AngularJS : Disable databinding inside a directive - angularjs

I have a directive which i am using to highlight code (syntax highlighting). Sometimes this text contains curly braces and angular tries to bind them. How can i disable that binding :
app.directive('highlightJs', ['$timeout',function ($timeout) {
return {
restrict: 'AE',
link : function (scope,elem,$scope) {
$timeout(function(){
var x=elem[0].innerHTML;
elem[0].innerHTML='<pre><code>'+x+'</code></pre>';
console.log(x);
hljs.highlightBlock(elem[0]);
},0);
}
};
Use example:
<highlight-js>
<img ng-src='{{url}}'/>
<highlight-js>
renders as <img ng-src=""/> and not <img ng-src="{{url}}"/>
Any help would be great.

just used this for the solution. Though this may not be a perfect solution still it works.
<highlight-js>
<code ng-non-bindable>
{{url}}
</code>
</highlight-js>

Related

Angularjs Interpolation using double curly braces not working under ng-if

UPDATE1: developed the plunker sample that will reproduce the problem. See below.
I have a strange problem in my project, where it appears in one place only. Finally, I was able to reproduce the problem using plunker sample:
http://plnkr.co/edit/JJbq54?p=preview
In the above sample, see the section "With ng-if" and "Without ng-if", enter something in the input text, and see how the double curly braces not working under ng-if, but ng-bind works fine. Also, if you remove check-if-required from the template sites-and-improvements.html also the problem is solved.
More details below:
I have the the following HTML5 code block:
<div ng-if="isFullCUSPAP" id="sites_and_imrpovements_comments">
<div class="form-row">
<div class="inputs-group">
<label>WIND TURBINE:</label>
<div class="input-binary">
<label>
<input type="radio" id="wind_turbine"
name="wind_turbine"
ng-model="$parent.wind_turbine"
value="Yes" force-model-update />
Yes
</label>
</div>
<div class="input-binary">
<label>
<input type="radio" id="wind_turbine"
name="wind_turbine"
ng-model="$parent.wind_turbine"
value="No" force-model-update />
No
</label>
</div>
<span ng-bind="wind_turbine"></span>
<span>wind_turbine = {{wind_turbine}}</span>
</div>
</div>
</div>
I know that ng-if will create a new child scope. See above code, scope variable wind_trubine. Only in this HTML5 file, the curly braces {{}} is not working. However, if I use ng-bind it works fine. In other HTML5 files, I have no problem what so ever. This HTML5 is implemented using directive as follows:
app.directive('sitesAndImprovements', function() {
return {
restrict: 'E',
replace:true,
templateUrl: '<path-to-file>/site-and-improvments.html',
link: function (scope, elem, attrs) {
//Business Logic for Sites and Improvements
}
}
})
And, simply, I put it in the parent as follows:
<sites-and-improvements></sites-and-improvements>
The only difference I could see, is that this implementation has two levels of nested ng-if, which would look like the following:
<div ng-if="some_expression">
...
...
<sites-and-improvements></sites-and-improvements>
...
...
</div>
Based on comments, I used controller As notation and defined MainController accordingly. See snapshots below. It seems there is a problem if ng-if is nested with two levels. The scope variable is completely confused. I don't get the same results using ng-bind and double curly braces.
If you examine the above snapshots, even though I used controller As notation, you will see that ng-bind gives different results when compared with interpolation using {{}}.
I even changed the default value of wind_turbine to be set as follows in the link function:
scope.MainController.wind_turbine = 'Yes';
I noticed that on page load, everything looks fine, but when I change the value of the input element wind_trubine using the mouse, all related reference are updated correctly except the one that uses {{}}.
Maybe this is because there are two nested levels of ng-if?
Appreciate your feedback.
Tarek
Remove the replace: true from the sites-and-improvements directive:
app.directive('sitesAndImprovements', function() {
return {
restrict: 'E',
̶r̶e̶p̶l̶a̶c̶e̶:̶t̶r̶u̶e̶,̶
templateUrl: 'site-and-improvments.html',
link: function (scope, elem, attrs) {
//debugger;
}
}
})
It is fighting the check-if-required directive:
app.directive('checkIfRequired', ['$compile', '$timeout', function ($compile, $timeout) {
return {
priority: 2000,
terminal: true,
link: function (scope, el, attrs) {
el.removeAttr('check-if-required');
$timeout(function(){
//debugger;
$(':input', el).each(function(key, child) {
if (child && child.id === 'test_me') {
angular.element(child).attr('ng-required', 'true');
}
if (child && child.id === 'testInput1') {
//debugger;
//angular.element(child).attr('ng-required', 'true');
}
});
$compile(el, null, 2000)(scope);
})
}
};
}])
The DEMO on PLNKR.
replace:true is Deprecated
From the Docs:
replace ([DEPRECATED!], will be removed in next major release - i.e. v2.0)
specify what the template should replace. Defaults to false.
true - the template will replace the directive's element.
false - the template will replace the contents of the directive's element.
-- AngularJS Comprehensive Directive API - replace deprecated
From GitHub:
Caitp-- It's deprecated because there are known, very silly problems with replace: true, a number of which can't really be fixed in a reasonable fashion. If you're careful and avoid these problems, then more power to you, but for the benefit of new users, it's easier to just tell them "this will give you a headache, don't do it".
-- AngularJS Issue #7636
For more information, see Explain replace=true in Angular Directives (Deprecated)
Another solution posted by AngularJS team here:
https://github.com/angular/angular.js/issues/16140#issuecomment-319332063
Basically, they recommend to convert the link() function to use compile() function instead. Here is the update code:
app.directive('checkIfRequired', ['$compile', '$timeout', function ($compile, $timeout) {
return {
priority: 2000,
terminal: true,
compile: function (el, attrs) {
el.removeAttr('check-if-required');
var children = $(':input', el);
children.each(function(key, child) {
if (child && child.id === 'test_me') {
angular.element(child).attr('ng-required', 'true');
}
});
var compiled = $compile(el, null, 2000);
return function( scope ) {
compiled( scope );
};
}
};
}]).directive('sitesAndImprovements', function() {
return {
restrict: 'E',
replace:true,
templateUrl: 'site-and-improvments.html'
}
});
The main problem I have with this solution is that I am using the scope parameter which is passed to the link() function. For example, in the .each() loop above, I need to get the value of the element ID which is based on interpolation using {{<angular expre>}}.
So I tried to use pre-link and post-link within the compile function where the scope is available. I noticed that the section with ng-if is removed when execution is in pre-link and then it is added shortly after that. So I had to use $watch to monitor changes to the children to run the needed process when required. I developed this plunker sample:
http://plnkr.co/edit/lsJvhr?p=preview
Even after all such effort, the issue is not resolved. So the bottom line for similar cases, is that if you need to use the scope then you have to remove replace: true.
Any feedback would be appreciated.
Tarek

