I'm creating a product gallery directive in Angular, which will allow the user to scroll through images with left/right arrows.
What is the most appropriate angular approach to feed my directive with the array of image URLs?
You can assume that the parent controller has already made an API call to receive this the array of URLs
E.g.
<div data-ng-controller="MyController as myController">
<my-image-gallery></my-image-gallery>
</div>
Should I just have an attribute of that takes in the JSON array? Perhaps something like:
<my-image-gallery images="myController.ImageList"></my-image-gallery>
Although, I'm not even sure if the above is possible. It would mean the JSON would have to be converted into a string?
There must be a better way
Edit
As per comments, I've tried the above method, but I can't access the "images" field from within my controller.
Here is what I have defined in my directive:
scope: {
imageSource: '='
},
Then in my controller, I assume I should just be able to reference the variable imageSource, shouldn't I?
I think you're using a kinda weird tutorial or something to learn angular. You can use the MyController as MyController syntax, but the goal of that is to avoid using $scope. I personally don't agree with it and don't understand why people would want to do that.
When you attach a value to $scope it becomes available in your view directly (without needing $scope). For example, $scope.images would be passed in to your directive as just images.
To have the directive process that value as a variable instead of a string it must be defined using an = (as opposed to an #) you can read more about this in the angular directive docs
Here is an example of how this would work:
Javascript
angular.module('app',[])
.controller('myCtrl',['$scope',function($scope){
$scope.imageList=['img1','img2','img3','img...'];
}])
.directive('myImageGallery',function(){
return {
restrict: 'E',
scope:{
images:'='
},
controller: ['$scope',function($scope){
console.log($scope.images);
}],
replace: true,
template: '<ul><li ng-repeat="img in images">{{img}}</li></ul>'
}
})
HTML
<body ng-app="app">
<div ng-controller="myCtrl">
<my-image-gallery images="imageList"></my-image-gallery>
</div>
</body>
and here is a plunker of it in action.
Related
I am trying to call (or use) few custom directives in ionic framework, dynamic is like <mydir-{{type}} where {{type}} will come from services and scope variable, having values radio, checkbox, select etc, and created my directives as mydirRadio, MydirCheckbox, mydirSelect, But its not working.
Is their any good approach to get the dynamic html as per {{type}} in scope?
Long story short; no you can't load directives dynamically in that way.
There are a few options for what you can do. You can, as other answers have mentioned, pass your context as an attribute (mydir type="checkbox"). You could make a directive that dynamically loads another directive, as also mentioned by others. Neither of these options are imo every good.
The first option only works if you write the directive yourself, not when using something like ionic. It also requires you to write multiple directives as one, which can get very messy very quickly. This mega directive will become hard to test and easy to mess up when maintaining it in the future. Note that this is the correct way to pass data to a directive from the view, it's just not good for this specific use case.
The second option is problematic because obfuscates things a bit too much. If someone reads your html and sees a directive called dynamic that is given dynamic data... they have no idea what is going to happen. If they see a directive called dropdown that is given a list they have a fair idea of what the result will be. Readability is important, don't skimp on it.
So I would suggest something simpler that requires much less work from you. Just use a switch:
<div ng-switch="type">
<mydir-select ng-switch-when="select"></mydir-select>
<mydir-checkbox ng-switch-when="checkbox"></mydir-checkbox>
</div>
I dont understand why do you need dynamic directives.
Simple use single directive and change the template accordingly.
For example -
angular.module('testApp')
.directive('dynamicDirective', function($compile,$templateCache,$http) {
return {
restrict: 'C',
link: function($scope,el) {
//get template
if(radio){
$http.get('radio.html', {cache: $templateCache}).success(function(html){
//do the things
el.replaceWith($compile(html)($scope));
});
} else if(checkbox){
//load checkbox template
} //vice-versa
}
};
});
You can inject service variable in directive also.
