How integrate cross-site multiple angular applications? - javascript

I have one big information system consisting of diferrent subsystems. One of my objectives is to organize navigation and localization between these subsystems.
When I was generating view in backend via JSP I simply used jsp:include referring to special web-app which returns header with cross-site navigation and also this web-app was responsible to store user locale for all subsystems.
Now I switched to angular and found out that it's impossible to replace jsp:include with ng-include. I have 2 different ng-apps - header (coming from outside web-app) and current, say, subsystem1 ng-app. ng-include directive in header doesn't work because I have to bootstrap it, but I can't bootstrap header ng-app because it is absent - I'm fetching it with ng-include. Vicious circle.
Now I see one way to solve my problem:
Fetch header markup in second ng-app (non-header, subsystem1's ng-app) via ajax call to special header-web-app. Then, insert incoming HTML to header via simple DOM manipulations and bootstrap it manually. Disadvantage is obvious - I will make DOM manipulations in subsystem ng-app but insert HTML outside it because 2 different ng-apps must not instersect or be nested. Is it OK?
Looks like I'm inventing bicycle, so I'm asking here, how integrate cross-site ng-apps? Is it possible to share data between different ng-apps in one web page? I know, that it's possible to share data between controllers via services and factories and this is good practice. Is there any angular-way to share data between ng-apps?
Please, do not provide JSP-like solutions as I want to keep angular way of development and thus make only static pages with angular markup and make all server side job via ajax calls. Probably, I misunderstood angular way but now I'm seeing it exactly as I describe.

Method #1 from this site looks good for me. In short, any ng-app consists of markup anf js. JS can be simply loaded by script src=... and many ng-apps can be used as a modules of one big root app. Markup can be loaded by ng-include.

Related

Create authentication in another AngularJS module

I have doubts on how to create a login page for the template BlurAdmin.
The Template has the index.html as masterpage. It has header, footer, sidebar, ... and the pages are loaded as template (ui-view).
But I would like to use login page the independent of index.html, I think the best way to create it using another ngApp, different from index.html, but how should I do? I looked much about, but the login.html is always loaded as a template (ui-view).
If you want to divide your application into few steps, it could be useful. So you can create separate index.html file which will include all html from logins template. Of course, you can also add another angular to this separate page to handle logic, but keep in mind how much logic you will need to add to this page, maybe it will be easier to use something with less weight for the login page.
Anyway, as a result, you should have the second separate application with included scripts and styles as it already implemented in the main application. So the answer to your question - you should handle building process for the second application which will be you login SPA, and you will have two single page applications with different scripts in each, they can use different angular versions or even different Frameworks.

How to load angular controller and template in a single HTTP request?

I am using angularjs. want to load parts of a page that I package as "components", wherein a component contains its controller, template, directives and a few other assets like CSS etc. When needed, I want to load all of this on demand.
I was able to load the controller and the template on-demand by specifying a resolver for the controller and the templateUrl for the template. But is there any way I can combine them into a single HTTP request? Any examples?
Sorry forgot to add: I want to do it only on-demand, not precompiled/pre-aggregated (lets just say thats is a requirement thats been given to me). Is there a way?
You can use angular templatecache to add your html to a module and package template cache along with controller, services, directives etc.
In order to pull your Angular code and your html templates together in one request from the server, you'd need to have the templates combined in with your js. That would imply using some kind of job to process your html into js and concatenate it in with the rest of your code. Something like grunt-angular-templates might do the trick.
Edit
With the added requirement that this should be an on-demand sort of thing, I could only add (with the current information) that this sort of thing can be accomplished with bundling and request processing on the server, but the specifics on how to do this are totally dependent on your specific server stack. Often a server will have features that allow for on-demand resource bundling, or rendering of partial-views that might be helpful in this capacity.

Security issues of Angular's ng- attributes in HTML and mitigation

I'm not sure whether seeing these directives in plain text poses any particular threat to our app hacking or not. But if nothing else one can clearly see our model structure and functionality. If Angular removed those after bootstrapping it would at least make it a bit harder to access...
Two questions
Would it be possible to remove all custom ng- attributes from markup after Angular app boostrapped? Would the app still work as expected?
Would it be possible to dynamically add ng- attributes on DOM Ready using jQuery, and then remove them as per #1? If this required manual app bootstrapping so be it?
By having the possibility of the #2 somehow we could externalize app configuration and HTML markup would never show any declarative directives (just in the time between configuration-bootstraping-removal). But at least there would be none if user disabled Javascript.
Anything that you expose via Angular will have to be exposed in some way anyway to the client if the client is supposed to show some data. If you want to have an interactive client-side application, then it needs to have some form of client-side model and data structure and code working on those things. Whether you express them purely in procedural code in a .js file or embed part of the structure into the HTML markup hardly makes any difference. It does not make anything any more hackable which wouldn't already be hackable to begin with.

