Angular: how do I init module (or service) with parameters? - angularjs

I need to create a module that will be used by different applications.
Each application is using its own set of vars (application name, REST urls, ...).
How do I set inner variable, by the hosting application, in module (or in service)?
Need to init these parameters as soon as possible as the application loads.
Thanks.

In your module have a provider. That way the client application can bootstrap configuration.
Read the "Provider Recipe" section on angular's site for an example of this.
You should use the Provider recipe only when you want to expose an API for application-wide configuration that must be made before the application starts. This is usually interesting only for reusable services whose behavior might need to vary slightly between applications.

Related

Using angularjs/react in a plguin based asp.net core application where plugins can be deployed independantly

Application is being built using .Net 5 MVC & Web API. Application has a plugin system which is organized as below.
[Starting MVC Application]
|__MainLayOut
|__Modules
|__Plugin1
|_Binaries (Web APIs, MVC Controllers, logic, db access local to this plugin)
|_Views (has shared, _viewimports etc.. local to this module)
|_wwwroot (has static files local to this module)
|
|__Plugin2
|_Binaries (Web APIs, MVC Controllers, logic, db access local to this plugin)
|_Views (has shared, _viewimports etc.. local to this module)
|_wwwroot (has static files local to this module)
As you can see plugins are self contained (ex:- if you delete a plugin directory and restart the app) Any features related to that plugin will not work. (Also you can just zip the entire plugin directory and deploy it with some config file changes) Common features like User management/ Permissions etc. are provided to plugins via the main app.
As of now UI is rendered from server and WebAPIs are being called by the MVC Controllers and MVC controllers talk to Web APIs which I don't want to do when I am actually going to develop the final app.
My problem is I can move the UI part and do it as an Angular/React app. but then I can't use the plugin system that I have now. If I can do that, I should be able to break the angular/react components to different physical locations (plugin directories) and then be able to distribute those independently so that upon deployment client app will identify plugin related angular/react code and then load/run as necessary.
I couldn't find such example out there. They all have a separate Angular/React app. The other option I was thinking is to use RequireJs and AMD pattern where I can modularize my javascript code in different plugins. Main UI rendering will happen at server but client will take care of WebAPI calls getting data and binding. However this will not give me MVVM change detection which can be very useful.
So can I use Angular/React in such a way that I don't create a separate app, but use angular code in the existing app, create angualr/react modules in different plugin directories and get them to work together?

Lazy load angular modules on demand and with permission

Take a SaaS company that wants to pack all its services into a single, uhm.. Single Page Application using Angular (1). Now there is a public area (landing page, etc.) and an internal area. There are various layers of protection in the backend. There are different user groups with different privileges.
If the complete app is compiled into a single javascript file, hints for all routes can be found in the JS file quite easily. Then, there are services / $resources for interacting with the API, which again contain quite essential information on the functionality of the application.
Now the question: How could someone put modules on a certain non-binary protection level, and only load this particular module when the user is authorized to see it, all while not reloading the page?
I can find a way to lazily add modules to an angular application. I can also protect single files server sided and only send them to authorized users. But that seems like an unscalable hassle when there are more and more user groups.
Do you know any generic libraries for that purpose, ideally in sync with koa, which do not create a vast overhead? Do you know of some grunt / gulp / whatever processes, which help with that?
Thanks!
You can use latest ui.router which allows you to lazy load routes.
https://ui-router.github.io/ng1/docs/latest/interfaces/state.statedeclaration.html#lazyload
Also you can use web pack and use multiple entry points to create seperate bundles. https://webpack.github.io/docs/multiple-entry-points.html
By following above steps you can optimise the app but I don't think that this will add any protection to the web assets. You can minify to make life bit difficult to understand what your JS code is doing.

conditionally inject device-specific Angular code at build time

I've joined a project that uses Angular+Gulp+Webpack+Bower.
The project is built for different devices like so:
gulp deviceA
gulp deviceB
For each different device type, I will have a module called device.js that provides different versions of the same functions eg
device.foo();
device.bar();
I would like to conditionally inject the correct version of device.js at build time depending on the parameter passed to Gulp. device.js should be available application-wide and before the application starts.
If I tackle it in a non-Angular way, I could easily inject some self-executing code into index.html at build time that provides the device object globally. However, I want to make it more Angular-friendly so that I can eg use $rootScope to broadcast device events to the app.
My understanding is that an Angular Provider would suit my needs. Is that correct, and if so, what would be the correct way to inject the appropriate Provider at build time?

How do I load angular modules, that are common and dynamic between pages?

