<?php
/**
* Part of the Joomla Framework Data Package
*
* @copyright Copyright (C) 2005 - 2021 Open Source Matters, Inc. All rights reserved.
* @license GNU General Public License version 2 or later; see LICENSE
*/
namespace Joomla\Data;
/**
* DataSet is a collection class that allows the developer to operate on a set of DataObjects as if they were in a typical PHP array.
*
* @since 1.0
*/
class DataSet implements DumpableInterface, \ArrayAccess, \Countable, \Iterator
{
/**
* The current position of the iterator.
*
* @var integer
* @since 1.0
*/
private $current = false;
/**
* The iterator objects.
*
* @var DataObject[]
* @since 1.0
*/
private $objects = [];
/**
* The class constructor.
*
* @param DataObject[] $objects An array of DataObject objects to bind to the data set.
*
* @since 1.0
* @throws \InvalidArgumentException if an object is not a DataObject.
*/
public function __construct(array $objects = [])
{
// Set the objects.
$this->initialise($objects);
}
/**
* The magic call method is used to call object methods using the iterator.
*
* Example: $array = $objectList->foo('bar');
*
* The object list will iterate over its objects and see if each object has a callable 'foo' method.
* If so, it will pass the argument list and assemble any return values. If an object does not have
* a callable method no return value is recorded.
* The keys of the objects and the result array are maintained.
*
* @param string $method The name of the method called.
* @param array $arguments The arguments of the method called.
*
* @return array An array of values returned by the methods called on the objects in the data set.
*
* @since 1.0
*/
public function __call($method, $arguments = [])
{
$return = [];
// Iterate through the objects.
foreach ($this->objects as $key => $object)
{
// Create the object callback.
$callback = [$object, $method];
// Check if the callback is callable.
if (\is_callable($callback))
{
// Call the method for the object.
$return[$key] = \call_user_func_array($callback, $arguments);
}
}
return $return;
}
/**
* The magic get method is used to get a list of properties from the objects in the data set.
*
* Example: $array = $dataSet->foo;
*
* This will return a column of the values of the 'foo' property in all the objects
* (or values determined by custom property setters in the individual DataObject's).
* The result array will contain an entry for each object in the list (compared to __call which may not).
* The keys of the objects and the result array are maintained.
*
* @param string $property The name of the data property.
*
* @return array An associative array of the values.
*
* @since 1.0
*/
public function __get($property)
{
$return = [];
// Iterate through the objects.
foreach ($this->objects as $key => $object)
{
// Get the property.
$return[$key] = $object->$property;
}
return $return;
}
/**
* The magic isset method is used to check the state of an object property using the iterator.
*
* Example: $array = isset($objectList->foo);
*
* @param string $property The name of the property.
*
* @return boolean True if the property is set in any of the objects in the data set.
*
* @since 1.0
*/
public function __isset($property)
{
$return = [];
// Iterate through the objects.
foreach ($this->objects as $object)
{
// Check the property.
$return[] = isset($object->$property);
}
return \in_array(true, $return, true);
}
/**
* The magic set method is used to set an object property using the iterator.
*
* Example: $objectList->foo = 'bar';
*
* This will set the 'foo' property to 'bar' in all of the objects
* (or a value determined by custom property setters in the DataObject).
*
* @param string $property The name of the property.
* @param mixed $value The value to give the data property.
*
* @return void
*
* @since 1.0
*/
public function __set($property, $value)
{
// Iterate through the objects.
foreach ($this->objects as $object)
{
// Set the property.
$object->$property = $value;
}
}
/**
* The magic unset method is used to unset an object property using the iterator.
*
* Example: unset($objectList->foo);
*
* This will unset all of the 'foo' properties in the list of DataObject's.
*
* @param string $property The name of the property.
