scope.
The are number of ways around it but probably the simplest one is to link your $compiled-ed element in the scope that is $parent of your directive scope:
var linkedInput = $compile(inputHtml)(scope.$parent);
Here is a working plunk: http://plnkr.co/edit/fLFwIKNqIRbnesMjZBGj?p=preview
The other alternative is to loose an isolated scope and "manually" take care of the 2-way data binding with the help from the $parse service.