a bit more code would help. I don't know, if its possible to do dynamic directives like the ones in a tag
<{dyntag}></{dyntag}>
but you also can use an expression like
<your-tag dynamic_element="{type}">...</your-tag>
which should have exactly the same functionality. In your case it would be like:
Your JSObject ($scope.dynamics):
{"radio", "checkbox", "select"}
and your HTML:
<div ng-repeat="dyn in dynamics">
<your-tag dynamic_element="{dyn}"></your-tag>
</div>
Yes, that's not a problem. You can interpolate your data using {{}} and in your directive compile a new element using that data:
myApp.directive('dynamic', function($compile, $timeout) {
return {
restrict: "E",
scope: {
data: "#var" // say data is `my-directive`
},
template: '<div></div>',
link: function (scope, element, attr) {
var dynamicDirective = '<' + scope.data + ' var="this works!"><' + scope.data + '>';
var el = $compile(dynamicDirective)(scope);
element.parent().append( el );
}
}
});
HTML:
<div ng-controller="MyCtrl">
<dynamic var="{{test}}"></dynamic>
</div>
Fiddle
I am passing a custom scope object to the $compile and creating a custom template. If I apply a directive on the elements inside the template, scope that is changing is the one that is passed to the $compile, and that's really what I wanted.
However, I just thought that it might be good to also have a controller on some elements inside the template,
<div ng-controller="controllerName" >
</div>
but ng-controller doesn't set data on the passed scope but creates its own and uses that one. Is there a way to make ngController to use existing scope and not create a new one ?
We create our controllers and wrap them in factories to make them accessible. We apply or controllers through directives (also going away). This gives you a controller that is scoped to the directive, which has better control for scope, this works for us as the directives where we do this for are usually components.
I don't know if this will be an option given the road you are down now. I would suggest trying to stop using ng-controller. You may want to look at angular 2 now just to keep it in mind as a migration path, it is coming in the fairly near future. They have removed ng-controller, a lot of what they are doing in angular 2 can be done now.
This is a good resource on why these things are a bad idea
https://www.youtube.com/watch?v=gNmWybAyBHI&t=9m10s
If you look at the source code for ng-controller, you will see it is very simple:
var ngControllerDirective = [function() {
return {
restrict: 'A',
scope: true,
controller: '#',
priority: 500
};
}];
You can actually create an almost identical alternate directive that just defines scope: false (or omits the scope key altogether, same thing):
app.directive('controllerNoScope', function () {
return {
restrict: 'A',
scope: false,
controller: '#',
priority: 500 // same as ng-controller
}
});
(You may want to give it a better name).
See this Plunkr for a demo that shows the scope has the same $id as the outer one, meaning it is the same scope.
I'm using ui.grid to get a list of parts. I've created a column that contains a button which launches a modal. What I'm having trouble with is sharing the scope of the part that is contained in the row. I want to share the properties of that row with the the button that I'm creating using cellTemplate. I then want to share the $scope of the part row with the modal that it will launch.
I'm a bit stumped on how to actually do this.
So far I've tried
• Wrapping an ng-repeat around the button that I want to target. This kind of works but makes the app super slow
• Data-binding on the button via ng-class. I can't seem to target this correctly.
How can you share the $scope of an object that you're receiving via $http.get into the ui.grid with elements that you're creating with cellTemplate?
Disclaimer -- I always use controllerAs syntax, so if referencing the controller in the context of HTML is weird to you, just ignore that part and pretend like you setup the methods to be directly on the scope. I also do everything in Typescript, not Javascript, so I'm going to write the pertinent parts of the code in here. They should be easy to plug into your application.
The answer is a combination of the two answers you already have from Sunil and S.Baggy.
What you want to do is use the getExternalScopes() function and attach something to the scope of the HTML where your grid resides. The thing you handed the grid will take in the row and call your modal popup. See below for a little clarification.
Your HTML -
<div ng-controller="MyController as myController">
<div ui-grid="myController.GridObject" external-scopes="myController"></div>
</div>
By using controllerAs syntax and making the controller the reference in the external scopes, we can now gain access to everything in our controller. So we can call methods in it.. In order to do that, however, we have to use a cellTemplate, which it sounds like you already know how to do, and in that cellTemplate we have to have the following:
ng-click="getExternalScopes().methodToLaunchModal()"
Now the last part of hooking all this up is to write the methodToLaunchModal() method into the controller. For that we're borrowing the code from S.Baggy's answer. Here is a very abbreviated controller with the GridObject (the same one I referenced from the controller above):
app.controller('MainCtrl', function($scope, $modal) {
GridObject = {
... setup of all the other things
columnDefs: [{ etc, etc, }, { etc, cellTemplate: '<div ng-click="getExternalScopes().methodToLaunchModal(row.entity)">whatever</div>' }]
};
methodToLaunchModal: function(row) {
var modalInstance = $modal.open({
templateUrl: 'someTemplate',
controller: 'ModalController',
resolve: {
rowObject: function () { return row; }
}
});
};
});
At this point your modal scope will have an object named rowObject on it that will have all the properties from your row. So you should be able to call rowObject.SomeProperty to get its value.