I have a site that is developed by multiple developers that has multiple pages. Each "page" initializes angular by calling angular.module(etc).
My question is, all pages share some modules, and some pages use specific modules. What is the best practice to achieve this? Do I trust that developers will insert the correct modules that will be needed across the site (i.e. Google Analytics) or do I create one call that is shared my all pages that loads ALL the modules. And is there a way to do both? Such as, initilize the modules that are needed across all the pages and then, load specific modules dynamically on their respective pages.
I would make one global module that is loaded by each individual app, much like modules like 'ngAnimate' are loaded... the global module could then initialize functionality common to all pages, such as Google analytics.
This requires some policing on all developers involved, but this is a good practice via code reviews, etc.
example page:
angular.module('individualPage', [
'globalModule',
'customPageModule'
]).config(
// etc
);
global module:
angular.module('globalModule', [
'googleAnalytics'
]).config(
// etc
);
I have a site that is developed by multiple developers that has multiple pages. Each "page" initializes angular by calling angular.module(etc).
My question is:
All pages share some modules, and some pages use specific modules. What is the best practice to achieve this?
I do not know the best practice when dealing with multiple pages.
IMHO, creating multiple pages is a BAD practice nowadays. I think of
web applications(SPAs) that have different views and states not web
sites with disjointed pages. So if you choose to go the
SPA(single page application) way, you can load all you core/common
modules before the application bootstraps. Views/pages that need
specific modules can lazy load them using something like
oclazyload.
Do I trust that developers will insert the correct modules that will be needed across the site (i.e. Google Analytics) or do I create one call that is shared my all pages that loads ALL the modules.
I can't say much about the question of trust as I do not know your
developers well enough. In general, developers are never to be
trusted, they will do anything that seems to work, high five
themselves and call it a day. The idea is to "Trust but verify", you
don't have to wire tap their phones or read their emails but never
ever take your eyes off the main git or svn repository. Anywhere, If
you were to use oclazyload as I suggested above for a SPA, you would
only need to worry about dynamically loading 'view/page' specific
modules which the developers can configure themselves.
And is there a way to do both? Such as, initilize the modules that are needed across all the pages and then, load specific modules dynamically on their respective pages.
Yes, yes, there is ... SPA approach that I have already outlined
above. I would also recommend using angular-ui-router for the
states and views approach. The idea is to design your application
whilst thinking of it as a desktop or mobile thick client that has
state transitions and so forth.
I have a site that is developed by multiple developers that has multiple pages.
Each "page" initialises angular by calling angular.module(etc).
My question is, all pages share some modules, and some pages use specific modules.
What is the best practice to achieve this?
Do I trust that developers will insert the correct modules that will be needed across the site (i.e. Google Analytics)
or do I create one call that is shared my all pages that loads ALL the modules.
And is there a way to do both?
Such as, initialise the modules that are needed across all the pages and then, load specific modules dynamically on their respective pages.
I would start off by defining what a page is.
Are you talking about a SPA or a more traditional setup a la client transitions between pages with a regular <a href="/page"> and
the server serves the client a piece of HTML?
If the latter is true, then I would urge you to reconsider your underlying approach to your Angular application.
The best (or rather, preferred) way of doing things would be to serve the client a single piece of HTML, and then
transition between pages (from now on I will refer to them as states), by using either ngRoute, angular router (2), or
better yet - ui-router.
For the remainder of my answer I am going to assume that you are in fact working with a SPA.
What is the best practice to achieve this?
As it stands, I would go out on a limb and say that there is no best practice defined for the case you present.
There are a ton of ways to do it, none of which have been officially recommended by the core development team / community standard as far as I'm concerned.
You could go with webpack-angularjs-lazyload, requirejs (angular-requirejs-seed), requirejs (angularAMD), SystemJS among others. Pick your poison of preference!
Do I trust that developers will insert the correct modules that will be needed across the site (i.e. Google Analytics)
or do I create one call that is shared my all pages that loads ALL the modules.
If code contained in an angular.module is required across the site, I would attach it to the main application module.
Such as:
/** Define core functionality that _is_ essential to the application running as expected **/
angular.module('core-module', [ 'route-definitions', 'http-interceptors', 'google-analytics' ]);
/** Inject the core functionality into a bundle module **/
angular.module('main-bundle-module', [ 'core-module' ]);
/** Bootstrap the bundle module as your application **/
angular.bootstrap(/* DOM element */, ['main-bundle-module']);
Now, whenever someone creates a new module for a specific state, they will need to inject said module into the main-bundle-module (barring lazy loaded modules).
As such, the core functionality will always be supplied and available, in your case Google Analytics. In a sense, you just tore down
the trust barrier.
Taking a step back, lets for a moment assume that you are not working with a SPA - and you are in fact re-initialising the
angular application on each page transition (bad move). How would you ensure that the required functionality is always present?
Decorating the angular.module method.
Note: This is not officially supported, be wary of what you are doing. Also it defeats the purpose of modularisation in my opinion, but I'll
showcase the way(s) of doing it.
You could go two ways here I reckon:
Kill the execution of JS if the required module is not a part of the developers module definition.
"Bad cop."
This would catch the 'untrusted developer' in his/her tracks during development, so as to ensure they are following the project standard.
Assist the 'untrusted developer' by automating the task of requiring the module.
"Good cop." (well, sort of...)
This would ensure that the required module is always present, albeit in every module.
"Good Cop"
(function(angular) {
// The always required module(s).
var ALWAYS_REQUIRED = ['cs.core'];
// Keep a reference to the original angular.module function.
var originalFn = angular.module;
// Keep track of registered modules.
var registered = {};
angular.module = function (name, dependencies, configFunction) {
var loaded;
// Ensure that we are always working with an array of dependencies.
dependencies = dependencies || [];
// If the module has not already been registered
if (!registered[name]) {
// Ensure that the required modules are available.
ALWAYS_REQUIRED.forEach(function (required) {
if (dependencies.indexOf(required) === -1) {
dependencies.push(required);
}
});
// Register the module and store it in the registered object for future reference.
loaded = registered[name] = original(name, dependencies, configFunction);
} else {
// Do not re-register the module, simply load it as per 'angular.module('name_of_module')';
loaded = original(name);
}
// Return the loaded module.
return loaded;
};
})(angular);
"Bad Cop"
(function(angular) {
var ALWAYS_REQUIRED = ['cs.core'];
var originalFn = angular.module;
angular.module = function (name, dependencies, configFunction) {
ALWAYS_REQUIRED.forEach(function (required) {
if (dependencies.indexOf(required) === -1) {
throw new Error('You need to add ' + required + ' to ' + name + '\'s module dependencies!');
}
});
return originalFn(name, dependencies, configFunction);
};
})(angular);
That's two ways of killing the trust issue, but in doing so we've introduced code that;
Is not very pretty.
Is definitely not very well tested / battle proven.
Kills modularisation to boot.
And is there a way to do both?
Such as, initialise the modules that are needed across all the pages and then, load specific modules dynamically on their respective pages.
I would say the best way to do so is to:
Take the steps necessary to convert to a SPA.
Write some documentation for all your developers so as to bring them up to speed on the requirements of the project.
Create a standalone module containing the required core functionality and attach it to your ng-app/angular.bootstrap module.
Get ui-router, ui-router-extras and ocLazyLoad to allow for lazy loaded module/state/component definitions.
Have a look at some of the following links for inspiration/ideas on what fits your specific project:
ocLazyLoad-SystemJS-Router by #lookfirst
ng-jspm-seed#futureStateConfig by #kasperlewau
ocLazyLoad#with-your-router
ocLazyLoad+requirejs plunker
webpack vs browserify #stackoverflow
angular + webpack slides
tl;dr
Convert to a SPA.
Bootstrap the application with core functionality supplied.
Write some documentation for untrusted developers.
Better yet, build trust. :)
Lazy load state-specific modules when needed.
You can try browserify to load and build your javascript in single file.
With this you can easy minify the javascript code, and also you can load nodejs modules like events and more, but this is not your question about.

