Ralph (Jan 19 2024 at 14:22): Ralph (Jan 19 2024 at 14:22):OK, bear with me, but I want to use javascript (NOT my language, though easy learn) to create a wasi:http component for preview 2. I can do custom wit components easily enough using this sample: https://github.com/bytecodealliance/ComponentizeJS/blob/main/EXAMPLE.md. What is done up front is to take a .wit file and then implement the function listed there, nothing fancy. So far so good. So I have the wasi wit block in a repo.... But I need to understand the binding step for js. In the example above, you merely reference hello and then implement hello and call jco componentize and you have a component.
Ralph (Jan 19 2024 at 14:22):But that's custom wit.
Ralph (Jan 19 2024 at 14:24):so for wasi:http, do I need to implement this?
Ralph (Jan 19 2024 at 14:24):interface incoming-handler {
use types.{incoming-request, response-outparam};
/// This function is invoked with an incoming HTTP Request, and a resource
/// response-outparam which provides the capability to reply with an HTTP
/// Response. The response is sent by calling the response-outparam.set
/// method, which allows execution to continue after the response has been
/// sent. This enables both streaming to the response body, and performing other
/// work.
///
/// The implementor of this function must write a response to the
/// response-outparam before returning, or else the caller will respond
/// with an error on its behalf.
handle: func(
request: incoming-request,
response-out: response-outparam
);
}
Ralph (Jan 19 2024 at 14:26):what I'm missing as a newbie here is the binding mechanism between the WIT function " and the js needed to implement it. Do I simply "implement the function" name, as I can do with the above hello function?
Ralph (Jan 19 2024 at 14:26):or is there a js binding generator for wasi:http/proxy that I need to locate and them merely "import" the types to use?
Ralph (Jan 19 2024 at 14:27):i get that concept, and I'm golden here.
Ralph (Jan 19 2024 at 15:14):wait, are these they: do I just need to reference them in the package.json?
Ralph (Jan 19 2024 at 15:14):},
"devDependencies": {
"@bytecodealliance/jco": "^0.14.2",
"@bytecodealliance/preview2-shim": "^0.14.2",
Ramon Klass (Jan 19 2024 at 15:23):I'm not sure if the shim includes wasi-http but in general yes, you add jco to your devDependencies and preview2-shim to your dependencies and then jco transpile'd components "just work" but as I said I only use preview2, I didn't follow. the wasi-http changes yet
Ralph (Jan 19 2024 at 15:27):I'm on preview 12_05, so that's fine
Ralph (Jan 19 2024 at 15:33):sorry for not using
Ralph (Jan 19 2024 at 15:33):
in terms of the JS to define to componentize, you'd want to write a JS file like:
export const incomingHandler = {
handle(request, response) {
// ...
},
};
we do have an example of using outgoing handler in ComponentizeJS in https://github.com/bytecodealliance/jco/blob/main/test/fixtures/componentize/wasi-http-proxy/source.js although it doesn't contain the incoming handler currently, so you'd need to check the types to figure it out.
Generating template JS / TypeScript bindings for these ComponentizeJS workflows has been a TODO for a while... agreed it should be a thing.
Ralph (Jan 19 2024 at 19:08):thanks Guy; if I've imported preview2-shim and npm intalled, I seem to get the incomingHandler type and it resolves, so hopefully that's really all I need to do.....
Ralph (Jan 19 2024 at 19:10):when you say generating bindings, what do you mean that's not:
image.png
Guy Bedford (Jan 19 2024 at 19:15):that looks right, although in ComponentizeJS the bindings have a different import convention - import 'wasi:http@0.2.0-rc-2024-01-16/incoming-handler etc instead
Guy Bedford (Jan 19 2024 at 19:16):but if you are just having this import for IDE types to work out making it an import type { IncomingHandler } from '@bytecodealliance/preview2/http' might make sense with tsc itself stripping that out
Ramon Klass (Jan 19 2024 at 19:16):at least with jco transpile, it does put the .d.ts files in the right locations and IDEs can just autocomplete imports
Guy Bedford (Jan 19 2024 at 19:17):yeah so if we had something similar for ComponentizeJS it might be useful to generate types that work for authoring components to arbitrary WIT
Ralph (Jan 19 2024 at 19:17):well, from my position I've been building all the wasi:http languages as best I can
Ralph (Jan 19 2024 at 19:18):I have dan's rust, Joe's go, and Joel's Python implementations of incomingHandler(). So here I am, wanting to make a JavaScript incomingHandler() impl for comparison.
Ralph (Jan 19 2024 at 19:19):but I couldn't figure out where to get the .js/.ts types for wasi:http
Ralph (Jan 19 2024 at 19:20):npm install preview2-shim gave them to me, which sure seemed easy to me......
Ralph (Jan 19 2024 at 19:21):but note, once I have this running I'll be at the point where I need to create a module from the .js (with spidermonkey) and then I can make that module a component.
Ramon Klass (Jan 19 2024 at 19:22):I think that's where componentizeJS comes in, it should implement the "make a component out of a js file and spidermonkey" step
Ralph (Jan 19 2024 at 19:23):that's what I think, too, but isn't jco component that comment?
Ralph (Jan 19 2024 at 19:23):command?
Ralph (Jan 19 2024 at 19:23):because help says that YOU MUST have a component on the argument line
Ramon Klass (Jan 19 2024 at 19:24):yeah I also was confused, from the docs both implement the same, @Guy Bedford probably needs to answer that
Ralph (Jan 19 2024 at 19:24):whoops, no, I'm wrong
Ralph (Jan 19 2024 at 19:24):apologies
Ralph (Jan 19 2024 at 19:25):It appears I need to: jco componentize -w <path> -o hello-wasi-http-js.wasm index.js
Ramon Klass (Jan 19 2024 at 19:25):transpile takes a component and turns that into browser and node-compatible js, componentize seems to implement the same as componentizeJS does, if going by the docs?
Ralph (Jan 19 2024 at 19:25):and that should work
Ralph (Jan 19 2024 at 19:26):yeah, just working over Guy's stuff so I can complain because he and wassim and yosh and others worked so hard
Ralph (Jan 19 2024 at 19:26)::-)
Ralph (Jan 19 2024 at 19:26):goint to give this a try
Ralph (Jan 19 2024 at 19:26):if it works, I'm going to drink and tell Guy it's amazing
Ramon Klass (Jan 19 2024 at 19:28):it was a weird feeling the first time I ran my own pyo3+python based example in a browser, it's impressive how far the component model has come :)
Last updated: Nov 22 2024 at 16:03 UTC