Single page application - load js file dynamically based on partial view - angularjs

I've just started learning Angular and following the tutorial here - http://docs.angularjs.org/tutorial/step_00
I'm downloaded the seed example from GitHub and it works great. I have a question though - if a partial view requires an external js file to be referenced, does it need to be added to the index.html file at the beginning? I want the app to be as lean as possible and only want to include the js references that are required for the present view. Is it possible to load the js files dynamically based on a view?

This just worked for me. Figured I would post it for anybody else seeking the lightest-weight solution.
I have a top-level controller on the page's html tag, and a secondary controller for each partial view.
In the top-level controller I defined the following function…
$scope.loadScript = function(url, type, charset) {
if (type===undefined) type = 'text/javascript';
if (url) {
var script = document.querySelector("script[src*='"+url+"']");
if (!script) {
var heads = document.getElementsByTagName("head");
if (heads && heads.length) {
var head = heads[0];
if (head) {
script = document.createElement('script');
script.setAttribute('src', url);
script.setAttribute('type', type);
if (charset) script.setAttribute('charset', charset);
head.appendChild(script);
}
}
}
return script;
}
};
So in the secondary controllers I can load the needed scripts with a call like the following…
$scope.$parent.loadScript('lib/ace/ace.js', 'text/javascript', 'utf-8');
There's a slight delay before the objects contained in the external script are available, so you'll need to verify their existence before attempting to use them.
Hope that saves somebody some time.

I just tried the https://oclazyload.readme.io/. It works out of the box.
bower install oclazyload --save
Load it in your module, and inject the required module in controller:
var myModule = angular.module('myModule', ['oc.lazyLoad'])
.controller('myController', ['$scope', '$ocLazyLoad', '$injector',
function($scope, $ocLazyLoad, $injector) {
$ocLazyLoad.load(
['myExtraModule.js',
'orAnyOtherBowerLibraryCopiedToPublicFolder.js'
])
.then(function() {
// Inject the loaded module
var myExraModule = $injector.get('myExtraModule');
});
}
]);

Related

How to use JSzip external library in angularjs(1.x) application

I'm trying to include typical javascript library(JSZip) in to my angularjs application.
At first i have added included JSZip library in to my application and then added script reference to my index page.
Next i have created a simple object of JSZip in one of my module and trying to create zip. but all of sudden, i am getting compilation error in typescript while building my application in VS2015(visual studio), saying that "Cannot find name JSZip".
How to load non angular dependency in angular application. i have spent a complete day. i didn't find any clue.
i have tried multiple ways to get the dependency dynamically and also tried oclazyload to load JSZip dependency ..but not helps.
var zip = new JSZip(); <=== this is where the problem is..
zip.file("File1", atob(response.Data));
zip.file("File2", atob(response.Data));
zip.generateAsync({ type: "blob" })
.then(function (content) {
// saveAs is from FileSaver.js
saveAs(content, "example.zip");
});
Inject non-angular JS libraries
Include the JS file into your HTML file
<script src="http://stuk.github.io/jszip/dist/jszip.js"></script>
In your module angular add constant 'jszip' for exemple
var app = angular.module('myApp', [])
.constant('jszip', window.JSZip)
.run(function($rootScope) {
$rootScope.JSZip = window.JSZip;
})
Inject 'jszip' in your controller, and you will solve your problem
app.controller('myCtrl', function($scope, 'jszip') {
var zip = new jszip();
...
});
For the downloading part (saveAs function), include FileSaver.js into your HTML file
<script src="https://cdnjs.cloudflare.com/ajax/libs/FileSaver.js/2.0.0/FileSaver.js"></script>
In your controller for exemple
$scope.exportZip = function(){
var zip = new JSZip();
zip.file("Hello.txt", "Hello World\n");
zip.generateAsync({type:"blob"})
.then(function(content) {
saveAs(content, "example.zip");
});
};

