CodeParadise Running Smalltalk apps in a JavaScript environment

Talk from ESUG 2024

"CodeParadise Running Smalltalk apps in a JavaScript environment"

PDF: http://archive.esug.org/ESUG2024/day3/04-Code-paradise.pdf

1. Erik Stel (aka ErikOnBike) - ESUG 2024 - July 10th 2024
CodeParadise
Running Smalltalk apps in a JavaScript environment

2. Topics
And some demos
•How it started
•Ease of development
•Implementation
•From WebApps to ServerApps
•Status

3. How it started
Creating WebApps with Smalltalk only
•Live programming experience in the browser
•Approach based on tiny Smalltalk image in the browser
•Most important part: DOM manipulation
•DOM elements, WebComponents and Events
•Fine grained control and performance

4. Ease of development
The MVP pattern
•Personal preference: thin UI/glass layer
•MVP with a Passive View
•Views are WebComponents
•Server side state
•No ‘sealing’ possible
P
M V
knows
knows

5. Implementation
Let’s keep it tiny
•Tiny (218kb) Smalltalk image in the browser

Client Environment
•Regular Smalltalk image on the ‘server’

Server Environment
•SqueakJS VM
•Class definitions and CompiledCode (no compiler)
•WebSockets

6. Architecture
Server
ServerEnvironment
ServerCommunicator
ZincWebSocketChannel
MvpWebApplication
Presenter Presenter
Client / Web Browser
ClientEnvironment (singleton)
ClientCommunicator
JavascriptWebSocketChannel
MvpWebClientBehavior
(singleton)
View
View
Server sends Messages and CompiledMethods (bytecode) to execute
Client sends Announcements

7. Demo
Talk is cheap

8. From WebApps to ServerApps
Or CLI tools
•Generic proxy mechanism
•Smalltalk Block interchangeable with JavaScript function
•Promises
•Node.js (built-in and external) modules
•Also ‘sealable’

9. Demo
REST assured

10. Status
200 / OK
•In use at

- ‘residential biologist’

- one Cycling Without Age ‘chapter’
•Room to evolve

- Documentation/examples/tests

- UI builder

- Node.js debugger

- Morph changed object (instances)

- …many more…

11. Questions!
Remarks?
•You can find CodeParadise at

github.com/ErikOnBike/CodeParadise
•You can find me on Discord/Slack as

ErikOnBike