Develop Reference

How to modify directives isolated scope variable in controller, while still keeping it isolated?

I have a directive with isolated scope. I am modifying one of the variables passed from the parent controller in the controller of the directive. The issue I'm running into is that when I use multiple instances of this directive (with different options and model) on the same view, the options object does not remain unique to each instance of the directive. Instead, it becomes a shared variable and all the instances of the directive use the same options object.
So if I had used them in my view like below, with optionsA.isFlagOn = true and optionsB.isFlagOn = false
<my-directive model="modelA" options="optionsA">
<my-directive model="modelB" options="optionsB">
Directive with modelB loads with the optionsA.
How do I keep options unique while modifying it for each specific instance?
angular.module('myModule', [])
.directive('myDirective', function($compile) {
template = '<h3><span ng-bind="model.title"><h3><p><span ng-bind="options"></span></p>';
return {
restrict: 'AE',
scope: {
model: "=",
options: "=?" //A JSON object
},
controller: function($scope) {
$scope.options = $scope.options || {};
//A function that sets default values if no options object passed
ensureDefaultOptions($scope);
//now based on some of the options passed in, I modify a property in the options object
if ($scope.options.isFlagOn)
$scope.options.thisProp = true;
},
link: function(scope, element, attr) {
let content = $compile(template)(scope);
element.append(content);
}
};
}
Edit: I solved my issue. My solution is posted in the answer below.

Can you change it to you one-way bindings with:
scope: {
model: "=",
options: "<?" //A JSON object
}

Your directive should make a copy of passed in options combined with defaults, so each directive instance have its own option object.
You can achieve that easily by using extend
var defaultOptions = { a:1, b:2, c:3 };
var options = angular.extend(defaultOption, $scope.options);
// then use options everywhere
Note that this will only be done once during init, so if your options come from controller asynchronously, you'll need extra handling.

I solved it using the bindToController property of Angular directive available in 1.4x or higher.
angular.module('myModule', [])
.directive('myDirective', function($compile) {
template = '<h3><span ng-bind="vm.model.title"><h3><p><span ng-bind="myOptions"></span></p>';
return {
restrict: 'AE',
bindToController: {
model: "=",
options: "=?" //A JSON object
},
scope: {},
controller: function() {
var vm = this;
//a function that handles modifying options
vm.setOptions = function(options){
let newOptions = {};
angular.copy(options, newOptions);
// modify newOptions here
return newOptions;
}
},
controllerAs: 'vm',
link: function(scope, element, attr) {
ensureDefaultOptions(scope.vm);
scope.myOptions = scope.vm.setOptions(scope.vm.options);
let content = $compile(template)(scope);
element.append(content);
}
};
});

How to access a require'd controller from another controller?

I have an Angular 1.3 module that looks something like this (directive that requires the presence of a parent directive, using controllerAs):
angular.module('fooModule', [])
.controller('FooController', function ($scope) {
this.doSomething = function () {
// Accessing parentDirectiveCtrl via $scope
$scope.parentDirectiveCtrl();
};
})
.directive('fooDirective', function () {
return {
// Passing in parentDirectiveCtrl into $scope here
link: function link(scope, element, attrs, parentDirectiveCtrl) {
scope.parentDirectiveCtrl = parentDirectiveCtrl;
},
controller: 'FooController',
controllerAs: 'controller',
bindToController: true,
require: '^parentDirective'
};
});
Here I'm just using $scope to pass through parentDirectiveCtrl, which seems a little clunky.
Is there another way to access the require-ed controller from the directive's controller without the linking function?

You must use the link function to acquire the require-ed controllers, but you don't need to use the scope to pass the reference of the controller to your own. Instead, pass it directly to your own controller:
.directive('fooDirective', function () {
return {
require: ["fooDirective", "^parentDirective"],
link: function link(scope, element, attrs, ctrls) {
var me = ctrls[0],
parent = ctrls[1];
me.parent = parent;
},
controller: function(){...},
};
});
Be careful, though, since the controller runs prior to link, so within the controller this.parent is undefined, until after the link function runs. If you need to know exactly when that happens, you can always use a controller function to pass the parentDirective controller to:
link: function link(scope, element, attrs, ctrls) {
//...
me.registerParent(parent);
},
controller: function(){
this.registerParent = function(parent){
//...
}
}

There is a way to avoid using $scope to access parent controller, but you have to use link function.
Angular's documentation says:
Require
Require another directive and inject its controller as the fourth
argument to the linking function...
Option 1
Since controllerAs creates namespace in scope of your controller, you can access this namespace inside your link function and put required controller directly on controller of childDirective instead of using $scope. Then the code will look like this.
angular.module('app', []).
controller('parentController', function() {
this.doSomething = function() {
alert('parent');
};
}).
controller('childController', function() {
this.click = function() {
this.parentDirectiveCtrl.doSomething();
}
}).
directive('parentDirective', function() {
return {
controller: 'parentController'
}
}).
directive('childDirective', function() {
return {
template: '<button ng-click="controller.click()">Click me</button>',
link: function link(scope, element, attrs, parentDirectiveCtrl) {
scope.controller.parentDirectiveCtrl = parentDirectiveCtrl;
},
controller: 'childController',
controllerAs: 'controller',
bindToController: true,
require: '^parentDirective'
}
});
Plunker:
http://plnkr.co/edit/YwakJATaeuvUV2RBDTGr?p=preview
Option 2
I usually don't use controllers in my directives at all and share functionality via services. If you don't need to mess with isolated scopes of parent and child directives, simply inject the same service to both of them and put all functionality to service.
angular.module('app', []).
service('srv', function() {
this.value = '';
this.doSomething = function(source) {
this.value = source;
}
}).
directive('parentDirective', ['srv', function(srv) {
return {
template: '<div>' +
'<span ng-click="srv.doSomething(\'parent\')">Parent {{srv.value}}</span>' +
'<span ng-transclude></span>' +
'</div>',
transclude: true,
link: function(scope) { scope.srv = srv; }
};
}]).
directive('childDirective', ['srv', function(srv) {
return {
template: '<button ng-click="srv.doSomething(\'child\')">Click me</button>',
link: function link(scope) { scope.srv = srv; }
}
}]);
Plunker
http://plnkr.co/edit/R4zrXz2DBzyOuhugRU5U?p=preview

Good question! Angular lets you pass "parent" controller. You already have it as a parameter on your link function. It is the fourth parameter. I named it ctrl for simplicity. You do not need the scope.parentDirectiveCtrl=parentDirectiveCtrl line that you have.
.directive('fooDirective', function () {
return {
// Passing in parentDirectiveCtrl into $scope here
link: function link(scope, element, attrs, ctrl) {
// What you had here is not required.
},
controller: 'FooController',
controllerAs: 'controller',
bindToController: true,
require: '^parentDirective'};});
Now on your parent controller you have
this.doSomething=function().
You can access this doSomething as
ctrl.doSomething().

Accessing directive function from controller using $scope.$parent.$$childHead.functionName in AngularJS

I have created a directive.
angular.module('app')
.directive('navtree', function (service) {
return {
restrict: 'A',
scope: {},
link: function (scope, el) {
scope.loadNavtree = function(){
service.data()
.then(function (data) {
///Do something
});
}
scope.loadNavtree();
}
};
});
from my controller I can access the method using
$scope.$parent.$$childHead.loadNavtree();
Though this is working, I feel that this is not the right approach. I want to understand what are the disadvantages of accessing function defined in directive from your controller like this.
I looked this link but I was not able to follow
var app = angular.module('plunker', []);
app.controller('MainCtrl', function($scope) {
/// How to call takeTablet() available in directive from here?
});
app.directive('focusin', function factory() {
return {
restrict: 'E',
replace: true,
template: '<div>A:{{internalControl}}</div>',
scope: {
control: '='
},
link : function (scope, element, attrs) {
scope.takeTablet = function() {
alert('from directive');//
}
}
};
});

this is not the correct approach because angular do not recommend to use its private variable to access to directive function so you need to get a good approach to do that here is an example to access the directive function from controller.
If you want to use isolated scopes you can pass a control object using bi-directional binding ('=') of a variable from the controller scope. In this way you can control also several instances of the same directive on a page.
plunkr
Controller/Directive:
var app = angular.module('plunker', []);
app.controller('MainCtrl', function($scope) {
$scope.focusinControl = {
};
});
app.directive('focusin', function factory() {
return {
restrict: 'E',
replace: true,
template: '<div>A:{{internalControl}}</div>',
scope: {
control: '='
},
link : function (scope, element, attrs) {
scope.internalControl = scope.control || {};
scope.internalControl.takenTablets = 0;
scope.internalControl.takeTablet = function() {
scope.internalControl.takenTablets += 1;
}
}
};
});
HTML:
<button ng-click="focusinControl.takeTablet()">Call directive function</button>
<h4>In controller scope:</h4>
{{focusinControl}}
<h4>In directive scope:</h4>
<focusin control="focusinControl"></focusin>
<h4>Without control object:</h4>
<focusin></focusin>

Alternative approach for eliminating $watch

As mentioned in the title in my angular application due to the below approach it leads to creation of many watch, i want to find some alternative methods for this.
<div ng-app="myapp">
<first></first>
</div>
var myApp = angular.module('myapp', []);
myApp.directive('first', [
function() {
return {
restrict: 'AE',
replace: true,
transclude: true,
template: '<div id="first"><second id="second" param="paramData"></second></div>',
scope: {
},
controller: [
'$scope',
'$element',
'$attrs',
function($scope, $element, $attrs) {
}
],
link: function(scope, element, attrs, ctrl,$timeout) {
scope.paramData = "Test";
scope.updateParamData = function(){
scope.paramData = "TimeOut";
};
//$timeout(scope.updateParamData,5000);
}
};
}
]);
myApp.directive('second', [
function() {
return {
restrict: 'AE',
replace: true,
template: '<div></div>',
scope: {
param: '=param'
},
controller: [
'$scope',
'$element',
'$attrs',
function($scope, $element, $attrs) {
console.log("inside controller",$scope.param);
}
],
link: function(scope, element, attrs) {
console.log("inside link",scope.param);
scope.$watch(scope.param,function(){
console.log("inside watch",scope.param);
element.innerHTML = scope.param;
});
}
};
}
]);
In the above example the param which is passed from first directive to the second directive is controlled by first directive so the para can change at any time so in the second directive i am using the watch to update the second directive HTML based on the param update.
So now the problem is if i used same kind of approach in my application at many places it leads to multiple watch, so i want to check is this approach is correct or is there is any other alternative approach for this.?

There must be a $watch somewhere to detect the change in the value.
One way to reduce the number of watches is not to use two-way binding scope: {param: "="} in the second directive, and instead use one-way binding of "&".
.directive("second", function(){
return {
scope: { param: "&" }, // this does not create a watch on the parent
template: "<div>{{param()}}</div>" // {{ }} creates a watch
}
})
Of course, you can also explicitly add a $watch in the link/controller (although in your particular example where you use element.innerHTML) it can easier be done with the template approach above):
link: function(scope, element){
scope.$watch(function(){ return scope.param(); },
function(newValue, oldValue){
console.log(newValue, oldValue);
});
}
So, the number of watches is 1 in each case.

I see no way to improve this. Since you need to actually listen for changes for param I do not see a way different from watchers in this case.

Angular Directive refresh on parameter change

I have an angular directive which is initialized like so:
<conversation style="height:300px" type="convo" type-id="{{some_prop}}"></conversation>
I'd like it to be smart enough to refresh the directive when $scope.some_prop changes, as that implies it should show completely different content.
I have tested it as it is and nothing happens, the linking function doesn't even get called when $scope.some_prop changes. Is there a way to make this happen ?

Link function only gets called once, so it would not directly do what you are expecting. You need to use angular $watch to watch a model variable.
This watch needs to be setup in the link function.
If you use isolated scope for directive then the scope would be
scope :{typeId:'#' }
In your link function then you add a watch like
link: function(scope, element, attrs) {
scope.$watch("typeId",function(newValue,oldValue) {
//This gets called when data changes.
});
}
If you are not using isolated scope use watch on some_prop

What you're trying to do is to monitor the property of attribute in directive. You can watch the property of attribute changes using $observe() as follows:
angular.module('myApp').directive('conversation', function() {
return {
restrict: 'E',
replace: true,
compile: function(tElement, attr) {
attr.$observe('typeId', function(data) {
console.log("Updated data ", data);
}, true);
}
};
});
Keep in mind that I used the 'compile' function in the directive here because you haven't mentioned if you have any models and whether this is performance sensitive.
If you have models, you need to change the 'compile' function to 'link' or use 'controller' and to monitor the property of a model changes, you should use $watch(), and take of the angular {{}} brackets from the property, example:
<conversation style="height:300px" type="convo" type-id="some_prop"></conversation>
And in the directive:
angular.module('myApp').directive('conversation', function() {
return {
scope: {
typeId: '=',
},
link: function(scope, elm, attr) {
scope.$watch('typeId', function(newValue, oldValue) {
if (newValue !== oldValue) {
// You actions here
console.log("I got the new value! ", newValue);
}
}, true);
}
};
});

I hope this will help reloading/refreshing directive on value from parent scope
<html>
<head>
<!-- version 1.4.5 -->
<script src="angular.js"></script>
</head>
<body ng-app="app" ng-controller="Ctrl">
<my-test reload-on="update"></my-test><br>
<button ng-click="update = update+1;">update {{update}}</button>
</body>
<script>
var app = angular.module('app', [])
app.controller('Ctrl', function($scope) {
$scope.update = 0;
});
app.directive('myTest', function() {
return {
restrict: 'AE',
scope: {
reloadOn: '='
},
controller: function($scope) {
$scope.$watch('reloadOn', function(newVal, oldVal) {
// all directive code here
console.log("Reloaded successfully......" + $scope.reloadOn);
});
},
template: '<span> {{reloadOn}} </span>'
}
});
</script>
</html>

angular.module('app').directive('conversation', function() {
return {
restrict: 'E',
link: function ($scope, $elm, $attr) {
$scope.$watch("some_prop", function (newValue, oldValue) {
var typeId = $attr.type-id;
// Your logic.
});
}
};
}

If You're under AngularJS 1.5.3 or newer, You should consider to move to components instead of directives.
Those works very similar to directives but with some very useful additional feautures, such as $onChanges(changesObj), one of the lifecycle hook, that will be called whenever one-way bindings are updated.
app.component('conversation ', {
bindings: {
type: '#',
typeId: '='
},
controller: function() {
this.$onChanges = function(changes) {
// check if your specific property has changed
// that because $onChanges is fired whenever each property is changed from you parent ctrl
if(!!changes.typeId){
refreshYourComponent();
}
};
},
templateUrl: 'conversation .html'
});
Here's the docs for deepen into components.