I am using AngularJS v1.2.1.
The improved ng-bind-html directive allows me to trust unsafe Html into my view.
Example
HTML:
<div ng-repeat="example in examples" ng-bind-html="example.content()"></div>
JS:
function controller($scope, $sce)
{
function ex()
{
this.click = function ()
{
alert("clicked");
}
this.content() = function ()
{
//if
return $sce.trustAsHtml('<button ng-click="click()">some text</button>');
// no problem, but click is not called
//when
return $sce.parseAsHtml('<button ng-click="click()">some text</button>');
//throw an error
}
}
$scope.examples = [new ex(), new ex()];
}
My question is, how to bind HTML content that may contain Angular expressions or directives ??
If you need dynamic templates per element, as your question suggests, one solution would be to use $compile within a directive to parse the HTML within the context of the local scope. A simple version of this is shown in this Plunk.
An example directive:
app.directive('customContent', function($compile) {
return function(scope, el, attrs) {
el.replaceWith($compile(scope.example.content)(scope));
}
});
The corresponding HTML:
<div ng-repeat="example in examples">
<div custom-content></div>
</div>
Notice that, in the Plunk controller, I've pulled out the click function into the scope for simplicity, since in the template HTML you are calling click() in the context of the scope, not on the example object. There are a couple ways you could use a different click function for each example, if that's what you'd like to do. This egghead.io screencast has a good example of passing an expression into a directive explicitly; in your case, it could be a click function or the whole example object, depending on what you need.
Related
I have a directive which consists of a form text element and a continue button along with the associated controller etc. This directive is going to be used in about 5 different pages, but on each page it is used the continue button will do something different.
My question is where can/should I put the code for the continue button if it does different things for each page?
Since its a directive I cant simply pass a different function into ng-click depending on what page im on (ie, if i simply replicated the code on each page it is used I could simply change the function called on ng-click and have that function in each of the page controllers.
Hopefully Im not being too vague with my question and you can make sense of what im asking. If not just say so and ill try to explain in more detail.
I would really appreciate some guidance on this matter.
Thanks.
There are two ways that you can do it. If you are creating your directive as a true component you can use isolated scope with & binding that binds to an expression.
Assume your directive looks like
<div do-work on-click="save()"></div>
and the generated html
<div>
<input ...>
<button ng-click="doAction()"><button>
</div>
The directive scope will be defined
scope:{
onClick:'&'
}
In your directive controller or link function you need to implement the button doAction, which in turns evaluates the onClick action
scope.doAction=function() {
scope.onClick({//if params are required});
}
Now you have linked the parent through the direct onClick reference. One thing to remember here is that this creates a directive with isolated scope.
In case you do not want isolated scope created you need to use
scope.$eval(attr.onClick); // this evaluates the expression on the current scope.
Hope this helps.
Ideally you should not create directives which are not re-usable.
In your case, you may do it like following -
create an isolated scope in the directive
add a function to be called and pass the page/ page id as parameter
call functions in controller based on parameter
Directive
myApp.directive('someDirecive', function () {
return {
// restrict options are EACM. we want to use it like an attribute
restrict: 'A',
// template : <inline template string>
// templateUrl = path to directive template.
// templateUrl: '',
scope: {
onButtonClick : '&'
},
controller: function ($scope, $element, $attrs, $transclude) {
$scope.onButtonClick = function(pageId) {
if (pageId == 1) {
// do something
}
else if (pageId == 2) {
// do something
}
}
},
//link: function (scope, iElement, iAttrs) {
//}
};
});
HTML
<div some-directive on-button-click="DoSomething(1)" />
I created a custom directive with an isolated scope that binds to a function from the enclosing controller and with references to a templateUrl. Here's what my code looks like:
the html
<div ng-controller='MyCtrl as my'>
<custom-directive data='my.data' on-search="my.find(param1, param2)"></custom-directive>
</div>
the directive
app.directive('customDirective', function() {
return {
restrict : 'E',
scope : {
data : '=data'
search : '&onSearch',
},
templateUrl : 'customDirective.html'
};
});
the template
<div>
<input ng-model='data.id'>
<a ng-click='find(param1, param2)'></a>
</div>
The arguments received by function find is also stored in data. The controller data binds to the directive but not the function. My log inside the function won't even show.
It seems there are different ways to do it as I have seen in many examples (see below) but none seems to work in my case.
