Is Rake Pipeline an alternative to Rails Asset pipeline? If yes, why and what is the history & pros/cons of these two solutions? If not, how are they related?
rake-pipeline is not a direct alternative to sprockets. rake-pipeline is infinitely more flexible and more powerful. The asset pipeline is really just a preprocessor with concatenation. It does not make things like source maps and module wrapping easy. Sprockets does "dependency management". I quote dependency management because writing something =require inside a javascript file is a horrible way to "manage dependencies".
Rake pipeline defines a the steps required to build assets. This is the pipeline. Here's a build process you may think of:
- Compile coffeescript into javascript
- Wrap all javascript files in minispade modules
- Concatenate all the files
- Minify the concatenated file.
You can construct very complicated build pipeline. See Iridium's Assetfile for probably the most complex rake pipeline example in the world. Rake-pipeline is not just for constructing assets for web applications. It can be used to build any sort of code base. Ember.js uses it to construct release files for both Ember.js and Ember-Data. You could do this with sprockets, but it would be a huge waste of time and extremely awkward.
Sprockets seems to be optimized for development, where rake-pipeline is optimized for complex applications. Individual assets are available in development. This makes developing faster because assets don't have to be concatenated (only preprocessed if need be). This is not possible with rake-pipeline. Rake-pipeline only cares about inputs and outputs. The intermediate build files are not accessible.
You can use rake-pipeline inside of rails if you like. The rake-pipeline gem bundles a rails engine to replace the asset pipeline with itself. If you are building a complex frontend application I may recommend this. If you only want to wrap JS files in modules, then you can look into the various projects for the asset pipeline.
With Rake pipeline, you addon the excellent rake-pipeline-web-filters to get all the concatenation, minification, pre-processing like scss, minispade etc. With Asset Pipeline, it seems hard to configure. One immediate limitation is that all my JS is eval'd immediately and I dont have support for minispade in the Assset Pipeline. The alternative to that is the minispade-rails gem.
See previous paragraph.
In general, I am trying to understand how to go about getting a similar build process with rake pipeline Assetfile in Rails Asset pipeline.
This is impossible with sprockets. Sprockets functionality is really a subset of rake-pipeline. Rake pipeline can do everything sprockets can do and do it better. The downside is that it requires more configuration.
I recommend you take a look at assetfile I linked. It can give you an idea what you can do with rake-pipeline. Here are some thing's I've done with rake-pipeline.
- Include environment specific JS/CCS (like production, development, test) etc in my final build
- Allow other code to tie into my build process with hooks
- Create initializer files for my Ember application
- Precompile handlebars templates
- Strip out assertions not required in production code.
- Generate an HTML5 Cache manifest from my inputs
You could do all of these with the asset pipeline but it's not worth the effort.
