Show loading animation for slow script using AngularJS? - javascript

In angularjs 1.2 operations like filtering an ng-repeat with many rows (>2,000 rows) can become quite slow (>1 sec).
I know I can optimize execution times using limitTo, pagination, custom filters, etc. but I'm still interested to know if it's possible to show a loading animation while the browser is busy running long scripts.
In case of angular I think that could be invoked whenever $digest is running because that seems to be the main function that takes up most time and might be called several times.
In a related question there were no useful answers given. Any help greatly appreciated!

The problem is that as long as Javascript is executing, the UI gets no chance to update. Even if you present a spinner before filtering, it will appear "frozen" as long as Angular is busy.
A way to overcome this is to filter in chunks and, if more data are available, filter again after a small $timeout. The timeout gives the UI thread a chance to run and display changes and animations.
A fiddle demonstrating the principle is here.
It does not use Angular's filters (they are synchronous). Instead it filters the data array with the following function:
function filter() {
var i=0, filtered = [];
innerFilter();
function innerFilter() {
var counter;
for( counter=0; i < $scope.data.length && counter < 5; counter++, i++ ) {
/////////////////////////////////////////////////////////
// REAL FILTER LOGIC; BETTER SPLIT TO ANOTHER FUNCTION //
if( $scope.data[i].indexOf($scope.filter) >= 0 ) {
filtered.push($scope.data[i]);
}
/////////////////////////////////////////////////////////
}
if( i === $scope.data.length ) {
$scope.filteredData = filtered;
$scope.filtering = false;
}
else {
$timeout(innerFilter, 10);
}
}
}
It requires 2 support variables: $scope.filtering is true when the filter is active, giving us the chance to display the spinner and disable the input; $scope.filteredData receives the result of the filter.
There are 3 hidden parameters:
the chunk size (counter < 5) is small on purpose to demonstrate the effect
the timeout delay ($timeout(innerFilter, 10)) should be small, but enough to give the UI thread some time to be responsive
the actual filter logic, which should probably be a callback in real life scenarios.
This is only a proof of concept; I would suggest refactoring it (to a directive probably) for real use.

Here are the steps:
First, you should use CSS animations. No JS
driven animations and GIFs should be used within heavy processes bec. of the single thread limit. The animation will freeze. CSS animations are separated from the UI thread and they are supported on IE 10+ and all major browsers.
Write a directive and place it outside of your ng-view with
fixed positioning.
Bind it to your app controller with some special flag.
Toggle this directive's visibility before and after long/heavy processes.
(You can even bind a text message to the directive to display some
useful info to the user). -- Interacting with this or anything else directly within a loop of heavy process will take way longer time to finish. That's bad for the user!
Directive Template:
<div class="activity-box" ng-show="!!message">
<img src="img/load.png" width="40" height="40" />
<span>{{ message }}</span>
</div>
activity Directive:
A simple directive with a single attribute message. Note the ng-show directive in the template above. The message is used both to toggle the activity indicator and also to set the info text for the user.
app.directive('activity', [
function () {
return {
restrict: 'EA',
templateUrl: '/templates/activity.html',
replace: true,
scope: {
message: '#'
},
link: function (scope, element, attrs) {}
};
}
]);
SPA HTML:
<body ng-controller="appController">
<div ng-view id="content-view">...</div>
<div activity message="{{ activityMessage }}"></div>
</body>
Note that the activity directive placed outside of ng-view. It will be available on each section of your single-page-app.
APP Controller:
app.controller('appController',
function ($scope, $timeout) {
// You would better place these two methods below, inside a
// service or factory; so you can inject that service anywhere
// within the app and toggle the activity indicator on/off where needed
$scope.showActivity = function (msg) {
$timeout(function () {
$scope.activityMessage = msg;
});
};
$scope.hideActivity = function () {
$timeout(function () {
$scope.activityMessage = '';
}, 1000); // message will be visible at least 1 sec
};
// So here is how we do it:
// "Before" the process, we set the message and the activity indicator is shown
$scope.showActivity('Loading items...');
var i;
for (i = 0; i < 10000; i += 1) {
// here goes some heavy process
}
// "After" the process completes, we hide the activity indicator.
$scope.hideActivity();
});
Of course, you can use this in other places too. e.g. you can call $scope.hideActivity(); when a promise resolves. Or toggling the activity on request and response of the httpInterceptor is a good idea too.
Example CSS:
.activity-box {
display: block;
position: fixed; /* fixed position so it doesn't scroll */
z-index: 9999; /* on top of everything else */
width: 250px;
margin-left: -125px; /* horizontally centered */
left: 50%;
top: 10px; /* displayed on the top of the page, just like Gmail's yellow info-box */
height: 40px;
padding: 10px;
background-color: #f3e9b5;
border-radius: 4px;
}
/* styles for the activity text */
.activity-box span {
display: block;
position: relative;
margin-left: 60px;
margin-top: 10px;
font-family: arial;
font-size: 15px;
}
/* animating a static image */
.activity-box img {
display: block;
position: absolute;
width: 40px;
height: 40px;
/* Below is the key for the rotating animation */
-webkit-animation: spin 1s infinite linear;
-moz-animation: spin 1s infinite linear;
-o-animation: spin 1s infinite linear;
animation: spin 1s infinite linear;
}
/* keyframe animation defined for various browsers */
#-moz-keyframes spin {
0% { -moz-transform: rotate(0deg); }
100% { -moz-transform: rotate(359deg); }
}
#-webkit-keyframes spin {
0% { -webkit-transform: rotate(0deg); }
100% { -webkit-transform: rotate(359deg); }
}
#-o-keyframes spin {
0% { -o-transform: rotate(0deg); }
100% { -o-transform: rotate(359deg); }
}
#-ms-keyframes spin {
0% { -ms-transform: rotate(0deg); }
100% { -ms-transform: rotate(359deg); }
}
#keyframes spin {
0% { transform: rotate(0deg); }
100% { transform: rotate(359deg); }
}
Hope this helps.

