Factories, Services and Controllers

week1gsoc1

So before I start the blog post, it is better if you know more about what sTeam web interface is and what are the capabilites of sTeam. Click here.

So what is a Controller ?

It is simply a a constructor function which is instantiated by AngularJS when it encounters ng-controller directive in HTML.

So what is a Factory ?

In Angular Js a factory is an injectable type which helps us in encapsulating repetitive logic.

How are they helpful for sTeam web interface ?

So as my first week of work started of for GSOC, the core concentration has been on primarily working with the controllers of the workarea and integrating them with the respective views. In an attempt i started of with adding a :

commentsCtrl

: Used for adding comments to the web interface

workspaceeditorCtrl

: Used for integrating textAngular to the web interface

Things apart, in a broader aspect here what should be understood is about how things should be implemented using controllers, factories and services. Let me illustrate how it should be properly done in angular js.

To start off

How are controllers really helpful in Angular and how should they be used ?

Generally we should understand that controllers responsible for augmenting the scope which is done by attaching models and functions to it that are subsequently accessed in the view. There are some things which are to be understood while writing controllers. Lets go one by one,

  • A Straight “No” for all the DOM manipulation. This must be achieved only with directives
  • If you are having a situation where you are about to write repeatable code, then don’t do it with controllers, instead encapsulate them in services.
  • If you are trying to expose the whole controller instance then it isn’t a good idea. In fact the scope object exists in order to clear separation of concern between controller and view .

So what about Factories ?

“Services, factories, and providers are all injectable types. We must understand that Factories in angular Js are just another example for an injectable type. It looks almost the same as Service but when it comes to implementation you can decide and determine what to instantiate and return from the factory”

scribes by hector | Akhil Pandey

Let me give you a small example before i wrap up, Have a look at the below image,

week1gsoc2

Observe broadcastItem, prepForBroadcast. If you look keenly essentially what i am doing there is creating an injectable type which enables me to change the message that which has to be printed depending on the broadcast item.

One more key thing about factories is that a factory can also depend on other services or factories. Also there is one more point to grab which is we are returning an object from the factory function, so we absolutely have the freedom to determine what should be the object which is to be returned, going further we can base it on certain parameters as well.

Thats it folks,
Happy Hacking !!

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