transclude usage in simple Directive Example - javascript

In the following simple example I am printing the name model from controller by directive on the view. The example is running fine, but what is the use of transclude I cannot understand. Can someone explain its usage?
<html>
<head>
<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.4.8/angular.min.js" ></script>
</head>
<body ng-app="myApp" ng-controller="myCtrl">
<people></people>
<script>
//module declaration
var app = angular.module("myApp",[]);
//controller declaration
app.controller('myCtrl',function($scope){
$scope.name = "Peter";
});
//directives declaration
app.directive('people',function(){
return{
restric: 'E',
template: '<div>{{name}}</div>',
transclude: true
}
});
</script>
</body>
</html>

Your code doesn't really demonstrate what transclude does:
Look at this plunk and change the true/false value:
Plunk
You will notice the effect now hopefully. The source from plunkr, with a couple of modifications.
<!DOCTYPE html>
<html>
<head>
<script data-require="angular.js#1.5.3" data-semver="1.5.3" src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.3/angular.min.js"></script>
<link rel="stylesheet" href="style.css" />
<script src="script.js"></script>
</head>
<body ng-app="myApp" ng-controller="myCtrl">
<people>HI there</people>
<script>
//module declaration
var app = angular.module("myApp",[]);
//controller declaration
app.controller('myCtrl',function($scope){
$scope.name = "Peter";
});
//directives declaration
app.directive('people',function(){
return{
restric: 'E',
template: '<div><ng-transclude></ng-transclude>: {{name}}</div>',
transclude: false
}
});
</script>
</body>
</html>
So when it is true, you will see that the contents are transcluded,
So it says HI There: Peter
When False, it removes the HI There, but keeps the name and my colon:
: Peter

Essentially, these are wrappers around any arbitrary content.
Supposing I have an accordion directive that shows or hides any content that you use it with with an animation.
app.directive('akordion', [function() {
return {
restrict: 'A',
replace: true,
transclude: true,
template: '<div class="accordion-wrapper">'
+'<div class="transcluded" ng-transclude></div>'
+'</div>',
link: function(scope, elem, attrs) {
scope.$watch(attrs.show, function(newVal){
toggle(newVal);
});
function toggle(show) {
var h = (show) ? 0 : '600px';
$(elem).css({ maxHeight: h });
}
}
}
}]);
You'd use it like this:
<div akordion="" id="league-admin">
<div>
foo
</div>
<my-directive></my-directive>
</div>
And the result (generated HTML) is:
<div class="accordion-wrapper" id="league-admin">
<div class="transcluded">
<div>
foo
</div>
<div id="my-directive">...</div>
</div>
</div>
The point is that by calling the akordion="", you take whatever is inside it and put it in the template (<div class="transcluded" ng-transclude>). In other words, the akordion directive wraps over (transcludes) the content you use it on.
Another example would be modal windows. You don't want to repeat the code that defines the modal each time you want to use it, so you define it once, and use transclusion to put any content into it. Check out modal in Bootstrap UI.

Basically If you have some content inside your directive it will be automatically replaced by the directive content
For Example, if you have<people>Test transclude</people> The Test transclude string will be automatically replace by angular when it process the directive. But what if you want 'Test transclude ' also to be displayed ? Here is where transclude come in to action.
Consider the following
app.directive('people',function(){
return{
restric: 'E',
template: '<div><div ng-transclude></div>{{name}}</div>',
transclude: true
}
});
Now the string 'Test transclude' will be also displayed inside tag
And this is the plunker link Plunk

Related

Directive showing empty tab

I want to implement directives in my app, but I can't even start with the simplest one. Can someone tell me why?
JS:
angular
.module('app.admin.catalog.nutritional_facts')
.directive('nutritionalInfo', nutritionalInfo);
function nutritionalInfo(){
return{
restrict: 'E',
scope: {
quantity: '=',
unit: '='
},
template: "<div> Hello world {{ '{{quantity.qty}} {{unit.u}}' }}</div>"
};
}
HTML:
<nutritional-info quantity="{qty:4}" unit="{u:'g'}"></nutritional-info>
I'm somewhat new to Angular, so it is probably the simplest question ever. It only shows the empty label, it doesn't even show the Hello world. I already tried sending ints, strings and objects as attributes.
I've corrected your code as shown below to get your directive working as expected :
Working Fiddle
My Changes :
Corrected directive name to camel case
Corrected the angular binding in html
Corrected the objects syntax that are passed to the directive.
HTML :
<nutritional-info quantity="{qty:4}" unit="{u:'g'}"></nutritional-info>
Controller :
angular.module('app.admin.catalog.nutritional_facts', [])
.directive('nutritionalInfo', nutritionalInfo);
function nutritionalInfo(){
return{
restrict: 'E',
scope: {
quantity: '=',
unit: '='
},
template: "<div> Hello world {{quantity.qty}} {{unit.u}}</div>"
};
}
You have a few issues:
NutritionalInfo should be nutritionalInfo (camelCase). That's how Angular will know to associate that directive with the <nutritional-info> HTML tag. See Directive Normalization.
You're not passing in objects correctly to the directive. quantity="{qty=4}" should be quantity="{qty: 4}".
You're not evaluating the expression correctly in the template. {{ '{{quantity.qty}} {{unit.u}}' }} can simply be {{quantity.q}} {{unit.u}}. Angular expressions are interpreted like JavaScript code run on the current scope. So, you can even build expressions like {{quantity.q.toFixed(1) + ' ' + unit.u.toUpperCase()}} (resulting in 4.0 G).
With all those fixes, here's a working fiddle.
Here is my full solution:
<!doctype html>
<html lang="en" ng-app="app.admin.catalog.nutritional_facts">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body >
<nutritional-info quantity="{qty: 3}" unit="{u: 'g'}"></nutritional-info>
<script
src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.19/angular.js">
</script>
<script>
function nutritionalInfo(){
return {
restrict: 'E',
scope: {
quantity: '=',
unit: '='
},
template: "<div> Hello world '{{quantity.qty}} {{unit.u}}'</div>"
};
}
angular
.module('app.admin.catalog.nutritional_facts', [])
.directive('nutritionalInfo', nutritionalInfo);
</script>
</body>
</html>