When to use module vs. controller

I'm new on angluarjs and trying to build an example-application.
This application is divided into 3 parts/sections:
A.) map
B.) "received"-area
C.) "send"-area
Every section has its own layout/view-area, not visible at the same time.
In part B.) you can load information from server by click or automatically, which will be displayed in part "B.)" as text and in section "A.)" as map-marker.
Additionally you can click inside section "A.)" to set a new marker.
In section "C.)" there is a send button to take the new marker from "A.)" in order to send this to the server.
Currently: all of the sections (A,B,C) are angular modules/own apps.
But I don't know, if that is the right way/best practice.
An other way could be a single module for the whole page an 3 controllers (A,B,C) which handle the logic for sections A,B and C.
What is the right way in angularjs?
From your description, I recommend designing it as a single AngularJS app with separate controllers for each view. It sounds like you would benefit from using an angular service to handle the client-side business logic and cache any shared data/models that could be used by the views. It is a best-practice in Angular to keep the controllers pretty lean and focused just on the view setup/binding and orchestrating the access to the services.
After searching the way to get some inspiration, i decided to realize the following think:
For all the self-made code, I use one module for the whole application and for all the external things, bundled with external plugins and services, I take a different module. This means: pne module for each "service-plugin bundle" (like google API & angular-google-maps plugin)
So I can switch the module, if the external service does not work, etc.
Looking at my example in the question this means:
Application part A: the map and all the map-specific things (set new marker, draw circle, etc) are insight a map-module. If I decide to use open street map instead of google maps i will plug in an new maps module
Application part A and B: this is my "main" app module with different controllers.

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