Crim

Crim is a crystal language micro framework inspired by Slim Framework 3 and other micro frameworks from PHP.

I made Crim to learn Crystal and it introduces me to a lot of different features of the language from macros to regular expressions. So far I believe I've used a lot of the crystal language base features in this project and it's been a blast. If you have any feedback or want to contribute please feel free to add a PR, but please remember currently not everything will be accepted as I'd like to dictate and keep this micro framework as minimal as possible.

Development

Crim is in early stages so please bare with me while I get the base of the project complete before contributing or using this framework.

Installation

Add the following to your dependencies

dependencies:
  Crim:
    github: exts/Crim
    version: <=1.0.0

Example Application

require "Crim"

include Crim::Http::Handlers
include Crim::Http::Router

# Example Action Controller
class ExampleController < Action
  def action(request, response)
    response.write "hello!, World it works!".to_slice
    response
  end
end

routes = RouteContainer.new
routes.get "/", {controller: ExampleController.new, action: nil}

app = Crim::Server.new
app.add_middleware LogHandler.new "example.log"
app.add_middleware RouteHandler.new routes
app.run

Routes & Group Routes

All routes require a route (String) and a NamedTuple(controller: Action, action: String) when being called. You also have optional parameters default and regex. Default allows you to force default values for named variables that don't match anything. You'd usually want to use it for optional parameters. The regex parameter allows you to force a named route variable to match your regular expression. So for instance you'd want only numbers for "page" you could do {"page" => %q(\d+)}. Currently the default & regex parameters are stored as a Hash(String, String). I'm contemplating changing it to Hash(String, String | Int32 | Float32), for now it seems fine for what we need.

Example of Group Routes

routes = RouteContainer.new
routes.group "/admin", do |route|
  route.group "/users", do |route|
    route.any "/update/:id", {controller: ExampleController.new, action: "update"}
  end
end

(Note: Group routes can be as deep as you want, but I wouldn't recommend it)

Example use of default & regex

routes = RouteContainer.new
routes.any "/post/:id[/:page]", {controller: ExampleController.new, action: nil}, default: {"page", "1"}

or

routes = RouteContainer.new
routes.any "/post/:id[/:page]", {controller: ExampleController.new, action: nil}, {"id", %q(\d+)}, {"page", "1"}

Optional Routes

Crim offers the ability to have optional routes because we use a cheap solution on converting square brackets into optional non capturing groups [] => (?:)? which allows us to pretty much have infinite grouped optional parameters like so:

/route[/:example[/:sub_route[/:another_sub_route]]]

Contributors