DEV Community

Tomasz Wegrzanowski
Tomasz Wegrzanowski

Posted on

Open Source Adventures: Episode 20: Imba 2 ROT-N

#imba #javascript

I want to start porting Imba 1 apps to Imba 2 with the simplest one - ROT-N decoder. Here's Imba 1 version.

You either paste text into the box or use file upload, and then it decodes every ROT-N from ROT-1 to ROT-25. It's somewhat useful for elementary hacking challenges.

Imba 1 app.imba

There's very little complicated here. rot(n) does the the rotating, upload handles upload events, and render renders the view.

tag App def setup @text = "Hello, world!" def rot(n) @text.replace /[a-z]/gi do |c| let i = c.charCodeAt(0) if i >= 97 and i <= 122 String.fromCharCode(((i - 97 + n) % 26) + 97) else if i >= 65 and i <= 90 String.fromCharCode(((i - 65 + n) % 26) + 65) else c def upload(event) let file = event.native:target:files[0] return unless file let reader = FileReader.new reader:onload = do |event| @text = event:target:result @error = nil Imba.commit reader.read-as-text(file) def render <self> <div.contents> <header> "ROT-N" <textarea[@text]> <div> <input#file type="file" :change.upload> <table> for i in [1..25] <tr .{"rot-{i}"}> <th> i <td> rot(i) Imba.mount <App>
Enter fullscreen mode Exit fullscreen mode

Imba 1 app.scss 

@import 'normalize-scss'; @include normalize(); .App { display: flex; justify-content: space-around; max-width: 1000px; margin: auto; header { font-size: 64px; text-align: center; } textarea { min-width: 50vw; min-height: 100px; } th { padding-right: 5px; } }
Enter fullscreen mode Exit fullscreen mode

Getting started

I had a boilerplate with settings I like, like GitHub Pages, SCSS, but let's start fresh with npx imba create imba2-rotn.

There are some truly attrocious settings in it - .vscode and .editorconfig forcing 4 space indentation, both straight into trash. Even if Imba insists on tabs, they should be visually 2 spaced, or it looks like ass.

OK, with that out of the way we can start coding.

app/index.html

This only requires changing the title, the rest is fine.

<html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>Imba 2 ROT-N</title> <!-- reference to the client script styles --> <style src='*'></style> </head> <body> <!-- reference to the client script --> <script type="module" src="./client.imba"></script> </body> </html>
Enter fullscreen mode Exit fullscreen mode

app/client.imba

This is fairly close to direct translation:

tag app prop text = "Hello, World!" def rot(n) text.replace /[a-z]/gi do |c| let i = c.charCodeAt(0) if i >= 97 and i <= 122 String.fromCharCode(((i - 97 + n) % 26) + 97) else if i >= 65 and i <= 90 String.fromCharCode(((i - 65 + n) % 26) + 65) else c def upload(event) let file = event.target.files[0] return unless file let reader = new FileReader reader.onload = do |event| text = event.target.result imba.commit() reader.readAsText(file) <self> <div.contents> <header> "ROT-N" <textarea bind=text> <div> <input#file type="file" :change.upload> <table> for i in [1 .. 25] <tr> <th> i <td> rot(i) css display: flex justify-content: space-around max-width: 1000px margin: auto ff: sans header font-size: 64px text-align: center textarea min-width: 50vw min-height: 100px th padding-right: 5px imba.mount <app>
Enter fullscreen mode Exit fullscreen mode

Some differences:

  • CSS is not in the component, getting translated the usual way just like Svelte does it
  • there's no wrapping render function, it's just a <self> (which becomes <app-tag>, it's all web components on top level)
  • syntax is a bit different <textarea[text]> becomes <textarea bind=text>
  • extra spaces needed in range [1 .. 25]
  • no more : vs . distinction
  • no more read-as-text becoming readAsText - Imba 2 still allows - in names, but it translates them to some Unicode character, so all DOM APIs will be uglyCamelCame
  • Ruby-style FileReader.new is now JavaScript-style new FileReader
  • I'm not totally sure where () are needed and where they aren't, the rules are different now

But overall it was very straightforward port.

Source code

Source code is in imba2-rotn repository. At some point I'll try to add GitHub Pages support for it.

Coming next

In the next few episodes I'll try to port a few more Imba 1 apps to Imba 2, and then I guess I'll summarize my thoughts about Imba situation.

Top comments (0)