AngularJs $watch issue - angularjs

in my application i have a controller and a directive which i use to draw a chart.
so my model is like this: $scope.d3DataGraph ={"selected":{"node":"","impiega":[],"impiegato": []} , "nodes":[],"links":[]};
in the controller i've set up a function that adds some data to the model:
$scope.d3DataGraph.nodes.push(articolo);
then i have the directive which is responsible to draw the graph by adding some svg tags to the dom:
in my directive i have a render function that have to be triggered when the model changed...
angular.module('myApp.directives')
.directive('d3Graph', ['d3', function(d3) {
return {
restrict: 'EA',
scope: {
data: "=",
query: "=",
label: "#",
onClick: "&"
},
link: function(scope, iElement, iAttrs) {
var svg = d3.select(iElement[0]).append("svg")
.attr("width", "100%")
.attr("height", "800px");
var datatree = {};
scope.$watch(function(){ return scope.data.nodes; }, function(){
return scope.render(scope.data, scope.query);
}
);
scope.render = function(datatreex, query){....
the directive is "called" whit this tag
<d3-graph data="d3DataGraph" selected = "selected" query = "selezionati"></d3-graph>
the problem is that the render function is called only when the page is loaded, but not when the controller updates the model ...
where i get wrong?
the overall set up seems to be correct, what do you think of it?

That's because $watch is just watching the reference of scope.data.nodes, so no matter what you push or pop, the reference will not change.
Instead of using $watch, you can use $watchCollection. It will detect the length of the array.
scope.$watchCollection('data.nodes', function(){
return scope.render(scope.data, scope.query);
});

Related

Please provide me explanation for the Slider directive

I am trying to understand the Slider directive provided here.
myApp.directive('slider', function() {
return {
restrict: 'A',
scope: {
ngModel: '='
},
link: function(scope, elem, attrs) {
console.log(scope.ngModel);
return $(elem).slider({
range: "min",
animate: true,
value: scope.ngModel,
slide: function(event, ui) {
return scope.$apply(function(){
scope.ngModel = ui.value;
});
}
});
}
};
});
Like purpose of ngmodel, range, animate, value:scope.ngModel etc. I have read some article about the same from here but this seems to be a little complicated for me.
This is a typical isolated scope directive configuration that is using a jQuery plugin .
scope.ngModel is passed in to the directive through the matching attribute ng-model in the html.
The '=' makes it a 2 way binding to it's parent.
As for the slider it is a jQuery UI slider and the options like animate and range etc are documented in their API
$apply() is used whenever events outside of angular context are used to modify scope. Angular needs to be told to run a digest to update the view

angularjs directive - get element bound text content

How do you get the value of the binding based on an angular js directive restrict: 'A'?
<span directiverestrict> {{binding}} </span>
I tried using elem[0].innerText but it returns the exact binding '{{binding}}' not the value of the binding
.directive('directiverestrict',function() {
return {
restrict:'A',
link: function(scope, elem, attr) {
// I want to get the value of the binding enclosed in the elements directive without ngModels
console.log(elem[0].textContent) //----> returns '{{binding}}'
}
};
});
You can use the $interpolate service, eg
.directive('logContent', function($log, $interpolate) {
return {
restrict: 'A',
link: function postLink(scope, element) {
$log.debug($interpolate(element.text())(scope));
}
};
});
Plunker
<span directiverestrict bind-value="binding"> {{binding}} </span>
SCRIPT
directive("directiverestrict", function () {
return {
restrict : "A",
scope : {
value : '=bindValue'
},
link : function (scope,ele,attr) {
alert(scope.value);
}
}
});
During the link phase the inner bindings are not evaluated, the easiest hack here would be to use $timeout service to delay evaluation of inner content to next digest cycle, such as
$timeout(function() {
console.log(elem[0].textContent);
},0);
Try ng-transclude. Be sure to set transclude: true on the directive as well. I was under the impression this was only needed to render the text on the page. I was wrong. This was needed for me to be able to get the value into my link function as well.

