I've been searching for an answer to simple but not trivial question: What is a right way to catch image' onload event in Angular only with jqLite? I found this question , but I want some solution with directives.
So as I said, this is not accepted for me:
.controller("MyCtrl", function($scope){
// ...
img.onload = function () {
// ...
}
because it is in controller, not in directive.
Here's a re-usable directive in the style of angular's inbuilt event handling directives:
angular.module('sbLoad', [])
.directive('sbLoad', ['$parse', function ($parse) {
return {
restrict: 'A',
link: function (scope, elem, attrs) {
var fn = $parse(attrs.sbLoad);
elem.on('load', function (event) {
scope.$apply(function() {
fn(scope, { $event: event });
});
});
}
};
}]);
When the img load event is fired the expression in the sb-load attribute is evaluated in the current scope along with the load event, passed in as $event. Here's how to use it:
HTML
<div ng-controller="MyCtrl">
<img sb-load="onImgLoad($event)">
</div>
JS
.controller("MyCtrl", function($scope){
// ...
$scope.onImgLoad = function (event) {
// ...
}
Note: "sb" is just the prefix I use for my custom directives.
Ok, jqLite' bind method doing well its job. It goes like this:
We are adding directive' name as attribute in our img tag . In my case , after loading and depending on its dimensions , image have to change its class name from "horizontal" to "vertical" , so directive's name will be "orientable" :
<img ng-src="image_path.jpg" class="horizontal" orientable />
And then we are creating simple directive like this:
var app = angular.module('myApp',[]);
app.directive('orientable', function () {
return {
link: function(scope, element, attrs) {
element.bind("load" , function(e){
// success, "onload" catched
// now we can do specific stuff:
if(this.naturalHeight > this.naturalWidth){
this.className = "vertical";
}
});
}
}
});
Example (explicit graphics!): http://jsfiddle.net/5nZYZ/63/
AngularJS V1.7.3 Added the ng-on-xxx directive:
<div ng-controller="MyCtrl">
<img ng-on-load="onImgLoad($event)">
</div>
AngularJS provides specific directives for many events, such as ngClick, so in most cases it is not necessary to use ngOn. However, AngularJS does not support all events and new events might be introduced in later DOM standards.
For more information, see AngularJS ng-on Directive API Reference.
Related
I'm monitoring a CSS style and updating a variable in the scope that's based on that CSS style's value. It works the first time around but when the browser is resized, the scope gets updated but ng-style does not update with the new scope parameter.
JS:
.directive('monitorStyle', function() {
return {
link: function(scope, element, attrs) {
scope[attrs.updateVariable] = $(element).css(attrs.monitorStyle);
angular.element(window).on('resize', function() {
scope[attrs.updateVariable] = $(element).css(attrs.monitorStyle);
});
}
}
})
HTML:
<p class="text" monitor-style="font-size" update-variable="textHeight">Press "<img class="mini up" src="img/select-arrow.png" src="Up" ng-style="{'height': textHeight}">
I'm trying to do this outside of the controller because that's what people recommend. Why is ng-style not updating when the scope gets updated?
The window event isn't an angular event, so angular don't know he have to update the model/scope. You have to add scope.$apply() to tell angular to refresh it :
angular.element(window).on('resize', function() {
scope[attrs.updateVariable] = $(element).css(attrs.monitorStyle);
scope.$apply();
});
Data bindig only works when your model is updated with angular event like $http, $timeout, ng-click, ...
A great article about it : http://jimhoskins.com/2012/12/17/angularjs-and-apply.html
Yo, I made this sick solution.
So if you want to watch styles (even an array of them on a particular element) and then send their values to the $scope you can use this JS:
.directive('monitorStyle', function($timeout) {
return {
link: function(scope, element, attrs) {
function addToScope() {
var updateVariable = attrs.updateVariable.split(',');
var monitorStyle = attrs.monitorStyle.split(',');
for (var i = 0; i < updateVariable.length; i++) {
scope[updateVariable[i]] = $(element).css(monitorStyle[i]);
}
}
addToScope();
angular.element(window).on('resize', function() {
addToScope();
scope.$apply();
});
}
}
})
And apply it like this:
<h2 monitor-style="font-size,line-height" update-variable="headerHeight,headerLineHeight">
This will update the $scope on initialization and on window resizes. You can of course modify it to your own purpose.
