364 lines
9.8 KiB
PHP
364 lines
9.8 KiB
PHP
|
<?php
|
||
|
|
||
|
/*
|
||
|
* This file is part of the Symfony package.
|
||
|
*
|
||
|
* (c) Fabien Potencier <fabien@symfony.com>
|
||
|
*
|
||
|
* For the full copyright and license information, please view the LICENSE
|
||
|
* file that was distributed with this source code.
|
||
|
*/
|
||
|
|
||
|
namespace Symfony\Component\Form;
|
||
|
|
||
|
use ArrayAccess;
|
||
|
use Iterator;
|
||
|
use OutOfBoundsException;
|
||
|
use Symfony\Component\Form\Exception\OptionDefinitionException;
|
||
|
|
||
|
/**
|
||
|
* Container for resolving inter-dependent options.
|
||
|
*
|
||
|
* Options are a common pattern for resolved classes in PHP. Avoiding the
|
||
|
* problems related to this approach is however a non-trivial task. Usually,
|
||
|
* both classes and subclasses should be able to set default option values.
|
||
|
* These default options should be overridden by the options passed to the
|
||
|
* constructor. Last but not least, the (default) values of some options may
|
||
|
* depend on the values of other options, which themselves may depend on other
|
||
|
* options.
|
||
|
*
|
||
|
* This class resolves these problems. You can use it in your classes by
|
||
|
* implementing the following pattern:
|
||
|
*
|
||
|
* <code>
|
||
|
* class Car
|
||
|
* {
|
||
|
* protected $options;
|
||
|
*
|
||
|
* public function __construct(array $options)
|
||
|
* {
|
||
|
* $_options = new Options();
|
||
|
* $this->addDefaultOptions($_options);
|
||
|
*
|
||
|
* $this->options = $_options->resolve($options);
|
||
|
* }
|
||
|
*
|
||
|
* protected function addDefaultOptions(Options $options)
|
||
|
* {
|
||
|
* $options->add(array(
|
||
|
* 'make' => 'VW',
|
||
|
* 'year' => '1999',
|
||
|
* ));
|
||
|
* }
|
||
|
* }
|
||
|
*
|
||
|
* $car = new Car(array(
|
||
|
* 'make' => 'Mercedes',
|
||
|
* 'year' => 2005,
|
||
|
* ));
|
||
|
* </code>
|
||
|
*
|
||
|
* By calling add(), new default options are added to the container. The method
|
||
|
* resolve() accepts an array of options passed by the user that are matched
|
||
|
* against the allowed options. If any option is not recognized, an exception
|
||
|
* is thrown. Finally, resolve() returns the merged default and user options.
|
||
|
*
|
||
|
* You can now easily add or override options in subclasses:
|
||
|
*
|
||
|
* <code>
|
||
|
* class Renault extends Car
|
||
|
* {
|
||
|
* protected function addDefaultOptions(Options $options)
|
||
|
* {
|
||
|
* parent::addDefaultOptions($options);
|
||
|
*
|
||
|
* $options->add(array(
|
||
|
* 'make' => 'Renault',
|
||
|
* 'gear' => 'auto',
|
||
|
* ));
|
||
|
* }
|
||
|
* }
|
||
|
*
|
||
|
* $renault = new Renault(array(
|
||
|
* 'year' => 1997,
|
||
|
* 'gear' => 'manual'
|
||
|
* ));
|
||
|
* </code>
|
||
|
*
|
||
|
* IMPORTANT: parent::addDefaultOptions() must always be called before adding
|
||
|
* new options!
|
||
|
*
|
||
|
* In the previous example, it makes sense to restrict the option "gear" to
|
||
|
* a set of allowed values:
|
||
|
*
|
||
|
* <code>
|
||
|
* class Renault extends Car
|
||
|
* {
|
||
|
* protected function addDefaultOptions(Options $options)
|
||
|
* {
|
||
|
* // ... like above ...
|
||
|
*
|
||
|
* $options->addAllowedValues(array(
|
||
|
* 'gear' => array('auto', 'manual'),
|
||
|
* ));
|
||
|
* }
|
||
|
* }
|
||
|
*
|
||
|
* // Fails!