AngularJS- Dynamic Loading of script files using LazyLoad- Webpack

Right now in my index.html page I have links to two CDN files one being a JS and the other a CSS file.
i.e.
in the the bottom of my body
https://somedomain.com/files/js/js.min.js
and in the head
https://somedomain.com/files/css/css.min.css
But right now they aren't needed on my homepage but just in one particular route. So I was looking into how I can lazy load these CDN resources when that routes gets hit i.e. /profile and only then ?
These aren't installed via bower or npm but just loaded via CDN url for example jquery. How in Angular 1 and Webpack can I lazy load that based on a route ?
Here you go.. It is made possible using oclazyload. Have a look at below code. A plunker linked below
I have a module Called myApp as below
angular.module('myApp', ['ui.router','oc.lazyLoad'])
.config(function ($stateProvider, $locationProvider, $ocLazyLoadProvider) {
$stateProvider
.state("home", {
url: "/home",
templateUrl: "Home.html",
controller: 'homeCtrl',
resolve: {
loadMyCtrl: ['$ocLazyLoad', function ($ocLazyLoad) {
return $ocLazyLoad.load('homeCtrl.js');
}]
}
})
.state("profile", {
url:"/profile",
templateUrl: "profile.html",
resolve: {
loadMyCtrl: ['$ocLazyLoad', function ($ocLazyLoad) {
return $ocLazyLoad.load('someModule.js');
}]
}
})
});
I have another module called someApp as below
(function () {
var mynewapp=angular.module('someApp',['myApp']);
mynewapp.config(function(){
//your code to route from here!
});
mynewapp.controller("profileCtrl", function ($scope) {
console.log("reached profile controller");
});
})();
I have a Live Plunker for your demo here
I have this JStaticLoader repo, to ease me loading static files whenever I need them. Though, it's not angularized, but you can still use it in your app as a directive, direct call it from your controller or even in the $rootScope to load your desired js.
JStaticLoader uses pure js and require no dependencies. It uses XMLHttpRequest to load the static files.
As an example use in your app.js (on $routeChangeStart or $stateChangeStart)
myApp
.run(['$rootScope', '$http', function ($rootScope, $http) {
var scriptExists = function (scriptId) {
if (document.getElementById(scriptId)) {
return true;
}
return false;
};
var addLazyScript = function (scriptId, url) {
if (scriptExists(scriptId)) return;
var js = document.createElement('script'),
els = document.getElementsByTagName('script')[0];
js.id = scriptId;
js.src = url;
js.type = "text/javascript";
els.parentNode.insertBefore(js, els);
};
$rootScope.$on('$routeChangeStart', function (e, current) {
if (current.controller === 'MainCtrl') {
var pathUrls = ["https://cdnjs.cloudflare.com/ajax/libs/materialize/0.97.8/js/materialize.js"],
scriptId = 'lazyScript1';
if (scriptExists(scriptId)) return;
JStaticLoader(pathUrls, { files: ['js'] }, function (vals, totalTime) {
/* Success */
for (var i = 0; i < vals.length; i++) {
var path = vals[i];
addLazyScript(scriptId, path);
}
}, function (error, totalTime) {
/* Error */
console.warn(error, totalTime);
});
}
});
}]);
On the sample above, I get a js file by using xhr, and append it as a script in my document once it's finished. The script will then be loaded from your browser's cache.
Strictly talking about the Webpack -
Webpack is just a module bundler and not a javascript loader.Since it packages files only from the local storage and doesn't load the files from the web(except its own chunks).ALthough other modules may be included into the webpack which may do the same process.
I will demonstrate only some of the modules which you can try,as there are many such defined on the web.
Therefore a better way to lazy load the cdn from the another domain would be using the javascript loader - script.js
It can be loaded in the following way -
var $script = require("script.js");
$script = ("https://somedomain.com/files/js/js.min.js or https://somedomain.com/files/css/css.min.css",function(){
//.... is ready now
});
This is possible because the script-loader just evaluates the javascript in the global context.
References here
Concerning about the issue of lazy loading the cdn into the angular app
The following library Lab JS is made specifically for this purpose.
It becomes very simple to load and bloack the javascript using this library.
Here is an example to demonstrate
<script src="LAB.js"></script>
<script>
$LAB
.script("/local/init.js").wait(function(){
waitfunction();
});
<script>
OR
You can use the require.js
Here is an example to load the jquery
require.config({
paths: {
"jquery": "https://ajax.googleapis.com/ajax/libs/jquery/1.8.1/jquery.min"
},
waitSeconds: 40
});
You should also consider the following paragraph from this article.
Loading third party scripts async is key for having high performance web pages, but those scripts still block onload. Take the time to analyze your web performance data and understand if and how those not-so-important content/widgets/ads/tracking codes impact page load times.