Use spin.js and the site http://fgnass.github.com/spin.js/ shows the step which is quite easy.
the loading animation is in CSS which separated from the UI thread and therefore loaded smoothly.

What you can do is detect the end of the ngRepeat as this post says.
I'll do something like, in the controller:
$scope.READY = false;
And in the directive, as the post above says, I'll do something like:
if (scope.$last) {
$scope.READY = true;
}
And you can have a css based loader/spinner with
<div class="loader" ng-show="!READY">
</div>
Ofcourse you can also have css based animations which are independent of js execution.

You could run the filter in another thread using WebWorkers, so your angularjs page won't block.
If you don't use webworkers the browser could get a javascript execution timeout and stop your angular app completely and even if you don't get any timeout your application freezes until the calculation is done.
UPDATE 23.04.14
I've seen a major performance improvement in a large scale project using scalyr and bindonce

Here is an working example :-
angular
.module("APP", [])
.controller("myCtrl", function ($scope, $timeout) {
var mc = this
mc.loading = true
mc.listRendered = []
mc.listByCategory = []
mc.categories = ["law", "science", "chemistry", "physics"]
mc.filterByCategory = function (category) {
mc.loading = true
// This timeout will start on the next event loop so
// filterByCategory function will exit just triggering
// the show of Loading... status
// When the function inside timeout is called, it will
// filter and set the model values and when finished call
// an inbuilt $digest at the end.
$timeout(function () {
mc.listByCategory = mc.listFetched.filter(function (ele) {
return ele.category === category
})
mc.listRendered = mc.listByCategory
$scope.$emit("loaded")
}, 50)
}
// This timeout is replicating the data fetch from a server
$timeout(function () {
mc.listFetched = makeList()
mc.listRendered = mc.listFetched
mc.loading = false
}, 50)
$scope.$on("loaded", function () { mc.loading = false })
})
function makeList() {
var list = [
{name: "book1", category: "law"},
{name: "book2", category: "science"},
{name: "book1", category: "chemistry"},
{name: "book1", category: "physics"}
]
var bigList = []
for (var i = 0; i <= 5000; i++) {
bigList = bigList.concat(list)
}
return bigList
}
button {
display: inline-block;
}
<html>
<head>
<title>This is an Angular Js Filter Workaround!!</title>
</head>
<body ng-app="APP">
<div ng-controller="myCtrl as mc">
<div class = "buttons">
<label>Select Category:- </label>
<button ng-repeat="category in mc.categories" ng-click="mc.filterByCategory(category)">{{category}}</button>
</div>
<h1 ng-if="mc.loading">Loading...</h1>
<ul ng-if="!mc.loading">
<li ng-repeat="ele in mc.listRendered track by $index">{{ele.name}} - {{ele.category}}</li>
</ul>
</div>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.5/angular.min.js"></script>
</body>
<html>

Promise/deferred can be used in this case, you can call notify to watch the progress of your code, documentation from angular.js: https://code.angularjs.org/1.2.16/docs/api/ng/service/$q
Here is a tutorial on heavy JS processing that uses ng-Promise: http://liamkaufman.com/blog/2013/09/09/using-angularjs-promises/, hope it is helpful.
//app Factory for holding the data model
app.factory('postFactory', function ($http, $q, $timeout){
var factory = {
posts : false,
getPosts : function(){
var deferred = $q.defer();
//avoiding the http.get request each time
//we call the getPosts function
if (factory.posts !== false){
deferred.resolve(factory.posts);
}else{
$http.get('posts.json')
.success(function(data, status){
factory.posts = data
//to show the loading !
$timeout(function(){
deferred.resolve(factory.posts)
}, 2000);
})
.error(function(data, status){
deferred.error('Cant get the posts !')
})
};
return deferred.promise;
},
getPost : function(id){
//promise
var deferred = $q.defer();
var post = {};
var posts = factory.getPosts().then(function(posts){
post = factory.posts[id];
//send the post if promise kept
deferred.resolve(post);
}, function(msg){
deferred.reject(msg);
})
return deferred.promise;
},
};
return factory;
});

