Modules Overview

Modules are packages that can be plugged into an application. They allow sharing of controllers, views, assets, and other code between multiple Revel applications or from third-party sources.

A module should have the same layout as a Revel application’s layout. The “hosting” application will merge it in as follows:

1. Any templates in module/app/views will be added to the Template Loader search path
2. Any controllers in module/app/controllers will be treated as if they were in your application
3. The assets are made available, via a route action of the form Static.ServeModule("modulename","public")
4. Routes can be included in your application with the route line of module:modulename - see routing

Revel comes with some built in modules such as testing and jobs.

Modules Repository

Enabling a module

In order to add a module to your app, add a line to conf/app.conf:

module.mymodulename = go/import/path/to/module

You can add an ordering method by insert a sortable string in between the word module and the name of the module like the following. This allows you to specify which order the views should be loaded, so your application will always be the first, then the order of the modules and finally the default views in Revel.

module.01.mymodulename = go/import/path/to/module
module.02.mymodulename2 = go/import/path/to/module2

An empty import path disables the module:

module.mymodulename =

For example, to enable the test runner module:

module.testrunner = github.com/revel/modules/testrunner

Routing a module

• See the modules config in app/routes

Building a module

Best Practices

It’s a good idea to make sure all your views are in their own namespace so that they will not conflict with other applications that your module is imported into. If you have a module called Reservation, it would be a good idea to have your view path look like app/views/Reservation/Controller/Action.html . This means that your controller needs to call RenderTemplate instead of Render so that the correct view path is chosen.

Module Initialization

The revel.RegisterModuleInit(func(*revel.Module)) can be for a module to be called immediately after all the modules are loaded. The revel.Module contained in the callback is the one assigned for that module. This can be used for a variety of purposes.

An example of a purpose would be to retrieve the logger initialized for the module like the following

var moduleLogger logger.MultiLogger

func init() {
	revel.RegisterModuleInit(func(module *revel.Module){
		moduleLogger = module.Log
		moduleLogger.Debug("Assigned Logger")
	})
}

The callback registered in the revel.RegisterModuleInit is called before the revel.OnAppStart functions are.