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JavaScript MVC 2.2 - Understanding a real AngularJS App-Controller

This is a part of my second short series about JavaScript MVC Frameworks. In this part I'll show you a real-life AngularJS App (albeit a simple one) and explain all relevant parts so that you can create your own. I've split it into multiple posts - this one explains all the angular magic in the Controller, while the other posts focus on the View, Model and more.

If you have not already read the previous parts, I would highly recommend you start there. Especially the post about the AngularJS App-View contains vital information + prerequisites so you can try all this code directly in your DNN.

Prerequisites

To learn AngularJS you will have to get your hands dirty. So go ahead and install DNN with 2sxc as explained in this post  and install this demo-App containing all the code explained here.

Continuing with the Controller

This is the controller code

And here the first relevant notes:

Understanding The Angular-Stuff

Now some of the more complicated things

  1. The parameters $scope, $sce etc. are dependencies. Angular will automatically ensure that they are provided to the controller. You could re-arrange them and they would still work, and you could add other things AngularJS manages, and they will be provided.
  2. $scope is the view model - it will contain the data which will be bound to the template and also contain actions like clicks or inits
  3. $sce is the Strict Contextual Escaping. This is an important helper to allow raw html-binding, without it, all html would be inserted as text. The functionality is similar to @Html.Raw() in Razor.
  4. $window is the same thing as the global window-variable, but used as a parameter so that it could be injected with something else (for testing)
  5. $attr is an array of attributes on the apps HTML-tag. We need it to retrieve the ModuleId - because the controller needs it...
    1.  to load the right data (it will ask 2sxc to give the data for this module-number)
    2. and to differentiate between multiple same modules on the same page
  6. importLoadedData is the callback which will map the data returned by the 2sxc-JSON-API into an AngularJS ViewModel

Summing it up

Basically that's it for the controller - because the...

...Angular controller should be used to

  1. Set up the initial state of the $scope object.
  2. Add behavior to the $scope object.

read more about this in the AngularJS documentation about the Controller.

Do not use Angurlar-Controllers to

  1. Manipulate DOM — Controllers should contain only business logic. Putting any presentation logic into Controllers significantly affects its testability. Angular has databinding for most cases and directives to encapsulate manual DOM manipulation.
  2. Format input — Use angular form controls instead.
  3. Filter output — Use angular filters instead.
  4. Share code or state across controllers — Use angular services instead.
  5. Manage the life-cycle of other components (for example, to create service instances).

So that's it for the controller.

You must get your hands dirty!

Reading this won't make you smarter if you don't try it yourself. Just use 30 minutes to download the App, make some adjustments (like adding fields or changing the JS-effects). That way you'll get smart really fast!

With love from Switzerland,
Daniel 

Daniel Mettler grew up in the jungles of Indonesia and is founder and CEO of 2sic internet solutions in Switzerland and Liechtenstein, an 20-head web specialist with over 600 DNN projects since 1999. He is also chief architect of 2sxc (2SexyContent - see forge), an open source module for creating attractive content and DNN Apps.

Daniel Mettler learned programming with the bible translation computer of his parents, deep in the jungles of Indonesia. Since he was only 12 years old at that time and the BIOS only had a version of BASICA, that's what got him started. With 16 he went back to Switzerland and learned German and basic city-survival skills. Equipped with this know-how he founded 2sic internet solutions in 1999 which was focused on web solutions on the Microsoft platform. After a few self-developed CMSs 2sic switched to DNN in 2003 and has been one of the largest partners (17 employees, 700+ projects) in Europe. Daniel is also the chief architect behind the open source 2sxc, a strong promoter of standardization (boostrap, patterns, AngularJS, checklists, etc.) and loves to eat anything - dead or alive. His motto: if the natives eat it, it game.
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