Using and abstracting away libraries

[GertSallaerts]

I have a question regarding best practices concerning the usage of libraries (like jQuery, handlebars, underscore, ...)

The readme from the project states:
"Abstract away utility libraries you are using (templating, DOM manipulation) so that you can swap them out for alternatives at any time without a great deal of effort."

If I understand correctly, this would be done by using extensions that add the library's functionality to app.core, but in a way so as to make these extensions to core library-independent.

Example:

• Library "a" has function "sum(x, y)" that adds x and y.
• Library "b" has function "add(x, y)" that adds x and y.

Would you then create these extensions?

• Extension "aura-a" that extends app.core.math with a function sum(x, y) which would execute the sum function from library "a"
• Extenstion "aura-b" that extends app.core.math with a function sum(x,y) which would execute the add function from library "b"

If I am correct in my assumptions, are there any of these extensions already available? The aura-examples I've seen don't seem to use a lot of libraries yet, mostly underscore which is usually used directly instead of using an extension that adds underscore functionality to app.sandbox.util

One thing I've seen is the aura-handlebars extension in aura-todos:

initialize: function(app) {
    var Handlebars = require('handlebars');
    app.core.template.hbs = Handlebars;
  }

This seems to contradict my understanding of how extensions should be used since it just inserts handlebars as-is.

[c4milo]

I have the same question here @addyosmani @sbellity

[addyosmani]

I believe with your latter question, the idea of the inline require here was to demonstrate inclusion of a library which wouldn't massively benefit from being done as an extension (i.e it was only being used for something quick and dirty). @sbellity can probably clarify. In a large-scale application there are going to be many cases where it does make sense to implement interfaces to these libraries using extensions, however you don't always want to introduce unnecessary overhead to your app. I believe this is what the handlebars line was demonstrating.

[sbellity]

I am not a huge believer of the abstraction of all libs.

It could work for some really basic ones - mostly the ones we have already abstracted in aura.base like basic dom manipulation or promises...

We could at some point introduce real interfaces through extensions to other common libs like templating (cf. visionmedia/consolidate.js) but I think that it out of Aura's scope.

Thoughts ?

[addyosmani]

I agree and think our messaging could be tightened to proved more guidance around when it does make sense to abstract and when it doesn't. For example it's not initially clear to those new to Aura whether they should abstract Backbone or use as is. If our demo apps use it abstracted our homepage should explain why this is suggested in this case vs no in others.