Angular: load environment properties before config/run

I'm developing a angular app, and this app has about a 10 configurable properties (depending on the environment and client).
I had those properties in json config files, but this is really troublesome: there must be specific builds per env/company. So I would like to retrieve those properties once from the backend on app load.
So in order to do this I created a Provider
var app = angular.module('myApp', [...]);
app.provider('environment', function() {
var self = this;
self.environment;
self.loadEnvironment = function (configuration, $http, $q) {
var def = $q.defer();
$http(...)
.success(function (data) {
self.environment = Environment.build(...);
def.resolve(self.environment);
}).error(function (err) {
...
});
return def.promise;
};
self.$get = function(configuration, $http, $q) {
if (!_.isUndefined(self.environment)) {
return $q.resolve(self.environment);
}
return self.loadEnvironment(configuration, $http, $q);
};
}
app.config(... 'environmentProvider', function(... environment) {
...
//The problem here is that I can't do environment.then(...) or something similar...
//Environment does exists though, with the available functions...
}
How to properly work with this Provider that executes a rest call to populate his environment variable?
Thanks in advance!
This is an excelent scenario to explore angularjs features.
Assuming that you really need the environment data loaded before the app loads, you can use angular tools to load the environment and then declare a value or a constant to store your environment configs before the app bootstraps.
So, instead of using ng-app to start your app, you must use angular.bootstrap to bootstrap it manually.
Observations: You mustn't use ng-app once you are bootstrapping the app manually, otherwise your app will load with the angular default system without respecting your environment loading. Also, make sure to bootstrap your application after declare all module components; i.e. declare all controllers, servieces, directives, etc. so then, you call angular.bootstrap
The below code implements the solution described previously:
(function() {
var App = angular.module("myApp", []);
// it will return a promisse of the $http request
function loadEnvironment () {
// loading angular injector to retrieve the $http service
var ngInjector = angular.injector(["ng"]);
var $http = ngInjector.get("$http");
return $http.get("/environment-x.json").then(function(response) {
// it could be a value as well
App.constant("environment ", response.data);
}, function(err) {
console.error("Error loading the application environment.", err)
});
}
// manually bootstrap the angularjs app in the root document
function bootstrapApplication() {
angular.element(document).ready(function() {
angular.bootstrap(document, ["myApp"]);
});
}
// load the environment and declare it to the app
// so then bootstraps the app starting the application
loadEnvironment().then(bootstrapApplication);
}());

Angular JS - Cannot identify the suitable place to put a piece of code that will be used by different pages

