Writing Modern Web Applications In Nim

Nim has two famous web frameworks for frontend and backend development - Jester and Karax, but this post not about them.

This post about HappyX web framework.

In HappyX a lot of things runs at compile-time due to metaprogramming (macro-oriented). It's mean that your web application will be faster than more other apps created in other web frameworks.

In HappyX you can write both server-side and client-side applications with the same code. This allows developers spend less time to development.

Here also a LOT of syntax sugar due to DSL (Domain-specific language), ex:

# Server-side application example
import happyx


# declare server at http://127.0.0.1:5000
serve "127.0.0.1", 5000:
  # Will match /user/id100, /user/id0, /user/id25, etc.
  # Don't match /user/idSomeId
  get "/user/id$id:int":
    # Respond JSON
    # `id` is immutable variable
    return {"response": fmt"Hello, user[{id}]"}

  # Will match /post/c0ffe, /post/babe, /post/cafe, etc.
  # Don't match /post/SomeId
  get "/post/$postId:/[a-fA-F0-9]+/":
    # Respond JSON
    # `postId` is immutable variable
    return {"response": postId}

There are also CLI for creating, building and serving your projects!

hpx create --name my_project --kind SPA --use-tailwind
cd my_project
hpx build
hpx dev --reload

You can also convert HTML files into HappyX files with html2tag command:

hpx html2tag source.html --output output

Frontend Example

import happyx

# Declare our application and set target element with id="app"
appRoutes "app":
  # Will be at example.com/#/home
  "/home":
    tDiv(class = "someClass"):  # equal to <div class="someClass">
      "Hello, world!"  # equal to Hello, world!

Backend Example

import happyx

# Declare our application
serve "127.0.0.1", 5000:
  # will be at http://127.0.0.1:5000/
  get "/":
    # plain/text
    return "Hello, world!