jester

Jester supports a simple cond template. If the condition evaluates to false, execution passes to the next matching route in the routes block.

routes:
  get "/@name":
    cond @"name" == "daniel"
    # This only executes if @"name" is "daniel"
    resp "Correct, my name is daniel."

  get "/@name":
    # This executes if the previous route's condition failed
    resp "No, that's not my name."

Jester is a Sinatra-like web framework for Nim. To create a basic application, use the routes macro and define HTTP methods like get with a path.

Security Warning: Jester is not yet hardened against HTTP security exploits. Always run your application behind a reverse proxy before exposing it to the public internet.

# example.nim
import htmlgen
import jester

routes:
  get "/":
    resp h1("Hello world")

To run the example:

cd tests/example
nim c -r example.nim

All routes must be wrapped in a routes block. Routes are executed in the order they are declared.

Path Patterns

Jester uses the @ symbol for path parameters (similar to Sinatra's :):

• get "/hello/@name": Matches /hello/fred. The value is accessible via the @name syntax.
• Optional parts: Use ? to make a path segment optional. For example, get "/hello/@name?" matches both /hello/fred and /hello/.
• Optional leading slash: To match both /hello and /hello/, use get "/hello/?@name?".

Note: Jester does not currently support wildcard patterns.

get "/hello/@name":
  resp "Hello " & @"name"

get "/hello/@name?":
  if @"name" == "":
    resp "No name received :("
  else:
    resp "Hello " & @"name"

By default, Jester serves static files from the ./public directory. You can change this using the setStaticDir function.

Note: Files must be readable by others (e.g., chmod o+r ./public/css/style.css on Unix/Linux) to be served.

If you need to run custom initialization code or pass dynamic settings before starting the async loop, you can implement a custom router using initJester instead of the routes macro.

import asyncdispatch, jester, os, strutils

router myrouter:
  get "/":
    resp "It's alive!"

proc main() =
  let port = paramStr(1).parseInt().Port
  let settings = newSettings(port=port)
  var jester = initJester(myrouter, settings=settings)
  jester.serve()

when isMainModule:
  main()

Use setCookie to set a cookie. You can specify an expiration using helpers like daysForward. To read cookies, access request.cookies, which returns a Table[string, string].

get "/":
  # Set a cookie "test:value" to expire in 5 days.
  setCookie("test", @"value", daysForward(5))

Route bodies have access to an implicit request object. To return a response, use one of the following methods:

• Use the resp functions.
• Set request.body, request.headers, and/or request.status, then call return.
• Use the redirect function.
• Use the attachment function.

You can use regular expressions for route matching. When a regex route matches, the captured subpatterns are stored in the request.matches array.

get re"^\/([0-9]{2})\.html$":
  resp request.matches[0]