Is it good practice to use requirejs to extend single pages instead of pure javascript applications?

So my question is mainly about the use case of RequireJS.
I read a lot about pure javascript driven web pages. Currently I extend single rendered views (e.g. provided by a PHP Framework) with AngularJS which adds a lot of value.
Sadly the dependency management gets harder and harder with every <script> tag on other 'single pages'. Even more when there is a main.js file which provides common libraries (e.g. jQuery and AngularJS itself).
I thought this doesn't fit into RequireJS philosophy to have one main file which requires all dependencies.
A good example would be an administration panel which uses some modules (defined by AngularJS's dependencies).
Example:
scripts/
adminpanel/
panel.app.js
panel.filters.js
panel.directives.js
antoherModule/
andAntoherModule/
require.js
tl;dr
When you use AngularJS to extend single pages, instead of building a completely javascript driven web application, is it good practice to use RequireJS for AMD loading modules which will be used on the single page ? And how is the best way to do it so ?
SPA usually means that the page doesn't refresh and all extra content is loaded on the fly. In essence the entire app is a single page. It doesn't mean that all of the content is loaded on the initial load (though if it is small enough, this could be the case). Using RequireJS / AMD architecture is really good for this kind of thing.
As the user navigates throughout the site, different partials / templates are retrieved as well as any supporting JavaScript.
The best way to do this is with define. Defining all of the requirements your script needs in order to work. All of the scripts needed will be loaded before the function is run, ensuring that you have everything you need. Furthermore, the items that you define as requirements can have their own define to specify the scripts they need... and so on.

