<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\base;

use Yii;
use yii\helpers\StringHelper;

/**
 * Component is the base class that implements the *property*, *event* and *behavior* features.
 *
 * Component provides the *event* and *behavior* features, in addition to the *property* feature which is implemented in
 * its parent class [[\yii\base\BaseObject|BaseObject]].
 *
 * Event is a way to "inject" custom code into existing code at certain places. For example, a comment object can trigger
 * an "add" event when the user adds a comment. We can write custom code and attach it to this event so that when the event
 * is triggered (i.e. comment will be added), our custom code will be executed.
 *
 * An event is identified by a name that should be unique within the class it is defined at. Event names are *case-sensitive*.
 *
 * One or multiple PHP callbacks, called *event handlers*, can be attached to an event. You can call [[trigger()]] to
 * raise an event. When an event is raised, the event handlers will be invoked automatically in the order they were
 * attached.
 *
 * To attach an event handler to an event, call [[on()]]:
 *
 * ```php
 * $post->on('update', function ($event) {
 *     // send email notification
 * });
 * ```
 *
 * In the above, an anonymous function is attached to the "update" event of the post. You may attach
 * the following types of event handlers:
 *
 * - anonymous function: `function ($event) { ... }`
 * - object method: `[$object, 'handleAdd']`
 * - static class method: `['Page', 'handleAdd']`
 * - global function: `'handleAdd'`
 *
 * The signature of an event handler should be like the following:
 *
 * ```php
 * function foo($event)
 * ```
 *
 * where `$event` is an [[Event]] object which includes parameters associated with the event.
 *
 * You can also attach a handler to an event when configuring a component with a configuration array.
 * The syntax is like the following:
 *
 * ```php
 * [
 *     'on add' => function ($event) { ... }
 * ]
 * ```
 *
 * where `on add` stands for attaching an event to the `add` event.
 *
 * Sometimes, you may want to associate extra data with an event handler when you attach it to an event
 * and then access it when the handler is invoked. You may do so by
 *
 * ```php
 * $post->on('update', function ($event) {
 *     // the data can be accessed via $event->data
 * }, $data);
 * ```
 *
 * A behavior is an instance of [[Behavior]] or its child class. A component can be attached with one or multiple
 * behaviors. When a behavior is attached to a component, its public properties and methods can be accessed via the
 * component directly, as if the component owns those properties and methods.
 *
 * To attach a behavior to a component, declare it in [[behaviors()]], or explicitly call [[attachBehavior]]. Behaviors
 * declared in [[behaviors()]] are automatically attached to the corresponding component.
 *
 * One can also attach a behavior to a component when configuring it with a configuration array. The syntax is like the
 * following:
 *
 * ```php
 * [
 *     'as tree' => [
 *         'class' => 'Tree',
 *     ],
 * ]
 * ```
 *
 * where `as tree` stands for attaching a behavior named `tree`, and the array will be passed to [[\Yii::createObject()]]
 * to create the behavior object.
 *
 * For more details and usage information on Component, see the [guide article on components](guide:concept-components).
 *
 * @property Behavior[] $behaviors List of behaviors attached to this component. This property is read-only.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @since 2.0
 */
class Component extends BaseObject
{
    /**
     * @var array the attached event handlers (event name => handlers)
     */
    private $_events = [];
    /**
     * @var array the event handlers attached for wildcard patterns (event name wildcard => handlers)
     * @since 2.0.14
     */
    private $_eventWildcards = [];
    /**
     * @var Behavior[]|null the attached behaviors (behavior name => behavior). This is `null` when not initialized.
     */
    private $_behaviors;

    /**
     * Returns the value of a component property.
     *
     * This method will check in the following order and act accordingly:
     *
     *  - a property defined by a getter: return the getter result
     *  - a property of a behavior: return the behavior property value
     *
     * Do not call this method directly as it is a PHP magic method that
     * will be implicitly called when executing `$value = $component->property;`.
     * @param string $name the property name
     * @return mixed the property value or the value of a behavior's property
     * @throws UnknownPropertyException if the property is not defined
     * @throws InvalidCallException if the property is write-only.
     * @see __set()
     */
    public function __get($name)
    {
        $getter = 'get' . $name;
        if (method_exists($this, $getter)) {
            // read property, e.g. getName()
            return $this->$getter();
        }

        // behavior property
        $this->ensureBehaviors();
        foreach ($this->_behaviors as $behavior) {
            if ($behavior->canGetProperty($name)) {
                return $behavior->$name;
            }
        }

        if (method_exists($this, 'set' . $name)) {
            throw new InvalidCallException('Getting write-only property: ' . get_class($this) . '::' . $name);
        }

        throw new UnknownPropertyException('Getting unknown property: ' . get_class($this) . '::' . $name);
    }

    /**
     * Sets the value of a component property.
     *
     * This method will check in the following order and act accordingly:
     *
     *  - a property defined by a setter: set the property value
     *  - an event in the format of "on xyz": attach the handler to the event "xyz"
     *  - a behavior in the format of "as xyz": attach the behavior named as "xyz"
     *  - a property of a behavior: set the behavior property value
     *
     * Do not call this method directly as it is a PHP magic method that
     * will be implicitly called when executing `$component->property = $value;`.
     * @param string $name the property name or the event name
     * @param mixed $value the property value
     * @throws UnknownPropertyException if the property is not defined
     * @throws InvalidCallException if the property is read-only.
     * @see __get()
     */
    public function __set($name, $value)
    {
        $setter = 'set' . $name;
        if (method_exists($this, $setter)) {
            // set property
            $this->$setter($value);

            return;
        } elseif (strncmp($name, 'on ', 3) === 0) {
            // on event: attach event handler
            $this->on(trim(substr($name, 3)), $value);

            return;
        } elseif (strncmp($name, 'as ', 3) === 0) {
            // as behavior: attach behavior
            $name = trim(substr($name, 3));
            $this->attachBehavior($name, $value instanceof Behavior ? $value : Yii::createObject($value));

            return;
        }

        // behavior property
        $this->ensureBehaviors();
        foreach ($this->_behaviors as $behavior) {
            if ($behavior->canSetProperty($name)) {
                $behavior->$name = $value;
                return;
            }
        }

        if (method_exists($this, 'get' . $name)) {
            throw new InvalidCallException('Setting read-only property: ' . get_class($this) . '::' . $name);
        }

        throw new UnknownPropertyException('Setting unknown property: ' . get_class($this) . '::' . $name);
    }

