class atk4\\ui\Console

Console

_images/console.png

With console you can output real-time information to the user directly from PHP. It can be used do direct output from slow method or even execute commands on the server (such as ping).

Demo: http://ui.agiletoolkit.org/demos/console.php

Basic Usage

atk4\\ui\Console::set($callback)
atk4\\ui\Console::send($callback)

After adding a console to your Render Tree, you just need to set a call-back:

$console = $app->add('Console');
$console->set(function($console) {

    // This will be executed through SSE request

    $console->output('hello');

    echo 'world'; // also will be redirected to console

    sleep(2);

    $console->send(new \atk4\ui\jsExpression('alert([])', ['The wait is over']);
});

Console uses Server Sent Event (jsSSE) which works pretty much out-of-the-box with the modern browsers and unlike websockets do not require you to set up additional ports on the server. JavaScript in a browser captures real-time events and displays it on a black background.

Console integrates nicely with DebugTrait (http://agile-core.readthedocs.io/en/develop/debug.html?highlight=debug), and also allows you to execute shell process on the server while redirecting output in real-time.

Using With Object

runMethod($callback);

We recommend that you pack up your busineess logic into your Model methods. When it’s time to call your method, you could either do this:

$user->generateReport(30);

Which would execute your own routine for some report generation, but doing it though a normal request will look like your site is slow and is unable to load page quick. Alternative is to run it through a console:

$console->runMethod($user, 'generateReport', [30]);

This will display console to the user and will even output information from inside the model:

use \atk4\core\DebugTrait();

function generateReport($pages) {
    $this->info('converting report to PDF');

    // slow stuff
    $this->info('almost done, be patient..');

    // more slow stuff
    return true;
}

You can also execute static methods:

$console->runMethod('StaticLib', 'myStaticMethod');

Executing Commands

exec($cmd, $args);

To execute a command, use:

$console->exec('/sbin/ping', ['-c', '5', '-i', '1', '192.168.0.1']);

This will run a command, and will stream command output to you. Console is implemented to capture both STDOUT and STDERR in real-time then display it on the console using color. Console does not support ANSI output.

Method exec can be executed directly on the $console or inside the callback:

$console->set(function($console){

    $console->eval();

});

Without call-back, eval will wrap itself into a callback but you can only execute a single command. When using callback form, you can execute multiple commands:

$app->add('Console')->set(function($c){
    $c
        ->exec('/sbin/ping', ['-c', '5', '-i', '1', '192.168.0.1'])
        ->exec('/sbin/ping', ['-c', '5', '-i', '2', '8.8.8.8'])
        ->exec('/bin/no-such-command')
        ;
});

Method exec() will return $this if command was run inside callback and was successful. It will return false on error and will return null if called outside of callback. You may also refer to :Console::last_exit_code which contains exit code of the last command.

Normally it’s safe to chain exec which ensures that execution will stack. Should any command fail, the subsequent exec won’t be performed.

NOTE that for each invocation exec will spawn a new process, but if you want to execute multiple processes, you can wrap them into bash -c:

$app->add('Console')->exec('bash', [
    '-c',
    'cd ..; echo "Running \'composer update\' in `pwd`"; composer --no-ansi update; echo "Self-updated. OK to refresh now!"'
]);

This also demonstrates argument escaping.