Thursday, May 20, 2021

A far too simple (hardcoded) tasks backend in Objective-S

Recently there was a question as to what one should use to create a backend for an iOS/macOS app these days. I couldn't resist mentioning Objective-S, and just to check for myself whether that's feasible, I quickly jotted down the following tiny backend that returns a hardcoded list of tasks via HTTP:
#!env stsh
framework:ObjectiveHTTPD load.

class Task {
   var <bool> done.
   var title.
   -description { "Task: {this:title} done: {this:done}". }

taskList ← #( #Task{ #title: 'Clean my room', #done: false }, #Task{ #title: 'Check twitter feed', #done: true } ).

scheme todo {
   var taskList.
   /tasks { 
      |= { 

todo := #todo{ #taskList: taskList }.
server := #MPWSchemeHttpServer{ #scheme: todo, #port: 8082 }.
server start.
shell runInteractiveLoop.

After loading the HTTP framework, we define a Task and a list of two example tasks. Then we define a scheme with a single path, just /tasks, which returns said tasks list. We then instantiate the scheme and serve it via HTTP on port 8082. Since this is a shell script and starting the server does not block, we finally start up the REPL.

Details such as coding the tasks as JSON, accessing a single task and modifying tasks are left as exercises for the reader.

No comments: