CollectionReadTrait::getIterator() - Code Metrics - Nayjest/Collection - Measure and Improve Code Quality continuously with Scrutinizer

CollectionReadTrait::getIterator() A
last analyzed 2016-07-22 15:36 UTC

↳ Parent: CollectionReadTrait

Complexity

Conditions	1
Paths	1

Size

Total Lines	7
Code Lines	2

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	2
CRAP Score	1

Importance

Changes	3
Bugs	0	Features	2

Metric	Value
c	3
b	0
f	2
dl	0
loc	7
ccs	2
cts	2
cp	1
rs	9.4285
cc	1
eloc	2
nc	1
nop	0
crap	1

<?php

namespace Nayjest\Collection;

use ArrayIterator;
use IteratorIterator;
use RuntimeException;

/**
 * Trait CollectionReadTrait.
 *
 * @implements \Nayjest\Collection\CollectionWriteInterface
 */
trait CollectionReadTrait
{
    /**
     * Returns reference to array storing collection items.
     *
     * @return array
     */
    abstract protected function &items();

    /**
     * Creates collection of items.
     *
     * Override it if you need to implement
     * derived collection that requires specific initialization.
     *
     * @param array $items
     *
     * @return static
     */
    protected function createCollection(array $items)
    {
        $collection = new static();
        $itemsRef = &$collection->items();
        $itemsRef = $items;

        return $collection;
    }

    /**
     * Returns collection items in array.
     *
     * @return array
     */
    public function toArray()
    {
        return $this->items();
    }

    /**
     * Returns true if collection is empty.
     *
     * @return bool
     */
    public function isEmpty()
    {
        return count($this->items()) === 0;
    }

    /**
     * {@inheritdoc}
     */
    public function count()
    {
        return count($this->items());
    }

    /**
     * Checks that collections contains target item.
     *
     * @param $item
     *
     * @return bool
     */
    public function contains($item)
    {
        return in_array($item, $this->items(), true);
    }

    /**
     * {@inheritdoc}
     */
    public function getIterator()
    {
        // Modifying or deleting values while iterating will not affect collection data.
        // ArrayIterator wrapped to IteratorIterator to deny modifying and deleting values while iterating.
        // That will help to avoid possible errors in client code.
        return new IteratorIterator(new ArrayIterator($this->items()));
    }

    /**
     * Returns first item of the collection or null if collection is empty.
     *
     * @return mixed|null
     */
    public function first()
    {
        return $this->isEmpty() ? null : array_values($this->items())[0];
    }

    /**
     * Iterates over each value in the <b>collection</b>
     * passing them to the <b>callback</b> function.
     * If the <b>callback</b> function returns true, the
     * current value from <b>collection</b> is returned into
     * the result collection.
     *
     * @param callable $callback the callback function to use
     * @param array|null $optionalArguments [optional] additional arguments passed to callback
     *
     * @return CollectionReadInterface|static filtered collection
     */
    public function filter(callable $callback, array $optionalArguments = null)
    {
        return $this->createCollection(array_filter(
            $this->items(),
            self::bindAdditionalArguments($callback, $optionalArguments)
        ));
    }

    /**
     * Iterates over each value in the <b>collection</b>
     * passing them to the <b>callback</b> function.
     * If the <b>callback</b> function returns true, the
     * current value from <b>collection</b> is returned.
     *
     * @param callable $callback the callback function to use
     * @param array|null $optionalArguments [optional] additional arguments passed to callback
     *
     * @return mixed|FALSE collection item or false if item is not found.
     */
    public function find(callable $callback, array $optionalArguments = null)
    {
        foreach ($this->items() as $item) {
            $arguments = ($optionalArguments === null)
                ? [$item]
                : array_merge([$item], $optionalArguments);
            if (call_user_func_array($callback, $arguments)) {
                return $item;
            }
        }

        return false;
    }


    /**
     * @param callable $callback the callback function to use
     * @param array|null $optionalArguments [optional] additional arguments passed to callback
     * @return CollectionReadInterface|static
     */
    public function map(callable $callback, array $optionalArguments = null)
    {
        return $this->createCollection(array_map(
            self::bindAdditionalArguments($callback, $optionalArguments),
            $this->items()
        ));
    }

    /**
     * Sorts collection items.
     *
     * This method preserves key order (stable sort) using Schwartzian Transform.
     * @see http://stackoverflow.com/questions/4353739/preserve-key-order-stable-sort-when-sorting-with-phps-uasort
     * @see http://en.wikipedia.org/wiki/Schwartzian_transform
     *
     * @param callable $compareFunction
     * @return CollectionReadInterface|static new collection with sorted items.
     */
    public function sort(callable $compareFunction)
    {
        $items = $this->toArray();