    /**
     * Checks if a property is set, i.e. defined and not null.
     *
     * This method will check in the following order and act accordingly:
     *
     *  - a property defined by a setter: return whether the property is set
     *  - a property of a behavior: return whether the property is set
     *  - return `false` for non existing properties
     *
     * Do not call this method directly as it is a PHP magic method that
     * will be implicitly called when executing `isset($component->property)`.
     * @param string $name the property name or the event name
     * @return bool whether the named property is set
     * @see https://secure.php.net/manual/en/function.isset.php
     */
    public function __isset($name)
    {
        $getter = 'get' . $name;
        if (method_exists($this, $getter)) {
            return $this->$getter() !== null;
        }

        // behavior property
        $this->ensureBehaviors();
        foreach ($this->_behaviors as $behavior) {
            if ($behavior->canGetProperty($name)) {
                return $behavior->$name !== null;
            }
        }

        return false;
    }

    /**
     * Sets a component property to be null.
     *
     * This method will check in the following order and act accordingly:
     *
     *  - a property defined by a setter: set the property value to be null
     *  - a property of a behavior: set the property value to be null
     *
     * Do not call this method directly as it is a PHP magic method that
     * will be implicitly called when executing `unset($component->property)`.
     * @param string $name the property name
     * @throws InvalidCallException if the property is read only.
     * @see https://secure.php.net/manual/en/function.unset.php
     */
    public function __unset($name)
    {
        $setter = 'set' . $name;
        if (method_exists($this, $setter)) {
            $this->$setter(null);
            return;
        }

        // behavior property
        $this->ensureBehaviors();
        foreach ($this->_behaviors as $behavior) {
            if ($behavior->canSetProperty($name)) {
                $behavior->$name = null;
                return;
            }
        }

        throw new InvalidCallException('Unsetting an unknown or read-only property: ' . get_class($this) . '::' . $name);
    }

    /**
     * Calls the named method which is not a class method.
     *
     * This method will check if any attached behavior has
     * the named method and will execute it if available.
     *
     * Do not call this method directly as it is a PHP magic method that
     * will be implicitly called when an unknown method is being invoked.
     * @param string $name the method name
     * @param array $params method parameters
     * @return mixed the method return value
     * @throws UnknownMethodException when calling unknown method
     */
    public function __call($name, $params)
    {
        $this->ensureBehaviors();
        foreach ($this->_behaviors as $object) {
            if ($object->hasMethod($name)) {
                return call_user_func_array([$object, $name], $params);
            }
        }
        throw new UnknownMethodException('Calling unknown method: ' . get_class($this) . "::$name()");
    }

    /**
     * This method is called after the object is created by cloning an existing one.
     * It removes all behaviors because they are attached to the old object.
     */
    public function __clone()
    {
        $this->_events = [];
        $this->_eventWildcards = [];
        $this->_behaviors = null;
    }

    /**
     * Returns a value indicating whether a property is defined for this component.
     *
     * A property is defined if:
     *
     * - the class has a getter or setter method associated with the specified name
     *   (in this case, property name is case-insensitive);
     * - the class has a member variable with the specified name (when `$checkVars` is true);
     * - an attached behavior has a property of the given name (when `$checkBehaviors` is true).
     *
     * @param string $name the property name
     * @param bool $checkVars whether to treat member variables as properties
     * @param bool $checkBehaviors whether to treat behaviors' properties as properties of this component
     * @return bool whether the property is defined
     * @see canGetProperty()
     * @see canSetProperty()
     */
    public function hasProperty($name, $checkVars = true, $checkBehaviors = true)
    {
        return $this->canGetProperty($name, $checkVars, $checkBehaviors) || $this->canSetProperty($name, false, $checkBehaviors);
    }

    /**
     * Returns a value indicating whether a property can be read.
     *
     * A property can be read if:
     *
     * - the class has a getter method associated with the specified name
     *   (in this case, property name is case-insensitive);
     * - the class has a member variable with the specified name (when `$checkVars` is true);
     * - an attached behavior has a readable property of the given name (when `$checkBehaviors` is true).
     *
     * @param string $name the property name
     * @param bool $checkVars whether to treat member variables as properties
     * @param bool $checkBehaviors whether to treat behaviors' properties as properties of this component
     * @return bool whether the property can be read
     * @see canSetProperty()
     */
    public function canGetProperty($name, $checkVars = true, $checkBehaviors = true)
    {
        if (method_exists($this, 'get' . $name) || $checkVars && property_exists($this, $name)) {
            return true;
        } elseif ($checkBehaviors) {
            $this->ensureBehaviors();
            foreach ($this->_behaviors as $behavior) {
                if ($behavior->canGetProperty($name, $checkVars)) {
                    return true;
                }
            }
        }

        return false;
    }

    /**
     * Returns a value indicating whether a property can be set.
     *
     * A property can be written if:
     *
     * - the class has a setter method associated with the specified name
     *   (in this case, property name is case-insensitive);
     * - the class has a member variable with the specified name (when `$checkVars` is true);
     * - an attached behavior has a writable property of the given name (when `$checkBehaviors` is true).
     *
     * @param string $name the property name
     * @param bool $checkVars whether to treat member variables as properties
     * @param bool $checkBehaviors whether to treat behaviors' properties as properties of this component
     * @return bool whether the property can be written
     * @see canGetProperty()
     */
    public function canSetProperty($name, $checkVars = true, $checkBehaviors = true)
    {
        if (method_exists($this, 'set' . $name) || $checkVars && property_exists($this, $name)) {
            return true;
        } elseif ($checkBehaviors) {
            $this->ensureBehaviors();
            foreach ($this->_behaviors as $behavior) {
                if ($behavior->canSetProperty($name, $checkVars)) {
                    return true;
                }
            }
        }

        return false;
    }

    /**
     * Returns a value indicating whether a method is defined.
     *
     * A method is defined if:
     *
     * - the class has a method with the specified name
     * - an attached behavior has a method with the given name (when `$checkBehaviors` is true).
     *
     * @param string $name the property name
     * @param bool $checkBehaviors whether to treat behaviors' methods as methods of this component
     * @return bool whether the method is defined
     */
    public function hasMethod($name, $checkBehaviors = true)
    {
        if (method_exists($this, $name)) {
            return true;
        } elseif ($checkBehaviors) {
            $this->ensureBehaviors();
            foreach ($this->_behaviors as $behavior) {
                if ($behavior->hasMethod($name)) {
                    return true;
                }
            }
        }

        return false;
    }

    /**
     * Returns a list of behaviors that this component should behave as.
     *
     * Child classes may override this method to specify the behaviors they want to behave as.
     *
     * The return value of this method should be an array of behavior objects or configurations
     * indexed by behavior names. A behavior configuration can be either a string specifying
     * the behavior class or an array of the following structure:
     *
     * ```php
     * 'behaviorName' => [
     *     'class' => 'BehaviorClass',
     *     'property1' => 'value1',
     *     'property2' => 'value2',
     * ]
     * ```
     *
     * Note that a behavior class must extend from [[Behavior]]. Behaviors can be attached using a name or anonymously.
     * When a name is used as the array key, using this name, the behavior can later be retrieved using [[getBehavior()]]
     * or be detached using [[detachBehavior()]]. Anonymous behaviors can not be retrieved or detached.
     *
     * Behaviors declared in this method will be attached to the component automatically (on demand).
     *
     * @return array the behavior configurations.
     */
    public function behaviors()
    {
        return [];
    }