Run 'ng-click' inside a directive's isolated scope

Thanks in advance for taking the time to look into this question
I have serverside generated code that renders a directive wrapped around pre-rendered content.
<serverside-demo color="blue">
<p><strong>Content from Server, wrapped in a directive.</strong></p>
<p>I want this color to show: <span ng-style="{color: color}">{{color}}</span></p>
<button ng-click="onClickButtonInDirective()">Click Me</button>
</serverside-demo>
This means that 1.) the directive tag, 2.) the content inside the directive tag, 3.)the ng-click and 4.) The curly braces syntax are all generated by the server.
I want AngularJs to pick up the generated code, recompile the template and deal with the scope.
The problem is that I am having trouble getting it working. I understand that because the ng-click is inside the controller block, it is picked up not by the directive isolated scope, but the parent controllers. Instead I want the opposite... to pick up the onClickButtonInDirective scope function inside the serversideDemo link
I have created a jsfiddle best explaining my problem, which aims to clearly demonstrate the working "traditional" way of loading the template separately (which works) comparing it to the server-side way.
https://jsfiddle.net/stevewbrown/beLccjd2/3/
What is the best way to do this?
Thank you!
There are two major problem in your code
1- directive name and dom element not matched, - missing in dom element
app.directive('serverSideDemo', function() {
use <server-side-demo color="blue"> instead of <serverside-demo color="blue">
2- you need to compile the html code of server-side-demo dom with directive scope in link function
$compile(element.contents())(scope);
Working jsfiddle
Use templateUrl instead of template to fetch the content of directive from server:
app.directive('serverSideDemo', function() {
return {
restrict: 'AE',
scope: {
color: '='
},
templateUrl: 'link/that/returns/html/content',
link: function(scope, element, attrs) {
scope.onClickButtonInDirective = function() {
console.log('You clicked the button in the serverside demo')
scope.color = scope.color === 'blue' ? 'red' : 'blue';
}
}
};
});
Have a look at angular docs for more details