How to render HTML Tags from ngModel?

I'm using AngularJS for binding JS variables to my HTML content, and it works fine.
JS
var app = angular.module("Tabs", [])
.controller("TabsController", ['$scope', function($scope){
$scope.events = my_JS_object;
})
HTML
<div>{{events.test}}</div>
It works as long as my_JS_object.test is a simple string, like "Hello World", but once I try to put HTML tag in there, such as Hello <b>World</b> It doesn't use the tags as HTML elements, but as simple text. Which makes sense, only I have no idea how to make the HTML tags work.
As stated by Angular documentation, you can use inbuilt ng-bind-html directive to evaluate model string and insert resulting HTML into element.
Example:
If you have model value like:
$scope.myHTML =
'I am an <code>HTML</code>string with ' +
'links! and other <em>stuff</em>';
Use ng-bind-html like:
<p ng-bind-html="myHTML"></p>
For detailed information go through: https://docs.angularjs.org/api/ng/directive/ngBindHtml
Note: Don't forget to inject ngSanitize service in your app.
You need to use the ngBindHtml directive that properly evaluates the expression and inserts the resulting HTML into the element in a secure way. To do this, you must include a reference to angular-sanitize.js in your HTML and then in your angular module, inject ngSanitize.
Like so
var app = angular.module("Tabs", ['ngSanitize'])
.controller("TabsController", ['$scope', function($scope){
$scope.events = my_JS_object;
})
<div ng-controller="TabsController">
<div ng-bind-html="events.test"></div>
</div>
Here is a full working example:
(function(angular) {
'use strict';
angular.module('bindHtmlExample', ['ngSanitize'])
.controller('ExampleController', ['$scope', function($scope) {
$scope.myHTML = 'Hello This is <b>BOLD<b/>';
}]);
})(window.angular);
<head>
<script src="//ajax.googleapis.com/ajax/libs/angularjs/1.5.0-beta.1/angular.min.js"></script>
<script src="//ajax.googleapis.com/ajax/libs/angularjs/1.5.0-beta.1/angular-sanitize.js"></script>
</head>
<body ng-app="bindHtmlExample">
<div ng-controller="ExampleController">
<p ng-bind-html="myHTML"></p>
</div>
</body>
Refer to the official angular documentation for details:
https://docs.angularjs.org/api/ng/directive/ngBindHtml
If you want to insert HTML into page you shouldn't do it this way.
There is sanitize for this task.
For example in your controller:
$scope.trustedHtml = "<b>Hello World</b>"
And in your html:
<div ng-bind-html="trustedHtml "></div>
Always check html if using a user given text before inserting.
Also don't forget to add ngSanitize as dependency while creating controller
It's easier to use transclusion if you want to embed custom HTML into your DOM tree.
angular.module('myApp', [])
.controller('MainCtrl', function ($scope) {
$scope.overwrite = false;
$scope.origin = 'parent controller';
})
.directive('myDirective', function() {
return {
restrict: 'E',
templateUrl: 'my-directive.html',
scope: {},
transclude: true,
link: function (scope) {
scope.overwrite = !!scope.origin;
scope.origin = 'link function';
}
};
});
<script src="https://code.angularjs.org/1.3.2/angular.min.js"></script>
<div ng-app="myApp">
<div ng-controller="MainCtrl">
<my-directive>
<p>HTML template</p>
<p>Scope from {{origin}}</p>
<p>Overwritten? {{overwrite}}</p>
</my-directive>
</div>
<script type="text/ng-template" id="my-directive.html">
<ng-transclude></ng-transclude>
<hr />
<p>Directive template</p>
<p>Scope from {{origin}}</p>
<p>Overwritten? {{overwrite}}</p>
</script>
</div>

angular directive not rendering

i'm trying to include directives in my application, but even basic directives aren't rendering. what am i doing wrong?
angularloader.js:
var main = angular.module('ngMain', [])
.directive('myScrollable', function () {
return {
restrict: 'AE',
template: '<h3>Hello World!!</h3>'
};
});
My HTML:
<html ng-app dir="auto">
<head>
<meta name="viewport" content="width=device-width" />
<title>#Model.Title</title>
<script src="/Scripts/Libs/angular.js"></script>
<script src="/Scripts/Custom/angularloader.js"></script>
</head>
<body dir="auto">
<my-scrollable></my-scrollable>
</body>
</html>
tried also using tag or attribute ..
you should use module name in ng-app="moduleName"
like:
<html ng-app="ngMain" dir="auto">
if you assign angular module in a variable then use that variable like bellow:
var main = angular.module('ngMain', []);
main.directive('myScrollable', function () {
return {
restrict: 'AE',
template: '<h3>Hello Worlds!!</h3>'
};
});
Working PLUNKER Link
You have define your module but forget to use in html with ng-app= "you module Name". One extra thing you don't need to declare a variable main your code will work without that also.
angular
.module('myModule', [])
.directive('myDir', function{
your code
});

Creating Custom directive do not work

I am trying to create a custom directive..
<head>
<script type="text/javascript" src="../Scripts/angular.min.js"></script>
<script type="text/javascript" src="../Scripts/DataDirectives.js"></script>
</head>
<body style="overflow: hidden" >
<div ng-app="myApp">
<SampleData></SampleData>
</div>
</body>
In a separate Javascript File called DataDirectives.js the followung code is present..
var app = angular.module('myApp', []);
app.directive('SampleData', function () {
return {
restrict: 'E',
template: '<div>Sample Div,To test angular Directives</div>'
};
});
So when I run the page,I cannot see any text on that page of that of the div element.What could be wrong with my above code.
Thanks for the help in Advance... :)
You have 2 ng-app as well as you are not following the required naming convensions
var app = angular.module('myApp', []);
app.directive('sampleData', function() {
return {
restrict: 'E',
template: '<div>Sample Div,To test angular Directives</div>'
};
});
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app="myApp">
<sample-data></sample-data>
</div>
in html write directive name: sample-data
in js sampleData
var app = angular.module('myApp', []);
app.directive('sampleData', function () {
return {
restrict: 'E',
template: '<div>Sample Div,To test angular Directives</div>'
};
});
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<body ng-app="myApp" style="overflow: hidden" >
<div ng-app="myApp">
<sample-data></SampleData>
</div>
</body>
You are defining the angular directive in your template using camelcase naming convention. The angular directive should be declared in template like sample-data. Then in javascript file you can reference it like sampleData.
Taking these into consideration, you should change the code in the following manner:
<div ng-app="myApp">
<sample-data></sample-data>
</div>
Another alternative would be to declare the directive inside an existing element. For example:
<div sample-data="exp"></dir>
And in javascript:
var app = angular.module('myApp', []);
app.directive('sampleData', function () {
return {
restrict: 'E',
template: '<div>Sample Div,To test angular Directives</div>'
};
});
Please see the lower cased version of sampleData.

AngularJS directive using another controller

I'm trying to create a directive that will output a HTML-template that is using data from a controller.
In sample.js I've added a module, controller and directive
var app = angular.module("myApp", []);
app.controller("MyCtrl", function($scope) {
$scope.someProperty = true;
})
app.directive("myElement", function() {
return {
restrict: "E",
scope: {name: "#"},
template:
'<div ng-show="someProperty">' +
' <p>This element is called {{name}}</p>' +
'</div>',
replace : true,
transclude : false
}
})
I'm using the element with the following HTML
<!DOCTYPE html>
<html ng-app="myApp">
<head>
<meta charset="UTF-8">
<script type="text/javascript" src="angular.min.js"></script>
<script type="text/javascript" src="sample.js"></script>
</head>
<body ng-controller="MyCtrl">
<div><my-element name="Mark"></my-element></div>
<div><my-element name="Vink"></my-element></div>
</body>
</html>
Since the controller is created in the body, I would expect the child-element to be able to use it's properties/methods. But there's no data showing up (without the ng-show, the data shows fine).
In this simplified sample I could move the ng-show to the DOM-element in the HTML, but in my actual application this wouldn't be an option. I really need my directive to be able to use properties (and methods) from my controller.
Is this possible? And what did I miss to get it to work?
Since you are using an isolated scope you have to declare someProperty to use it like this
app.directive("myElement", function() {
return {
restrict: "E",
scope: {
name: "#",
someProperty: "="
},
template:
'<div ng-show="someProperty">' +
' <p>This element is called {{name}}</p>' +
'</div>',
replace : true,
transclude : false
}
});
and you can use it like this
<my-element name="Vink" some-property="someProperty"></my-element>

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