    /**
     * Returns a value indicating whether there is any handler attached to the named event.
     * @param string $name the event name
     * @return bool whether there is any handler attached to the event.
     */
    public function hasEventHandlers($name)
    {
        $this->ensureBehaviors();

        foreach ($this->_eventWildcards as $wildcard => $handlers) {
            if (!empty($handlers) && StringHelper::matchWildcard($wildcard, $name)) {
                return true;
            }
        }

        return !empty($this->_events[$name]) || Event::hasHandlers($this, $name);
    }

    /**
     * Attaches an event handler to an event.
     *
     * The event handler must be a valid PHP callback. The following are
     * some examples:
     *
     * ```
     * function ($event) { ... }         // anonymous function
     * [$object, 'handleClick']          // $object->handleClick()
     * ['Page', 'handleClick']           // Page::handleClick()
     * 'handleClick'                     // global function handleClick()
     * ```
     *
     * The event handler must be defined with the following signature,
     *
     * ```
     * function ($event)
     * ```
     *
     * where `$event` is an [[Event]] object which includes parameters associated with the event.
     *
     * Since 2.0.14 you can specify event name as a wildcard pattern:
     *
     * ```php
     * $component->on('event.group.*', function ($event) {
     *     Yii::trace($event->name . ' is triggered.');
     * });
     * ```
     *
     * @param string $name the event name
     * @param callable $handler the event handler
     * @param mixed $data the data to be passed to the event handler when the event is triggered.
     * When the event handler is invoked, this data can be accessed via [[Event::data]].
     * @param bool $append whether to append new event handler to the end of the existing
     * handler list. If false, the new handler will be inserted at the beginning of the existing
     * handler list.
     * @see off()
     */
    public function on($name, $handler, $data = null, $append = true)
    {
        $this->ensureBehaviors();

        if (strpos($name, '*') !== false) {
            if ($append || empty($this->_eventWildcards[$name])) {
                $this->_eventWildcards[$name][] = [$handler, $data];
            } else {
                array_unshift($this->_eventWildcards[$name], [$handler, $data]);
            }
            return;
        }

        if ($append || empty($this->_events[$name])) {
            $this->_events[$name][] = [$handler, $data];
        } else {
            array_unshift($this->_events[$name], [$handler, $data]);
        }
    }

    /**
     * Detaches an existing event handler from this component.
     *
     * This method is the opposite of [[on()]].
     *
     * Note: in case wildcard pattern is passed for event name, only the handlers registered with this
     * wildcard will be removed, while handlers registered with plain names matching this wildcard will remain.
     *
     * @param string $name event name
     * @param callable $handler the event handler to be removed.
     * If it is null, all handlers attached to the named event will be removed.
     * @return bool if a handler is found and detached
     * @see on()
     */
    public function off($name, $handler = null)
    {
        $this->ensureBehaviors();
        if (empty($this->_events[$name]) && empty($this->_eventWildcards[$name])) {
            return false;
        }
        if ($handler === null) {
            unset($this->_events[$name], $this->_eventWildcards[$name]);
            return true;
        }

        $removed = false;
        // plain event names
        if (isset($this->_events[$name])) {
            foreach ($this->_events[$name] as $i => $event) {
                if ($event[0] === $handler) {
                    unset($this->_events[$name][$i]);
                    $removed = true;
                }
            }
            if ($removed) {
                $this->_events[$name] = array_values($this->_events[$name]);
                return $removed;
            }
        }

        // wildcard event names
        if (isset($this->_eventWildcards[$name])) {
            foreach ($this->_eventWildcards[$name] as $i => $event) {
                if ($event[0] === $handler) {
                    unset($this->_eventWildcards[$name][$i]);
                    $removed = true;
                }
            }
            if ($removed) {
                $this->_eventWildcards[$name] = array_values($this->_eventWildcards[$name]);
                // remove empty wildcards to save future redundant regex checks:
                if (empty($this->_eventWildcards[$name])) {
                    unset($this->_eventWildcards[$name]);
                }
            }
        }

        return $removed;
    }

    /**
     * Triggers an event.
     * This method represents the happening of an event. It invokes
     * all attached handlers for the event including class-level handlers.
     * @param string $name the event name
     * @param Event $event the event parameter. If not set, a default [[Event]] object will be created.
     */
    public function trigger($name, Event $event = null)
    {
        $this->ensureBehaviors();

        $eventHandlers = [];
        foreach ($this->_eventWildcards as $wildcard => $handlers) {
            if (StringHelper::matchWildcard($wildcard, $name)) {
                $eventHandlers = array_merge($eventHandlers, $handlers);
            }
        }

        if (!empty($this->_events[$name])) {
            $eventHandlers = array_merge($eventHandlers, $this->_events[$name]);
        }

        if (!empty($eventHandlers)) {
            if ($event === null) {
                $event = new Event();
            }
            if ($event->sender === null) {
                $event->sender = $this;
            }
            $event->handled = false;
            $event->name = $name;
            foreach ($eventHandlers as $handler) {
                $event->data = $handler[1];
                call_user_func($handler[0], $event);
                // stop further handling if the event is handled
                if ($event->handled) {
                    return;
                }
            }
        }

        // invoke class-level attached handlers
        Event::trigger($this, $name, $event);
    }

    /**
     * Returns the named behavior object.
     * @param string $name the behavior name
     * @return null|Behavior the behavior object, or null if the behavior does not exist
     */
    public function getBehavior($name)
    {
        $this->ensureBehaviors();
        return isset($this->_behaviors[$name]) ? $this->_behaviors[$name] : null;
    }

    /**
     * Returns all behaviors attached to this component.
     * @return Behavior[] list of behaviors attached to this component
     */
    public function getBehaviors()
    {
        $this->ensureBehaviors();
        return $this->_behaviors;
    }