I am making a page that is extracting some information from the server and showing it on the interface. I am using angular js for this. So I have made a controller that has $http.get() method which gets data from the server and then the data binding is used to bind data to the html page. I am using this controller...
mission_vision_mod.controller('mission_visionCtrl', ['$scope','$http', function($scope, $http) {
$scope.visiontext = "Here is the content of vision";
$scope.bkclr = ['bk-clr-one','bk-clr-two','bk-clr-three','bk-clr-four'];
$scope.progressbar = ['progress-bar-warning','progress-bar-danger','progress-bar-success','progress-bar-primary'];
$scope.missioncount = ['col-md-0','col-md-12','col-md-6','col-md-4','col-md-3','col-md-2.5','col-md-2'];
$http.get('m_id.json').success(function(data){
$scope.missions = data;
$scope.len = data.length;
});
}]);
Now i want to make a page that allows the users to edit this info, this page also requires the same above code (code inside the controller). I also have to make a different controller for the new page to send whatever data that has been edited to server.
How do i use the above code for both the pages while i have to make a new controller for the second one for editing purpose. I want to use the same code for both the controllers.
I would suggest moving that code to a Service, then inject and use that service in each of the controllers where you need this functionality.
Services are often the best place to add code that is shared between multiple controllers or if you need a mechanism to pass data betweeen controllers.
Hope this helps!
Service/factory/value are meant for this , please refer the below example hope you get a better idea .
var app = angular.module('myApp',[]);
//controller
app.controller('myCtrl',myCtrl);
//inject dependencies
myCtrl.$inject = ["$scope","httpService"];
function myCtrl($scope,httpFactory){
$scope.data = httpFactory.getData;
}
//factory : http factory
app.factory('httpFactory',httpFactory);
//inject dependencies
httpFactory.$inject = ["$http"];
function httpFactory($http){
var datas = [];
return {
getData:function(){
$http.get('url').success(function(data){
datas.push(data);
}).
error(function(){
console.log('error');
});
return datas
}
}
}

AngularJS access service from different module

'use strict';
var trkiApp = angular.module('trkiApp', [
'trkiApp.tStatus',
'trkiApp.feed'
]);
var tStatus = angular.module('trkiApp.tStatus', [])
.factory('Status', ['$q']);
var feed = angular.module('trkiApp.feed', []);
And now i dont understand how is possible that i can access the service Status which is defined on another module?
'use strict';
feed
.controller('FeedController', ['$scope','$http','Status']);
I should not right? But somehow i am...or is that a correct behaviour?
A Module is a collection of configuration and run blocks which get applied to the application during the bootstrap process. Modules can list other modules as their dependencies. Depending on a module implies that required module needs to be loaded before the requiring module is loaded.
var myModule = angular.module('myModule', ['module1','module2']);
When you injected your module, the services got registered during the configuration phase and you could access them, so to make a long story short, it's the correct behavior and the core fundamentals of dependency injection in Angular.
For example
angular.module('module1').service('appservice', function(appservice) {
var serviceCall = $http.post('api/getUser()',"Role");
});
So how it can be accessed using angular.module('myModule');
angular.module('myModule').controller('appservice', function(appservice)
{
var Servicedata= appservice.ServiceCall('role');
}
This how it can be accessed. If anyone has another suggestion please say so.
after made some changes
html should look like:
<body ng-app="myModule" ng-controller="appservices"></body>
Above section of code used to bootstrap your angular module
angular should look like:
var myModule = angular.module('myModule', ['module1','module2']);
myModule.controller("appservices",["$scope","mod1factory","mod2factory",function($scope,mod1factory,mod2factory){
console.log(mod1factory.getData()) ;
console.log(mod2factory.getData()) ;
}]);
var mod1 = angular.module('module1',[]);
mod1.factory("mod1factory",function(){
var mod1result = {};
mod1result = {
getData: function(){
return "calling module 1 result";
}
}
return mod1result;
});
var mod2 = angular.module('module2',[]);
mod2.factory("mod2factory",function(){
var mod2result = {};
mod2result = {
getData: function(){
return "calling module 2 result";
}
}
return mod2result;
});
Explanation: created a main module myModule and inject other modules(in my case module1 and module2) as dependency so by this you can access both the module inside the main module and share the data between them
console.log(mod1factory.getData()) ;
console.log(mod2factory.getData()) ;
created two factory and inject it in my controller mod1factory and mod12factory in my case .
so mod1 & mod2 are both differnt modules but can share info. inside main controller myModule
I had a similar issue when trying to inject dependencies from another module. Alex's answer didn't work for me. I was getting a circular dependencies error.
To fix it, make sure you are including all the module-specific JavaScript before. For example moduleA was defined in another JS file.
var app = angular.module('plunker', ['moduleA']);
app.controller('MainCtrl', function($scope, MainService) {
$scope.name = 'World';
$scope.hello = MainService.hello();
});
Working example Plunker

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