Questions about the AngularJS source code

[pomerantsev]

• In the src/ folder there are several files with .prefix and .suffix extensions. As far as I see they merely wrap the code inside the main .js file, and they get into the built angular.js file unaltered. Why is code divided into several chunks in such a way?
• ng-view directive (src/ngRoute/directive) - why are two ng-view directives being registered?
• minErr (src/minErr.js) - there is a paragraph in the opening comments to the file that minErr instances should have specific names. I totally don't understand why it is so.
• What is transclusion essentially? Except that I can wrap some content into the directive's template. The comments in this issue are rather obscure to me: Isolated scope not isolated angular/angular.js#7716. It looks like much more is going on under the hood.

[al-the-x]

Just some notes regarding those topics. All great questions...

Re the .prefix and .suffix files:

I found someone else wondering the same which means this could be a little clearer. Probably worthy of a blog post or SO question. It has to do with the build process and wrapping up the built library in a self-calling closure for namespace protection. If that makes no sense, there's at least a half-hour of discussion around this topic.

Why are two ng-view Directives registered?

This gets complicated quickly, so probably worthy of another half-hour. The two (there are actually three in that file) are collaborating to produce the effect we see as ng-view. As API consumers, we only use the ng-view Directive; the others are by-products of our usage.

What is minErr and how is it used?

This is easier to demonstrate than to explain succinctly because it has to do with error states and displaying consistent error messages when an Error (JavaScript Exception) is thrown within the framework or userland code.

What is "transclusion" essentially?

This will take a full hour or more to cover, easily, and is one of the most confusing parts of Angular. Until you really understand how $scope works in Angular, the transclude voodoo does not make sense. I have to work it out on paper myself, sometimes.

[al-the-x]

Here is some sample code:

function doNothing () {
  console.log('nothing');
}

[al-the-x]

When to use link vs compile in Directives.