    /**
     * Attaches a behavior to this component.
     * This method will create the behavior object based on the given
     * configuration. After that, the behavior object will be attached to
     * this component by calling the [[Behavior::attach()]] method.
     * @param string $name the name of the behavior.
     * @param string|array|Behavior $behavior the behavior configuration. This can be one of the following:
     *
     *  - a [[Behavior]] object
     *  - a string specifying the behavior class
     *  - an object configuration array that will be passed to [[Yii::createObject()]] to create the behavior object.
     *
     * @return Behavior the behavior object
     * @see detachBehavior()
     */
    public function attachBehavior($name, $behavior)
    {
        $this->ensureBehaviors();
        return $this->attachBehaviorInternal($name, $behavior);
    }

    /**
     * Attaches a list of behaviors to the component.
     * Each behavior is indexed by its name and should be a [[Behavior]] object,
     * a string specifying the behavior class, or an configuration array for creating the behavior.
     * @param array $behaviors list of behaviors to be attached to the component
     * @see attachBehavior()
     */
    public function attachBehaviors($behaviors)
    {
        $this->ensureBehaviors();
        foreach ($behaviors as $name => $behavior) {
            $this->attachBehaviorInternal($name, $behavior);
        }
    }

    /**
     * Detaches a behavior from the component.
     * The behavior's [[Behavior::detach()]] method will be invoked.
     * @param string $name the behavior's name.
     * @return null|Behavior the detached behavior. Null if the behavior does not exist.
     */
    public function detachBehavior($name)
    {
        $this->ensureBehaviors();
        if (isset($this->_behaviors[$name])) {
            $behavior = $this->_behaviors[$name];
            unset($this->_behaviors[$name]);
            $behavior->detach();
            return $behavior;
        }

        return null;
    }

    /**
     * Detaches all behaviors from the component.
     */
    public function detachBehaviors()
    {
        $this->ensureBehaviors();
        foreach ($this->_behaviors as $name => $behavior) {
            $this->detachBehavior($name);
        }
    }

    /**
     * Makes sure that the behaviors declared in [[behaviors()]] are attached to this component.
     */
    public function ensureBehaviors()
    {
        if ($this->_behaviors === null) {
            $this->_behaviors = [];
            foreach ($this->behaviors() as $name => $behavior) {
                $this->attachBehaviorInternal($name, $behavior);
            }
        }
    }

    /**
     * Attaches a behavior to this component.
     * @param string|int $name the name of the behavior. If this is an integer, it means the behavior
     * is an anonymous one. Otherwise, the behavior is a named one and any existing behavior with the same name
     * will be detached first.
     * @param string|array|Behavior $behavior the behavior to be attached
     * @return Behavior the attached behavior.
     */
    private function attachBehaviorInternal($name, $behavior)
    {
        if (!($behavior instanceof Behavior)) {
            $behavior = Yii::createObject($behavior);
        }
        if (is_int($name)) {
            $behavior->attach($this);
            $this->_behaviors[] = $behavior;
        } else {
            if (isset($this->_behaviors[$name])) {
                $this->_behaviors[$name]->detach();
            }
            $behavior->attach($this);
            $this->_behaviors[$name] = $behavior;
        }

        return $behavior;
    }
}


<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\db;

use yii\base\BaseObject;
use yii\helpers\StringHelper;

/**
 * ColumnSchema class describes the metadata of a column in a database table.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @since 2.0
 */
class ColumnSchema extends BaseObject
{
    /**
     * @var string name of this column (without quotes).
     */
    public $name;
    /**
     * @var bool whether this column can be null.
     */
    public $allowNull;
    /**
     * @var string abstract type of this column. Possible abstract types include:
     * char, string, text, boolean, smallint, integer, bigint, float, decimal, datetime,
     * timestamp, time, date, binary, and money.
     */
    public $type;
    /**
     * @var string the PHP type of this column. Possible PHP types include:
     * `string`, `boolean`, `integer`, `double`, `array`.
     */
    public $phpType;
    /**
     * @var string the DB type of this column. Possible DB types vary according to the type of DBMS.
     */
    public $dbType;
    /**
     * @var mixed default value of this column
     */
    public $defaultValue;
    /**
     * @var array enumerable values. This is set only if the column is declared to be an enumerable type.
     */
    public $enumValues;
    /**
     * @var int display size of the column.
     */
    public $size;
    /**
     * @var int precision of the column data, if it is numeric.
     */
    public $precision;
    /**
     * @var int scale of the column data, if it is numeric.
     */
    public $scale;
    /**
     * @var bool whether this column is a primary key
     */
    public $isPrimaryKey;
    /**
     * @var bool whether this column is auto-incremental
     */
    public $autoIncrement = false;
    /**
     * @var bool whether this column is unsigned. This is only meaningful
     * when [[type]] is `smallint`, `integer` or `bigint`.
     */
    public $unsigned;
    /**
     * @var string comment of this column. Not all DBMS support this.
     */
    public $comment;

    /**
     * Converts the input value according to [[phpType]] after retrieval from the database.
     * If the value is null or an [[Expression]], it will not be converted.
     * @param mixed $value input value
     * @return mixed converted value
     */
    public function phpTypecast($value)
    {
        return $this->typecast($value);
    }

    /**
     * Converts the input value according to [[type]] and [[dbType]] for use in a db query.
     * If the value is null or an [[Expression]], it will not be converted.
     * @param mixed $value input value
     * @return mixed converted value. This may also be an array containing the value as the first element
     * and the PDO type as the second element.
     */
    public function dbTypecast($value)
    {
        // the default implementation does the same as casting for PHP, but it should be possible
        // to override this with annotation of explicit PDO type.
        return $this->typecast($value);
    }

    /**
     * Converts the input value according to [[phpType]] after retrieval from the database.
     * If the value is null or an [[Expression]], it will not be converted.
     * @param mixed $value input value
     * @return mixed converted value
     * @since 2.0.3
     */
    protected function typecast($value)
    {
        if ($value === ''
            && !in_array(
                $this->type,
                [
                    Schema::TYPE_TEXT,
                    Schema::TYPE_STRING,
                    Schema::TYPE_BINARY,
                    Schema::TYPE_CHAR
                ],
                true)
        ) {
            return null;
        }

        if ($value === null
            || gettype($value) === $this->phpType
            || $value instanceof ExpressionInterface
            || $value instanceof Query
        ) {
            return $value;
        }

        if (is_array($value)
            && count($value) === 2
            && isset($value[1])
            && in_array($value[1], $this->getPdoParamTypes(), true)
        ) {
            return new PdoValue($value[0], $value[1]);
        }

        switch ($this->phpType) {
            case 'resource':
            case 'string':
                if (is_resource($value)) {
                    return $value;
                }
                if (is_float($value)) {
                    // ensure type cast always has . as decimal separator in all locales
                    return StringHelper::floatToString($value);
                }
                return (string) $value;
            case 'integer':
                return (int) $value;
            case 'boolean':
                // treating a 0 bit value as false too
                // https://github.com/yiisoft/yii2/issues/9006
                return (bool) $value && $value !== "\0";
            case 'double':
                return (float) $value;
        }

        return $value;
    }

    /**
     * @return int[] array of numbers that represent possible PDO parameter types
     */
    private function getPdoParamTypes()
    {
        return [\PDO::PARAM_BOOL, \PDO::PARAM_INT, \PDO::PARAM_STR, \PDO::PARAM_LOB, \PDO::PARAM_NULL, \PDO::PARAM_STMT];
    }
}