You can use this code taken from this url:
http://www.directiv.es/angular-loading-bar
there you can find a workin demo also.
Here is thei code:
<!DOCTYPE html>
<html ng-app="APP">
<head>
<meta charset="UTF-8">
<title>angular-loading-bar example</title>
<link rel="stylesheet" type="text/css" href="/application/html/js/chieffancypants/angular-loading-bar/loading-bar.min.css"/>
<style>
body{
padding:25px;
}
</style>
</head>
<body ng-controller="ExampleController">
<button id="reloader" ng-click="getUsers()">Reload</button>
<ul ng-repeat="person in data">
<li>{{person.lname}}, {{person.fname}}</li>
</ul>
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.2.0-rc.2/angular.min.js"></script>
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.2.0-rc.2/angular-animate.min.js"></script>
<script src="/application/html/js/chieffancypants/angular-loading-bar/loading-bar.min.js"></script>
<script>
angular.module('APP', ['chieffancypants.loadingBar', 'ngAnimate']).
controller("ExampleController",['$scope','$http',function($scope,$http){
$scope.getUsers = function(){
$scope.data=[];
var url = "http://www.filltext.com/?rows=10&fname={firstName}&lname={lastName}&delay=3&callback=JSON_CALLBACK"
$http.jsonp(url).success(function(data){
$scope.data=data;
})
}
$scope.getUsers()
}])
</script>
</body>
</html>
How do I use it?
Install it via npm or bower
$ npm install angular-loading-bar
$ bower install angular-loading-bar
To use, simply include it as a dependency in your app and you're done!
angular.module('myApp', ['angular-loading-bar'])

Related

Browser not rendering updated values after callback function is called

I'm using a callback function after an animation, and I'm getting a result that I don't understand.
The reader's current_state should increase by 1, then the reader should move right, and then this should repeat 3 more times.
When I run the program using my web inspector, I see that the current_state does indeed increase before moving each step. However, in my browser window I only see the reader's text change values during the first step. So when the program ends, I see a 2 in the reader's text on my screen, but the value of the reader's current_state is actually 5.
To perplex me even more, I was tinkering around and added a random button with an empty click event attached. Hitting this button will make the current_state appear as the reader's text on the screen. So if I repeatedly click this button while the program runs, it looks perfect.
I'm not looking for an entirely different way to do this, as this isn't my actual code, just an example to illustrate the issue. In my code I'm trying to stick to using angular and a recursive callback function after an animation, if it's possible to fix this issue.
Thanks in advance, this has been driving me crazy!
https://jsfiddle.net/snookieordie/ns09cvqc/7/
var app = angular.module("turingApp", []);
app.controller("turingController", ["$scope", function ($scope) {
$scope.reader = {
current_state: 1,
}
$scope.run_program = function() {
if($scope.reader.current_state < 5) {
$scope.reader.current_state++;
$(".reader").animate({"left": "+=50px"}, 1000, function() {
$scope.run_program();
});
}
}
}]);
CSS:
.reader {
position: relative;
height: 50px;
width: 50px;
left: 0px;
font-size: 35px;
background-color: coral;
}
HTML:
<body ng-app="turingApp" ; ng-controller="turingController">
<div class="reader">{{reader.current_state}}</div>
<br/><br/>
<input type="button" class="code_submit" value="Run Code" ng-click="run_program()" />
<br/><br/>
<input type="button" value="Empty Click Event" ng-click="" />
</body>
Use $scope.apply() just after animate call back function is being called, Below I have edited js code
var app = angular.module("turingApp", []);
app.controller("turingController", ["$scope", function($scope) {
$scope.reader = {
current_state: 1,
}
$scope.run_program = function() {
if ($scope.reader.current_state < 5) {
$scope.reader.current_state++;
$(".reader").animate({"left": "+=50px"}, 1000, function() {
$scope.run_program();
$scope.$apply(); // Have added this line onlye
});
}
}
}]);
Why this is needed? actually angular has watchers concept and when you are doing this complex kind of functionality watchers need to keep deep eye on variable changes, which is not present auto to achieve speed, but can be added/enhanced manually.

Don't ng-show element until ng-hide CSS transition is complete?

