How Angular assign scope when we dynamic add DOM element in it - angularjs

All:
I am pretty new to Angular Directive, from API doc:
https://code.angularjs.org/1.3.20/docs/api/ng/function/angular.element
scope() - retrieves the scope of the current element or its parent.
Requires Debug Data to be enabled.
And say I have a directive like:
.directive("test", function($compile){
return {
restrict: "AE",
scope: { data: "=" },
replace:true,
template:"<div id='viz'></div>",
link: function(scope, EL, attrs){
console.log(angular.element(EL).scope(), EL);
console.log(scope);
}
}
})
And HTML like:
<body ng-controller="main">
<test></test>
</body>
One interesting thing is:
The two scopes printed out in console are not same scope, I wonder why this happens?
If like the API doc says: scope() will return current element's scope, if not, then its parent's. I think they both should return the isolate scope of test, but why angular.element(EL).scope() return its parent's scope?
Thanks

Related

Pass variable to AngularJS directive without isolated scope

I am learning AngularJS directive, and one thing I want to do is to pass some variable $scope.message in the parent scope (a scope of a controller), and I want it to be renamed to param inside the directive alert. I can do this with an isolated scope:
<div alert param="message"></div>
and define
.directive("alert", function(){
return{
restrict: "A",
scope: {
param: "="
},
link: function(scope){
console.log(scope.param) # log the message correctly
}
}
})
But can I do this without using isolated scope? Suppose I want to add another directive toast to the <div toast alert></div> and utilize the same param (keeping the 2-way data-binding), naively I will do
.directive("toast", function(){
return{
restrict: "A",
scope: {
param: "="
},
link: function(scope){
console.log(scope.param)
}
}
})
I surely will get an error Multiple directives [alert, toast] asking for new/isolated scope on:<div...
So in all, my question is, how to rename parent scope variable without isolated scope, and how to share variables when two directives are placed on a single DOM?
Modify your toast directive:
.directive("toast", function(){
return{
restrict: "A",
link: function(scope, elem, attrs){
var param = scope.$eval(attrs.param);
console.log(param)
}
}
})
Example fiddle.
Since toast is now on the same scope as the parent would have been (if it was allowed to be isolate scope), you can simply call $eval on scope with the param attribute to get the value.

Pass variable from parent directive to child-directive?

I have two directives that look like this:
<g-map centerlong="{{myLocation.long}}" centerlat="{{myLocation.lat}}" zoom="12" id="map" class="map">
<g-marker poslong="{{myLocation.long}}" poslat="{{myLocation.lat}}" title="g-marker"></g-marker>
</g-map>
g-map creates a google map, and now I wish to apply g-marker to it.
Therefore g-marker needs access to the object created in g-map. How can I pass it
directive('gMap', function(googleMaps){
return{
restrict: 'E',
replace: true,
transclude: true,
template: "<div ng-transclude></div>",
scope: true,
link: function(scope, element, attrs){
scope.$on('location', function(){
//här ska den recentreras
})
//create the map
var center = googleMaps.makePosition(attrs.centerlat, attrs.centerlong)
//update map on load
var options = googleMaps.setMapOptions(center, attrs.zoom);
scope.map = googleMaps.createMap(options, attrs.id)
}
}]
};
}).
directive('gMarker', function(googleMaps, $timeout){
return{
//require: "^gMap",
restrict: 'E',
scope: true,
link: function(scope, element, attrs, controller){
var location = googleMaps.makePosition(attrs.poslat, attrs.poslong)
$timeout(function(){
//this is where I want to access the scope.map variable
googleMaps.addMarker(map, location,attrs.title)
}, 0);
}
}
})
As you said, googlempas replaces the html tag, so you use transclude, which makes the parent scope inaccessible to the child scope.
Here are some options:
The easiest solution is to make the parent scope non-isolate, so just remove scope : true in the parent directive, and set scope.map in the controller of the parent directive. This ensures that the property is immediately available in the child link function (no need for $timeout). however, if you are doing dom manipulation, you have to do it in the link function)
Or you could set up bi-directional data binding between parent and child directive:
scope : {map : '=map'}
Or, if you prefer not to expose the whole map object to the child, you could expose a method of the parent scope that the child can call:
In gMap, create a controller:
controller : [function() {
this.addMarker(location, title)
}];
in gMarker, require the gMap:
require: "^gMap"
This injects the gMap controller into your link directive:
link: function(scope, element, attrs, gMapController){
gMapController.addMarker(location, attrs,title)
}
I have made an example for each option in this plunker:
http://plnkr.co/edit/1UyNVhFZl4HtFdqeYhie?p=preview
I'd prefer the third option, since it's not necessary that a child can access the whole map object.
Please note that it's possible that other factors can cause any of the options to fail. Please report back if it doesn't work.