Move function from controller to directive

I have a function in my controller that manipulates the DOM. I understand this to be a bad practice and DOM manipulations should be moved into a directive. I'm having trouble pulling it out of the controller and into its own directive.
I have the following example code in my controller:
$scope.sidebarToggle = function() {
if ($scope.request = null) {
$(#container).switchClass('bottom', 'top', 400, 'linear');
$scope.editing = true;
}
else {
$(#container).switchClass('top', 'bottom', 400 'linear');
$scope.editing = false;
{
};
The above code's if conditions are very simplified, in the live code there are multiple conditions. Otherwise an ng-show/hide directive might have been possible.
The purpose of the code is to recognize the state the user is in, reveal/hide an off-screen sidebar (the class assignments), and set the 'editing' state of the controller.
How can this be refactored into a directive to accomplish the same goal?
Take a look at the documentation for angular directives to get started.
https://docs.angularjs.org/guide/directive
For 'angularising' the class of the container, use ng-class.
example # Adding multiple class using ng-class
You probably don't need to create your own directive for that.
Angular have already created some directives that could help you out.
In your case, you should use angular directive : ng-show and ng-class or ng-style
Exemple :
HTML
<div ng-show="request == null"> Edit </div>
<div ng-class="{'class-top': request == null,'class-bottom' : request != null}"> <div>
CSS :
.class-top{
...
}
.class-bottom{
...
}
Let me know if it works for you,
Nico
Try this:
app.directive('test', function() {
return {
restrict: 'E',
scope: {
},
link: sidebarToggle
};
});
I think it's creating a directive and link to your function sidebarToggle

Is it possible to conditionally apply transclution to directive?

Is it possible to decide whether to apply transclusion to an element based on a scope variable ?
For example ( Stupid simplified reduced example of what i'm trying to achieve )
app.directive('myHighlight', function () {
return {
transclude : true,
template : "<div style='border:1px solid red'><span ng-transclude></span></div>"
}
});
app.directive('myDirective', function () {
return {
template : "<span>some text</span>",
link : function (scope,element,attr) {
if ( 'shouldHighlight' in attr) {
// wrap this directive with my-highlight
}
}
}
});
And then in the html
<span my-directive></span>
<span my-directive should-highlight></span>
Note, please don't tell me to just add the highlight instead of should-highlight, as i said this is a dumb reduced example. Thanks.
Instead of optionally applying the highlight directive, always apply it and do the optional wrapping inside that directive. The optional wrapping is achieved with an ng-if and a boolean passed from myDirective to myHighlight via markup:
<div my-highlight="someBooleanValue">some text</div>
The myHighlight template:
<div ng-if="actuallyTransclude" style="border:1px solid red">
<span ng-transclude></span>
</div>
<div ng-if="!actuallyTransclude" ng-transclude></div>
Working jsfiddle: http://jsfiddle.net/wilsonjonash/X6eB5/
Sure. When you specify the transclude option, you know that you can declaratively indicate where the content should go using ng-transclude.
In the linking function of the directive, you will also get a reference to a transclude function (https://docs.angularjs.org/api/ng/service/$compile, see link section):
function link(scope, iElement, iAttrs, controller, transcludeFn) { ... }
The transcludeFn will return the transcluded content, so you can conditionally insert that were and when you want to in the link function of your directive.
Example (http://jsfiddle.net/DKLY9/22/)
HTML
<parentdir flg="1">
Child Content
</parentdir>
JS
app.directive('parentdir', function(){
return {
restrict : 'AE',
scope: {
flg : "="
},
transclude : true,
template : "<div>Parent {{childContent}} Content</div>",
link : function(scope, elem, attr, ctrl, transcludeFn){
if (scope.flg==1){
scope.childContent="Include Me instead";
}
else {
scope.childContent = transcludeFn()[0].textContent;
}
}
}
});
This is a simplified example. To get a better idea of how to use the transclude function, refer to the following : http://blog.omkarpatil.com/2012/11/transclude-in-angularjs.html
When I approach these kind of problems I just look at what angular did. Usually their source code is very readable and easy to re-use. ngTransclude is no different:
https://github.com/angular/angular.js/blob/master/src/ng/directive/ngTransclude.js
I leave the rest to you. You can either create your own transclusion directive that receives also a condition, or just duplicate the code into your specific directive when the if condition is true.
If you still have trouble, please let me know and we'll set up a plunker.