<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\widgets;

use Yii;
use yii\base\InvalidConfigException;
use yii\base\Widget;
use yii\data\Pagination;
use yii\helpers\ArrayHelper;
use yii\helpers\Html;

/**
 * LinkPager displays a list of hyperlinks that lead to different pages of target.
 *
 * LinkPager works with a [[Pagination]] object which specifies the total number
 * of pages and the current page number.
 *
 * Note that LinkPager only generates the necessary HTML markups. In order for it
 * to look like a real pager, you should provide some CSS styles for it.
 * With the default configuration, LinkPager should look good using Twitter Bootstrap CSS framework.
 *
 * For more details and usage information on LinkPager, see the [guide article on pagination](guide:output-pagination).
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @since 2.0
 */
class LinkPager extends Widget
{
    /**
     * @var Pagination the pagination object that this pager is associated with.
     * You must set this property in order to make LinkPager work.
     */
    public $pagination;
    /**
     * @var array HTML attributes for the pager container tag.
     * @see \yii\helpers\Html::renderTagAttributes() for details on how attributes are being rendered.
     */
    public $options = ['class' => 'pagination'];
    /**
     * @var array HTML attributes which will be applied to all link containers
     * @since 2.0.13
     */
    public $linkContainerOptions = [];
    /**
     * @var array HTML attributes for the link in a pager container tag.
     * @see \yii\helpers\Html::renderTagAttributes() for details on how attributes are being rendered.
     */
    public $linkOptions = [];
    /**
     * @var string the CSS class for the each page button.
     * @since 2.0.7
     */
    public $pageCssClass;
    /**
     * @var string the CSS class for the "first" page button.
     */
    public $firstPageCssClass = 'first';
    /**
     * @var string the CSS class for the "last" page button.
     */
    public $lastPageCssClass = 'last';
    /**
     * @var string the CSS class for the "previous" page button.
     */
    public $prevPageCssClass = 'prev';
    /**
     * @var string the CSS class for the "next" page button.
     */
    public $nextPageCssClass = 'next';
    /**
     * @var string the CSS class for the active (currently selected) page button.
     */
    public $activePageCssClass = 'active';
    /**
     * @var string the CSS class for the disabled page buttons.
     */
    public $disabledPageCssClass = 'disabled';
    /**
     * @var array the options for the disabled tag to be generated inside the disabled list element.
     * In order to customize the html tag, please use the tag key.
     *
     * ```php
     * $disabledListItemSubTagOptions = ['tag' => 'div', 'class' => 'disabled-div'];
     * ```
     * @since 2.0.11
     */
    public $disabledListItemSubTagOptions = [];
    /**
     * @var int maximum number of page buttons that can be displayed. Defaults to 10.
     */
    public $maxButtonCount = 10;
    /**
     * @var string|bool the label for the "next" page button. Note that this will NOT be HTML-encoded.
     * If this property is false, the "next" page button will not be displayed.
     */
    public $nextPageLabel = '»';
    /**
     * @var string|bool the text label for the "previous" page button. Note that this will NOT be HTML-encoded.
     * If this property is false, the "previous" page button will not be displayed.
     */
    public $prevPageLabel = '«';
    /**
     * @var string|bool the text label for the "first" page button. Note that this will NOT be HTML-encoded.
     * If it's specified as true, page number will be used as label.
     * Default is false that means the "first" page button will not be displayed.
     */
    public $firstPageLabel = false;
    /**
     * @var string|bool the text label for the "last" page button. Note that this will NOT be HTML-encoded.
     * If it's specified as true, page number will be used as label.
     * Default is false that means the "last" page button will not be displayed.
     */
    public $lastPageLabel = false;
    /**
     * @var bool whether to register link tags in the HTML header for prev, next, first and last page.
     * Defaults to `false` to avoid conflicts when multiple pagers are used on one page.
     * @see http://www.w3.org/TR/html401/struct/links.html#h-12.1.2
     * @see registerLinkTags()
     */
    public $registerLinkTags = false;
    /**
     * @var bool Hide widget when only one page exist.
     */
    public $hideOnSinglePage = true;
    /**
     * @var bool whether to render current page button as disabled.
     * @since 2.0.12
     */
    public $disableCurrentPageButton = false;

    /**
     * Initializes the pager.
     */
    public function init()
    {
        parent::init();

        if ($this->pagination === null) {
            throw new InvalidConfigException('The "pagination" property must be set.');
        }
    }

    /**
     * Executes the widget.
     * This overrides the parent implementation by displaying the generated page buttons.
     */
    public function run()
    {
        if ($this->registerLinkTags) {
            $this->registerLinkTags();
        }
        echo $this->renderPageButtons();
    }

    /**
     * Registers relational link tags in the html header for prev, next, first and last page.
     * These links are generated using [[\yii\data\Pagination::getLinks()]].
     * @see http://www.w3.org/TR/html401/struct/links.html#h-12.1.2
     */
    protected function registerLinkTags()
    {
        $view = $this->getView();
        foreach ($this->pagination->getLinks() as $rel => $href) {
            $view->registerLinkTag(['rel' => $rel, 'href' => $href], $rel);
        }
    }

    /**
     * Renders the page buttons.
     * @return string the rendering result
     */
    protected function renderPageButtons()
    {
        $pageCount = $this->pagination->getPageCount();
        if ($pageCount < 2 && $this->hideOnSinglePage) {
            return '';
        }

        $buttons = [];
        $currentPage = $this->pagination->getPage();

        // first page
        $firstPageLabel = $this->firstPageLabel === true ? '1' : $this->firstPageLabel;
        if ($firstPageLabel !== false) {
            $buttons[] = $this->renderPageButton($firstPageLabel, 0, $this->firstPageCssClass, $currentPage <= 0, false);
        }

