Adding a custom blueprint action to all models

custom-blueprint.md

Reference: https://gitter.im/balderdashy/sails?at=58be4b1af1a33b62758d57ea

Is there anyway that I can add a method to all routes?

The issue

Given a Sails app with two models User and Pet, how do we create a single controller action foo and have it automatically run on requests for both /user/foo and /pet/foo?

The solution

There are a few ways to accomplish this, which differ between Sails v0.12.x and Sails 1.0, but the following approach should work with both.

1. Create a shared controller file

This can be called anything; we'll use api/controllers/SharedController.js.

2. Create the foo action

Inside of api/controllers/SharedController.js, we'll add our example foo action, which will simply respond with the name of the relevant model and the number of attributes that model has.

module.exports = {
  foo: function(req, res) {
    // Get the model name from the route URL.
    var modelName = req.param('model');
    // Make sure a Sails model with that name exists.  If not, just respond with a 404.
    if (!req._sails.models[modelName]) {
      return res.notFound();
    }
    // Get a reference to the Sails model.
    var Model = req._sails.models[modelName];
    // Respond with some info about the model.
    res.send('Called the `foo` action for the `' + modelName + '` model which as ' + Object.keys(Model.attributes).length + ' attributes.');
  }
};

If you have the sails global turned on in your app, you can replace req._sails with just sails.

3. Route to the foo action

By using a dynamic route parameter, we can route both /user/foo and /pet/foo to the foo action. In config/routes.js:

'GET /:model/foo': 'SharedController.foo'

Note that this will route xyz/foo, blag/foo, etc. to the foo action as well, which is why the action checks first that the model param represents a valid Sails model.

I like the approach here. What if this were to be made a module to be installed via npm or its alternatives?