Simple question, but I'm having implementation troubles. If I have the following DOM setup:
<h1 class="fade" ng-repeat="child in parent.children" ng-show="parent.activeChild== child ">#{{ child.title }}</h1>
When the activeChild property of the parent model changes, how can I fade out the currently active child, before the model changes, and then fade in the newly active child post-change.
I have it working roughly, with just CSS transitions using this:
.fade.ng-hide-add {
transition:opacity 1s ease;
}
.fade.ng-hide-remove {
transition:opacity 1s ease 1s;
}
.fade.ng-hide-add {
opacity:1;
&.ng-hide-add-active {
opacity:0;
}
}
.fade.ng-hide-remove {
opacity:0;
&.ng-hide-remove-active {
opacity:1;
}
}
But, this ends up producing this problem (Plunkr):
Essentially, I want to chain my animation. I've tried reading the ng-animate docs, but I'm having trouble the syntax necessary to deliver the effect I want.
I've seen the Angular docs have something like this:
app.animation('.fade', [function() {
return {
addClass: function(element, className, doneFn) {
},
removeClass: function(element, className, doneFn) {
}
};
}]);
What is className? Is it the class I want to apply while fading in/out? The class I'm expecting?
What is doneFn meant to be? I assume it's a function that's run once the animation is complete? What goes in there?
What do I do in the addClass and removeClass function then, if I already have a doneFn?
The Goal
I'd like to generate a working animation directly using Angular's ngAnimate module, with either CSS or JS. How can I achieve this?
Why do you use a separate <h1> for each heading. You can use a single <h1> tag to show your heading.
I have created a demo for your problem and I have successfully done your requirement.
Updated
Note, codes are edited to use ngAnimate module. When you use ngAnimate module, it will create a class .ng-hide when you hide an element,
Here is the controller for your app,
app2.controller("testController", ["$scope", "$timeout", function ($scope, $timeout) {
$scope.heading = {};
$scope.heading.show = true;
$scope.parent = {};
$scope.parent.children = ["A", "B", "C", "D"];
$scope.parent.activeChild = "A";
$scope.changeHeading = function (child) {
$timeout(function () {
$scope.parent.activeChild = child;
$scope.heading.show = true;
}, 1000);
}
}]);
And your html page should be look like this,
<div ng-controller="testController">
<h1 class="myAnimateClass" ng-show="heading.show" ng-class="{fadeIn : heading.fadeInModel==true, fadeOut : heading.fadeOutModel}"> {{parent.activeChild}} </h1>
<p ng-repeat="child in parent.children" ng-click="heading.show = false;changeHeading(child)">{{child}}</p>
</div>
And I have used CSS3 to implement the fade in and fade out animation,
.myAnimateClass {
-webkit-transition: opacity 1s ease-in-out;
-moz-transition: opacity 1s ease-in-out;
-o-transition: opacity 1s ease-in-out;
-ms-transition: opacity 1s ease-in-out;
transition: opacity 1s ease-in-out;
opacity:1;
}
.myAnimateClass.ng-hide {
opacity: 0;
}
Explanation
To achieve your requirement, I have used ng-class and $timeout in angularJS.
You can see that, I have only one <h1> tag to display your heading. When I change the heading I just change it's binding property $scope.parent.activeChild.
And I have used two scope variables $scope.heading.fadeOutModel and $scope.heading.fadeInModel to add and remove classes fadeIn and fadeOut dynamically.
When user clicks to change the heading, I have added the class fadeOut to your heading. So, this will show an animation of fade out. And also I have fired a function in app.js, changeHeading().
You can see that, I forced the angular to wait for 1000 milliseconds to finish fade out animation. After this time, it will replace the selected heading to new one and add a class fadeIn. So, it will start animation for fade in.
Hope this will help you !!!
A more ng-animate way to show a specific element depending on a selection would be to use ngSwitch. This directive is used to conditionally swap DOM structure on your template based on a scope expression. Here is a example.
HTML
<button ng-repeat="item in items" ng-click="parent.selection = item">{{ item }}</button>
<div class="animate-switch-container" ng-switch on="parent.selection">
<div class="animate-switch" ng-switch-when="foo">foo</div>
<div class="animate-switch" ng-switch-when="bar">bar</div>
</div>
Javascript
$scope.items = ['foo', 'bar'];
$scope.parent = {
selection: $scope.items[0]
}
CSS
.animate-switch-container {
position:relative;
height:40px;
overflow:hidden;
}
.animate-switch {
padding:10px;
}
.animate-switch.ng-animate {
transition:opacity 1s ease;
}
.animate-switch.ng-leave.ng-leave-active,
.animate-switch.ng-enter {
opacity: 0;
}
.animate-switch.ng-leave,
.animate-switch.ng-enter.ng-enter-active {
opacity: 1;
}
This is not chaining, but it is a working animation directly using Angular's ngAnimate module. Also here is a example of it on angular's website.
You can use .animation to define animations that are Javascript based. For example, the functions you define as the values of addClass and removeClass
app.animation('.fade', [function() {
return {
addClass: function(element, className, doneFn) {
},
removeClass: function(element, className, doneFn) {