*
* @return void
*
* @since 1.0
*/
public function __unset($property)
{
// Iterate through the objects.
foreach ($this->objects as $object)
{
unset($object->$property);
}
}
/**
* Gets an array of keys, existing in objects
*
* @param string $type Selection type 'all' or 'common'
*
* @return array Array of keys
*
* @since 1.2.0
* @throws \InvalidArgumentException
*/
public function getObjectsKeys($type = 'all')
{
$keys = null;
if ($type == 'all')
{
$function = 'array_merge';
}
elseif ($type == 'common')
{
$function = 'array_intersect_key';
}
else
{
throw new \InvalidArgumentException("Unknown selection type: $type");
}
foreach ($this->objects as $object)
{
$objectVars = json_decode(json_encode($object), true);
$keys = ($keys === null) ? $objectVars : $function($keys, $objectVars);
}
return array_keys($keys);
}
/**
* Gets all objects as an array
*
* @param boolean $associative Option to set return mode: associative or numeric array.
* @param string ...$keys Unlimited optional property names to extract from objects.
*
* @return array Returns an array according to defined options.
*
* @since 1.2.0
*/
public function toArray($associative = true, ...$keys)
{
if (empty($keys))
{
$keys = $this->getObjectsKeys();
}
$return = [];
$i = 0;
foreach ($this->objects as $key => $object)
{
$arrayItem = [];
$key = ($associative) ? $key : $i++;
$j = 0;
foreach ($keys as $property)
{
$propertyKey = ($associative) ? $property : $j++;
$arrayItem[$propertyKey] = $object->$property ?? null;
}
$return[$key] = $arrayItem;
}
return $return;
}
/**
* Gets the number of data objects in the set.
*
* @return integer The number of objects.
*
* @since 1.0
*/
public function count()
{
return \count($this->objects);
}
/**
* Clears the objects in the data set.
*
* @return DataSet Returns itself to allow chaining.
*
* @since 1.0
*/
public function clear()
{
$this->objects = [];
$this->rewind();
return $this;
}
/**
* Get the current data object in the set.
*
* @return DataObject|false The current object, or false if the array is empty or the pointer is beyond the end of the elements.
*
* @since 1.0
*/
public function current()
{
return is_scalar($this->current) ? $this->objects[$this->current] : false;
}
/**
* Dumps the data object in the set, recursively if appropriate.
*
* @param integer $depth The maximum depth of recursion (default = 3).
* For example, a depth of 0 will return a stdClass with all the properties in native
* form. A depth of 1 will recurse into the first level of properties only.
* @param \SplObjectStorage $dumped An array of already serialized objects that is used to avoid infinite loops.
*
* @return array An associative array of the data objects in the set, dumped as a simple PHP stdClass object.
*
* @see DataObject::dump()
* @since 1.0
*/
public function dump($depth = 3, \SplObjectStorage $dumped = null)
{
// Check if we should initialise the recursion tracker.
if ($dumped === null)
{
$dumped = new \SplObjectStorage;
}
// Add this object to the dumped stack.
$dumped->attach($this);
$objects = [];
// Make sure that we have not reached our maximum depth.
if ($depth > 0)
{
// Handle JSON serialization recursively.
foreach ($this->objects as $key => $object)
{
$objects[$key] = $object->dump($depth, $dumped);
}
}
return $objects;
}
/**
* Gets the data set in a form that can be serialised to JSON format.
*
* Note that this method will not return an associative array, otherwise it would be encoded into an object.
* JSON decoders do not consistently maintain the order of associative keys, whereas they do maintain the order of arrays.
*
* @return array
*
* @since 1.0
*/
public function jsonSerialize()
{
$return = [];
// Iterate through the objects.
foreach ($this->objects as $object)
{
// Call the method for the object.
$return[] = $object;
}
return $return;
}
/**
* Gets the key of the current object in the iterator.
*
* @return integer|false The object key on success; false on failure.
*
* @since 1.0
*/
public function key()
{
return $this->current;
}
/**
* Gets the array of keys for all the objects in the iterator (emulates array_keys).