Illegal use of ngTransclude directive in the template

I have two directive
app.directive('panel1', function ($compile) {
return {
restrict: "E",
transclude: 'element',
compile: function (element, attr, linker) {
return function (scope, element, attr) {
var parent = element.parent();
linker(scope, function (clone) {
parent.prepend($compile( clone.children()[0])(scope));//cause error.
// parent.prepend(clone);// This line remove the error but i want to access the children in my real app.
});
};
}
}
});
app.directive('panel', function ($compile) {
return {
restrict: "E",
replace: true,
transclude: true,
template: "<div ng-transclude ></div>",
link: function (scope, elem, attrs) {
}
}
});
And this is my view :
<panel1>
<panel>
<input type="text" ng-model="firstName" />
</panel>
</panel1>
Error: [ngTransclude:orphan] Illegal use of ngTransclude directive in the template! No parent directive that requires a transclusion found. Element: <div class="ng-scope" ng-transclude="">
I know that panel1 is not a practical directive. But in my real application I encounter this issue too.
I see some explanation on http://docs.angularjs.org/error/ngTransclude:orphan. But I don't know why I have this error here and how to resolve it.
EDIT
I have created a jsfiddle page. Thank you in advance.
EDIT
In my real app panel1 does something like this:
<panel1>
<input type="text>
<input type="text>
<!--other elements or directive-->
</panel1>
result =>
<div>
<div class="x"><input type="text></div>
<div class="x"><input type="text></div>
<!--other elements or directive wrapped in div -->
</div>
The reason is when the DOM is finished loading, angular will traverse though the DOM and transform all directives into its template before calling the compile and link function.
It means that when you call $compile(clone.children()[0])(scope), the clone.children()[0] which is your <panel> in this case is already transformed by angular.
clone.children() already becomes:
<div ng-transclude="">fsafsafasdf</div>
(the panel element has been removed and replaced).
It's the same with you're compiling a normal div with ng-transclude. When you compile a normal div with ng-transclude, angular throws exception as it says in the docs:
This error often occurs when you have forgotten to set transclude:
true in some directive definition, and then used ngTransclude in the
directive's template.
DEMO (check console to see output)
Even when you set replace:false to retain your <panel>, sometimes you will see the transformed element like this:
<panel class="ng-scope"><div ng-transclude=""><div ng-transclude="" class="ng-scope"><div ng-transclude="" class="ng-scope">fsafsafasdf</div></div></div></panel>
which is also problematic because the ng-transclude is duplicated
DEMO
To avoid conflicting with angular compilation process, I recommend setting the inner html of <panel1> as template or templateUrl property
Your HTML:
<div data-ng-app="app">
<panel1>
</panel1>
</div>
Your JS:
app.directive('panel1', function ($compile) {
return {
restrict: "E",
template:"<panel><input type='text' ng-model='firstName'>{{firstName}}</panel>",
}
});
As you can see, this code is cleaner as we don't need to deal with transcluding the element manually.
DEMO
Updated with a solution to add elements dynamically without using template or templateUrl:
app.directive('panel1', function ($compile) {
return {
restrict: "E",
template:"<div></div>",
link : function(scope,element){
var html = "<panel><input type='text' ng-model='firstName'>{{firstName}}</panel>";
element.append(html);
$compile(element.contents())(scope);
}
}
});
DEMO
If you want to put it on html page, ensure do not compile it again:
DEMO
If you need to add a div per each children. Just use the out-of the box ng-transclude.
app.directive('panel1', function ($compile) {
return {
restrict: "E",
replace:true,
transclude: true,
template:"<div><div ng-transclude></div></div>" //you could adjust your template to add more nesting divs or remove
}
});
DEMO (you may need to adjust the template to your needs, remove div or add more divs)
Solution based on OP's updated question:
app.directive('panel1', function ($compile) {
return {
restrict: "E",
replace:true,
transclude: true,
template:"<div ng-transclude></div>",
link: function (scope, elem, attrs) {
elem.children().wrap("<div>"); //Don't need to use compile here.