}
};
}]);
are called by Angular when it detects that you are adding or removing a class from an element, from one of the methods:
{{ }} interpoation in a template. E.g. <span class="{{shouldFade ? 'fade' : ''}}">....
Using ng-class in a template. E.g. <span ng-class="{fade: shouldFade}">...
Using the $animate service in a directive. E.g. $animate.addClass(element, 'fade') or $animate.removeClass(element, 'fade')
What is className? Is it the class I want to apply while fading in/out? The class I'm expecting?
In this example it will be fade. It a bit strange admittedly as in the example it is already clear this is the class name involved. However, if in the same digest cycle you're adding multiple classes to the same element, then the concatenation of them are passed as this string.
What is doneFn meant to be? I assume it's a function that's run once the animation is complete? What goes in there?
It's a function that you call once whatever Javascript animation you define is done. For example, to define an animation that does nothing as all:
addClass: function(element, className, doneFn) {
doneFn();
},
Calling it tells Angular that the animation has complete. This will, among other things, remove the ng-animate class from the element.
What do I do in the addClass and removeClass function then, if I already have a doneFn?
You put in them some code, perhaps using timeouts or a 3rd party library, to change the element somehow. When you have finished, you call doneFn. For example, a 1 step opacity "animation":
addClass: function(element, className, doneFn) {
element.css('opacity', 0.5);
setTimeout(function() {
doneFn();
}, 1000);
},
I'd like to generate a working animation directly using Angular's ngAnimate module, with either CSS or JS.
This doesn't really have much to do with the answers above! If I were doing a real-case, I strongly suspect I would position the elements absolutely, as anything else (that I can think of) at least, is a bit overly complicated.
However, if you do really want to chain the animations using ngAnimate, one possible way is to use the fact that $animate.addClass and $animate.removeClass returns a promise when it completes. In order to chain onto the end of such a promise returned when hiding an element, it must be called from some sort of central location, and keep track of which element is visible, being hidden, and being shown.
A way of doing this is to use 2 custom directives. One will be on each element to show and hide, that could be used very much like ngShow. The other will be a parent directive that will allow only one element to be visible at any time, and chain removal of the ng-hide class (and associated animations) after any addition of ng-hide. The directives will have to communicate, could be called something like ngShowUnique and ngShowUniqueController, such as in the following example.
<div ng-show-unique-controller>
<h1 class="fade" ng-repeat="child in parent.children" ng-show-unique="parent.activeChild == child">#{{child.title}}</h1>
</div>
and they could be implemented as below.
app.directive('ngShowUniqueController', function($q, $animate) {
return {
controller: function($scope, $element) {
var elements = [];
var expressions = [];
var watchers = [];
var unregisterWatchers = null;
var visibleElement = null;
function registerWatchers() {
unregisterWatchers = $scope.$watchGroup(expressions, function(vals) {
var newCurrentIndex = vals.indexOf(true);
var addPromise;
if (visibleElement) {
// Set a fixed height, as there is a brief interval between
// removal of this class and addition of another
$element.css('height', $element[0].getBoundingClientRect().height + 'px');
addPromise = $animate.addClass(visibleElement, 'ng-hide');
} else {
addPromise = $q.when();
}
visibleElement = elements[newCurrentIndex] || null;
if (!visibleElement) return;
addPromise.then(function() {
if (visibleElement) {
$animate.removeClass(visibleElement, 'ng-hide').then(function() {
$element.css('height', '');
});
}
})
});
}
this.register = function(element, expression) {
if (unregisterWatchers) unregisterWatchers();
elements.push(element[0]);
expressions.push(expression);
registerWatchers();
// Hide elements initially
$animate.addClass(element, 'ng-hide');
};
this.unregister = function(element) {
if (unregisterWatchers) unregisterWatchers();
var index = elements.indexOf(element[0]);
if (index > -1) {
elements.splice(index, 1);
expressions.splice(index, 1);
}
registerWatchers();
};
}
};
});
app.directive('ngShowUnique', function($animate) {
return {
require: '^ngShowUniqueController',
link: function(scope, element, attrs, ngShowUniqueController) {
ngShowUniqueController.register(element, function() {
return scope.$eval(attrs.ngShowUnique);
});
scope.$on('$destroy', function() {
ngShowUniqueController.unregister(element);
});
}
};
});
This can be seen at http://plnkr.co/edit/1eJUou4UaH6bnAN0nJn7?p=preview . I have to admit, it's all a bit faffy.
using ngRepeat that shows only one element at time, in my opinion, is a bad idea... because you're showing only one element!
you can use the parent.activeChild property directly...
Have a look on what follows:
Note: I did this snippet in just ten minutes, it's unoptimized and can have some bug... you can use it as starter :)