        // prev page
        if ($this->prevPageLabel !== false) {
            if (($page = $currentPage - 1) < 0) {
                $page = 0;
            }
            $buttons[] = $this->renderPageButton($this->prevPageLabel, $page, $this->prevPageCssClass, $currentPage <= 0, false);
        }

        // internal pages
        list($beginPage, $endPage) = $this->getPageRange();
        for ($i = $beginPage; $i <= $endPage; ++$i) {
            $buttons[] = $this->renderPageButton($i + 1, $i, null, $this->disableCurrentPageButton && $i == $currentPage, $i == $currentPage);
        }

        // next page
        if ($this->nextPageLabel !== false) {
            if (($page = $currentPage + 1) >= $pageCount - 1) {
                $page = $pageCount - 1;
            }
            $buttons[] = $this->renderPageButton($this->nextPageLabel, $page, $this->nextPageCssClass, $currentPage >= $pageCount - 1, false);
        }

        // last page
        $lastPageLabel = $this->lastPageLabel === true ? $pageCount : $this->lastPageLabel;
        if ($lastPageLabel !== false) {
            $buttons[] = $this->renderPageButton($lastPageLabel, $pageCount - 1, $this->lastPageCssClass, $currentPage >= $pageCount - 1, false);
        }

        $options = $this->options;
        $tag = ArrayHelper::remove($options, 'tag', 'ul');
        return Html::tag($tag, implode("\n", $buttons), $options);
    }

    /**
     * Renders a page button.
     * You may override this method to customize the generation of page buttons.
     * @param string $label the text label for the button
     * @param int $page the page number
     * @param string $class the CSS class for the page button.
     * @param bool $disabled whether this page button is disabled
     * @param bool $active whether this page button is active
     * @return string the rendering result
     */
    protected function renderPageButton($label, $page, $class, $disabled, $active)
    {
        $options = $this->linkContainerOptions;
        $linkWrapTag = ArrayHelper::remove($options, 'tag', 'li');
        Html::addCssClass($options, empty($class) ? $this->pageCssClass : $class);

        if ($active) {
            Html::addCssClass($options, $this->activePageCssClass);
        }
        if ($disabled) {
            Html::addCssClass($options, $this->disabledPageCssClass);
            $disabledItemOptions = $this->disabledListItemSubTagOptions;
            $tag = ArrayHelper::remove($disabledItemOptions, 'tag', 'span');

            return Html::tag($linkWrapTag, Html::tag($tag, $label, $disabledItemOptions), $options);
        }
        $linkOptions = $this->linkOptions;
        $linkOptions['data-page'] = $page;

        return Html::tag($linkWrapTag, Html::a($label, $this->pagination->createUrl($page), $linkOptions), $options);
    }

    /**
     * @return array the begin and end pages that need to be displayed.
     */
    protected function getPageRange()
    {
        $currentPage = $this->pagination->getPage();
        $pageCount = $this->pagination->getPageCount();

        $beginPage = max(0, $currentPage - (int) ($this->maxButtonCount / 2));
        if (($endPage = $beginPage + $this->maxButtonCount - 1) >= $pageCount) {
            $endPage = $pageCount - 1;
            $beginPage = max(0, $endPage - $this->maxButtonCount + 1);
        }

        return [$beginPage, $endPage];
    }
}


<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\caching;

use Yii;
use yii\helpers\FileHelper;

/**
 * FileCache implements a cache component using files.
 *
 * For each data value being cached, FileCache will store it in a separate file.
 * The cache files are placed under [[cachePath]]. FileCache will perform garbage collection
 * automatically to remove expired cache files.
 *
 * Please refer to [[Cache]] for common cache operations that are supported by FileCache.
 *
 * For more details and usage information on Cache, see the [guide article on caching](guide:caching-overview).
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @since 2.0
 */
class FileCache extends Cache
{
    /**
     * @var string a string prefixed to every cache key. This is needed when you store
     * cache data under the same [[cachePath]] for different applications to avoid
     * conflict.
     *
     * To ensure interoperability, only alphanumeric characters should be used.
     */
    public $keyPrefix = '';
    /**
     * @var string the directory to store cache files. You may use [path alias](guide:concept-aliases) here.
     * If not set, it will use the "cache" subdirectory under the application runtime path.
     */
    public $cachePath = '@runtime/cache';
    /**
     * @var string cache file suffix. Defaults to '.bin'.
     */
    public $cacheFileSuffix = '.bin';
    /**
     * @var int the level of sub-directories to store cache files. Defaults to 1.
     * If the system has huge number of cache files (e.g. one million), you may use a bigger value
     * (usually no bigger than 3). Using sub-directories is mainly to ensure the file system
     * is not over burdened with a single directory having too many files.
     */
    public $directoryLevel = 1;
    /**
     * @var int the probability (parts per million) that garbage collection (GC) should be performed
     * when storing a piece of data in the cache. Defaults to 10, meaning 0.001% chance.
     * This number should be between 0 and 1000000. A value 0 means no GC will be performed at all.
     */
    public $gcProbability = 10;
    /**
     * @var int the permission to be set for newly created cache files.
     * This value will be used by PHP chmod() function. No umask will be applied.
     * If not set, the permission will be determined by the current environment.
     */
    public $fileMode;
    /**
     * @var int the permission to be set for newly created directories.
     * This value will be used by PHP chmod() function. No umask will be applied.
     * Defaults to 0775, meaning the directory is read-writable by owner and group,
     * but read-only for other users.
     */
    public $dirMode = 0775;

    /**
     * Initializes this component by ensuring the existence of the cache path.
     */
    public function init()
    {
        parent::init();
        $this->cachePath = Yii::getAlias($this->cachePath);
        if (!is_dir($this->cachePath)) {
            FileHelper::createDirectory($this->cachePath, $this->dirMode, true);
        }
    }

