<?php
/**
* Provide a common container for a set of models.
*
* Advantage of extending ArrayIterator is that php built-in
* array-walk functions reset(), next(), key(), current()
* can be replaced by class-implemented counterparts
* and vice versa. In other words, if $iterator is an instance
* of P4_Iterator class then $iterator->next()
* and next($iterator) are equivalent and same for all other pairs.
*
* @copyright 2011 Perforce Software. All rights reserved.
* @license Please see LICENSE.txt in top-level folder of this distribution.
* @version <release>/<patch>
*/
class P4_Iterator extends ArrayIterator
{
const FILTER_INVERSE = 'INVERSE';
const FILTER_COPY = 'COPY';
/**
* Define the type of models we want to accept in this iterator.
*/
protected $_allowedModelClass = 'P4_ConnectedInterface';
/**
* Store custom iterator properties
*/
protected $_properties = array();
/**
* Create a new model iterator.
* If an array of models is given, populate from the array.
*
* @param array $models optional - the set of models to contain.
*/
public function __construct($models = null)
{
if (isset($models) && is_array($models)) {
foreach ($models as $model) {
if (!$model instanceof $this->_allowedModelClass) {
throw new InvalidArgumentException("Models array contains one or more invalid elements.");
}
}
parent::__construct($models);
} else {
parent::__construct(array());
}
}
/**
* Set the model under the given key
*
* @param string|integer $key the key to store the model under.
* @param P4_Model $model the model to store.
* @return void
*/
public function offsetSet($key, $model)
{
if (!$model instanceof $this->_allowedModelClass) {
throw new InvalidArgumentException("Invalid model supplied.");
}
return parent::offsetSet($key, $model);
}
/**
* Seek to an absolute position.
*
* @param integer $position the numeric position to seek to.
*/
function seek($position)
{
if (!is_integer($position)) {
throw new OutOfBoundsException('Invalid seek position.');
}
$this->rewind();
$current = 0;
while ($current < $position && $this->valid()) {
$this->next();
$current++;
}
if (!$this->valid()) {
throw new OutOfBoundsException('Invalid seek position.');
}
}
/**
* Overwrite next() method to return current value or false.
*
* If php built-in next() function is not called then array
* pointer is not advanced and other php array-walk functions
* like current() or key() won't work.
*
* @return false | mixed
*/
public function next()
{
parent::next();
next($this);
return $this->valid() ? $this->current() : false;
}
/**
* Overwrite rewind() method to reset array pointer.
*
* If php built-in reset() function is not called then array
* pointer is not advanced and other php array-walk functions
* like current() or key() won't work.
*/
public function rewind()
{
parent::rewind();
reset($this);
}
/**
* Return the key of the array element that's currently being
* pointed to by the internal pointer.
* It does not move the pointer in any way.
*
* @return string|integer|null
*/
public function key()
{
return key($this);
}
/**
* Get all of the keys for all of the entries in this iterator.
*
* @return array a list of the keys in the iterator.
*/
public function keys()
{
return array_keys($this->getArrayCopy());
}
/**
* Return the value of the array element that's currently being
* pointed to by the internal pointer.
* It does not move the pointer in any way.
*
* @return P4_Model
*/
public function current()
{
return current($this);
}
/**
* Get the value of the first element.
*
* @return P4_ModelInterface
*/
public function first()
{
$this->rewind();
return $this->current();
}
/**
* Get the value of the last element.
*
* @return P4_ModelInterface
*/
public function last()
{
end($this);
return $this->current();
}
/**
* Will run the specified function on each entry in the iterator, optionally
* passing arguments.
*
* An array of function return values will be returned.
*
* @param string $functionName The name of the function to execute
* @param array $params Optional array of paramaters to pass the function
* @returns array Array of return values
* @throws InvalidArgumentException If any entry lacks the specified function
*/
public function invoke($functionName, $params = array())
{
$results = array();
foreach ($this as $entry) {
if (!is_object($entry) || !method_exists($entry, $functionName)) {
throw new InvalidArgumentException(
'One or more entries lack the specified function'
);
}
$results[] = call_user_func_array(array($entry, $functionName), $params);
}
return $results;
}
/**
* Filter items of this instance by callback function.
*
* Callback must be callable function with at least one
* parameter represents the allowed model class instance.
*
* Additional parameters can be set in params, in this
* case callback will be called with model instance
* parameter followed by params.
*
* Item (model) is acceptable if and only if callback
* function with item passed as first parameter returns
* true.
*
* Valid filter options are:
*
* FILTER_INVERSE - inverse filtering behavior - acceptable items are removed
* FILTER_COPY - return a filtered copy without modifying original
*
* @param callback $callback callback function to determine if item is acceptable
* @param mixed $params optional additional callback parameters
* @param string|array $options optional - one or more filtering options
* @return P4Cms_Model_Iterator provides fluent interface
*/
public function filterByCallback($callback, $params = null, $options = array())
{
if (!is_callable($callback)) {
throw new Exception('Callback for P4Cms_Model_Iterator must be callable function.');
}
$copy = new static;
// remove items where callback returns false
foreach ($this->getArrayCopy() as $key => $model) {
$passesFilter = call_user_func_array($callback, array($model, $params));
// inverse behavior if FILTER_INVERSE option is set
if (in_array(self::FILTER_INVERSE, $options)) {
$passesFilter = !$passesFilter;
}
if (!$passesFilter && !in_array(static::FILTER_COPY, $options, true)) {
$this->offsetUnset($key);
} else if ($passesFilter && in_array(static::FILTER_COPY, $options, true)) {
$copy[$key] = $model;
}
}
return in_array(static::FILTER_COPY, $options, true) ? $copy : $this;
}
/**
* Merges the passed iterator's values into this iterator.
*
* If the input iterator has the same string keys, then the later value for
* that key will overwrite the previous one. If, however, the key are numeric,
* the later value will not overwrite the original value, but will be appended.
*
* @param P4_Iterator $iterator The new values to merge in
* @return P4_Model_Iterator provides fluent interface
*/
public function merge(P4_Iterator $iterator)
{
foreach ($iterator as $key => $value) {
if (is_int($key)) {
$this[] = $value;
} else {
$this[$key] = $value;
}
}
return $this;
}
/**
* Check if iterator has a particular property.
*
* @param string $name the property name to check for the existence of
* @return boolean true if the iterator has the named property, false otherwise.
*/
public function hasProperty($name)
{
return array_key_exists($name, $this->_properties);
}
/**
* Get a particular property value of this iterator.
*
* @param string $name name of the property to get the value of
* @return mixed the value of the property name
* @throws InvalidArgumentException if the property name does not exist
*/
public function getProperty($name)
{
// return property value if it was set, otherwise throw an exception
if ($this->hasProperty($name)) {
return $this->_properties[$name];
}
throw new InvalidArgumentException(
"Cannot find iterator property '$name'. Property was not set."
);
}
/**
* Get all properties of this iterator.
*
* @return array all properties set to this iterator
*/
public function getProperties()
{
return $this->_properties;
}
/**
* Set a particular property of this iterator.
*
* @param string $name name of the property to set the value of
* @param mixed $value value to set
* @return P4_Iterator provides a fluent interface
*/
public function setProperty($name, $value)
{
$this->_properties[$name] = $value;
return $this;
}
/**
* Set iterator properties.
*
* @param array $properties array with properties to set
* @return P4_Iterator provides a fluent interface
*/
public function setProperties(array $properties)
{
$this->_properties = $properties;
return $this;
}
}