Example 1: pass a mapping of parameter and values in the template
<div>
<input ng-model='data.id'>
<a ng-click='find.({param1: data.value1, param2: data.value2})'></a>
</div>
Example 2: put a link in the directive
app.directive('customDirective', function() {
return {
restrict : 'E',
scope : {
data : '=data'
search : '&onSearch',
},
templateUrl : 'customDirective.html',
link : function(scope, elem, attr) {
scope.retrieve({param1: scope.data.value1,
param2: scope.data.value2});
}
};
});
Example 3 : use scope.$apply(), $parse in link but haven't tried this
Could someone show me how to do it and also explain to me the link part (I don't understand that part) and if you're feeling generous, show the working alternatives as shown by the examples. Thanks
You don't have to passe params for your function just the reference so in your html
<custom-directive data='my.data' on-search="my.find"></custom-directive>
and your template directive directly call
<div>
<input ng-model='data.id'>
<a ng-click='find(data.value1, data.value2)'></a>
</div>
I also suggest you to use $scope and not the controller. So in your controller define
$scope.data = {
id: 1,
value1: "value1",
value2: "value2"
}
$scope.find = function (param1, param2) {
//Your logic
}
And in your template put directly
<custom-directive data='data' on-search="find"></custom-directive>
I hope this answer to your question
About link this text from angular js doc is pretty clear I think
Directives that want to modify the DOM typically use the link option.
link takes a function with the following signature, function
link(scope, element, attrs) { ... } where:
scope is an Angular scope object. element is the jqLite-wrapped
element that this directive matches.
attrs is a hash object with key-value pairs of normalized attribute names and their
corresponding attribute values.
In our link function, we want to update the
displayed time once a second, or whenever a user changes the time
formatting string that our directive binds to. We will use the
$interval service to call a handler on a regular basis. This is easier
than using $timeout but also works better with end-to-end testing,
where we want to ensure that all $timeouts have completed before
completing the test. We also want to remove the $interval if the
directive is deleted so we don't introduce a memory leak.
I'm new to AngularJS. I've learned that I can find elements in the DOM using queries like the following:
var e = angular.element(document.querySelector('#id'));
var e = angular.element(elem.querySelector('.classname'));
This is useful for finding elements by ID, or by CSS class name. However, I need to be able to find an element using a different approach. I have an element that looks like the following:
<div my-directive class='myContainer'>...</div>
I can't query on 'myContainer' because of how much its reused. For that reason, I would like to find any element with the attribute 'my-directive'. How do I search the DOM and find any element that makes use of 'my-directive'?
Rather than querying the DOM for elements (which isn't very angular see "Thinking in AngularJS" if I have a jQuery background?) you should perform your DOM manipulation within your directive. The element is available to you in your link function.
So in your myDirective
return {
link: function (scope, element, attr) {
element.html('Hello world');
}
}
If you must perform the query outside of the directive then it would be possible to use querySelectorAll in modern browers
angular.element(document.querySelectorAll("[my-directive]"));
however you would need to use jquery to support IE8 and backwards
angular.element($("[my-directive]"));
or write your own method as demonstrated here Get elements by attribute when querySelectorAll is not available without using libraries?
You haven't stated where you're looking for the element. If it's within the scope of a controller, it is possible, despite the chorus you'll hear about it not being the 'Angular Way'. The chorus is right, but sometimes, in the real world, it's unavoidable. (If you disagree, get in touch—I have a challenge for you.)
If you pass $element into a controller, like you would $scope, you can use its find() function. Note that, in the jQueryLite included in Angular, find() will only locate tags by name, not attribute. However, if you include the full-blown jQuery in your project, all the functionality of find() can be used, including finding by attribute.
So, for this HTML:
<div ng-controller='MyCtrl'>
<div>
<div name='foo' class='myElementClass'>this one</div>
</div>
</div>
This AngularJS code should work:
angular.module('MyClient').controller('MyCtrl', [
'$scope',
'$element',
'$log',
function ($scope, $element, $log) {
// Find the element by its class attribute, within your controller's scope
var myElements = $element.find('.myElementClass');
// myElements is now an array of jQuery DOM elements
if (myElements.length == 0) {
// Not found. Are you sure you've included the full jQuery?
} else {
// There should only be one, and it will be element 0
$log.debug(myElements[0].name); // "foo"
}
}
]);
Your use-case isn't clear. However, if you are certain that you need this to be based on the DOM, and not model-data, then this is a way for one directive to have a reference to all elements with another directive specified on them.
The way is that the child directive can require the parent directive. The parent directive can expose a method that allows direct directive to register their element with the parent directive. Through this, the parent directive can access the child element(s). So if you have a template like:
<div parent-directive>
<div child-directive></div>
<div child-directive></div>
</div>
Then the directives can be coded like:
app.directive('parentDirective', function($window) {
return {
controller: function($scope) {
var registeredElements = [];
this.registerElement = function(childElement) {
registeredElements.push(childElement);
}
}
};
});
app.directive('childDirective', function() {
return {
require: '^parentDirective',
template: '<span>Child directive</span>',
link: function link(scope, iElement, iAttrs, parentController) {
parentController.registerElement(iElement);
}
};
});
You can see this in action at http://plnkr.co/edit/7zUgNp2MV3wMyAUYxlkz?p=preview
I'm using inline editing with CKEditor, and I'd like to bind an element to an angular scope value.
