ZF\Console: Console Tool Helper

Introduction

zf-console provides functionality on top of Zend\Console, specifically a methodology for creating standalone PHP console applications using Zend\Console's DefaultRouteMatcher. It includes built-in "help" and "version" commands, and colorization (via Zend\Console), as well as support for shell autocompletion.

Requirements

Please see the composer.json file.

Installation

Run the following composer command:

$ composer require zfcampus/zf-console

Alternately, manually add the following to your composer.json, in the require section:

"require": {
    "zfcampus/zf-console": "^1.3"
}

And then run composer update to ensure the module is installed.

Creating an application

Console applications written with zf-console consist of:

• Defining console routes
• Mapping route names to PHP callables
• Creating and running the application

Defining console routes

Routes in zf-console are typically configuration driven. Each route is an associative array consisting of the following members:

• name (required): The name of the route. Names MUST be unique across the application.
• route (optional): The "route", or console arguments, to match (more below); if not specified, name is utilized. Additionally, if the route does not start with name, name will be prepended to the route (unless you opt out of this feature).
• description (optional): A detailed help description for the given route.
• short_description (optional): A short help description for the given route, used in command summaries.
• options_descriptions (optional): An array of option name/description pairs, corresponding to the arguments the route matches.
• constraints (optional): An array of name/regex pairs to use when matching arguments, corresponding to the arguments in the route. If a regex fails for a given argument, the route will not match.
• aliases (optional): An array of alias/argument pairs; if an alias is provided in the arguments, it will be returned as the named argument on a successful match.
• defaults (optional): Default values to return on a successful match for arguments that were not matched.
• filters (optional): An array of name/Zend\Filter\FilterInterface pairs. The filter provided will be used to filter/normalize the named argument when matched.
• validators (optional): An array of name/Zend\Validator\ValidatorInterface pairs. The validator provided will be used to validate the named argument when matched; failure to validate will cause the route not to match.
• handler (optional): A PHP callable, or a class name of a class with no constructor arguments which is also invokable; if specified, and no command has been mapped in the Dispatcher, this handler will be used to handle the command when invoked.
• prepend_command_to_route (optional): A flag that, if specified, indicates whether or not the command name will be prepended to the route. Since this is the default behavior, only a value of boolean false makes sense here.

Alternately, you can create a ZF\Console\Route instance. The signature is similar:

$route = new ZF\Console\Route(
    $name,
    $route,
    $constraints, // optional
    $defaults,    // optional
    $aliases,     // optional
    $filters,     // optional
    $validators   // optional
);
$route->setDescription($description);
$route->setShortDescription($shortDescription);
$route->setOptionsDescription($optionsDescription);

When defining routes, you will need to provide either an array or Traversable object of route configuration arrays or Route instances (they can be mixed).

We suggest putting your routes in a configuration file:

// config/routes.php

return array(
    array(
        'name'  => 'self-update',
        'description' => 'When executed via the Phar file, performs a self-update by querying
the package repository. If successful, it will report the new version.',
        'short_description' => 'Perform a self-update of the script',
    ),
    array(
        'name' => 'build',
        'route' => '<package> [--target=]',
        'description' => 'Build a package, using <package> as the package filename, and --target
as the application directory to be packaged.',
        'short_description' => 'Build a package',
        'options_descriptions' => array(
            '<package>' => 'Package filename to build',
            '--target'  => 'Name of the application directory to package; defaults to current working directory',
        ),
        'defaults' => array(
            'target' => getcwd(), // default to current working directory
        ),
        'handler' => 'My\Builder',
    ),
);

On Routes

ZF\Console\Route is an extension of Zend\Console\RouteMatcher\DefaultRouteMatcher, and follows its rules for route definitions and matching. In general, a route string will consist of:

• Literal parameters (literal strings to match; e.g., build)
• Literal flags (e.g., --help, -h, etc; flags do not have associated values)
• Positional value parameters (named captures that do not use flags; e.g., <email>)
• Value flag parameters (aka long options, with associated values; e.g., '--target=')

Most parameters may be made optional by surrounding them with brackets (e.g., [--target=], [<command>]).