*
* @return array The array of keys
*
* @since 1.0
*/
public function keys()
{
return array_keys($this->objects);
}
/**
* Applies a function to every object in the set (emulates array_walk).
*
* @param callable $funcname Callback function.
*
* @return boolean
*
* @since 1.2.0
* @throws \InvalidArgumentException
*/
public function walk(callable $funcname)
{
foreach ($this->objects as $key => $object)
{
$funcname($object, $key);
}
return true;
}
/**
* Advances the iterator to the next object in the iterator.
*
* @return void
*
* @since 1.0
*/
public function next()
{
// Get the object offsets.
$keys = $this->keys();
// Check if _current has been set to false but offsetUnset.
if ($this->current === false && isset($keys[0]))
{
// This is a special case where offsetUnset was used in a foreach loop and the first element was unset.
$this->current = $keys[0];
}
else
{
// Get the current key.
$position = array_search($this->current, $keys);
// Check if there is an object after the current object.
if ($position !== false && isset($keys[$position + 1]))
{
// Get the next id.
$this->current = $keys[$position + 1];
}
else
{
// That was the last object or the internal properties have become corrupted.
$this->current = null;
}
}
}
/**
* Checks whether an offset exists in the iterator.
*
* @param mixed $offset The object offset.
*
* @return boolean
*
* @since 1.0
*/
public function offsetExists($offset)
{
return isset($this->objects[$offset]);
}
/**
* Gets an offset in the iterator.
*
* @param mixed $offset The object offset.
*
* @return DataObject|null
*
* @since 1.0
*/
public function offsetGet($offset)
{
return $this->objects[$offset] ?? null;
}
/**
* Sets an offset in the iterator.
*
* @param mixed $offset The object offset.
* @param DataObject $object The object object.
*
* @return void
*
* @since 1.0
* @throws \InvalidArgumentException if an object is not an instance of DataObject.
*/
public function offsetSet($offset, $object)
{
if (!($object instanceof DataObject))
{
throw new \InvalidArgumentException(
sprintf(
'The $object argument must be an instance of "%s", a %s was given.',
DataObject::class,
\gettype($object) === 'object' ? \get_class($object) : \gettype($object)
)
);
}
// Set the offset.
if ($offset === null)
{
$this->objects[] = $object;
}
else
{
$this->objects[$offset] = $object;
}
}
/**
* Unsets an offset in the iterator.
*
* @param mixed $offset The object offset.
*
* @return void
*
* @since 1.0
*/
public function offsetUnset($offset)
{
if (!isset($this[$offset]))
{
// Do nothing if the offset does not exist.
return;
}
// Check for special handling of unsetting the current position.
if ($offset == $this->current)
{
// Get the current position.
$keys = $this->keys();
$position = array_search($this->current, $keys);
// Check if there is an object before the current object.
if ($position > 0)
{
// Move the current position back one.
$this->current = $keys[$position - 1];
}
else
{
// We are at the start of the keys AND let's assume we are in a foreach loop and `next` is going to be called.
$this->current = false;
}
}
unset($this->objects[$offset]);
}
/**
* Rewinds the iterator to the first object.
*
* @return void
*
* @since 1.0
*/
public function rewind()
{
// Set the current position to the first object.
if (empty($this->objects))
{
$this->current = false;
}
else
{
$keys = $this->keys();
$this->current = array_shift($keys);
}
}
/**
* Validates the iterator.
*
* @return boolean
*
* @since 1.0
*/
public function valid()
{
// Check the current position.
if (!is_scalar($this->current) || !isset($this->objects[$this->current]))
{
return false;
}
return true;
}
/**
* Initialises the list with an array of objects.
*
* @param array $input An array of objects.
*
* @return void
*
* @since 1.0
* @throws \InvalidArgumentException if an object is not a DataObject.
*/
private function initialise(array $input = [])
{
foreach ($input as $key => $object)
{
if ($object !== null)
{
$this[$key] = $object;
}
}
$this->rewind();
}
}