//Just wrap the children in a div, you could adjust this logic to add class to div depending on your children
}
}
});
DEMO
You are doing a few things wrong in your code. I'll try to list them:
Firstly, since you are using angular 1.2.6 you should no longer use the transclude (your linker function) as a parameter to the compile function. This has been deprecated and should now be passed in as the 5th parameter to your link function:
compile: function (element, attr) {
return function (scope, element, attr, ctrl, linker) {
....};
This is not causing the particular problem you are seeing, but it's a good practice to stop using the deprecated syntax.
The real problem is in how you apply your transclude function in the panel1 directive:
parent.prepend($compile(clone.children()[0])(scope));
Before I go into what's wrong let's quickly review how transclude works.
Whenever a directive uses transclusion, the transcluded content is removed from the dom. But it's compiled contents are acessible through a function passed in as the 5th parameter of your link function (commonly referred to as the transclude function).
The key is that the content is compiled. This means you should not call $compile on the dom passed in to your transclude.
Furthermore, when you are trying to insert your transcluded DOM you are going to the parent and trying to add it there. Typically directives should limit their dom manipulation to their own element and below, and not try to modify parent dom. This can greatly confuse angular which traverses the DOM in order and hierarchically.
Judging from what your are trying to do, the easier way to accomplish it is to use transclude: true instead of transclude: 'element'. Let's explain the difference:
transclude: 'element' will remove the element itself from the DOM and give you back the whole element back when you call the transclude function.
transclude: true will just remove the children of the element from the dom, and give you the children back when you call your transclude.
Since it seems you care only about the children, you should use transclude true (instead of getting the children() from your clone). Then you can simply replace the element with it's children (therefore not going up and messing with the parent dom).
Finally, it is not good practice to override the transcluded function's scope unless you have good reason to do so (generally transcluded content should keep it's original scope). So I would avoid passing in the scope when you call your linker().
Your final simplified directive should look something like:
app.directive('panel1', function ($compile) {
return {
restrict: "E",
transclude: true,
link: function (scope, element, attr, ctrl, linker) {
linker(function (clone) {
element.replaceWith(clone);
});
}
}
});
Ignore what was said in the previous answer about replace: true and transclude: true. That is not how things work, and your panel directive is fine and should work as expected as long as you fix your panel1 directive.
Here is a js-fiddle of the corrections I made hopefully it works as you expect.
http://jsfiddle.net/77Spt/3/
EDIT:
It was asked if you can wrap the transcluded content in a div. The easiest way is to simply use a template like you do in your other directive (the id in the template is just so you can see it in the html, it serves no other purpose):
app.directive('panel1', function ($compile) {
return {
restrict: "E",
transclude: true,
replace: true,
template: "<div id='wrappingDiv' ng-transclude></div>"
}
});
Or if you want to use the transclude function (my personal preference):
app.directive('panel1', function ($compile) {
return {
restrict: "E",
transclude: true,
replace: true,
template: "<div id='wrappingDiv'></div>",
link: function (scope, element, attr, ctrl, linker) {
linker(function (clone) {
element.append(clone);
});
}
}
});
The reason I prefer this syntax is that ng-transclude is a simple and dumb directive that is easily confused. Although it's simple in this situation, manually adding the dom exactly where you want is the fail-safe way to do it.
Here's the fiddle for it:
http://jsfiddle.net/77Spt/6/
I got this because I had directiveChild nested in directiveParent as a result of transclude.
The trick was that directiveChild was accidentally using the same templateUrl as directiveParent.