For a full overview of how to create route specification strings, please review the ZF2 console routes documentation.

Route definitions

Note that, by default, the route name will be prefixed to the route you pass. In the example above, the build route becomes build <package> [--target=]. If you wish to be explicit, you can include the command name in your route definition yourself, or pass the prepend_command_to_route flag with a boolean false value to disable prepending the command name.

Prepending is done to make explicit the idea the mapping of the command name to the route -- which is particularly prudent when considering usage of the help system (which is command centric).

Mapping routes to callables

In order to execute commands, you will need to map route names to code that will dispatch them. ZF\Console\Dispatcher provides the ability to define such a map, via its map() method:

$dispatcher = new ZF\Console\Dispatcher;
$dispatcher->map('some-command-name', $callable)

The $callable argument may be any PHP callable. Additionally, you may provide a string class name, so long as that class can be instantiated without constructor arguments, and so long as it defines an __invoke() method.

All callables should expect up to two arguments:

function (\ZF\Console\Route $route, \Zend\Console\Adapter\AdapterInterface $console) {
}

Additionally, callables should return an integer status to use as the application's exit status; a 0 indicates success, while anything else indicates a failure.

Callables may be defined in route configuration

As noted in the previous section, you can also provide the callable for handling the route via the handler key of your route configuration. The same rules apply to that argument as for the map() method.

Any callables mapped directly to the Dispatcher instance will be preferred over those passed via configuration.

Creating and running the application

Creating the application consists of

• Setting up or retrieving the list of routes
• Setting up the dispatch map
• Instantiating the application
• Running the application

For the following example, we'll assume that the classes My\SelfUpdate and My\Build are autoloadable, and each define the method __invoke().

use My\SelfUpdate;
use Zend\Console\Console;
use ZF\Console\Application;
use ZF\Console\Dispatcher;

require_once __DIR__ . '/vendor/autoload.php'; // Composer autoloader

define('VERSION', '1.1.3');

$dispatcher = new Dispatcher();
$dispatcher->map('self-update', new SelfUpdate($version));
$dispatcher->map('build', 'My\Build');

$application = new Application(
    'Builder',
    VERSION,
    include __DIR__ . '/config/routes.php',
    Console::getInstance(),
    $dispatcher
);
$exit = $application->run();
exit($exit);

Features

zf-console provides a number of features "out of the box." These include:

• Usage reporting
• Help message reporting
• Version reporting
• Shell autocompletion
• Exception handling

Usage reporting may be observed by executing an application with no arguments, or with only the help argument:

$ ./script.php
Builder, version 1.1.3

Available commands:

 autocomplete   Command autocompletion setup
 build          Build a package
 help           Get help for individual commands
 self-update    Perform a self-update of the script
 version        Display the version of the script

Help reporting for individual commands may be observed by executing script help <command name>:

$ ./script.php help self-update
Builder, version 1.1.3

Usage:
 self-update

Help:
When executed via the Phar file, performs a self-update by querying
the package repository. If successful, it will report the new version.

Name routes after the command

We recommend naming routes after the command name. In part, this simplifies finding the matching route definition, but more importantly: if a user specifies the command, but does not specify valid arguments for it, the command will be used to provide a help usage message for that route.

As an example, in the above, if I typed script.php build without any additional arguments, the usage message for the build command will be displayed, since the command and route name match.

Version reporting can be observed by executing script --version or script -v:

$ ./script --version
Builder, version 1.1.3

You can override the default behavior in several ways.

First, you can override either of the help or version commands by mapping them in your Dispatcher instance prior to creating your Application instance:

$dispatcher->map('help', $myCustomHelpCommand);
$dispatcher->map('version', $myVersionCommand);

Second, you can set both custom banners and footers for the usage and help messages using the setBanner() and/or setFooter() methods of the Application instance. Each accepts either a string message, or a callable that to invoke in order to display the message; if using a callable, it will be passed the Console instance as the sole argument.