        # Sorting with Schwartzian Transform
        # If stable sort is not required,
        # following code can be replaced to usort($items, $compareFunction);
        $index = 0;
        foreach ($items as &$item) {
            $item = [$index++, $item];
        }
        usort($items, function ($a, $b) use ($compareFunction) {
            $result = call_user_func($compareFunction, $a[1], $b[1]);
            return $result == 0 ? $a[0] - $b[0] : $result;
        });
        foreach ($items as &$item) {
            $item = $item[1];
        }
        # End of sorting with Schwartzian Transform

        return $this->createCollection($items);
    }

    /**
     * @return mixed|null
     */
    public function random()
    {
        if ($this->isEmpty()) {
            return null;
        }
        $index = array_rand($this->items(), 1);
        return $index === null ? null : $this->items()[$index];
    }

    /**
     * @param $item
     * @return CollectionReadInterface|static
     */
    public function beforeItem($item)
    {
        if (!$this->contains($item)) {
            throw new RuntimeException(
                'Can\'t select collection items before target element'
                . ' because collection does not contain target element'
            );
        }
        $items = [];
        foreach ($this->items() as $i) {
            if ($i === $item) {
                break;
            }
            $items[] = $i;
        }
        return $this->createCollection($items);
    }

    /**
     * @param $item
     * @return CollectionReadInterface|static
     */
    public function afterItem($item)
    {
        if (!$this->contains($item)) {
            throw new RuntimeException(
                'Can\'t select collection items before target element'
                . ' because collection does not contain target element'
            );
        }
        $items = [];
        $found = false;
        foreach ($this->items() as $i) {
            if ($i === $item) {
                $found = true;
                continue;
            }
            if ($found) {
                $items[] = $i;
            }
        }
        return $this->createCollection($items);
    }

    public function isWritable()
    {
        return $this instanceof CollectionWriteInterface;
    }

    protected static function bindAdditionalArguments(callable $callback, array $additionalArguments = null)
    {
        if ($additionalArguments === null) {
            return $callback;
        }
        return function ($item) use ($callback, $additionalArguments) {
            $arguments = array_merge([$item], $additionalArguments);
            return call_user_func_array($callback, $arguments);
        };
    }
}