Detect if a transclude content has been given for a angularjs directive

I have a directive (a progressbar) which should have two possible states, one without any description and one with a label on the left side.
It would be cool to simple use the transcluded content for this label.
Does anyone know how I can add a class to my directive depending whether a transclude content has been given or not?
So I want to add:
<div class="progress" ng-class="{withLabel: *CODE GOES HERE*}">
<div class="label"><span ng-transclude></span>
<div class="other">...</div>
</div>
Thanks a lot!
After release of Angular v1.5 with multi-slot transclusion it's even simpler. For example you have used component instead of directive and don't have access to link or compile functions. Yet you have access to $transclude service. So you can check presence of content with 'official' method:
app.component('myTransclude', {
transclude: {
'slot': '?transcludeSlot'
},
controller: function ($transclude) {
this.transcludePresent = function() {
return $transclude.isSlotFilled('slot');
};
}
})
with template like this:
<div class="progress" ng-class="{'with-label': withLabel}">
<div class="label"><span ng-transclude="slot"></span>
<div class="other">...</div>
</div>
Based on #Ilan's solution, you can use this simple $transclude function to know if there is transcluded content or not.
$transclude(function(clone){
if(clone.length){
scope.hasTranscluded = true;
}
});
Plnkr demonstrating this approach with ng-if to set default content if nothing to transclude: http://plnkr.co/hHr0aoSktqZYKoiFMzE6
Here is a plunker: http://plnkr.co/edit/ednJwiceWD5vS0orewKW?p=preview
You can find the transcluded element inside the linking function and check it's contents:
Directive:
app.directive('progressbar', function(){
return {
scope: {},
transclude: true,
templateUrl: "progressbar.html",
link: function(scope,elm){
var transcluded = elm.find('span').contents();
scope.withLabel = transcluded.length > 0; // true or false
}
}
})
Template:
<div class="progress" ng-class="{'with-label': withLabel}">
<div class="label"><span ng-transclude></span>
<div class="other">...</div>
</div>
You can also create your custom transclusion directive like so:
app.directive('myTransclude', function(){
return {
link: function(scope, elm, attrs, ctrl, $transclude){
$transclude(function(clone){
// Do something with this:
// if(clone.length > 0) ...
elm.empty();
elm.append(clone);
})
}
}
})
Based on the solution from #plong0 & #Ilan, this seems to work a bit better since it works with whitespace as well.
$transcludeFn(function(clonedElement) {
scope.hasTranscludedContent = clonedElement.html().trim() === "";
});
where previously <my-directive> </my-directive> would return that it has a .length of 1 since it contains a text node. since the function passed into $transcludeFn returns a jQuery object of the contents of the transcluded content, we can just get the inner text, remove whitespace on the ends, and check to see if it's blank or not.
Note that this only checks for text, so including html elements without text will also be flagged as empty. Like this: <my-directive> <span> </span> </my-directive> - This worked for my needs though.

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