Angularjs - Pass argument to directive

Im wondering if there is a way to pass an argument to a directive?
What I want to do is append a directive from the controller like this:
$scope.title = "title";
$scope.title2 = "title2";
angular.element(document.getElementById('wrapper')).append('<directive_name></directive_name>');
Is it possible to pass an argument at the same time so the content of my directive template could be linked to one scope or another?
here is the directive:
app.directive("directive_name", function(){
return {
restrict:'E',
transclude:true,
template:'<div class="title"><h2>{{title}}</h3></div>',
replace:true
};
})
What if I want to use the same directive but with $scope.title2?
You can pass arguments to your custom directive as you do with the builtin Angular-directives - by specifying an attribute on the directive-element:
angular.element(document.getElementById('wrapper'))
.append('<directive-name title="title2"></directive-name>');
What you need to do is define the scope (including the argument(s)/parameter(s)) in the factory function of your directive. In below example the directive takes a title-parameter. You can then use it, for example in the template, using the regular Angular-way: {{title}}
app.directive('directiveName', function(){
return {
restrict:'E',
scope: {
title: '#'
},
template:'<div class="title"><h2>{{title}}</h2></div>'
};
});
Depending on how/what you want to bind, you have different options:
= is two-way binding
# simply reads the value (one-way binding)
& is used to bind functions
In some cases you may want use an "external" name which differs from the "internal" name. With external I mean the attribute name on the directive-element and with internal I mean the name of the variable which is used within the directive's scope.
For example if we look at above directive, you might not want to specify another, additional attribute for the title, even though you internally want to work with a title-property. Instead you want to use your directive as follows:
<directive-name="title2"></directive-name>
This can be achieved by specifying a name behind the above mentioned option in the scope definition:
scope: {
title: '#directiveName'
}
Please also note following things:
The HTML5-specification says that custom attributes (this is basically what is all over the place in Angular applications) should be prefixed with data-. Angular supports this by stripping the data--prefix from any attributes. So in above example you could specify the attribute on the element (data-title="title2") and internally everything would be the same.
Attributes on elements are always in the form of <div data-my-attribute="..." /> while in code (e.g. properties on scope object) they are in the form of myAttribute. I lost lots of time before I realized this.
For another approach to exchanging/sharing data between different Angular components (controllers, directives), you might want to have a look at services or directive controllers.
You can find more information on the Angular homepage (directives)
Here is how I solved my problem:
Directive
app.directive("directive_name", function(){
return {
restrict: 'E',
transclude: true,
template: function(elem, attr){
return '<div><h2>{{'+attr.scope+'}}</h2></div>';
},
replace: true
};
})
Controller
$scope.building = function(data){
var chart = angular.element(document.createElement('directive_name'));
chart.attr('scope', data);
$compile(chart)($scope);
angular.element(document.getElementById('wrapper')).append(chart);
}
I now can use different scopes through the same directive and append them dynamically.
You can try like below:
app.directive("directive_name", function(){
return {
restrict:'E',
transclude:true,
template:'<div class="title"><h2>{{title}}</h3></div>',
scope:{
accept:"="
},
replace:true
};
})
it sets up a two-way binding between the value of the 'accept' attribute and the parent scope.
And also you can set two way data binding with property: '='
For example, if you want both key and value bound to the local scope you would do:
scope:{
key:'=',
value:'='
},
For more info,
https://docs.angularjs.org/guide/directive
So, if you want to pass an argument from controller to directive, then refer this below fiddle
http://jsfiddle.net/jaimem/y85Ft/7/
Hope it helps..
Controller code
myApp.controller('mainController', ['$scope', '$log', function($scope, $log) {
$scope.person = {
name:"sangeetha PH",
address:"first Block"
}
}]);
Directive Code
myApp.directive('searchResult',function(){
return{
restrict:'AECM',
templateUrl:'directives/search.html',
replace: true,
scope:{
personName:"#",
personAddress:"#"
}
}
});
USAGE
File :directives/search.html
content:
<h1>{{personName}} </h1>
<h2>{{personAddress}}</h2>
the File where we use directive
<search-result person-name="{{person.name}}" person-address="{{person.address}}"></search-result>
<button my-directive="push">Push to Go</button>
app.directive("myDirective", function() {
return {
restrict : "A",
link: function(scope, elm, attrs) {
elm.bind('click', function(event) {
alert("You pressed button: " + event.target.getAttribute('my-directive'));
});
}
};
});
here is what I did
I'm using directive as html attribute and I passed parameter as following in my HTML file. my-directive="push" And from the directive I retrieved it from the Mouse-click event object. event.target.getAttribute('my-directive').
Insert the var msg in the click event with scope.$apply to make the changes to the confirm, based on your controller changes to the variables shown in ng-confirm-click therein.
<button type="button" class="btn" ng-confirm-click="You are about to send {{quantity}} of {{thing}} selected? Confirm with OK" confirmed-click="youraction(id)" aria-describedby="passwordHelpBlock">Send</button>
app.directive('ngConfirmClick', [
function() {
return {
link: function(scope, element, attr) {
var clickAction = attr.confirmedClick;
element.on('click', function(event) {
var msg = attr.ngConfirmClick || "Are you sure? Click OK to confirm.";
if (window.confirm(msg)) {
scope.$apply(clickAction)
}
});
}
};
}
])

Data-binding in a directive template

I'm trying to build a really basic Angular directive that generates a "div" that can have two states: "on" and "off".
I've naively come up with an implementation that you can find here: http://jsfiddle.net/wSz2f/
The initial display is correct but the visual state is not updated when the scope state changes.
Here is the Angular directive definition:
var test = angular.module("test", []);
test.directive("led", function()
{
return {
restrict: "E",
replace: true,
template: "<div class='led led-off' ng-class='{ \"led-on\": isOn }'>{{isOn}}</div>",
link: function(scope, element, attributes, controller)
{
scope.isOn = false;
element.bind("click", function()
{
scope.isOn = !scope.isOn;
});
}
};
});
I guess I'm doing something stupid but what...?
Moreover, in term of design, am doing it the "Angular way" or is there better practices?
Thanks for any input. :)
Final edit:
Thanks to Mark, Bertrand and James for their input:
you have to either call scope.$apply() after updating the "isOn" property to make Angular aware of its change (thinking about it this is how it works too in other frameworks like WPF/Silverlight with the INotifyPropertyChanged interface, but not in Flex with all its magic binding) or use ng-click like suggested by Bertrand
you have to provide "ng-class" a condition for each CSS class
In your case you have to fire the digest
element.bind("click", function()
{
scope.isOn = !scope.isOn;
scope.$apply();
});
or even better, you could use the ng-click directive in your template to change the state of isOn.
var test = angular.module("test", []);
test.directive("led", function()
{
return {
restrict: "E",
replace: true,
template: "<div class='led led-off' ng-class='{ \"led-on\": isOn, \"led-off\": !isOn }' ng-click='onOff()'>{{isOn}}</div>",
link: function(scope, element, attributes, controller)
{
scope.isOn = false;
scope.onOff = function () {
scope.isOn = !scope.isOn;
}
}
};
});
Here is a fiddle
You're code looks good. You are missing the scope.$appy(); after updating the data. The exact internal reasons of why you need to call scope.$apply(); are only partly clear to me. I've read a few articles on it but am no expert yet.
Updated fiddle: http://jsfiddle.net/wSz2f/1/
Reading: http://jimhoskins.com/2012/12/17/angularjs-and-apply.html

Angularjs passing object to directive

Angular newbie here. I am trying to figure out what's going wrong while passing objects to directives.
here's my directive:
app.directive('walkmap', function() {
return {
restrict: 'A',
transclude: true,
scope: { walks: '=walkmap' },
template: '<div id="map_canvas"></div>',
link: function(scope, element, attrs)
{
console.log(scope);
console.log(scope.walks);
}
};
});
and this is the template where I call the directive:
<div walkmap="store.walks"></div>
store.walks is an array of objects.
When I run this, scope.walks logs as undefined while scope logs fine as an Scope and even has a walks child with all the data that I am looking for.
I am not sure what I am doing wrong here because this exact method has worked previously for me.
EDIT:
I've created a plunker with all the required code: http://plnkr.co/edit/uJCxrG
As you can see the {{walks}} is available in the scope but I need to access it in the link function where it is still logging as undefined.
Since you are using $resource to obtain your data, the directive's link function is running before the data is available (because the results from $resource are asynchronous), so the first time in the link function scope.walks will be empty/undefined. Since your directive template contains {{}}s, Angular sets up a $watch on walks, so when the $resource populates the data, the $watch triggers and the display updates. This also explains why you see the walks data in the console -- by the time you click the link to expand the scope, the data is populated.
To solve your issue, in your link function $watch to know when the data is available:
scope.$watch('walks', function(walks) {
console.log(scope.walks, walks);
})
In your production code, just guard against it being undefined:
scope.$watch('walks', function(walks) {
if(walks) { ... }
})
Update: If you are using a version of Angular where $resource supports promises, see also #sawe's answer.
you may also use
scope.walks.$promise.then(function(walks) {
if(walks) {
console.log(walks);
}
});
Another solution would be to add ControllerAs to the directive by which you can access the directive's variables.
app.directive('walkmap', function() {
return {
restrict: 'A',
transclude: true,
controllerAs: 'dir',
scope: { walks: '=walkmap' },
template: '<div id="map_canvas"></div>',
link: function(scope, element, attrs)
{
console.log(scope);
console.log(scope.walks);
}
};
});
And then, in your view, pass the variable using the controllerAs variable.
<div walkmap="store.walks" ng-init="dir.store.walks"></div>
Try:
<div walk-map="{{store.walks}}"></div>
angular.module('app').directive('walkMap', function($parse) {
return {
link: function(scope, el, attrs) {
console.log($parse(attrs.walkMap)(scope));
}
}
});
your declared $scope.store is not visible from the controller..you declare it inside a function..so it's only visible in the scope of that function, you need declare this outside:
app.controller('MainCtrl', function($scope, $resource, ClientData) {
$scope.store=[]; // <- declared in the "javascript" controller scope
ClientData.get({}, function(clientData) {
self.original = clientData;
$scope.clientData = new ClientData(self.original);
var storeToGet = "150-001 KT";
angular.forEach(clientData.stores, function(store){
if(store.name == storeToGet ) {
$scope.store = store; //declared here it's only visible inside the forEach
}
});
});
});

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