Is it ok watch the scope inside a custom directive?

I'm trying to write a directive to create a map component so I can write something like:
<map></map>
Now the directive looks like this:
angular.module('myApp')
.directive('map', function (GoogleMaps) {
return {
restrict: 'E',
link: function(scope, element, attrs) {
scope.$watch('selectedCenter', function() {
renderMap(scope.selectedCenter.location.latitude, scope.selectedCenter.location.longitude, attrs.zoom?parseInt(attrs.zoom):17);
});
function renderMap(latitude, longitude, zoom){
GoogleMaps.setCenter(latitude, longitude);
GoogleMaps.setZoom(zoom);
GoogleMaps.render(element[0]);
}
}
};
});
The problem is that 'watch' inside the directive doesn't looks very well thinking in the reusability of the component. So I guess the best thing is being able to do something like:
<map ng-model="selectedCenter.location"></map>
But I don't know if it's even a good thing using angular directives inside custom directives or how can I get the object indicated in the ng-model attribute in the custom-directive's link function.
You will need to do something like that
angular.module('myApp')
.directive('map', function (GoogleMaps) {
return {
restrict: 'E',
scope: {
ngModel: '=' // set up bi-directional binding between a local scope property and the parent scope property
},
as of now you could safely watch your scope.ngModel and when ever the relevant value will be changed outside the directive you will be notified.
Please note that adding the scope property to our directive will create a new isolated scope.
You can refer to the angular doc around directive here and especially the section "Directive Definition Object" for more details around the scope property.
Finally you could also use this tutorial where you will find all the material to achieve a directive with two way communication form your app to the directive and opposite.
Without scope declaration in directive:
html
<map ng-model="selectedCenter"></map>
directive
app.directive('map', function() {
return {
restrict: 'E',
require: 'ngModel',
link: function(scope, el, attrs) {
scope.$watch(attrs.ngModel, function(newValue) {
console.log("Changed to " + newValue);
});
}
};
});
One easy way you can achieve this would be to do something like
<map model="selectedCenter"></map>
and inside your directive change the watch to
scope.$watch(attrs.model, function() {
and you are good to go

scope change in a directive not a apply in view

I have a directive in a template.html, included by a ng-include, in this directive I change the scope , but it is not change in my view
Here is my html
<div ng-controller="myCtrl">
<div id="modal">
<div ng-show="showDIv">Somthing to controll</div>
</div>
<div ng-include src="template.html">
</div>
Here is my template
<a ng-support></a>
And here is my directive
app.directive('ngSupport', function(){
return {
restrict: 'A',
link: function(scope, elem, attr, ctrl) {
elem.bind('click', function(e) {
$("#modal").dialog({height:518,width:900,modal:true });
scope.showDiv = true;
scope.$apply();
});
}
};
});
When i change the scope in the directive it is not apply in the view, anyone could help please ?
ng-include creates a new scope so scope.showDiv only affects the local scope.
Depending on how you want to structure your application, you could try accessing scope.$parent.showDiv instead, but it is not really future proof as it will depend on the HTML nesting.
A better solution would be to have the showDiv property stored inside an object in the parent scope. For example scope.ui = {}, this way, when you set scope.ui.showDiv = true in your directive, it will look up the parent scope automatically (using prototype inheritance), instead of adding the property to the local scope.
Finally, another solution would be to refactor your code to make it less complex: I think using a ng-include just for adding one element is an overkill, you could put directly <a ng-support></a> inside your html, which would avoid the problem you have with an intermediary scope being generated.
Another option is to broadcast an event, and watch for it in the controller. Something like this.
app.directive('ngSupport', function($rootScope){
return {
restrict: 'A',
link: function(scope, elem, attr, ctrl) {
elem.bind('click', function(e) {
$("#modal").dialog({height:518,width:900,modal:true });
$rootScope.$broadcast('event:modal-clicked');
});
}
};
});
With this in your controller.
$scope.$on('event:modal-clicked', function() {
$scope.showDiv = true;
});

Resources