$application->setBanner('Some ASCI art for a banner!'); // string
$application->setBanner(function ($console) {           // callable
    $console->writeLine(
        $console->colorize('Builder', \Zend\Console\ColorInterface::BLUE)
        . ' - for building deployment packages'
    );
    $console->writeLine('');
    $console->writeLine('Usage:', \Zend\Console\ColorInterface::GREEN);
    $console->writeLine(' ' . basename(__FILE__) . ' command [options]');
    $console->writeLine('');
});

$application->setFooter('Copyright 2014 Zend Technologies');

Disabling banners

The banner is shown by default. In some cases, you may not want to display it; e.g., when piping output to another process.

Starting with version 1.3.0, you can disable banner output using:

$application->setBannerDisabledForUserCommands(true);

Additionally, starting with 1.3.0, you can explicitly nullify both the banner and footer:

$application->setBanner(null);
$application->setFooter(null);

Autocompletion

Autocompletion is a useful feature of many login shells. zf-console provides autocompletion support for bash, zsh, and any shell that understands autocompletion rules in a similar fashion. Rules are generated per-script, using the autocomplete command:

$ ./script autocomplete

Running this will output a shell script that you can save and add to your toolchain; the script itself contains information on how to save it and add it to your shell. In most cases, this will look something like:

$ {script} autocomplete > > $HOME/bin/{script}_autocomplete.sh
$ echo "source \$HOME/bin/{script}_autocomplete.sh" > > $HOME/{your_shell_rc}

where {script} is the name of the command, and {your_shell_rc} is the location of your shell's runtime configutation file (e.g., .bashrc, .zshrc).

Dispatcher callables

The Dispatcher will invoke the callable associated with a given route by calling it with two arguments:

• The ZF\Console\Route instance that matched
• The Zend\Console adapter currently in use

In most cases, you will use the Route instance to gather arguments passed to the application, and the Console instance to provide any feedback or to prompt for any additional information.

The Route instance contains several methods of interest:

• getMatches() will return an array of all named arguments matched.
• matchedParam($name) will tell you if a given argument was matched.
• getMatchedParam($name, $default = null) will return the value for the given argument as matched, and, if not matched, the $default value you provide.
• getName() will return the name of the route (which may be useful if you use the same callable for multiple routes).

Custom dispatchers

• Since 1.3.0

You may create a custom dispatcher by implementing ZF\Console\DispatcherInterface, which defines the following methods:

namespace ZF\Console;

use Zend\Console\Adapter\AdapterInterface as ConsoleAdapter;

interface DispatcherInterface
{
    /**
     * Map a command name to its handler.
     *
     * @param string $command
     * @param callable|string $command A callable command, or a string service
     *     or class name to use as a handler.
     * @return self Should implement a fluent interface.
     */
    public function map($command, $callable);

    /**
     * Does the dispatcher have a handler for the given command?
     *
     * @param string $command
     * @return bool
     */
    public function has($command);

    /**
     * Dispatch a routed command to its handler.
     *
     * @param Route $route
     * @param ConsoleAdapter $console
     * @return int The exit status code from the command.
     */
    public function dispatch(Route $route, ConsoleAdapter $console);
}

When you do, instantiate your custom dispatcher and pass it to the Application instance when initializing it:

$application = new Application('App', 1.0, $routes, null, $dispatcher);

Pulling commands from a container

• Since 1.3.0

Instead of specifying a callable or a class name for a command handler, you may store your handlers within a dependency injection container compatible with container-interop; when you do so, you can specify the service name of the handler instead.

