CLI and App

App is a singleton instance of an Astal.Application.

Depending on gtk version import paths will differ

import { App } from "astal/gtk3"
import { App } from "astal/gtk4"

Entry point

app.ts

App.start({
    main() {
        // setup anything
        // instantiate widgets
    },
})

Instance identifier

You can run multiple instances by defining a unique instance name.

App.start({
    instanceName: "my-instance", // defaults to "astal"
    main() { },
})

Messaging from CLI

If you want to interact with an instance from the CLI, you can do so by sending a message.

App.start({
    requestHandler(request: string, res: (response: any) => void) {
        if (request == "say hi") {
            return res("hi cli")
        }
        res("unknown command")
    },
    main() { },
})

astal say hi
# hi cli

If you want to run arbitrary JavaScript from CLI, you can use App.eval which will evaluate the passed string as the body of an async function.

App.start({
    main() {},
    requestHandler(js, res) {
        App.eval(js).then(res).catch(res)
    },
})

If the string does not contain a semicolon, a single expression is assumed and returned implicity.

astal "'hello'"
# hello

If the string contains a semicolon, you have to return explicitly

astal "'hello';"
# undefined

astal "return 'hello';"
# hello

Toggling Windows by their name

In order for Astal to know about your windows, you have to register them. You can do this by specifying a unique name and calling App.add_window

import { App } from "astal/gtk3"

function Bar() {
    return <window name="Bar" setup={self => App.add_window(self)}>
        <box />
    </window>
}

You can also invoke App.add_window by simply passing the App to the application prop.

import { App } from "astal/gtk3"

function Bar() {
    return <window name="Bar" application={App}>
        <box />
    </window>
}

WARNING

When assigning the application prop make sure name comes before. Props are set sequentially and if name is applied after application it won't work.

astal -t Bar

Client

The first time you execute your script the main function gets called. While that instance is running any subsequent execution of the script will call the client function.

main.ts

App.start({
    // main instance
    main(...args: Array<string>) {
        print(...args)
    },

    // every subsequent calls
    client(message: (msg: string) => string, ...args: Array<string>) {
        const res = message("you can message the main instance")
        print(res)
    },

    // this runs in the main instance
    requestHandler(request: string, res: (response: any) => void) {
        res("response from main")
    },
})