<div contentEditable="true">
<p>Here is the value: {{testval}}</p>
</div>
testval should update in the same manner as it would outside the editor.
To protect this text in the editor, I'd like to do something similar to the placeholder plugin. In other words I plan to have a placeholder, dynamically displaying the final text rather than just the placeholder.
I've seen several examples of how to bind the entire contents with angular, but not individual elements. I'm still fairly new to both angular and ckeditor, so any help or pointers would be much appreciated.
It sounds to me like you will need to use a directive for what you want. I might be soewhat off because I'm not completely familiar, but goig by what you've provided, let's assume this example.
html
<body ng-app="myApp">
<div content-editable content="content"></div>
</body>
javascript
angular.module('myApp', [])
.directive('contentEditable', function() {
restrict: 'A',
replace: true,
scope: {
// Assume this will be html content being bound by the controller
// In the controller you would have:
// $scope.content = '<div>Hello World</div>'
content: "="
},
template: '<div contentEditable="true"><p>Here is the value {{ content }}</p></div>'
});
Still not sure if I completely comprehend, but let me know if I'm getting closer.
I assume that you want to bind the HTML text in model to the element. I used ng-bind-html to render what is in the model and I created the directive ck-inline to add the inline feature and bind the model to the changes that happen in the inline editor. This directive requires a ng-bind-html to work and you also need to have ngSanitize added to your module. Add directive ck-inline to your element and
I also use $timeout because I noticed that if I don't the text is rendered and then ckeditor somehow deletes all the values which messes up the model (this does not happen with the non-inline option). Here is the code.
yourModule.directive('ckInline', ['$sce', '$timeout', function($sce, $timeout){
return{
require : '?ngBindHtml',
scope:{value:"=ngBindHtml"},
link : function(scope, elm, attr, ngBindHtml)
{
$timeout(function()
{
var ck_inline;
elm.attr("contenteditable", "true");
CKEDITOR.disableAutoInline = true;
ck_inline = CKEDITOR.inline(elm[0]);
if (!attr.ngBindHtml)
return;
ck_inline.on('instanceReady', function()
{
ck_inline.setData(elm.html());
});
function updateHtml()
{
scope.$apply(function()
{
scope.value = $sce.trustAsHtml(ck_inline.getData());
});
}
ck_inline.on('blur', updateHtml);
ck_inline.on('dataReady', updateHtml);
});
}
};
}]);
When you create a directive, you can put code into the compiler, the link function or the controller.
In the docs, they explain that:
compile and link function are used in different phases of the angular
cycle
controllers are shared between directives
However, for me it is not clear, which kind of code should go where.
E.g.: Can I create functions in compile and have them attached to the scope in link or only attach functions to the scope in the controller?
How are controllers shared between directives, if each directive can have its own controller? Are the controllers really shared or is it just the scope properties?
Compile :
This is the phase where Angular actually compiles your directive. This compile function is called just once for each references to the given directive. For example, say you are using the ng-repeat directive. ng-repeat will have to look up the element it is attached to, extract the html fragment that it is attached to and create a template function.
If you have used HandleBars, underscore templates or equivalent, its like compiling their templates to extract out a template function. To this template function you pass data and the return value of that function is the html with the data in the right places.
The compilation phase is that step in Angular which returns the template function. This template function in angular is called the linking function.
Linking phase :
The linking phase is where you attach the data ( $scope ) to the linking function and it should return you the linked html. Since the directive also specifies where this html goes or what it changes, it is already good to go. This is the function where you want to make changes to the linked html, i.e the html that already has the data attached to it. In angular if you write code in the linking function its generally the post-link function (by default). It is kind of a callback that gets called after the linking function has linked the data with the template.
Controller :
The controller is a place where you put in some directive specific logic. This logic can go into the linking function as well, but then you would have to put that logic on the scope to make it "shareable". The problem with that is that you would then be corrupting the scope with your directives stuff which is not really something that is expected.
So what is the alternative if two Directives want to talk to each other / co-operate with each other? Ofcourse you could put all that logic into a service and then make both these directives depend on that service but that just brings in one more dependency. The alternative is to provide a Controller for this scope ( usually isolate scope ? ) and then this controller is injected into another directive when that directive "requires" the other one. See tabs and panes on the first page of angularjs.org for an example.
I wanted to add also what the O'Reily AngularJS book by the Google Team has to say:
Controller - Create a controller which publishes an API for communicating across directives. A good example is Directive to Directive Communication
Link - Programmatically modify resulting DOM element instances, add event listeners, and set up data binding.