Very large single page application design problems

I am currently writing whats going to be a very, very large single page web/javascript application.
Technologies I am using are ASP.NET MVC4, jquery, knockout.js and amplify.js.
The problem I am having is that most if not all of the single page application examples are for smaller applications where having all of the script templates (be it jquery, handlbars, etc...) are all in the same file along with the rest of the html code. This is fine for smaller apps but the application I am building is an entire maintenance logistics application with many, many, many screens.
The approach I took so far is I have an outer shell (my main index.cshtml file) and I am using jquery's load() method to load or rather inject the particular file I need when a user makes a certain selection.
example:
function handleLoginClick(){
App.mainContentContainer.delegate('#btnLogin', 'click', function() {
App.loadModule('Home/ProductionControlMenu', App.MainMenuView.render());
});
}
here's the code for the App.loadModule function:
App.loadModule = function(path, callback){
App.mainContentContainer.load(App.siteRoot + path, callback);
};
All was going well until I needed to actually start interacting with the various form elements on the newly loaded screen. jquery can't seem to get a handle on them directly. I can't use .live() or .delegate() because they aren't events, they are textboxes and buttons and sometimes I need to change their css classes.
They only way I found is to get a handle on an element from the outer shell (something that wasn't loaded via .load() ) and use jquery's .find() method like so:
App.mainContentContainer.find('#btnLogin').addClass('disabled');
clearly I don't want to have to do something like this everytime I need to interact with or even retrieve values from a form element.
Does anybody have any ideas as to how I can create a maintainable very large single page application with potentially hundreds of .html files without having to have all that html code located in a single file and still get around this .load() issue I am having?
Any thoughts would be greatly appreciated. :-)
V/R
Chris
UPDATE
I thought I'd post an update and as to how things went and what worked. After much research I decided to go with Google's AngularJS Javascript framework. It simplified the ordeal exponentially and I would definitely, definitely advise all who are looking into making a large SPA to give it a look.
Links:
Main Site
http://angularjs.org/
Awesome free short videos on Angular:
http://www.egghead.io/
This is actually a very complicated question as it really gets down to the design of your architecture.
For large-scale single-page applications, it's best to use some sort of front-end MV* style framework such as backbone.js, which ties in to jQuery quite usefully. You should also think about using some sort of dependency management framework such as require.js in order to load your scripts and dependencies asynchronously, and even better -- use the AMD pattern in your application design to make your architecture modular and easier to manage.
As far as how this relates to your MVC4 project, you have some options:
Do you want to use MVC as a "service layer" of sorts, that simply returns JSON objects, allowing your front-end to do the markup/template creation (think handlebars.js), or
Do you want your MVC project to return partial views (HTML) as a response, where you leverage the Razor templating system and simply use the front end to display what comes back from the server?
Either way, you will have to devise a way to handle front-end events and navigation (backbone provides both of these things when coupled with jQuery). Even more complicated is the pattern you choose to notify one view of another view's activities (there are many ways to do this) -- a publish/subscribe pattern for example.
I hope I have helped a bit, I know I'm not fully answering the question, but the answer could get really long!
Lots of things are wrong with your approach. What I'd recommend is to watch some presentations on how people build Single Page Applications and what tooling is mostly used.
This seems like something reasonable: http://singlepageappbook.com/
You will at least want
some kind of modules system (I recommend AMD – http://requirejs.org)
an MV* framework (Backbone, Ember.js etc.)
DOM/AJAX Framework (jQuery, Mootools etc.). Some frameworks offer this and all of the above (Dojo, YUI, Sencha)
build solution (to have different environment in development / production)
Couple of good links:
http://nerds.airbnb.com/slides-and-video-from-spike-brehms-tech-talk
http://video.copenhagenjs.dk/video/3413395/simon-hjberg-swipely-building
http://backstage.soundcloud.com/2012/06/building-the-next-soundcloud/
http://www.youtube.com/watch?v=vXjVFPosQHw
If you don't need a complicated truly SOFEA Single Page App then I recommend you go the PJAX route.
Then you just write your app as a normal web 1.0 app with the performance benefits of a single page load. I urge you to consider this an option as it allows you to do most of your validation work server side.
The idea is very simple on every response your sending the whole page back minus the header and footer (which contains the javascript and css includes). DOM rendering time is incredible fast these days... whats not is a full page reload, So don't worry about the size of the HTML your returning back.
Also the "PJAX way" is much easier to cache, Google SEO friendly and is in fact what the new Basecamp does.
Note: Wanted this to be a comment not an answer but don't have enough exp to post comments ;(
[any corrections by community members welcome!]
Important points to consider for single page apps:
Lazy loading is vital as you don't want hundreds of js files loaded straight away as user first loads the page (very slow load time).
Good File organisation,- helps making changes easier, reduces complexity a bit and promotes reusable components. Makes testing of components easier.
Testing,- Since single page apps have a lot of javascript going on under the hood you would need a test framework for automatically testing components. This testing is on top of the tests you would use to confirm if certain user controls are rendered etc as you wouldn't want a viewless component making an ajax call to server when it shouldn't etc.
+1 for gryzzly's point about using a framework.
Sencha have a nice MVC like framework for their ExtJs product. They have data stores, ajax, lazy loading, class hierarchies and a lot more all bundled into the package. They have a good api page also to lookup object properties and methods (handy since there doesn't seem to be any intellisense for javascript :/ ). Their api page is; as far as I know, an example of a single page app. I know much of the stuff ExtJs does you can find an open source alternative but I like that it's just the one library and I don't have to download a couple of different frameworks to do various operations. [note: I have no affiliation to Sencha except for being a customer of theirs and like their stuff.]
Conclusion:
I'd say it would be quite difficult to manage a large single page app without using some client side framework; whether open source or not, and without using some architectural pattern like a client side MVC.
Single page apps I think are more complicated so your team would need to be quite handy at understanding the concept of a single page app and how to implement it. If you pull it off the site will be amazing in terms of user experience.
I would recommend to use Sammy.js and split various viewmodels in knockout to a separate url. And if you're using asp.net mvc 4, use partial views (user controls) so that you put all code in one file. And name all and split all js-code in a meaningful way, filename and namespace in js. That will help a lot in maintainability and your own sanity in the long run.
And use common sense!
The way I did it was to include javascript code related to the template along with the template itself. And then load the whole template+script thing using ajax. If you want to try this be warned that most browsers don't execute <script> tags injected into the page. Especially if done using innerHTML. As such you should eval the script tags yourself (alternatively you can use document.createElement to inject the script but this does not offer any additional advantages compared to eval since the browser will blindly execute the script anyway).
In my case, to make it easier to grab the html and script portions of the template I store my templates in XML files instead of plain old HTML. That way I can simply use .responseXML of the ajax request to parse the template. My template has the following basic structure:
<template options...>
<title>Optional</title>
<html><![CDATA[
Template body
]]></html>
<init><![CDATA[
// code that only needs to execute once
]]></init>
<script><![CDATA[
// code that needs to run every time
// the template loads
]]></script>
</template>
You also need to remember to configure your server to reply with the correct content type for you templates. Otherwise resultXML won't work. This is not the only way to implement this system of course. You could simply save your templates as HTML and then parse that HTML to extract scripts to execute.
The main bulk of your code, the functions, constructors, objects etc. can be included in a js file. The template script only need to call those functions to tell the rest of the page how to work with the template.
If you further separate your data from your template and only populate the template with data on the page or make a separate ajax request for JSON data then you can configure your server to make the browser cache your templates. This is especially useful for often used templates (such as templates for dialog boxes). This allows the browser to download the template only once and use the cached version the next time you call the template.
Anyway, that's how I did it last time. It scaled well enough to serve facebook users (the web app was a facebook app). Just sharing my experience. Hope it helps.
I've written a few huge single page application using Dojo Toolkit. I'm pretty sure whatever JavaScript framework you choose will probably work for you. I use Dojo because it provides me with features that makes huge single page application development easier to manage.
You can use Dojo's widget system to help you define all your screens and forms as widgets and then when you need them you can just instantiate and insert them wherever you need it. When ever you want to get rid of it, you can simply call destroy or destroyRecursive on that particular widget and its gone. Dojo's widget system also help you separate your HTML from your JavaScript, but still keep it together so that they are not located all over the place.
I've include a simple widget definition for a Login form.
This is the HTML template.
/* mine/forms/Login.html */
<div>
${form_name}
<label>Username</label>
<input data-dojo-type="dijit.form.TextBox"
data-dojo-attach-point="_usrfld" />
<br />
<label>Password</label>
<input data-dojo-type="dijit.form.TextBox"
data-dojo-props="type: 'password'"
data-dojo-attach-point="_pwdfld" />
<br />
<input data-dojo-type="dijit.form.Button"
data-dojo-props="label: 'Login'"
data-dojo-attach-event="onClick:_handleLogin" />
</div>
This is the JavaScript portion for the widget.
/* mine/forms/Login.js */
define([
"dojo/_base/declare",
"dijit/_Widget",
"dijit/_Templated",
"dijit/_WidgetsInTemplateMixin",
"dijit/form/Button",
"dijit/form/TextBox",
"dojo/text!./Login.html"
], function(
declare,
_Widget,
_Templated,
_WidgetsInTemplateMixin,
Button,
TextBox,
template
) {
return declare("mine.forms.Login", [_Widget, _Templated, _WidgetsInTemplateMixin], {
// assign the template
templateString: template,
// signal that we will have widgets within our template and the parser should
// locate them and instantiate them
widgetsInTemplate: true,
form_name: "My Login Form",
// place holders that will be referencing the corresponding widgets
// that I have placed a data-dojo-attach-point on
_usrfld: null,
_pwdfld: null,
_lgbtn: null,
// a call back function that will be trigger when the Login button is clicked
_handleLogin: function() {
var usr = this._usrfld.get('value');
var pwd = this._pwdfld.get('value');
// now you have the username & password
// you can use it to login
}
});
});
There are a few benefits that the widget system provides:
The HTML template will be loaded for you when needed
You can have widgets within widgets. Dojo takes care of instantiating and even destroying those widgets for you
You can use dojo's simple template language to help with inserting strings. The example above uses ${form_name}. If you want to use a more sophisticate facility dojo also supports a Django similar syntax templating language. This will allow you to use most of the tags available with Django like for, if-then-else, etc.
data-dojo-attach-point is very helpful. If you use this, you will never need to assign id to a DOM element anymore. You will not need to locate the element in your HTML DOM tree. The variable you name in data-dojo-attach-point will be auto assign to reference the widget or DOM element you have defined in your template. The example above uses the _usrfld, _pwdfld, and _lgbtn.
data-dojo-attach-event is also very helpful. If you use this, you will not have to manully add an event hook to the button, Dojo's widget system will hook it for you and will also clear the hook when your widget is destroyed.
If you use Dojo's build system, which is a system that takes all your JavaScript codes and compresses them, Dojo will replace your template with the actual HTML so that when you load your widget in production mode, Dojo doesn't have to make another AJAX request to grab your template.
These are just some of the features I use daily when I develop my projects. Hopefully it will provide you with some insight that you can use to make your decision when choosing the proper JavaScript framework for your project. As a side note, I'm not advocating Dojo or anything, just wanted to share what works for me.
To handle large size single page application it's recommended to break the individual module into different apps.
example : apps like search page app and result page app.

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