    /**
     * Checks whether a specified key exists in the cache.
     * This can be faster than getting the value from the cache if the data is big.
     * Note that this method does not check whether the dependency associated
     * with the cached data, if there is any, has changed. So a call to [[get]]
     * may return false while exists returns true.
     * @param mixed $key a key identifying the cached value. This can be a simple string or
     * a complex data structure consisting of factors representing the key.
     * @return bool true if a value exists in cache, false if the value is not in the cache or expired.
     */
    public function exists($key)
    {
        $cacheFile = $this->getCacheFile($this->buildKey($key));

        return @filemtime($cacheFile) > time();
    }

    /**
     * Retrieves a value from cache with a specified key.
     * This is the implementation of the method declared in the parent class.
     * @param string $key a unique key identifying the cached value
     * @return string|false the value stored in cache, false if the value is not in the cache or expired.
     */
    protected function getValue($key)
    {
        $cacheFile = $this->getCacheFile($key);

        if (@filemtime($cacheFile) > time()) {
            $fp = @fopen($cacheFile, 'r');
            if ($fp !== false) {
                @flock($fp, LOCK_SH);
                $cacheValue = @stream_get_contents($fp);
                @flock($fp, LOCK_UN);
                @fclose($fp);
                return $cacheValue;
            }
        }

        return false;
    }

    /**
     * Stores a value identified by a key in cache.
     * This is the implementation of the method declared in the parent class.
     *
     * @param string $key the key identifying the value to be cached
     * @param string $value the value to be cached. Other types (If you have disabled [[serializer]]) unable to get is
     * correct in [[getValue()]].
     * @param int $duration the number of seconds in which the cached value will expire. 0 means never expire.
     * @return bool true if the value is successfully stored into cache, false otherwise
     */
    protected function setValue($key, $value, $duration)
    {
        $this->gc();
        $cacheFile = $this->getCacheFile($key);
        if ($this->directoryLevel > 0) {
            @FileHelper::createDirectory(dirname($cacheFile), $this->dirMode, true);
        }
        // If ownership differs the touch call will fail, so we try to
        // rebuild the file from scratch by deleting it first
        // https://github.com/yiisoft/yii2/pull/16120
        if (is_file($cacheFile) && function_exists('posix_geteuid') && fileowner($cacheFile) !== posix_geteuid()) {
            @unlink($cacheFile);
        }
        if (@file_put_contents($cacheFile, $value, LOCK_EX) !== false) {
            if ($this->fileMode !== null) {
                @chmod($cacheFile, $this->fileMode);
            }
            if ($duration <= 0) {
                $duration = 31536000; // 1 year
            }

            return @touch($cacheFile, $duration + time());
        }

        $error = error_get_last();
        Yii::warning("Unable to write cache file '{$cacheFile}': {$error['message']}", __METHOD__);
        return false;
    }

    /**
     * Stores a value identified by a key into cache if the cache does not contain this key.
     * This is the implementation of the method declared in the parent class.
     *
     * @param string $key the key identifying the value to be cached
     * @param string $value the value to be cached. Other types (if you have disabled [[serializer]]) unable to get is
     * correct in [[getValue()]].
     * @param int $duration the number of seconds in which the cached value will expire. 0 means never expire.
     * @return bool true if the value is successfully stored into cache, false otherwise
     */
    protected function addValue($key, $value, $duration)
    {
        $cacheFile = $this->getCacheFile($key);
        if (@filemtime($cacheFile) > time()) {
            return false;
        }

        return $this->setValue($key, $value, $duration);
    }

    /**
     * Deletes a value with the specified key from cache
     * This is the implementation of the method declared in the parent class.
     * @param string $key the key of the value to be deleted
     * @return bool if no error happens during deletion
     */
    protected function deleteValue($key)
    {
        $cacheFile = $this->getCacheFile($key);

        return @unlink($cacheFile);
    }

    /**
     * Returns the cache file path given the cache key.
     * @param string $key cache key
     * @return string the cache file path
     */
    protected function getCacheFile($key)
    {
        if ($this->directoryLevel > 0) {
            $base = $this->cachePath;
            for ($i = 0; $i < $this->directoryLevel; ++$i) {
                if (($prefix = substr($key, $i + $i, 2)) !== false) {
                    $base .= DIRECTORY_SEPARATOR . $prefix;
                }
            }

            return $base . DIRECTORY_SEPARATOR . $key . $this->cacheFileSuffix;
        }

        return $this->cachePath . DIRECTORY_SEPARATOR . $key . $this->cacheFileSuffix;
    }

    /**
     * Deletes all values from cache.
     * This is the implementation of the method declared in the parent class.
     * @return bool whether the flush operation was successful.
     */
    protected function flushValues()
    {
        $this->gc(true, false);

        return true;
    }

    /**
     * Removes expired cache files.
     * @param bool $force whether to enforce the garbage collection regardless of [[gcProbability]].
     * Defaults to false, meaning the actual deletion happens with the probability as specified by [[gcProbability]].
     * @param bool $expiredOnly whether to removed expired cache files only.
     * If false, all cache files under [[cachePath]] will be removed.
     */
    public function gc($force = false, $expiredOnly = true)
    {
        if ($force || mt_rand(0, 1000000) < $this->gcProbability) {
            $this->gcRecursive($this->cachePath, $expiredOnly);
        }
    }

    /**
     * Recursively removing expired cache files under a directory.
     * This method is mainly used by [[gc()]].
     * @param string $path the directory under which expired cache files are removed.
     * @param bool $expiredOnly whether to only remove expired cache files. If false, all files
     * under `$path` will be removed.
     */
    protected function gcRecursive($path, $expiredOnly)
    {
        if (($handle = opendir($path)) !== false) {
            while (($file = readdir($handle)) !== false) {
                if ($file[0] === '.') {
                    continue;
                }
                $fullPath = $path . DIRECTORY_SEPARATOR . $file;
                if (is_dir($fullPath)) {
                    $this->gcRecursive($fullPath, $expiredOnly);
                    if (!$expiredOnly) {
                        if (!@rmdir($fullPath)) {
                            $error = error_get_last();
                            Yii::warning("Unable to remove directory '{$fullPath}': {$error['message']}", __METHOD__);
                        }
                    }
                } elseif (!$expiredOnly || $expiredOnly && @filemtime($fullPath) < time()) {
                    if (!@unlink($fullPath)) {
                        $error = error_get_last();
                        Yii::warning("Unable to remove file '{$fullPath}': {$error['message']}", __METHOD__);
                    }
                }
            }
            closedir($handle);
        }
    }
}


<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\helpers;

use yii\base\Arrayable;
use yii\base\InvalidArgumentException;
use yii\web\JsExpression;
use yii\base\Model;

/**
 * BaseJson provides concrete implementation for [[Json]].
 *
 * Do not use BaseJson. Use [[Json]] instead.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @since 2.0
 */
class BaseJson
{
    /**
     * List of JSON Error messages assigned to constant names for better handling of version differences.
     * @var array
     * @since 2.0.7
     */
    public static $jsonErrorMessages = [
        'JSON_ERROR_DEPTH' => 'The maximum stack depth has been exceeded.',
        'JSON_ERROR_STATE_MISMATCH' => 'Invalid or malformed JSON.',
        'JSON_ERROR_CTRL_CHAR' => 'Control character error, possibly incorrectly encoded.',
        'JSON_ERROR_SYNTAX' => 'Syntax error.',
        'JSON_ERROR_UTF8' => 'Malformed UTF-8 characters, possibly incorrectly encoded.', // PHP 5.3.3
        'JSON_ERROR_RECURSION' => 'One or more recursive references in the value to be encoded.', // PHP 5.5.0
        'JSON_ERROR_INF_OR_NAN' => 'One or more NAN or INF values in the value to be encoded', // PHP 5.5.0
        'JSON_ERROR_UNSUPPORTED_TYPE' => 'A value of a type that cannot be encoded was given', // PHP 5.5.0
    ];