(function(window, angular, APP) {
APP
.value('menuObject', {
name: 'Main Navigation',
current: null,
children: [{
label: 'Don\'t ng-show element until ng-hide CSS transition is complete?',
url: 'http://stackoverflow.com/questions/33336249/dont-ng-show-element-until-ng-hide-css-transition-is-complete',
isCurrent: false
},
{
label: 'Hitmands - Linkedin',
url: 'http://it.linkedin.com/in/giuseppemandato',
isCurrent: false
},
{
label: 'Hitmands - Github',
url: 'https://github.com/hitmands',
isCurrent: false
},
{
label: 'Hitmands - StackOverflow',
url: 'http://stackoverflow.com/users/4099454/hitmands',
isCurrent: false
}
]})
.directive('menu', function(menuObject, $q) {
function menuCtrl($scope, $element) {
$scope.parent = menuObject;
this.getCurrentChild = function() {
return $scope.parent.current;
};
this.getDomContext = function() {
return $element;
};
this.setCurrentChild = function(child) {
return $q.when($scope.parent)
.then(function(parent) {
parent.current = child;
return parent;
})
.then(function(parent) {
return parent.children.forEach(function(item) {
item.isCurrent = child && (item.label === child.label);
});
})
};
}
return {
restrict: 'A',
templateUrl: 'embedded-menutemplate',
scope: {},
controller: menuCtrl
};
})
.directive('menuItem', function($animate, $q, $timeout) {
function menuItemPostLink(iScope, iElement, iAttributes, menuCtrl) {
iElement.bind('click', setCurrentTitle);
iScope.$on('$destroy', function() {
iElement.unbind('click', setCurrentTitle);
})
function setCurrentTitle(event) {
event.preventDefault();
var title;
return $q
.when(menuCtrl.getDomContext())
.then(function(_menuElement) {
title = angular.element(
_menuElement[0].querySelector('#menuItemCurrent')
);
})
.then(function() {
return title.addClass('fade-out');
})
.then(function() {
return $timeout(menuCtrl.setCurrentChild, 700, true, iScope.child);
})
.then(function() {
return title.removeClass('fade-out');
})
}
}
return {
require: '^menu',
link: menuItemPostLink,
restrict: 'A'
};
})
;
})(window, window.angular, window.angular.module('AngularAnimationExample', ['ngAnimate']));
nav {
text-align: center;
}
.link {
display: inline-block;
background-color: lightseagreen;
color: black;
padding: 5px 15px;
margin: 1em;
}
#menuItemCurrent {
padding: 1em;
text-transform: uppercase;
border: 1px solid black;
}
#menuItemCurrent span {
transition: 500ms opacity linear;
opacity: 1;
}
#menuItemCurrent.fade-out span {
opacity: 0;
}
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.7/angular-animate.js"></script>
<article ng-app="AngularAnimationExample">
<nav menu></nav>
<script id="embedded-menutemplate" type="text/ng-template">
<nav >
<a menu-item class="link" ng-repeat="child in parent.children track by $index" ng-bind="child.label" ng-href="{{ child.url }}"></a>
<h1 id="menuItemCurrent"><span ng-bind="parent.current.url || 'NoMenuCurrentSelected'"></span></h1>
{{ parent.current || json }}
</nav>
</script>
</article>
The problem is that H1 is a block level element that is positioned within it's parent and no overlap is allowed. That is why you see one animation that's disappearing pushing down the animation that is appearing.
You can see that this is happening more clearly here: Demo
To fix this, you want to keep the block level element H1, and make its position relative, so that it can keep its relative position in the overall flow of the page. Then set the child SPAN elements to have absolute positioning - absolute position relative to the parent H1. This allows all span elements to overlap each other.
CSS
.fade {
opacity: 1;
position: relative;
}
.fade.ng-hide-add {
transition:opacity 1s ease;
position: absolute;
}
.fade.ng-hide-remove {
transition:opacity 1s ease 1s;
position: absolute;
}
.fade.ng-hide-add {
opacity:1;
}
.fade.ng-hide-add.ng-hide-add-active {
opacity:0;
}
.fade.ng-hide-remove {
opacity:0;
}
.fade.ng-hide-remove.ng-hide-remove-active {
opacity:1;
}
HTML
<body ng-controller="MainCtrl">
<h1><span class="fade" ng-repeat="child in parent.children" ng-show="parent.activeChild == child ">#{{child.title}}</span></h1>
<button ng-repeat="child in parent.children" ng-click="parent.activeChild = child">{{ child.title }}</button>
</body>
There is one problem though... Since the SPAN elements have absolute positioning, it is removed from flow when animating, and the parent H1 can't resize to fit the SPAN contents. This causes the SPAN to jump unexpectedly.
The way to address this (and admittedly, it's a bit of a hack) is by adding an empty space after the SPAN repeater. So when the ngRepeat SPANS get pulled out of normal flow because of absolute positioning, the empty space which is outside the ngRepeat preserves the spacing of the H1.
Here is a working Plunker.
You might want to look into transitionend event which is supported by all modern browsers.
element.addEventListener('transitionend', callback, false);
Quick answer to this - To solve this problem in the past I have always positioned the content absolute. This way when the transition takes place it stays in the same position.
There is no other way around it because the content takes up space in the dom if its inline or inline-block which is why you see the jump until the transition is finished