1		<?php
2
3		namespace Nayjest\Collection;
4
5		use ArrayIterator;
6		use IteratorIterator;
7		use RuntimeException;
8
9		/**
10		* Trait CollectionReadTrait.
11		*
12		* @implements \Nayjest\Collection\CollectionWriteInterface
13		*/
14		trait CollectionReadTrait
15		{
16		/**
17		* Returns reference to array storing collection items.
18		*
19		* @return array
20		*/
21		abstract protected function &items();
22
23		/**
24		* Creates collection of items.
25		*
26		* Override it if you need to implement
27		* derived collection that requires specific initialization.
28		*
29		* @param array $items
30		*
31		* @return static
32		*/
33		protected function createCollection(array $items)
34		{
35		$collection = new static();
36		$itemsRef = &$collection->items();
37		$itemsRef = $items;
38
39		return $collection;
40		}
41
42		/**
43		* Returns collection items in array.
44		*
45		* @return array
46		*/
47	15	public function toArray()
48		{
49	15	return $this->items();
50		}
51
52		/**
53		* Returns true if collection is empty.
54		*
55		* @return bool
56		*/
57	12	public function isEmpty()
58		{
59	12	return count($this->items()) === 0;
60		}
61
62		/**
63		* {@inheritdoc}
64		*/
65	5	public function count()
66		{
67	5	return count($this->items());
68		}
69
70		/**
71		* Checks that collections contains target item.
72		*
73		* @param $item
74		*
75		* @return bool
76		*/
77	6	public function contains($item)
78		{
79	6	return in_array($item, $this->items(), true);
80		}
81
82		/**
83		* {@inheritdoc}
84		*/
85	12	public function getIterator()
86		{
87		// Modifying or deleting values while iterating will not affect collection data.
88		// ArrayIterator wrapped to IteratorIterator to deny modifying and deleting values while iterating.
89		// That will help to avoid possible errors in client code.
90	12	return new IteratorIterator(new ArrayIterator($this->items()));
91		}
92
93		/**
94		* Returns first item of the collection or null if collection is empty.
95		*
96		* @return mixed\|null
97		*/
98	4	public function first()
99		{
100	4	return $this->isEmpty() ? null : array_values($this->items())[0];
101		}
102
103		/**
104		* Iterates over each value in the <b>collection</b>
105		* passing them to the <b>callback</b> function.
106		* If the <b>callback</b> function returns true, the
107		* current value from <b>collection</b> is returned into
108		* the result collection.
109		*
110		* @param callable $callback the callback function to use
111		* @param array\|null $optionalArguments [optional] additional arguments passed to callback
112		*
113		* @return CollectionReadInterface\|static filtered collection
114		*/
115	5	public function filter(callable $callback, array $optionalArguments = null)
116		{
117	5	return $this->createCollection(array_filter(
118	5	$this->items(),
119	5	self::bindAdditionalArguments($callback, $optionalArguments)
120	5	));
121		}
122
123		/**
124		* Iterates over each value in the <b>collection</b>
125		* passing them to the <b>callback</b> function.
126		* If the <b>callback</b> function returns true, the
127		* current value from <b>collection</b> is returned.
128		*
129		* @param callable $callback the callback function to use
130		* @param array\|null $optionalArguments [optional] additional arguments passed to callback
131		*
132		* @return mixed\|FALSE collection item or false if item is not found.
133		*/
134	5	public function find(callable $callback, array $optionalArguments = null)
135		{
136	5	foreach ($this->items() as $item) {
137	5	$arguments = ($optionalArguments === null)
138	5	? [$item]
139	5	: array_merge([$item], $optionalArguments);
140	5	if (call_user_func_array($callback, $arguments)) {
141	5	return $item;
142		}
143	5	}
144
145	1	return false;
146		}
147
148
149		/**
150		* @param callable $callback the callback function to use
151		* @param array\|null $optionalArguments [optional] additional arguments passed to callback
152		* @return CollectionReadInterface\|static
153		*/
154		public function map(callable $callback, array $optionalArguments = null)
155		{
156		return $this->createCollection(array_map(
157		self::bindAdditionalArguments($callback, $optionalArguments),
158		$this->items()
159		));
160		}
161
162		/**
163		* Sorts collection items.
164		*
165		* This method preserves key order (stable sort) using Schwartzian Transform.
166		* @see http://stackoverflow.com/questions/4353739/preserve-key-order-stable-sort-when-sorting-with-phps-uasort
167		* @see http://en.wikipedia.org/wiki/Schwartzian_transform
168		*
169		* @param callable $compareFunction
170		* @return CollectionReadInterface\|static new collection with sorted items.
171		*/
172		public function sort(callable $compareFunction)
173		{
174		$items = $this->toArray();
175
176		# Sorting with Schwartzian Transform
177		# If stable sort is not required,
178		# following code can be replaced to usort($items, $compareFunction);
179		$index = 0;
180		foreach ($items as &$item) {
181		$item = [$index++, $item];
182		}
183		usort($items, function ($a, $b) use ($compareFunction) {
184		$result = call_user_func($compareFunction, $a[1], $b[1]);
185		return $result == 0 ? $a[0] - $b[0] : $result;
186		});
187		foreach ($items as &$item) {
188		$item = $item[1];
189		}
190		# End of sorting with Schwartzian Transform
191
192		return $this->createCollection($items);
193		}
194
195		/**
196		* @return mixed\|null
197		*/
198	4	public function random()
199		{
200	4	if ($this->isEmpty()) {
201	4	return null;
202		}
203	4	$index = array_rand($this->items(), 1);
204	4	return $index === null ? null : $this->items()[$index];
205		}
206
207		/**
208		* @param $item
209		* @return CollectionReadInterface\|static
210		*/
211		public function beforeItem($item)
212		{
213		if (!$this->contains($item)) {
214		throw new RuntimeException(
215		'Can\'t select collection items before target element'
216		. ' because collection does not contain target element'
217		);
218		}
219		$items = [];
220		foreach ($this->items() as $i) {
221		if ($i === $item) {
222		break;
223		}
224		$items[] = $i;
225		}
226		return $this->createCollection($items);
227		}
228
229		/**
230		* @param $item
231		* @return CollectionReadInterface\|static
232		*/
233		public function afterItem($item)
234		{
235		if (!$this->contains($item)) {
236		throw new RuntimeException(
237		'Can\'t select collection items before target element'
238		. ' because collection does not contain target element'
239		);
240		}
241		$items = [];
242		$found = false;
243		foreach ($this->items() as $i) {
244		if ($i === $item) {
245		$found = true;
246		continue;
247		}
248		if ($found) {
249		$items[] = $i;
250		}
251		}
252		return $this->createCollection($items);
253		}
254
255		public function isWritable()
256		{
257		return $this instanceof CollectionWriteInterface;
258		}
259
260	5	protected static function bindAdditionalArguments(callable $callback, array $additionalArguments = null)
261		{
262	5	if ($additionalArguments === null) {
263	5	return $callback;
264		}
265	4	return function ($item) use ($callback, $additionalArguments) {
266	4	$arguments = array_merge([$item], $additionalArguments);
267	4	return call_user_func_array($callback, $arguments);
268	4	};
269		}
270		}
271

Nayjest / Collection

CollectionReadTrait::getIterator() A last analyzed 2016-07-22 15:36 UTC

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CollectionReadTrait::getIterator() A
last analyzed 2016-07-22 15:36 UTC