    /**
     * Encodes the given value into a JSON string.
     *
     * The method enhances `json_encode()` by supporting JavaScript expressions.
     * In particular, the method will not encode a JavaScript expression that is
     * represented in terms of a [[JsExpression]] object.
     *
     * Note that data encoded as JSON must be UTF-8 encoded according to the JSON specification.
     * You must ensure strings passed to this method have proper encoding before passing them.
     *
     * @param mixed $value the data to be encoded.
     * @param int $options the encoding options. For more details please refer to
     * <https://secure.php.net/manual/en/function.json-encode.php>. Default is `JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE`.
     * @return string the encoding result.
     * @throws InvalidArgumentException if there is any encoding error.
     */
    public static function encode($value, $options = 320)
    {
        $expressions = [];
        $value = static::processData($value, $expressions, uniqid('', true));
        set_error_handler(function () {
            static::handleJsonError(JSON_ERROR_SYNTAX);
        }, E_WARNING);
        $json = json_encode($value, $options);
        restore_error_handler();
        static::handleJsonError(json_last_error());

        return $expressions === [] ? $json : strtr($json, $expressions);
    }

    /**
     * Encodes the given value into a JSON string HTML-escaping entities so it is safe to be embedded in HTML code.
     *
     * The method enhances `json_encode()` by supporting JavaScript expressions.
     * In particular, the method will not encode a JavaScript expression that is
     * represented in terms of a [[JsExpression]] object.
     *
     * Note that data encoded as JSON must be UTF-8 encoded according to the JSON specification.
     * You must ensure strings passed to this method have proper encoding before passing them.
     *
     * @param mixed $value the data to be encoded
     * @return string the encoding result
     * @since 2.0.4
     * @throws InvalidArgumentException if there is any encoding error
     */
    public static function htmlEncode($value)
    {
        return static::encode($value, JSON_UNESCAPED_UNICODE | JSON_HEX_QUOT | JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS);
    }

    /**
     * Decodes the given JSON string into a PHP data structure.
     * @param string $json the JSON string to be decoded
     * @param bool $asArray whether to return objects in terms of associative arrays.
     * @return mixed the PHP data
     * @throws InvalidArgumentException if there is any decoding error
     */
    public static function decode($json, $asArray = true)
    {
        if (is_array($json)) {
            throw new InvalidArgumentException('Invalid JSON data.');
        } elseif ($json === null || $json === '') {
            return null;
        }
        $decode = json_decode((string) $json, $asArray);
        static::handleJsonError(json_last_error());

        return $decode;
    }

    /**
     * Handles [[encode()]] and [[decode()]] errors by throwing exceptions with the respective error message.
     *
     * @param int $lastError error code from [json_last_error()](https://secure.php.net/manual/en/function.json-last-error.php).
     * @throws InvalidArgumentException if there is any encoding/decoding error.
     * @since 2.0.6
     */
    protected static function handleJsonError($lastError)
    {
        if ($lastError === JSON_ERROR_NONE) {
            return;
        }

        $availableErrors = [];
        foreach (static::$jsonErrorMessages as $const => $message) {
            if (defined($const)) {
                $availableErrors[constant($const)] = $message;
            }
        }

        if (isset($availableErrors[$lastError])) {
            throw new InvalidArgumentException($availableErrors[$lastError], $lastError);
        }

        throw new InvalidArgumentException('Unknown JSON encoding/decoding error.');
    }

    /**
     * Pre-processes the data before sending it to `json_encode()`.
     * @param mixed $data the data to be processed
     * @param array $expressions collection of JavaScript expressions
     * @param string $expPrefix a prefix internally used to handle JS expressions
     * @return mixed the processed data
     */
    protected static function processData($data, &$expressions, $expPrefix)
    {
        if (is_object($data)) {
            if ($data instanceof JsExpression) {
                $token = "!{[$expPrefix=" . count($expressions) . ']}!';
                $expressions['"' . $token . '"'] = $data->expression;

                return $token;
            } elseif ($data instanceof \JsonSerializable) {
                return static::processData($data->jsonSerialize(), $expressions, $expPrefix);
            } elseif ($data instanceof Arrayable) {
                $data = $data->toArray();
            } elseif ($data instanceof \SimpleXMLElement) {
                $data = (array) $data;
            } else {
                $result = [];
                foreach ($data as $name => $value) {
                    $result[$name] = $value;
                }
                $data = $result;
            }

            if ($data === []) {
                return new \stdClass();
            }
        }

        if (is_array($data)) {
            foreach ($data as $key => $value) {
                if (is_array($value) || is_object($value)) {
                    $data[$key] = static::processData($value, $expressions, $expPrefix);
                }
            }
        }

        return $data;
    }

    /**
     * Generates a summary of the validation errors.
     * @param Model|Model[] $models the model(s) whose validation errors are to be displayed.
     * @param array $options the tag options in terms of name-value pairs. The following options are specially handled:
     *
     * - showAllErrors: boolean, if set to true every error message for each attribute will be shown otherwise
     *   only the first error message for each attribute will be shown. Defaults to `false`.
     *
     * @return string the generated error summary
     * @since 2.0.14
     */
    public static function errorSummary($models, $options = [])
    {
        $showAllErrors = ArrayHelper::remove($options, 'showAllErrors', false);
        $lines = self::collectErrors($models, $showAllErrors);

        return json_encode($lines);
    }

    /**
     * Return array of the validation errors
     * @param Model|Model[] $models the model(s) whose validation errors are to be displayed.
     * @param $showAllErrors boolean, if set to true every error message for each attribute will be shown otherwise
     * only the first error message for each attribute will be shown.
     * @return array of the validation errors
     * @since 2.0.14
     */
    private static function collectErrors($models, $showAllErrors)
    {
        $lines = [];
        if (!is_array($models)) {
            $models = [$models];
        }

        foreach ($models as $model) {
            $lines = array_unique(array_merge($lines, $model->getErrorSummary($showAllErrors)));
        }

        return $lines;
    }
}