|
||
|
* $renault = new Renault(array(
|
||
|
* 'gear' => 'v6',
|
||
|
* ));
|
||
|
* </code>
|
||
|
*
|
||
|
* Now it is impossible to pass a value in the "gear" option that is not
|
||
|
* expected.
|
||
|
*
|
||
|
* Last but not least, you can define options that depend on other options.
|
||
|
* For example, depending on the "make" you could preset the country that the
|
||
|
* car is registered in.
|
||
|
*
|
||
|
* <code>
|
||
|
* class Car
|
||
|
* {
|
||
|
* protected function addDefaultOptions(Options $options)
|
||
|
* {
|
||
|
* $options->add(array(
|
||
|
* 'make' => 'VW',
|
||
|
* 'year' => '1999',
|
||
|
* 'country' => function (Options $options) {
|
||
|
* if ('VW' === $options['make']) {
|
||
|
* return 'DE';
|
||
|
* }
|
||
|
*
|
||
|
* return null;
|
||
|
* },
|
||
|
* ));
|
||
|
* }
|
||
|
* }
|
||
|
*
|
||
|
* $car = new Car(array(
|
||
|
* 'make' => 'VW', // => "country" is "DE"
|
||
|
* ));
|
||
|
* </code>
|
||
|
*
|
||
|
* When overriding an option with a closure in subclasses, you can make use of
|
||
|
* the second parameter $parentValue in which the value defined by the parent
|
||
|
* class is stored.
|
||
|
*
|
||
|
* <code>
|
||
|
* class Renault extends Car
|
||
|
* {
|
||
|
* protected function addDefaultOptions(Options $options)
|
||
|
* {
|
||
|
* $options->add(array(
|
||
|
* 'country' => function (Options $options, $parentValue) {
|
||
|
* if ('Renault' === $options['make']) {
|
||
|
* return 'FR';
|
||
|
* }
|
||
|
*
|
||
|
* return $parentValue;
|
||
|
* },
|
||
|
* ));
|
||
|
* }
|
||
|
* }
|
||
|
*
|
||
|
* $renault = new Renault(array(
|
||
|
* 'make' => 'VW', // => "country" is still "DE"
|
||
|
* ));
|
||
|
* </code>
|
||
|
*
|
||
|
* @author Bernhard Schussek <bschussek@gmail.com>
|
||
|
*/
|
||
|
class Options implements ArrayAccess, Iterator
|
||
|
{
|
||
|
/**
|
||
|
* A list of option values and LazyOption instances.
|
||
|
* @var array
|
||
|
*/
|
||
|
private $options = array();
|
||
|
|
||
|
/**
|
||
|
* A list of Boolean locks for each LazyOption.
|
||
|
* @var array
|
||
|
*/
|
||
|
private $lock = array();
|
||
|
|
||
|
/**
|
||
|
* Whether the options have already been resolved.
|
||
|
*
|
||
|
* Once resolved, no new options can be added or changed anymore.
|
||
|
*
|
||
|
* @var Boolean
|
||
|
*/
|
||
|
private $resolved = false;
|
||
|
|
||
|
/**
|
||
|
* Returns whether the given option exists.
|
||
|
*
|
||
|
* @param string $option The option name.
|
||
|
*
|
||
|
* @return Boolean Whether the option exists.
|
||
|
*
|
||
|
* @see ArrayAccess::offsetExists()
|
||
|
*/
|
||
|
public function offsetExists($option)
|
||
|
{
|
||
|
return isset($this->options[$option]);
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Returns the value of the given option.
|
||
|
*
|
||
|
* After reading an option for the first time, this object becomes
|
||
|
*
|
||
|
* @param string $option The option name.
|
||
|
*
|
||
|
* @return mixed The option value.
|
||
|
*
|
||
|
* @throws OutOfBoundsException If the option does not exist.
|
||
|
* @throws OptionDefinitionException If a cyclic dependency is detected
|
||
|
* between two lazy options.
