Building multiple outputs through the same build process with external config - gruntjs

Question

I'm trying to leverage GruntJS to create a build process that is uniform across multiple teams and projects at my company. The idea hear is that we have a config file for each application that only specifies the files that need to be processed and what bundles they need to be concatenated into at the end. The build process would be the same for all apps: pick up the config for the app, process files in each bundle using a uniform build process.
For Example:
asset.json config file specifies two bundles, "main" with 1.js + 2.js and "secondary" with 2.js and 3.js
Build process says for each bundle, preprocess, minify, then concatenate into a js file based on the bundle
Get output of "main.js" and "secondary.js"
The problem I'm running into is that Grunt takes a "static" configuration and executes it. I've already abstracted out the building of the configuration so that I can add chunks dynamically, but right now I don't see a better way forward than literally looping over each bundle and building out a unique task for each section of the build process for each bundle, building up queues of tasks to execute, and then running each task in the queues during the build process. Its definitely possible, but its a lot of manual work and seems prone to breaking. Is there way to just execute each task in order as I loop over the bundles? Any better way to achieve the same net result of config + source in, N bundles out?
I want to be clear that I am fully aware that Grunt CAN build multiple files. What I'm trying to do is separate the specification of how many bundles from the build steps themselves. Grunt core has to bake these two things together which means each project would have to go in and alter their build steps rather than an external configuration. As per the example above, I should be able to swap out the asset.json file specified in step 1 for any config file that has 1, 2, 3, ... N bundles with N files in each one (and potentially specifying a "type" like scripts or styles).

Answer 1

Edit 10/12/13: The Nitty Gritty posted an article yesterday that might be another approach to tackling your issue.
This can be done by passing the module name you want to build as a command line argument and loading in the whole assets file in your grunt config. Please note this is example code, I have not tested this, so it's possible you need to set paths etc. correct for your case.
Start with updating the assets.json file to a plain JavaScript file, and reform it like so:
module.exports = {
main: ["1.js", "2.js"],
secondary: ["2.js","3.js"]
}
Next, you can pass a command line argument to Grunt, which should specify one of the module names in assets.js. Example:
grunt --bundle=main
Now, you'll need to load in the assets.js file in the Gruntfile:
var assets = require('./assets'); // assuming assets.js is on the same level as your Gruntfile
And then you can get the argument name by using:
var bundle = grunt.option("bundle");
Now you can use bundle as your output file name and assets.bundle to get the array files for that bundle.