Kraut

Kraut is a router for Karax frontend framework.

Kraut is best served with Sauer 👨‍🍳

Installation

Install Kraut with nimble:

$ nimble install kraut

Add it to your .nimble file:

require "kraut >= 1.0.0"

Kraut doesn’t have any dependencies outside stdlib except for Karax (duh).

Usage

First, define your routes as an array or sequence of pattern-renderer pairs.

Pattern is a string that Kraut uses to match against the hash part of the URI.

Renderer is proc that takes a single argument of type Context and returns a VNode.

Context is an object that holds the URL params extracted from the hash part in its urlParams field and the query params in qryParams.

Nim offers nice syntax to define Kraut routes:

# app.nim

const routes = {
  "/": index.render,
  "/users/": users.render,
  "/users/{userId}/": user.render
}

In this example, "/users/{userId}" is a pattern and user.render us a renderer.

You can split your routes into groups for maintainability and even store the groups in different modules:

const
  indexRoute = @{"/": index.render}
  userRoutes = @{"/users/": users.render, "/users/{userId}/": user.render}
  routes = indexRoute & userRoutes

Next, define your renderers:

# user.nim
import kraut

proc render*(context: Context): VNode =
  buildHtml(tdiv):
    text "User id: " & context.urlParams["userId"]

Finally, generate the route renderer proc. It’s a proc that accepts a single RouterData argument and returns a VNode. It can be passed directly to Karax’s setRenderer proc or used inside another proc:

# app.nim
import kraut

let renderer = routerRenderer(routes)

proc render(routerData: RouterData): VNode = 
  buildHtml(tdiv):
    h1: text "Header"

    renderer(routerData)

setRenderer(render)

See the complete example in the demo folder.

Why you should use Kraut

1. Route definition is dead simple.
2. You can split your definitions and store them in separate modules.
3. Renderer proc doesn’t have to be anything special, it’s just a regular proc you would use in Karax without Kraut, sans the Context argument.
4. Kraut is efficient. No heavy regexes or hash maps, just iteration and string comparison that stops with the first match.