|
||
|
*
|
||
|
* @see ArrayAccess::offsetGet()
|
||
|
*/
|
||
|
public function offsetGet($option)
|
||
|
{
|
||
|
if (!array_key_exists($option, $this->options)) {
|
||
|
throw new OutOfBoundsException('The option "' . $option . '" does not exist');
|
||
|
}
|
||
|
|
||
|
$this->resolved = true;
|
||
|
|
||
|
if ($this->options[$option] instanceof LazyOption) {
|
||
|
if ($this->lock[$option]) {
|
||
|
$conflicts = array_keys(array_filter($this->lock, function ($locked) {
|
||
|
return $locked;
|
||
|
}));
|
||
|
|
||
|
throw new OptionDefinitionException('The options "' . implode('", "', $conflicts) . '" have a cyclic dependency');
|
||
|
}
|
||
|
|
||
|
$this->lock[$option] = true;
|
||
|
$this->options[$option] = $this->options[$option]->evaluate($this);
|
||
|
$this->lock[$option] = false;
|
||
|
}
|
||
|
|
||
|
return $this->options[$option];
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Sets the value of a given option.
|
||
|
*
|
||
|
* @param string $option The name of the option.
|
||
|
* @param mixed $value The value of the option. May be a closure with a
|
||
|
* signature as defined in DefaultOptions::add().
|
||
|
*
|
||
|
* @throws OptionDefinitionException If options have already been read.
|
||
|
* Once options are read, the container
|
||
|
* becomes immutable.
|
||
|
*
|
||
|
* @see DefaultOptions::add()
|
||
|
* @see ArrayAccess::offsetSet()
|
||
|
*/
|
||
|
public function offsetSet($option, $value)
|
||
|
{
|
||
|
// Setting is not possible once an option is read, because then lazy
|
||
|
// options could manipulate the state of the object, leading to
|
||
|
// inconsistent results.
|
||
|
if ($this->resolved) {
|
||
|
throw new OptionDefinitionException('Options cannot be set after reading options');
|
||
|
}
|
||
|
|
||
|
$newValue = $value;
|
||
|
|
||
|
// If an option is a closure that should be evaluated lazily, store it
|
||
|
// inside a LazyOption instance.
|
||
|
if ($newValue instanceof \Closure) {
|
||
|
$reflClosure = new \ReflectionFunction($newValue);
|
||
|
$params = $reflClosure->getParameters();
|
||
|
$isLazyOption = count($params) >= 1 && null !== $params[0]->getClass() && __CLASS__ === $params[0]->getClass()->getName();
|
||
|
|
||
|
if ($isLazyOption) {
|
||
|
$currentValue = isset($this->options[$option]) ? $this->options[$option] : null;
|
||
|
$newValue = new LazyOption($newValue, $currentValue);
|
||
|
}
|
||
|
|
||
|
// Store locks for lazy options to detect cyclic dependencies
|
||
|
$this->lock[$option] = false;
|
||
|
}
|
||
|
|
||
|
$this->options[$option] = $newValue;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Removes an option with the given name.
|
||
|
*
|
||
|
* @param string $option The option name.
|
||
|
*
|
||
|
* @throws OptionDefinitionException If options have already been read.
|
||
|
* Once options are read, the container
|
||
|
* becomes immutable.
|
||
|
*
|
||
|
* @see ArrayAccess::offsetUnset()
|
||
|
*/
|
||
|
public function offsetUnset($option)
|
||
|
{
|
||
|
if ($this->resolved) {
|
||
|
throw new OptionDefinitionException('Options cannot be unset after reading options');
|
||
|
}
|
||
|
|
||
|
unset($this->options[$option]);
|
||
|
unset($this->allowedValues[$option]);
|
||
|
unset($this->lock[$option]);
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Returns the names of all defined options.
|
||
|
*
|
||
|
* @return array An array of option names.
|
||
|
*/
|
||
|
public function getNames()
|
||
|
{
|
||
|
return array_keys($this->options);
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* @see Iterator::current()
|
||
|
*/
|
||
|
public function current()
|
||
|
{
|
||
|
return $this->offsetGet($this->key());
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* @see Iterator::next()
|
||
|
*/
|
||
|
public function next()
|
||
|
{
|
||
|
next($this->options);
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* @see Iterator::key()
|
||
|
*/
|
||
|
public function key()
|
||
|
{
|
||
|
return key($this->options);
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* @see Iterator::valid()
|
||
|
*/
|
||
|
public function valid()
|
||
|
{
|
||
|
return null !== $this->key();
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* @see Iterator::rewind()
|
||
|
*/
|
||
|
public function rewind()
|
||
|
{
|
||
|
reset($this->options);
|
||
|
}
|
||
|
}
|