Spinner in Angular.js

I want to use a spinner which I can show during some of the rest api calls for a better UX. I have come across many existing github projects which does exactly similar things.
https://github.com/cgross/angular-busy
https://github.com/urish/angular-spinner
But I'm not able to use any of the existing projects. I think before I start writing something of my own, I want to know if things which I'm looking for can be done using these projects or any other existing project.
Requirement:
During some of the rest api calls like uploading images, fetching some data, deleting images, etc, I want to show a spinner with background faded. Once I have the result, I can show the background again and remove the spinner.
I want to use this spinner with start/stop from my controller not from my html.
I don't want this spinner for all the xhr requests by default.
I think angular-busy demo does solves most of the above requirements except that it needs a promise param in html. Is there anyway by which I can control the start/stop dynamically from my controller rather than giving a promise.
Angular-spinner demo is good but it doesn't fade out background. Is there any way to fade out background ?
Can anyone give me some pointers how exactly can I solve my problem ?
I always create my own spinner with this logic:
js:
app.directive('ngSpinnerBar', ['$rootScope',
function ($rootScope) {
return {
link: function (scope, element, attrs) {
// by defult hide the spinner bar
element.addClass('hide');
// count how many time requests were sent to the server
// so when they all done the spinner will be removed
scope.counter = 0;
$rootScope.$on('$stateNetworkRequestStarted', function () {
scope.counter++;
element.removeClass('hide'); // show spinner bar
// $('body').addClass('page-on-load');
});
$rootScope.$on('$stateNetworkRequestEnded', function () {
scope.counter--;
if (scope.counter <= 0) {
scope.counter = 0;
element.addClass('hide'); // show spinner bar
// $('body').removeClass('page-on-load'); // remove page loading indicator
}
});
}
};
}
])
html:
<div ng-spinner-bar></div>
As you can see every time i send a request to the api i show the spinner (css create the spinning - link) and when result come back i send event to hide the spinner.
if you want to make things easier for you, you should create a service which send all the api requests (wrap $http). that way you can ensure every request will show the spinner.
EDIT
the first result in google gave me this - fade background in angular
It seems like http://bsalex.github.io/angular-loading-overlay/_site/ fits the requirements.
For example:
var app = angular.module('app-http-integration-with-reference-id-and-matchers', [
'bsLoadingOverlay',
'bsLoadingOverlayHttpInterceptor'
])
.factory('randomTextInterceptor', function(bsLoadingOverlayHttpInterceptorFactoryFactory) {
return bsLoadingOverlayHttpInterceptorFactoryFactory({
referenceId: 'random-text-spinner',
requestsMatcher: function(requestConfig) {
return requestConfig.url.indexOf('hipsterjesus') !== -1;
}
});
})
.factory('randomUserInterceptor', function(bsLoadingOverlayHttpInterceptorFactoryFactory) {
return bsLoadingOverlayHttpInterceptorFactoryFactory({
referenceId: 'random-user-spinner',
requestsMatcher: function(requestConfig) {
return requestConfig.url.indexOf('randomuser') !== -1;
}
});
})
.config(function($httpProvider) {
$httpProvider.interceptors.push('randomTextInterceptor');
$httpProvider.interceptors.push('randomUserInterceptor');
}).run(function($sce, bsLoadingOverlayService) {
bsLoadingOverlayService.setGlobalConfig({
/*
It is only an example, don't use this url in production.
Copy this template to your code base or use integration with Spin.js (see Docs & Examples)
*/
templateUrl: $sce.trustAsResourceUrl('https://raw.githubusercontent.com/bsalex/angular-loading-overlay/gh-pages/_site/loading-overlay-template.html')
});
});
app.controller('HttpIntegrationWithReferenceIdAndMatchersController', function($scope, $http, $sce, bsLoadingOverlayService) {
$scope.randomText = $sce.trustAsHtml('Fetch result here');
$scope.randomUser = undefined;
$scope.fetchRandomText = function() {
$http.get('http://hipsterjesus.com/api/')
.success(function(data) {
$scope.randomText = $sce.trustAsHtml(data.text);
})
.error(function() {
$scope.randomText = $sce.trustAsHtml('Can not get the article');
});
};
$scope.fetchRandomUser = function() {
$http.get('https://randomuser.me/api/')
.success(function(data) {
$scope.randomUser = data.results[0];
});
};
});
.random-result {
display: flex;
height: 170px;
margin-top: 1em;
}
.random-result__text,
.random-result__user {
position: relative;
overflow: auto;
border: 2px dashed #C00;
flex: 1;
margin: 0.5em;
padding: 0.5em;
text-align: center;
}
.user__photo {
width: 100px;
height: 100px;
border-radius: 50%;
margin: 0;
}
.user__name {
font-size: 1.5em;
margin: 0.5em;
padding: 0;
text-align: center;
}
<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/1.5.0/angular.min.js"></script>
<script src="https://rawgit.com/bsalex/angular-loading-overlay/master/dist/angular-loading-overlay.js"></script>
<script src="https://rawgit.com/bsalex/angular-loading-overlay-http-interceptor/master/dist/angular-loading-overlay-http-interceptor.js"></script>
<div ng-app="app-http-integration-with-reference-id-and-matchers">
<div ng-controller="HttpIntegrationWithReferenceIdAndMatchersController">
<div class="well well-lg bs-loading-container">
<button ng-click="fetchRandomText()">Fetch random text</button>
<button ng-click="fetchRandomUser()">Fetch random user</button>
<div class="random-result">
<div class="random-result__text" bs-loading-overlay bs-loading-overlay-reference-id="random-text-spinner" bs-loading-overlay-delay="3000">
<p ng-bind-html="randomText"></p>
</div>
<div class="random-result__user user" bs-loading-overlay bs-loading-overlay-reference-id="random-user-spinner" bs-loading-overlay-delay="3000">
<div ng-if="randomUser">
<img ng-src="{{randomUser.picture.large}}" alt="" class="user__photo" />
<p class="user__name">
{{randomUser.name.first}} {{randomUser.name.last}}
</p>
</div>
</div>
</div>
</div>
</div>
</div>
In the snippet above I've used integration with $http service. It matches requests and shows spinner with specified referenceId.
Also, the following features are available:
You can show and hide spinners from controllers injecting bsLoadingOverlayService and calling bsLoadingOverlayService.start(); and bsLoadingOverlayService.stop();;
You can wrap Promises to show and hide spinners with bsLoadingOverlayService.wrap();
You can create preconfigured handlers (bsLoadingOverlayService.createHandler({referenceId: 'handler-overlay'});), to keep options in one place and then just call preconfiguredHandler.start(); and preconfiguredHandler.stop();

Angular way to do an Element Directive animation when Object is deleted?

