https://docs.angularjs.org/guide/bootstrap
In this guide it says "Placing script tags at the end of the page improves app load time because the HTML loading is not blocked by loading of the angular.js"
But what exactly does it mean in the next statement "Angular initializes automatically upon DOMContentLoaded event". Can anyone explain what this initialize means and then how angular.js can block the HTML loading?
When the HTML parser comes across any script elements, It assumes that document.write may be present in the script and it blocks HTML loading. That's why it's recommended to load all scripts at the bottom of the page to ensure page loads fast.
By the statement, Angular initializes automatically upon DOMContentLoaded event, it means that angular bootstraps the app once the DOM is ready.
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I want to know how boot process is done in angular. Which file is executed first and when execution started js file is executed first and execution of html body is started?
Placing the script tag at the bottom of the page improves app load time because the HTML loading is not blocked by loading of the angular.js script.
AngularJS does not need to be placed in the HEAD, and actually you normally shouldn't, since this would block loading the HTML.
However, when you load AngularJS at the bottom of the page, you will need to use ng-cloak or ng-bind to avoid the "flash of uncompiled content". Note that you only need to use ng-cloak/ng-bind on your "index.html" page. When ng-include or ng-view or other Angular constructs are used to pull in additional content after the initial page load, that content will be compiled by Angular before it is displayed.
I have a basic angular page, it pulls some records from a database and displays in a table via ng-repeat - this is working fine as a standalone page.
I'm using bootstrap remote tabs https://github.com/thecodeassassin/bootstrap-remote-data and am calling the above page as one of the tabs' content. The angular page is loaded but angular is not initialising though for some reason. Nothing is binding.
I've tried putting the angular scripts both inside / outside of the tab, and also putting ngApp inside of the tab (remote page) and outside of the tab (parent page) and it doesn't make any difference. Is there something I'm missing?
I am not sure what you are trying to do, but I think the problem is that the angular finishes the loop for initializing the content before the pages are loaded inside the tabs.
have you tried to use ng-include to load the content of the tabs dynamically.
also you may need to call for angular apply to re initiate the binding.
another note, if you are trying to use the tabs to load the data asynchronously, you can use regular tabs and let angular handles the loading of the data using ng-include.
I just learned how to create custom directives with angular today via codeschool and it is fantastic! The way it taught me was to make a directive in my JS file, link it to an html file, then write the tag accordingly in the index.html file which is my main file.
My question is does creating a whole new html file for a custom directive hurt load times on the main page? If you want a reference to the section I'm in, it is shaping up with angular level 4 (custom directives).
It depends on whether or not you precompile the templates directly into your main.js or not.
If you precompile them, your main.js will take longer to load, but, when rendering the view, angular won't need to send an http request to get the template so rendering will happen faster.
If you don't precompile them, the up front load time will be faster, but rendering the view may be slower the first time because angular needs to send an http request to get the template for the first time. after the first load, it will be cached in the template cache.
You could also use a hybrid solution, precompiling things needed for the main entry to your app, and letting angular request the rest as needed.
which one is better is a debate not suited for stackoverflow.
I have some animation libraries that are loaded at the end of the page. Problem is they are not binding to the html that is populated via the directives.
Is there a way to load the scripts after the view has been completely rendered (including the directives)?
When a script is placed inside angular app element (ng-app on html not body or <script> inside body), <script ng-src="...> will force first bootstrap angular and then only put scripts for download. But mind the fact that if you have multiple libs they will be downloaded in parallel, and order in html won't be tracked in contrary to scripts directly loaded from head at page load.
Alternatively you can add ng-if="doLoadExternalScripts", for example, and specify a truthy value to this variablle when you consider it is right time, for example if your directives are not rendered on init of app
I'm developing a chrome extension using angularjs (with a content script open a popup),but it meet some problem when it's parent page already use angularjs, it's parent try to compile the content inserted, so is there anyway to prevent the parent angularjs instance to compile the element I added, and the angularjs instance in extension can bootstrap the element manually ?
It's hard to answer without an example, or what is your extension flow.
Basically, angular shouldn't compile anything on it's own, it either does it when bootstrapping the app, or when you explicitly tell it to.
What I guess you are doing is have the html change before angular is loaded, and then when it loads it compiles your stuff as well.
Try adding your directives etc. after angular has finished loading on the main page (how to detect that angular finished bootstrapping is a whole other question :)).
And after you add your new element with your ng-app <div ng-app="myAngularExtensionApp"></div>, however I am not sure how it will work if it's nested inside another angular application, I don't think it will allow you to do it. If the ng-app of the main application is on the body you can add your div outside the body (weird, but legit), and it shouldn't conflict. but if it's on the html it might cause problems. (I tested it, you can bootstrap another one inside an existing app, but it can cause some really weird problems, I'd avoid it).
A bullet proof solution, that makes things a little more complicated is one I used and I like it alot:
Create an iframe on the page, which you add the angularJS script inside, and it will be your application, do not set the src of the iframe, but rather use iframe.document.open() .write(
<html><body ng-app="myExtensionApp"> etc (i.e. a complete bone structure of an angular page), now since the src is the same, you won't have same origin problems, and you can access the main page with top.
I recommend having services that will interact with the main page.
I am not sure what you want to do, but if you want a directive on the main page for example, first create it in the iframe, then move it to the main page via jquery, it will belong to YOUR angular application (since scope binding is based on prototype and the chain doesn't get broken by moving the element), it will keep reacting to changes to your scope.
However you have to remember that styles are unaffected etc.