Each time the $scope changes you can update other styles like this:
<div ng-style="{'height': headerHeight, 'line-height': headerLineHeight}">
Angular's ng-model is not updating when using jquery-ui spinner.
Here is the jsfiddle http://jsfiddle.net/gCzg7/1/
<div ng-app>
<div ng-controller="SpinnerCtrl">
<input type="text" id="spinner" ng-model="spinner"/><br/>
Value: {{spinner}}
</div>
</div>
<script>
$('#spinner').spinner({});
</script>
If you update the text box by typing it works fine (you can see the text change). But if you use the up or down arrows the model does not change.
Late answer, but... there's a very simple and clean "Angular way" to make sure that the spinner's spin events handle the update against ngModel without resorting to $apply (and especially without resorting to $parse or an emulation thereof).
All you need to do is define a very small directive with two traits:
The directive is placed as an attribute on the input element you want to turn into a spinner; and
The directive configures the spinner such that the spin event listener calls the ngModel controller's $setViewValue method with the spin event value.
Here's the directive in all its clear, tiny glory:
function jqSpinner() {
return {
restrict: 'A',
require: 'ngModel',
link: function (scope, element, attrs, c) {
element.spinner({
spin: function (event, ui) {
c.$setViewValue(ui.value);
}
});
}
};
};
Note that $setViewValue is intended for exactly this situation:
This method should be called when an input directive wants to change
the view value; typically, this is done from within a DOM event
handler.
Here's a link to a working demo.
If the demo link provided above dies for some reason, here's the full example script:
(function () {
'use strict';
angular.module('ExampleApp', [])
.controller('ExampleController', ExampleController)
.directive('jqSpinner', jqSpinner);
function ExampleController() {
var c = this;
c.exampleValue = 123;
};
function jqSpinner() {
return {
restrict: 'A',
require: 'ngModel',
link: function (scope, element, attrs, c) {
element.spinner({
spin: function (event, ui) {
c.$setViewValue(ui.value);
}
});
}
};
};
})();
And the minimal example template:
<div ng-app="ExampleApp" ng-controller="ExampleController as c">
<input jq-spinner ng-model="c.exampleValue" />
<p>{{c.exampleValue}}</p>
</div>
Your fiddle is showing something else.
Besides this: Angular can not know about any changes that occur from outside its scope without being aknowledged.
If you change a variable of the angular-scope from OUTSIDE angular, you need to call the apply()-Method to make Angular recognize those changes. Despite that implementing a spinner can be easily achieved with angular itself, in your case you must:
1. Move the spinner inside the SpinnerCtrl
2. Add the following to the SpinnerCtrl:
$('#spinner').spinner({
change: function( event, ui ) {
$scope.apply();
}
}
If you really need or want the jQuery-Plugin, then its probably best to not even have it in the controller itself, but put it inside a directive, since all DOM-Manipulation is ment to happen within directives in angular. But this is something that the AngularJS-Tutorials will also tell you.
Charminbear is right about needing $scope.$apply(). Their were several problems with this approach however. The 'change' event only fires when the spinner's focus is removed. So you have to click the spinner then click somewhere else. The 'spin' event is fired on each click. In addition, the model needs to be updated before $scope.$apply() is called.
Here is a working jsfiddle http://jsfiddle.net/3PVdE/
$timeout(function () {
$('#spinner').spinner({
spin: function (event, ui) {
var mdlAttr = $(this).attr('ng-model').split(".");
if (mdlAttr.length > 1) {
var objAttr = mdlAttr[mdlAttr.length - 1];
var s = $scope[mdlAttr[0]];
for (var i = 0; i < mdlAttr.length - 2; i++) {
s = s[mdlAttr[i]];
}
s[objAttr] = ui.value;
} else {
$scope[mdlAttr[0]] = ui.value;
}
$scope.$apply();
}
}, 0);
});
Here's a similar question and approach https://stackoverflow.com/a/12167566/584761
as #Charminbear said angular is not aware of the change.
However the problem is not angular is not aware of a change to the model rather that it is not aware to the change of the input.
here is a directive that fixes that:
directives.directive('numeric', function() {
return function(scope, element, attrs) {
$(element).spinner({
change: function(event, ui) {
$(element).change();
}
});
};
});
by running $(element).change() you inform angular that the input has changed and then angular updates the model and rebinds.
note change runs on blur of the input this might not be what you want.