I'm rendering an scoped Array of Objects(payments in this case), and passing each one to a payment Directive like this:
<div id="payable" ng-controller="PaymentsController">
<payment ng-repeat="payment in payments" data="payment" class="payment"></payment>
</div>
This works really well! So when I delete an element from the scoped Array from the controller like this:
app.controller('PaymentsController', function($scope) {
//The Payments Array(each object passed to a Directive)
$scope.payments = [ { id: 1, amount: 10 }, { id: 2, amount: 15 } ];
$scope.deletePayment = function(index) {
//This deletes the Array Element and removes associated
//Directive template from the DOM
$scope.payments.splice(index, 1);
}
});
The CSS (uses compass mixins for simplicity)
.payment.ng-enter {
#include transition(all 2s ease-out);
opacity: 0;
}
.payment.ng-enter-active {
opacity: 1;
}
.payment.ng-leave {
#include transition(all 2s ease-out);
}
.payment.ng-leave-active {
opacity: 0;
}
Again, the above works as expected, I delete an element from the payments Array and the directive-template/view corresponding to the deleted Array element is removed from the DOM, This is PERFECT, except for the fact it's removed instantly!
EDIT:
The reason the animations like fadeOut don't work and the result is that the ( < payment > ) is removed instantly(after a specified time in the CSS) is that the animation is acting over the ( < payment >) custom tag, which is just a wrapper for the actual element.
Directive JS definition:
(function() {
var app = angular.module('paymentDirectives', []);
app.directive('payment', function() {
return {
restrict: 'E',
scope: {
payment: '=data'
},
templateUrl: 'partials/payment.html'
};
});
})();
The animation should act on the template referenced/wrapped by the directive custom tag( < payment > )
partials/payment.html
<div class="a-payment">
<div class="content">
<p>
<label>{{payment.amount}}</label>
</p>
</div>
</div>
In this case it would be the div with class="a-payment" of course and when the animation is complete it should then remove the payment tag element
What is the Angular way(for the latest version) to do an animation for this case(ie. Element Directive is removed from the DOM)?
Thank you very much in advance, and let me know if you need more from the code I'm using.
This is likely to do with the fact that most custom tags, such as your <payment>, are display: inline; by default.
You should set their style to be display: block in the CSS/SASS.
You can do this in many ways, for example, you can create a class that will trigger the CSS animation, and before deleting the object, you first assign it that class. Here's how:
var deleteAnimDuration = 1000; // let's use one second for our example
$scope.deletePayment = function(index) {
//This deletes the Array Element and removes associated
//Directive template from the DOM
$scope.payments[index].deleteAnim = true; // or whatever property makes sense to you
$timeout(function(){
$scope.payments.splice(index, 1);
}, deleteAnimDuration);
}
Then on the directive, you can use ng-class:
<payment
ng-repeat="payment in payments"
data="payment"
ng-class="{deleting: payment.deleteAnim}">
</payment>
Then in the CSS:
payment.deleting {
transition: opacity 1s linear; // again, one second
opacity: 0;
}
Since this sample animation (opacity fade) will run for one second, you need to set deleteAnimDuration for the $timeout to one second (1000 in milliseconds).
So, what happens:
you click delete on a payment
it sets payment.deleteAnim to true, which assigns the deleting class to the element
the timeout for the animation duration is set
animation starts
animation ends
element removed from the DOM
This is the concept from the DOM standpoint:
var divs = document.getElementsByTagName('div');
for (var i = 0; i < divs.length; i++) {
divs[i].addEventListener('click', function(e) {
e.target.className = 'deleting';
deleteEl(this)
})
}
function deleteEl(el) {
setTimeout(function() {
el.parentElement.removeChild(el);
}, 1000);
}
.deleting {
transition: opacity 1s linear;
opacity: 0;
}
div {
width: 50px;
height: 50px;
display: inline-block;
background: #eee;
}
<div>Click me</div>
<div>Click me</div>
<div>Click me</div>
<div>Click me</div>
Of course, this can work with JS animations as well.
Load angular-animate.min.js in your HTML.
Add ngAnimate into your module dependencies.
Add a class to your payment directive element: e.g. <payment class="my-animation" ...></payment>.
Add the following CSS (referencing your class in step 3):
.my-animation.ng-leave { opacity: 1; transition: opacity 300ms linear; }
.my-animation.ng-leave.ng-leave-active { opacity: 0; transition: opacity 300ms linear; }
Celebrate

Javascript execution timing - ensure synchronous flow, not just order of execution

I am working with JavaScript (Jquery) trying to run some operations in order. In my real code, I have a function I run on .ready() to initiate some variables. As part of this flow I read in some data from local storage to remove elements which were removed in a previous visit. The elements which I remove have a css transition class applied. When the page first loads, I do not want these animations to occur, so I require that the <body> element has the class="fully-loaded" applied in my CSS for transition to work. I am trying to add the fully-loaded class only after I know all of the additions and everything else is loaded. I have tried setting up multiple .ready() statements, using queues, etc. in order to control the order or execution.
While I think I have things running in order, the initiation function does not seem to be complete before I run the script to add the fully-loaded class. I am pasting a mini version of my code which exhibits the same problem. My question is: How can I ensure that anything run as part of my initiation function init() complete before I run the addClass call?
HTML body:
<body>
<section id="secA"> <p>Sec A</p> </section>
<section id="secB"> <p>Sec B</p> </section>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script>
//$(document).ready( Tester.init() );
//$(document).ready( $("body").addClass('fully-loaded') );
//$(document).ready( Tester.init() );
$.when(Tester.init()).done(function(){
$("body").addClass('fully-loaded');
console.log("Desired Order: 4");
});
</script>
</body>
JavaScript in another file
var Tester = (function() {
function init() {
initEvents();
}
function initEvents(){
console.log("Desired Order: 1");
setTimeout(
'$("#secA").remove(); console.log("Desired Order: 2");',
2000
);
console.log("Desired Order: 3");
}
return { init : init };
})();
CSS Code
section { width:200px; height:200px; position:absolute;}
#secA { background-color:green; }
#secB { background-color:red; }
section:nth-of-type(1) { top: 0; left: 0; }
section:nth-of-type(2) { top: 0; left: 50%; }
.fully-loaded section {
-webkit-transition: all 2.5s ease-in-out;
-moz-transition: all 2.5s ease-in-out;
transition: all 2.5s ease-in-out;
}
I think in my real code that there is something that is taking a bit of time which is async like the setTimeout. Desired Action: 4 occurs before Desired Action: 2 How do I make $("body").addClass('fully-loaded'); wait until everything started by Tester.init() is complete in a general way?

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