To do this, you will need to create a Dispatcher instance, passing it the container you are using at instantiation:

$serviceManager = new ServiceManager(/* ... */);

// use `zend-servicemanager` as container
$dispatcher = new Dispatcher($serviceManager);

From there, you can configure routes using the service name (which is often a class name):

$routes = [
    [
        'name' => 'hello',        
        'handler' => HelloCommand::class,
    ]
];

Finally, do not forget to pass your dispatcher to your application when you initialize it:

$application = new Application('App', 1.0, $routes, null, $dispatcher);

In the above examples, when the hello route is matched, the Dispatcher will attempt to pull the HelloCommand service from the container prior to dispatching it.

Exception Handling

zf-console provides exception handling by default, via ZF\Console\ExceptionHandler. When your console application raises an exception, this handler will provide a "pretty" view of the error, instead of the full stack trace (unless you want to include the stack trace in your view!).

The default message looks like the following:

======================================================================
   The application has thrown an exception!
======================================================================

 :className:
 :message

where :className will be filled with the exception's class name, and message will contain the exception message, if any.

You may provide your own template if desired:

$application->getExceptionHandler()->setMessageTemplate($template);

The following template variables are defined:

• :className
• :message
• :code
• :file
• :line
• :stack
• :previous (this is used to report previous exceptions in a trace)

If you want to provide your own exception handler, you may do so by providing any PHP callable to the setExceptionHandler() method:

$application->setExceptionHandler($handler);

Debug mode

If you want normal PHP stack traces and error reporting, you can put the application into debug mode:

$application->setDebug(true);

Using zf-console in Zend Framework 2 Applications

While Zend Framework 2 integrates console functionality into the MVC, you may want to write scripts that do not use the MVC. For instance, it may be easier to write an application-specific script without going through the hoops of creating a controller, adding console configuration, etc. However, you will likely still want access to services provided within modules, and also want the ability to honor service and configuration overrides.

To do this, you will need to bootstrap your application first. We'll assume you're putting your script in your application's bin/ directory for this example.

use Zend\Console\Console;
use Zend\Console\ColorInterface as Color;
use ZF\Console\Application;
use ZF\Console\Dispatcher;

chdir(dirname(__DIR__));
require 'init_autoloader.php'; // grabs the Composer autoloader and/or ZF2 autoloader
$application = Zend\Mvc\Application::init(require 'config/application.config.php');
$services    = $application->getServiceManager();

$buildModel = $services->get('My\BuildModel');

$dispatcher = new Dispatcher();
$dispatcher->map('build', function ($route, $console) use ($buildModel) {
    $opts = $route->getMatches();
    $result = $buildModel->build($opts['package'], $opts['target']);
    if (! $result) {
        $console->writeLine('Error building package!', Color::WHITE, Color::RED);
        return 1;
    }

    $console->writeLine('Finished building package ' . $opts['package'], Color::GREEN);
    return 0;
});

$application = new Application(
    'Builder',
    VERSION,
    array(
        array(
            'name' => 'build',
            'route' => 'build <package> [--target=]',
            'description' => 'Build a package, using <package> as the package filename, and --target
    as the application directory to be packaged.',
            'short_description' => 'Build a package',
            'options_descriptions' => array(
                '<package>' => 'Package filename to build',
                '--target'  => 'Name of the application directory to package; defaults to current working directory',
            ),
            'defaults' => array(
                'target' => getcwd(), // default to current working directory
            ),
        ),
    ),
    Console::getInstance(),
    $dispatcher
);
$exit = $application->run();
exit($exit);

Essentially, you're calling Zend\Mvc\Application::init(), but not it's run() method. This ensures all modules are bootstrapped, which means all configuration is loaded and merged, all services are wired, and all listeners are attached. You then pull relevant services from the ServiceManager and pass them to your console callbacks.

Best Practices

We recommend the following practices when creating applications using zf-console.

Use Zend\Console to create output

Use Zend\Console to create any output you send. This ensures that the output works cross-platform (including Unix-like systems and Windows). As examples:

$dispatcher->map('some-command', function ($route, $console) {
    $console->writeLine('Executing some-command!');
});

Install your script via Composer

You can tell Composer to install your script in the vendor/bin/ directory, making it trivial for end-users to locate and execute your script within their own applications.