I know I'm late to the party, but I do it by updating the model with the ui.value in the spin event. Here's the updated fiddle.
function SpinnerCtrl($scope, $timeout) {
$timeout(function () {
$('#spinner').spinner({
spin: function (event, ui) {
$scope.spinner = ui.value;
$scope.$apply();
}
}, 0);
});
}
If this method is "wrong", any suggestions would be appreciated.
Here is a solution that updates the model like coder’s solution, but it uses $parse instead of parsing the ng-model parameter itself.
app.directive('spinner', function($parse) {
return function(scope, element, attrs) {
$(element).spinner({
spin: function(event, ui) {
setTimeout(function() {
scope.$apply(function() {
scope._spinnerVal = = element.val();
$parse(attrs.ngModel + "=_spinnerVal")(scope);
delete scope._spinnerVal;
});
}, 0);
}
});
};
});
I found this Angular Directive online to add a twitter share button. It all seems staright forward but I can't work out what the attrs.$observe is actually doing.
I have looked in the docs but can't see $observe referenced anywhere.
The directive just seems to add the href which would come from the controller so can anyone explain what the rest of the code is doing?
module.directive('shareTwitter', ['$window', function($window) {
return {
restrict: 'A',
link: function($scope, element, attrs) {
$scope.share = function() {
var href = 'https://twitter.com/share';
$scope.url = attrs.shareUrl || $window.location.href;
$scope.text = attrs.shareText || false;
href += '?url=' + encodeURIComponent($scope.url);
if($scope.text) {
href += '&text=' + encodeURIComponent($scope.text);
}
element.attr('href', href);
}
$scope.share();
attrs.$observe('shareUrl', function() {
$scope.share();
});
attrs.$observe('shareText', function() {
$scope.share();
});
}
}
}]);
Twitter
In short:
Everytime 'shareTwitterUrl' or 'shareTwitterText' changes, it will call the share function.
From another stackoverflow answer: (https://stackoverflow.com/a/14907826/2874153)
$observe() is a method on the Attributes object, and as such, it can
only be used to observe/watch the value change of a DOM attribute. It
is only used/called inside directives. Use $observe when you need to
observe/watch a DOM attribute that contains interpolation (i.e.,
{{}}'s). E.g., attr1="Name: {{name}}", then in a directive:
attrs.$observe('attr1', ...). (If you try scope.$watch(attrs.attr1,
...) it won't work because of the {{}}s -- you'll get undefined.) Use
$watch for everything else.
From Angular docs: (http://docs.angularjs.org/api/ng/type/$compile.directive.Attributes)
$compile.directive.Attributes#$observe(key, fn);
Observes an interpolated attribute.
The observer function will be invoked once during the next $digest fol
lowing compilation. The observer is then invoked whenever the interpolated value changes.
<input type="text" ng-model="value" >
<p sr = "_{{value}}_">sr </p>
.directive('sr',function(){
return {
link: function(element, $scope, attrs){
attrs.$observe('sr', function() {
console.log('change observe')
});
}
};
})
Using Angular, I'm trying to create a directive that will be placed on a button that will launch a search dialog. There are multiple instances of the search button, but obviously I only want a single instance of the dialog. The dialog should be built from a template URL and have it's own controller, but when the user selects an item, the directive will be used to set the value.
Any ideas on how to create the dialog with it's own controller from the directive?
Here's what I've go so far (basically just the directive)...
http://plnkr.co/edit/W9CHO7pfIo9d7KDe3wH6?p=preview
Here is the html from the above plkr...
Find
Here is the code from the above plkr...
var app = angular.module('plunker', []);
app.controller('MainCtrl', function($scope) {
var person = {};
person.name = 'World';
$scope.person = person;
$scope.setPerson = function(newPerson) {
person = newPerson;
$scope.person = person;
}
});
app.directive('myFind', function () {
var $dlg; // holds the reference to the dialog. Only 1 per app.
return {
restrict: 'A',
link: function (scope, el, attrs) {
if (!$dlg) {
//todo: create the dialog from a template.
$dlg = true;
}
el.bind('click', function () {
//todo: use the dialog box to search.
// This is just test data to show what I'm trying to accomplish.
alert('Find Person');
var foundPerson = {};
foundPerson.name = 'Brian';
scope.$apply(function () {
scope[attrs.myFind](foundPerson);
});
});
}
}
})
This is as far as I've gotten. I can't quite figure out how to create the dialog using a template inside the directive so it only occurs once and then assign it a controller. I think I can assign the controller inside the template, but first I need to figure out how to load the template and call our custom jQuery plugin to generate the dialog (we have our own look & feel for dialogs).
