Cookoo

A chain-of-command framework written in Go

Usage

$ cd $GOPATH
$ go get github.com/Masterminds/cookoo

Use it as follows (from example/example.go):

package main

import (
	// This is the path to Cookoo
	"fmt"
	"github.com/Masterminds/cookoo"
)

func main() {

	// Build a new Cookoo app.
	registry, router, context := cookoo.Cookoo()

	// Fill the registry.
	registry.AddRoutes(
		cookoo.Route{
			Name: "TEST",
			Help: "A test route",
			Does: cookoo.Tasks{
				cookoo.Cmd{
					Name: "hi",
					Fn:   HelloWorld,
				},
			},
		},
	)

	// Execute the route.
	router.HandleRequest("TEST", context, false)
}

func HelloWorld(cxt cookoo.Context, params *cookoo.Params) (interface{}, cookoo.Interrupt) {
	fmt.Println("Hello World")
	return true, nil
}

Documentation

• The Web App tutorial
• The CLI Tutorial
• The API Reference

A Real Example

For a real example of Cookoo, take a look at Skunk.

Here's what Skunk's registry looks like:

	registry.
	Route("scaffold", "Scaffold a new app.").
		Does(LoadSettings, "settings").
			Using("file").WithDefault(homedir + "/settings.json").From("cxt:SettingsFile").
		Does(MakeDirectories, "dirs").
			Using("basedir").From("cxt:basedir").
			Using("directories").From("cxt:directories").
		Does(RenderTemplates, "template").
			Using("tpldir").From("cxt:homedir").
			Using("basedir").From("cxt:basedir").
			Using("templates").From("cxt:templates").
	Route("help", "Print help").
		Does(Usage, "Testing")

This has two routes:

• scaffold
• help

The help route just runs the command Usage, which looks like this:

func Usage(cxt cookoo.Context, params *cookoo.Params) interface{} {
	fmt.Println("Usage: skunk PROJECTNAME")
	return true
}

That is a good example of a basic command.

The scaffold route is more complex. It performs the following commands (in order):

• LoadSettings: Load a settings.json file into the context.
• MakeDirectories: Make a bunch of directories.
• RenderTemplates: Perform template conversions on some files.

The MakeDirectories command is an example of a more complex command. It takes two parameters (declared with Using().From()):

1. basedir: The base directory where the new subdirectories will be created. This comes from the cxt:basedir source, which means Cookoo looks in the Context object for a value named basedir.
2. directoies: An array of directory names that this command will create. These come from cxt:directories, which means that the Context object is queried for the value of directories. In this case, that value is actually loaded from the settings.json file into the context by the LoadSettings command.`

With that in mind, let's look at the command:

// The MakeDirectories command.
// All commands take a Context and a Params object, and return an
// interface{}
func MakeDirectories(cxt cookoo.Context, params *cookoo.Params) interface{} {

	// This is how we get something out of the Params object. This is the
	// value that was passed in by `Using('basedir').From('cxt:basedir')
	basedir := params.Get("basedir", ".").(string)

	// This is another way to get a parameter value. This form allows us
	// to conveniently check that the parameter exists.
	d, ok := params.Has("directories")
	if !ok {
		// Did nothing. But we don't want to raise an error.
		return false
	}

	// We do have to do an explicit type conversion.
	directories := d.([]interface{})

	// Here we do the work of creating directories.
	for _, dir := range directories {
		dname := path.Join(basedir, dir.(string))
		os.MkdirAll(dname, 0755)
	}

	// We don't really have anything special to return, so we just
	// indicate that the command was successful.
	return true
}

This is a basic example of working with Cookoo. But far more sophisticated workflows can be built inexpensively and quickly, and in a style that encourages building small and re-usable chunks of code.