{
    "require": {
        "php": ">=5.3.23",
        "zfcampus/zf-console": "~1.0-dev"
    },
    "bin": ["script.php"]
}

If you do this, be sure to name your script uniquely.

Use filters or validators

Zend\Console's RouteMatcher sub-component allows you to specify filters and/or validators for each matched argument of a route. These let you provide normalization (filters) and more robust validation logic when desired.

As an example, consider a common scenario of using comma-separated values for an argument; you could split those into an array as follows:

// config/routes.php

use Zend\Filter\Callback as CallbackFilter;

return array(
    array(
        'name' => 'filter',
        'route' => 'filter [--exclude=]',
        'default' => array(
            'exclude' => array(),
        ),
        'filters' => array(
            'exclude' => new CallbackFilter(function ($value) {
                if (! is_string($value)) {
                    return $value;
                }
                $exclude = explode(',', $value);
                array_walk($exclude, 'trim');
                return $exclude;
            }),
        ),
    )
);

Using filters and validators well, you can ensure that when your dispatch callbacks receive data, it is already sanitized and ready to use.

Filters provided by zf-console

zf-console provides several filters for your convenience:

• ZF\Console\Filter\Explode allows you to specify a delimiter to use to "explode" a string value to an array of values. As an example:

  // config/routes.php
  
  use ZF\Console\Filter\Explode as ExplodeFilter;
  
  return array(
      array(
          'name' => 'filter',
          'route' => 'filter [--exclude=]',
          'default' => array(
              'exclude' => array(),
          ),
          'filters' => array(
              'exclude' => new ExplodeFilter(','),
          ),
      )
  );

  The above would explode values provided to --exclude using a ,; --exclude=foo,bar,baz would set exclude to array('foo', 'bar', 'baz'). By default, if no delimiter is provided, , is assumed.

• ZF\Console\Filter\Json allows you to specify a JSON-formatted string; it will then deserialize it to native PHP values.

  // config/routes.php
  
  use ZF\Console\Filter\Json as JsonFilter;
  
  return array(
      array(
          'name' => 'filter',
          'route' => 'filter [--exclude=]',
          'default' => array(
              'exclude' => array(),
          ),
          'filters' => array(
              'exclude' => new JsonFilter(),
          ),
      )
  );

  The above would deserialize a JSON value provided to --exclude; --exclude='["foo","bar","baz"]' would set exclude to array('foo', 'bar', 'baz').

• ZF\Console\Filter\QueryString allows you to specify a form-encoded string; it will then deserialize it to native PHP values.

  // config/routes.php
  
  use ZF\Console\Filter\QueryString;
  
  return array(
      array(
          'name' => 'filter',
          'route' => 'filter [--exclude=]',
          'default' => array(
              'exclude' => array(),
          ),
          'filters' => array(
              'exclude' => new QueryString(),
          ),
      )
  );

  The above would deserialize a form-encoded value provided to --exclude; --exclude='foo=bar&baz=bat' would set exclude to array('foo' => 'bar', 'baz' => 'bat').

Classes

This library defines the following classes:

• ZF\Console\Application, which handles actual execution of the script, including usage reporting.
• ZF\Console\Dispatcher, which maps route names to PHP callables, and dispatches them when selected.
• ZF\Console\HelpCommand, which provides the default "help" logic for displaying command usage.
• ZF\Console\Route, an extension of Zend\Console\RouteMatcher\DefaultRouteMatcher that adds aggregation of route metadata, including the name and description.
• ZF\Console\RouteCollection, which implements Zend\Console\RouteMatcher\RouteMatcherInterface, aggregates ZF\Console\Route instances, and performs route matching.
• ZF\Console\Filter\Explode, which implements Zend\Filter\FilterInterface, and which is described above.
• ZF\Console\Filter\Json, which implements Zend\Filter\FilterInterface, and which is described above.
• ZF\Console\Filter\QueryString, which implements Zend\Filter\FilterInterface, and which is described above.