Utilities

AGS comes with some builtin utilities for common operations.

File functions

Reading files

import { readFile, readFileAsync } from "ags/file"

function readFile(path: string): string
function readFileAsync(path: string): Promise<string>

Writing files

import { writeFile, writeFileAsync } from "ags/file"

function writeFile(path: string, content: string): void
function writeFileAsync(path: string, content: string): Promise<void>

Monitoring files

If path is a directory it will be recursively monitored.

import { monitorFile } from "ags/file"

function monitorFile(
  path: string,
  callback: (file: string, event: Gio.FileMonitorEvent) => void,
): Gio.FileMonitor

Timeouts and Intervals

import { interval, timeout, idle, createPoll } from "astal/time"

You can use javascript native setTimeout or setInterval they return a GLib.Source instance. Alternatively you can use these functions provided by Astal, which return an AstalIO.Time instance.

AstalIO.Time has a now signal and a cancelled signal.

Interval

Will immediately execute the function and every interval millisecond.

function interval(interval: number, callback?: () => void): AstalIO.Time

Timeout

Will execute the callback after timeout millisecond.

function timeout(timeout: number, callback?: () => void): AstalIO.Time

Idle

Executes callback whenever there are no higher priority events pending.

function idle(callback?: () => void): AstalIO.Time

Example:

const timer = interval(1000, () => {
  console.log("optional callback")
})

timer.connect("now", () => {
  console.log("tick")
})

timer.connect("cancelled", () => {
  console.log("cancelled")
})

timer.cancel()

createPoll

createPoll creates a signal that only polls when there is at least one subscriber.

function createPoll(
  init: string,
  interval: number,
  exec: string | string[],
): Accessor<string>

function createPoll<T>(
  init: T,
  interval: number,
  exec: string | string[],
  transform: (stdout: string, prev: T) => T,
): Accessor<T>

function createPoll<T>(
  init: T,
  interval: number,
  fn: (prev: T) => T | Promise<T>,
): Accessor<T>

Example:

function Counter() {
  const conuter = createPoll(0, 1000, (prev) => prev + 1)

  return <label label={counter((c) => c.toString())} />
}

Process functions

Import from astal or astal/process

import { subprocess, exec, execAsync, createSubprocess } from "astal/process"

Subprocess

You can start a subprocess and run callback functions whenever it outputs to stdout or stderr. AstalIO.Process has a stdout and stderr signal.

function subprocess(args: {
  cmd: string | string[]
  out?: (stdout: string) => void
  err?: (stderr: string) => void
}): AstalIO.Process

function subprocess(
  cmd: string | string[],
  onOut?: (stdout: string) => void,
  onErr?: (stderr: string) => void,
): AstalIO.Process

Example:

const proc = subprocess(
  "some-command",
  (out) => console.log(out), // optional
  (err) => console.error(out), // optional
)

// or with signals
const proc = subprocess("some-command")
proc.connect("stdout", (_, out) => console.log(out))
proc.connect("stderr", (_, err) => console.error(err))

Executing external commands and scripts

function exec(cmd: string | string[]): string
function execAsync(cmd: string | string[]): Promise<string>

Example:

try {
  const out = exec("/path/to/script")
  console.log(out)
} catch (err) {
  console.error(err)
}

execAsync(["bash", "-c", "/path/to/script.sh"])
  .then((out) => console.log(out))
  .catch((err) => console.error(err))

WARNING

subprocess, exec, and execAsync executes the passed executable as is. They are not executed in a shell environment, they do not expand ENV variables like $HOME, and they do not handle logical operators like && and ||.

If you want bash, run them with bash.

exec(["bash", "-c", "command $VAR && command"])
exec("bash -c 'command $VAR' && command")

createSubprocess

createSubprocess creates a signal that starts a subprocess when the first subscriber appears and kills the subprocess when number of subscribers drop to zero.

export function createSubprocess(
  init: string,
  exec: string | string[],
): Accessor<string>

export function createSubprocess<T>(
  init: T,
  exec: string | string[],
  transform: (stdout: string, prev: T) => T,
): Accessor<T>

Example:

function Log() {
  const log = createSubprocess("", "journalctl -f")

  return <label label={log} />
}

Http requests

import { fetch, URL } from "ags/fetch"

const url = new URL("https://some-site.com/api")
url.searchParams.set("hello", "world")

const res = await fetch(url, {
  method: "POST",
  body: JSON.stringify({ hello: "world" }),
  headers: {
    "Content-Type": "application/json",
  },
})

const json = await res.json()