So I believe the question is, how do I load a template inside of a directive? However, if there is a different way of thinking about this problem, I would be interested in that as well.
I will show you how to do it using bootstrap-ui. (you can modify it easily, if it does not suit your needs).
Here is a skeleton of the template. You can normally bound to any properties and functions that are on directive's scope:
<div class="modal-dialog">
<div class="modal-content">
<div class="modal-header">
... // e.g. <div class="button" ng-click=cancel()></div>
</div>
<div class="modal-body">
...
</div>
<div class="modal-footer">
...
</div>
</div>
</div>
Here is how to create/declare directive in your module:
.directive("searchDialog", function ($modal) {
return {
controller: SearchDialogCtrl,
scope : {
searchDialog: '=' // here you will set two-way data bind with a property from the parent scope
},
link: function (scope, element, attrs) {
element.on("click", function (event) { // when button is clicked we show the dialog
scope.modalInstance = $modal.open({
templateUrl: 'views/search.dialog.tpl.html',
scope: scope // this will pass the isoleted scope of search-dialog to the angular-ui modal
});
scope.$apply();
});
}
}
});
Then controller may look something like that:
function SearchDialogCtrl(dep1, dep2) {
$scope.cancel = function() {
$scope.modalInstance.close(); // the same instance that was created in element.on('click',...)
}
// you can call it from the template: search.dialog.tpl.html
$scope.someFunction = function () { ... }
// it can bind to it in the search.dialog.tpl.html
$scope.someProperty;
...
// this will be two-way bound with some property from the parent field (look below)
// if you want to perform some action on it just use $scope.$watch
$scope.searchDialog;
}
Then it your mark-up you can just use it like that:
<div class="buttonClass" search-dialog="myFieldFromScope">search</div>
I recommend this plugin:
https://github.com/trees4/ng-modal
Demo here:
https://trees4.github.io/ngModal/demo.html
Create a dialog declaratively; and it works with existing controllers. The content of the dialog can be styled however you like.
In the link function, is there a more "Angular" way to bind a function to a click event?
Right now, I'm doing...
myApp.directive('clickme', function() {
return function(scope, element, attrs) {
scope.clickingCallback = function() {alert('clicked!')};
element.bind('click', scope.clickingCallback);
} });
Is this the Angular way of doing it or is it an ugly hack? Perhaps I shouldn't be so concerned, but I'm new to this framework and would like to know the "correct" way of doing things, especially as the framework moves forward.
You may use a controller in directive:
angular.module('app', [])
.directive('appClick', function(){
return {
restrict: 'A',
scope: true,
template: '<button ng-click="click()">Click me</button> Clicked {{clicked}} times',
controller: function($scope, $element){
$scope.clicked = 0;
$scope.click = function(){
$scope.clicked++
}
}
}
});
Demo on plunkr
More about directives in Angular guide. And very helpfull for me was videos from official Angular blog post About those directives.
I think it is fine because I've seen many people doing this way.
If you are just defining the event handler within the directive,
you do not have to define it on the scope, though.
Following would be fine.
myApp.directive('clickme', function() {
return function(scope, element, attrs) {
var clickingCallback = function() {
alert('clicked!')
};
element.bind('click', clickingCallback);
}
});
Shouldn't it simply be:
<button ng-click="clickingCallback()">Click me<button>
Why do you want to write a new directive just to map your click event to a callback on your scope ? ng-click already does that for you.
You should use the controller in the directive and ng-click in the template html, as suggested previous responses. However, if you need to do DOM manipulation upon the event(click), such as on click of the button, you want to change the color of the button or so, then use the Link function and use the element to manipulate the dom.
If all you want to do is show some value on an HTML element or any such non-dom manipulative task, then you may not need a directive, and can directly use the controller.
In this case, no need for a directive. This does the job :
<button ng-click="count = count + 1" ng-init="count=0">
Increment
</button>
<span>
count: {{count}}
</span>
Source: https://docs.angularjs.org/api/ng/directive/ngClick
myApp.directive("clickme",function(){
return function(scope,element,attrs){
element.bind("mousedown",function(){
<<call the Controller function>>
scope.loadEditfrm(attrs.edtbtn);
});
};
});
this will act as onclick events on the attribute clickme