mcrumm / pecan
An event-driven, non-blocking shell for ReactPHP based on the Symfony Console Shell.
Requires
- php: >= 5.4
- react/react: 0.4.*
- symfony/console: ~2.4
This package is not auto-updated.
Last update: 2024-10-26 16:05:14 UTC
README
Event-driven, non-blocking shell for ReactPHP.
Pecan (/pɪˈkɑːn/
) provides a non-blocking alternative to the shell provided in the Symfony Console component. Additionally, Pecan includes a basic, framework-agnostic shell component called Drupe
that can be used as the basis for building custom shells.
Shells
Drupe
Pecan\Drupe
is a standalone component for building event-driven console components. I like to think of it as Pecan without the Shell.
Pass an EventLoopInterface
to start()
listening for input.
$loop = \React\EventLoop\Factory::create();
$shell = new \Pecan\Drupe();
// $shell->start() returns $loop to allow this chaining.
$shell->start($loop)->run();
Drupe Events
running
- The shell is running.data
- Data was received fromSTDIN
.error
- Indicates an I/O problem.close
- The shell was closed.
Shell
Pecan\Shell
extends Drupe
to provide an event-driven wrapper for a standard Symfony\Component\Console\Application
. It can be used as a drop-in replacement for Symfony\Component\Console\Shell
.
Note: To maintain a Symfony Console-like workflow, calling
$shell->run()
onPecan\Shell
starts the EventLoop, so make sure it gets called last.
Shell Events
Shell
emits the same events as Drupe
.
Readline
Pecan\Readline
provides an interface for reading line-by-line input from STDIN
. This component is heavily inspired by, and strives for parity with the NodeJS Readline Component.
Readline Events
line
- A line has been read fromSTDIN
.pause
- Reading from the stream has been paused.resume
- Reading from the stream has resumed.error
- The input stream encountered an error.close
- Then input stream was closed.
Console
Pecan\Console\Console
provides a standard interface for working with STDOUT
and STDERR
. It is inspired heavily by the NodeJS Console Component and takes some functionality from the Symfony Console Component
Output
The Output classes extend the base Console Output. StreamOutput
wraps a single stream resource, while ConsoleOutput
contains both the STDOUT
and STDERR
streams.
StreamOutputInterface
ConsoleOutputInterface
PecanOutput
Using Pecan
Using Drupe as a Standalone Shell
use Pecan\Drupe; $loop = \React\EventLoop\Factory::create(); $shell = new Drupe(); // Example one-time callback to write the initial prompt. // This resumes reading from STDIN and kicks off the shell. $shell->once('running', function (Drupe $shell) { $shell->setPrompt('drupe> ')->prompt(); }); // Example callback for the data event. // By convention, any call to write() will be followed by a call to prompt() // once the data has been written to the output stream. $shell->on('data', function ($line, Drupe $shell) { $command = (!$line && strlen($line) == 0) ? false : rtrim($line); if ('exit' === $command || false === $command) { $shell->close(); } else { $shell->writeln(sprintf(PHP_EOL.'// in: %s', $line)); } }); // Example callback for the close event. $shell->on('close', function ($code, Drupe $shell) { $shell->writeln([ '// Goodbye.', sprintf('// Shell exits with code %d', $code), ]); }); $shell->start($loop)->run();
Using Shell with Symfony Console Applications
Here is a shell that echoes back any input it receives, and then exits.
// Pecan\Shell wraps a standard Console Application. use Symfony\Component\Console\Application; use Pecan\Shell; $shell = new Shell(new Application('pecan')); $shell->on('data', function($line, Shell $shell) { $shell->write($line)->then(function($shell) { $shell->close(); }); }); $shell->run();
Injecting An EventLoopInterface
into Pecan\Shell
Unless you pass \Pecan\Shell
an object implementing EventLoopInterface
as its second constructor method, the Shell
will get one from the EventLoop Factory. Keep this in mind if you want to integrate Pecan into an existing ReactPHP project.
use Symfony\Component\Console\Application; use Pecan\Shell; $loop = \React\EventLoop\Factory::create(); // Do other things requiring $loop... $shell = new Shell(new Application('pecan'), $loop); // We must still let the shell run the EventLoop. $shell->run();
Example exit
callback
// Example callback for the exit event. $shell->on('exit', function($code, \Pecan\Shell $shell) { $shell->emit('output', [ [ 'Goodbye.', sprintf('// Shell exits with code %d', $code) ], true ]); });