Compile - Programmatically modify the DOM template for features across copies of a directive, as when used in ng-repeat. Your compile function can also return link functions to modify the resulting element instances.
A directive allows you to extend the HTML vocabulary in a declarative fashion for building web components. The ng-app attribute is a directive, so is ng-controller and all of the ng- prefixed attributes. Directives can be attributes, tags or even class names, comments.
How directives are born (compilation and instantiation)
Compile: We’ll use the compile function to both manipulate the DOM before it’s rendered and return a link function (that will handle the linking for us). This also is the place to put any methods that need to be shared around with all of the instances of this directive.
link: We’ll use the link function to register all listeners on a specific DOM element (that’s cloned from the template) and set up our bindings to the page.
If set in the compile() function they would only have been set once (which is often what you want). If set in the link() function they would be set every time the HTML element is bound to data in the
object.
<div ng-repeat="i in [0,1,2]">
<simple>
<div>Inner content</div>
</simple>
</div>
app.directive("simple", function(){
return {
restrict: "EA",
transclude:true,
template:"<div>{{label}}<div ng-transclude></div></div>",
compile: function(element, attributes){
return {
pre: function(scope, element, attributes, controller, transcludeFn){
},
post: function(scope, element, attributes, controller, transcludeFn){
}
}
},
controller: function($scope){
}
};
});
Compile function returns the pre and post link function. In the pre link function we have the instance template and also the scope from the controller, but yet the template is not bound to scope and still don't have transcluded content.
Post link function is where post link is the last function to execute. Now the transclusion is complete, the template is linked to a scope, and the view will update with data bound values after the next digest cycle. The link option is just a shortcut to setting up a post-link function.
controller: The directive controller can be passed to another directive linking/compiling phase. It can be injected into other directices as a mean to use in inter-directive communication.
You have to specify the name of the directive to be required – It should be bound to same element or its parent. The name can be prefixed with:
? – Will not raise any error if a mentioned directive does not exist.
^ – Will look for the directive on parent elements, if not available on the same element.
Use square bracket [‘directive1′, ‘directive2′, ‘directive3′] to require multiple directives controller.
var app = angular.module('app', []);
app.controller('MainCtrl', function($scope, $element) {
});
app.directive('parentDirective', function() {
return {
restrict: 'E',
template: '<child-directive></child-directive>',
controller: function($scope, $element){
this.variable = "Hi Vinothbabu"
}
}
});
app.directive('childDirective', function() {
return {
restrict: 'E',
template: '<h1>I am child</h1>',
replace: true,
require: '^parentDirective',
link: function($scope, $element, attr, parentDirectCtrl){
//you now have access to parentDirectCtrl.variable
}
}
});
Also, a good reason to use a controller vs. link function (since they both have access to the scope, element, and attrs) is because you can pass in any available service or dependency into a controller (and in any order), whereas you cannot do that with the link function. Notice the different signatures:
controller: function($scope, $exceptionHandler, $attr, $element, $parse, $myOtherService, someCrazyDependency) {...
vs.
link: function(scope, element, attrs) {... //no services allowed
this is a good sample for understand directive phases
http://codepen.io/anon/pen/oXMdBQ?editors=101
var app = angular.module('myapp', [])
app.directive('slngStylePrelink', function() {
return {
scope: {
drctvName: '#'
},
controller: function($scope) {
console.log('controller for ', $scope.drctvName);
},
compile: function(element, attr) {
console.log("compile for ", attr.name)
return {
post: function($scope, element, attr) {
console.log('post link for ', attr.name)
},
pre: function($scope, element, attr) {
$scope.element = element;
console.log('pre link for ', attr.name)
// from angular.js 1.4.1
function ngStyleWatchAction(newStyles, oldStyles) {
if (oldStyles && (newStyles !== oldStyles)) {
forEach(oldStyles, function(val, style) {
element.css(style, '');
});
}
if (newStyles) element.css(newStyles);
}
$scope.$watch(attr.slngStylePrelink, ngStyleWatchAction, true);
// Run immediately, because the watcher's first run is async
ngStyleWatchAction($scope.$eval(attr.slngStylePrelink));
}
};
}
};
});
html
<body ng-app="myapp">
<div slng-style-prelink="{height:'500px'}" drctv-name='parent' style="border:1px solid" name="parent">
<div slng-style-prelink="{height:'50%'}" drctv-name='child' style="border:1px solid red" name='child'>
</div>
</div>
</body>
compile: used when we need to modify directive template, like add new expression, append another directive inside this directive
controller: used when we need to share/reuse $scope data
link: it is a function which used when we need to attach event handler or to manipulate DOM.