Apologies if any of the syntax is slightly off.
I use the bootstrap $modal directive with code like this...
clickFunction: function (event, row) {
event.stopPropagation(); // prevents the current row from appearing as selected
var modalInstance = $modal.open({
templateUrl: 'views/modalcontent.tpl.html',
controller: 'ModalMessageController',
size: 'lg',
resolve: {
message: function () { return row.entity.serial_number; }
}
}
);
Then I just refer to {{message}} in the template. Of course you could pass in any other piece of data too.
You can access row and its properties on row selection or ng-click of that row using externalscopes
ng-click="getExternalScopes().onRowClick(row)"
onRowClick: function (row) {
row.entity.Property1; /// and so on for all row properties
}
I'm somewhat new to AngularJs, so forgive me if this is a newb question, but I've looked around a bit and haven't been able to figure this out.
I'm trying to send an attribute of an object into a directive and I'm not quite sure why this isn't working.
I've got a scope variable that's an object, something like:
$scope.player = {name:"", hitpoints:10};
In my HTML, I'm attempting to bind that to a directive:
<span accelerate target="player.hitpoints" increment="-1">Take Damage</span>
In my directive, I'm attempting to modify player.hitpoints like this:
scope[attrs.target] += attrs.increment;
When I trace it out, scope[attrs.target] is undefined, even though attrs.target is "player.hitpoints." When I use target="player", that traces out just fine but I don't want to have to manipulate the .hitpoints property explicitly in the directive.
Edit: I've made a jsfiddle to illustrate what I'm trying to do: http://jsfiddle.net/csafo41x/
There is a way to share scope between your controller and directive. Here is very good post by Dan Wahlin on scope sharing in Directive - http://weblogs.asp.net/dwahlin/creating-custom-angularjs-directives-part-2-isolate-scope
There are 3 ways to do so
# Used to pass a string value into the directive
= Used to create a two-way binding to an object that is passed into the directive
& Allows an external function to be passed into the directive and invoked
Just a very basic example on how the above mentioned scope are to be used
angular.module('directivesModule').directive('myIsolatedScopeWithModel', function () {
return {
scope: {
customer: '=' //Two-way data binding
},
template: '<ul><li ng-repeat="prop in customer">{{ prop }}</li></ul>'
};
});
There are a number of things going on here:
#1 - scope
Once you define your isolated scope (along the lines of #Yasser's answer), then you don't need to deal with attrs - just use scope.target.
#2 - template
Something actually needs to handle the click event. In your fiddle there is just <span class="btn"...>. You need ng-click somewhere. In your case, you probably want the directive to handle the click. So modify the directive's template and define the click handler in the directive's scope:
...
template: "<button class='btn' ng-click='click()'>Button</button>",
link: function(scope, element, attrs)
{
scope.click = function(){
scope.target += parseInt(attrs.increment);
}
}
...
#3 - transclude
Now, you need to get the contents of the directive to be the contents of the button within your directive's template. You can use transclude parameter with ng-transclude - for location, for that. So, the template above is modified to something like the following:
...
template: "<button class='btn' ng-click='click()'><div ng-transclude</div></button>",
transclude: true,
...
Here's your modified fiddle
I've got a tiny problem with an angular directive that's now working and I don't know why. I think it's a fairly simple issue that I'm overlooking, maybe you can help me out.
Directive is defined like this:
angular.module('directives', [])
.directive('my-directive', function () {
return {
restrict: 'AE',
scope: {
name: '=name'
},
template: '<h1>{{name}}</h1>'
};
});
Then index.cshtml:
<my-directive name="test"></my-directive>
Application.js:
var app = angular.module('MyApp', [
...,
'directives'
]);
And here's controllers.js
angular.module('controllers', ['apiServices', 'directives'])
.controller('homecontroller', function($scope, $resource, webApiService, $log, $translate, $localStorage, $sessionStorage) {
Ok confirmed that directives.js is loaded, otherwise application.js nags about 'unknown module'. There are no error messages in the console, the thing just doesn't show. Any ideas?
EDIT
So as pointed out, I changed the directive name to camelCase, but still no luck:
<my-directive name="John Doe"></my-directive>
And
.directive('myDirective', function () {
But nothing is showing yet.
EDIT
Problem is that angular expects an object to be passed into the attribute, not a string literal. If you create an object person = { name: 'John' }, pass the person in, then write {{ person.name }} ( assuming we named the attribute person + scope var person too ).
During normalization, Angular converts - delimited name to camelCase.
So use camelCase while specifying the directive inside JS:
.directive('myDirective', function () {
Fiddle
I'm sure you've figured this out already, but if you change your scope definition for name to be
scope: {
name: '#'
}
you will then be able to pass a string. The '#' interpolates the attribute while the '=' binds it. Additionally, you don't need to include an attribute name if it is the same as the scope variable.
The problem appears to be in the directive definition. You note in your question that Angular expects an object; this is true for the "=" scope, but not for the "#" scope. In the "#" scope, Angular expects a string only. I have created a snippet below.
Too many modules
Unless you are reusing the directive in multiple applications, do not create a new module for it. Add the directive definition to the module that you created for the application. In my example below, I called the module back by using "angular.module( moduleName )"... When only one argument is used, Angular returns the existing object rather than creating a new one. This is how we can separate the code into many files.
Things to Note
You will notice the following:
You do not need to load the module into the app variable. Calling the Singleton each time is actually safer and easier on memory management.
The directive is in camel case, as you have already noted.
I am setting the name attribute to a string value and not an object; this works because of the "#" scope setting.
The div is set to ng-app='MyApp'. This usually is set to the html element, but I did not want to mess with the DOM on Stack Exchange. The ng-app directive can be set on any element, and the directives associated with that module will be applied on all elements that are within that element's scope. Without the ng-app directive, Angular does not know which module to run on the page.
//app.js - this defines the module, it uses two parameters to tell the injector what to do.
angular.module('MyApp',[]);
//directive.js stored elsewhere
//this calls back the module that has been created. It uses one parameter because the injector is no longer needed.
angular.module('MyApp').directive('myDirective', function () {
return {
restrict: 'AE',
scope: {
name: '#'
},
template: '<h1>{{name}}</h1>'
};
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app="MyApp">
<h1>Successful Load</h1>
<my-directive name="test"></my-directive>
<p>By applying the directive definition to the MyApp module, the MyApp module knows to activate the directive within this scope. In this form, it does not get injected.</p>
</div>
Using Injection
When you have a different module for each and every directive or controller, each one must be injected into the application's module definition. This leaves a lot of room for error. As a best practice, only create a new module when necessary, and make the module a container for a group of related functionality and not a single item.
The code below demonstrates proper injection.
angular.module( "MyApp", ['ReusableDirectives'] );
angular.module( "MyApp" ).directive( "myDirective", function(){
return {
restrict: "AE",
scope: { name: "#" },
template: "<p>This is the directive I defined in the example above. It uses <u>the same module</u> as my main application, because it is not going to be reused over and over again. In fact, I will need it just for this application, so I don't need to complicate things with a new module. This directive takes an attribute called 'name' and if it is a string allows me to manipulate the string within my templates scope to do things like this: {{'hello ' + name + '!'}}</p>"
};
} );
angular.module( "ReusableDirectives", [] );
angular.module( "ReusableDirectives" ).directive("reusableDirective", function(){
return {
restrict: "E",
template: "<p>This is a directive that I intend to use in many, many applications. Because I will reuse it so much, I am putting it in a separate module from my main application, and I will inject this directive. This is the only reason that this directive is not in the same module as the one I defined above.</p>"
};
} ).directive("reusableDirective2", function(){
return {
restrict: "E",
template: "<p>This is a second directive that I intend to use in multiple applications. I have stored it in a module with the first directive so that I can freely inject it into as many apps as I like.</p>"
};
} )
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app="MyApp">
<h1>Successful Load</h1>
<my-directive name="Johnny"></my-directive>
<p>By applying the directive definition to the MyApp module, the MyApp module knows to activate the directive within this scope. In this form, it does not get injected.</p>
<h3>Injected Directives</h3>
<reusable-directive></reusable-directive>
<reusable-directive2></reusable-directive2>
</div>
Keep it simple. Define your directives on a single module for your application. Once you have that done and working, if you need the directives again in another application, refactor and experiment with injections at that time after you have some more Angular practice under your belt.
You have a bright future with Angular, keep up the good work!
Your directive must be camel-cased
.directive('myDirective', function () {
then in your html, your are free whether to call it my-directive or myDirective
Both are valid
<my-directive name="test"></my-directive>
<myDirective name="test"></myDirective>
Just to follow up on this, I had to use the following way to get my directive to work.
<my-directive name="test"></my-directive>