ObjectFactory::constructClassInstance() - Code Metrics - wikimedia/mediawiki - Measure and Improve Code Quality continuously with Scrutinizer

ObjectFactory::constructClassInstance() C
last analyzed 2016-11-13 17:42 UTC

↳ Parent: ObjectFactory

Complexity

Conditions	14
Paths	13

Size

Total Lines	69
Code Lines	53

Duplication

Lines	12
Ratio	17.39 %

Importance

Changes

Metric	Value
cc	14
eloc	53
nc	13
nop	2
dl	12
loc	69
rs	5.6823
c	0
b	0
f	0

How to fix Long Method Complexity

<?php
/**
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 */

/**
 * Construct objects from configuration instructions.
 *
 * @author Bryan Davis <[email protected]>
 * @copyright © 2014 Bryan Davis and Wikimedia Foundation.
 */
class ObjectFactory {

	/**
	 * Instantiate an object based on a specification array.
	 *
	 * The specification array must contain a 'class' key with string value
	 * that specifies the class name to instantiate or a 'factory' key with
	 * a callable (is_callable() === true). It can optionally contain
	 * an 'args' key that provides arguments to pass to the
	 * constructor/callable.
	 *
	 * Values in the arguments collection which are Closure instances will be
	 * expanded by invoking them with no arguments before passing the
	 * resulting value on to the constructor/callable. This can be used to
	 * pass IDatabase instances or other live objects to the
	 * constructor/callable. This behavior can be suppressed by adding
	 * closure_expansion => false to the specification.
	 *
	 * The specification may also contain a 'calls' key that describes method
	 * calls to make on the newly created object before returning it. This
	 * pattern is often known as "setter injection". The value of this key is
	 * expected to be an associative array with method names as keys and
	 * argument lists as values. The argument list will be expanded (or not)
	 * in the same way as the 'args' key for the main object.
	 *
	 * @param array $spec Object specification
	 * @return object
	 * @throws InvalidArgumentException when object specification does not
	 * contain 'class' or 'factory' keys
	 * @throws ReflectionException when 'args' are supplied and 'class'
	 * constructor is non-public or non-existent
	 */
	public static function getObjectFromSpec( $spec ) {
		$args = isset( $spec['args'] ) ? $spec['args'] : [];
		$expandArgs = !isset( $spec['closure_expansion'] ) ||
			$spec['closure_expansion'] === true;

		if ( $expandArgs ) {
			$args = static::expandClosures( $args );
		}

		if ( isset( $spec['class'] ) ) {
			$clazz = $spec['class'];
			if ( !$args ) {
				$obj = new $clazz();
			} else {
				$obj = static::constructClassInstance( $clazz, $args );
			}
		} elseif ( isset( $spec['factory'] ) ) {
			$obj = call_user_func_array( $spec['factory'], $args );
		} else {
			throw new InvalidArgumentException(
				'Provided specification lacks both factory and class parameters.'
			);
		}

		if ( isset( $spec['calls'] ) && is_array( $spec['calls'] ) ) {
			// Call additional methods on the newly created object
			foreach ( $spec['calls'] as $method => $margs ) {
				if ( $expandArgs ) {
					$margs = static::expandClosures( $margs );
				}
				call_user_func_array( [ $obj, $method ], $margs );
			}
		}

		return $obj;
	}

	/**
	 * Iterate a list and call any closures it contains.
	 *
	 * @param array $list List of things
	 * @return array List with any Closures replaced with their output
	 */
	protected static function expandClosures( $list ) {
		return array_map( function ( $value ) {
			if ( is_object( $value ) && $value instanceof Closure ) {
				// If $value is a Closure, call it.
				return $value();
			} else {
				return $value;
			}
		}, $list );
	}

	/**
	 * Construct an instance of the given class using the given arguments.
	 *
	 * PHP's `call_user_func_array()` doesn't work with object construction so
	 * we have to use other measures. Starting with PHP 5.6.0 we could use the
	 * "splat" operator (`...`) to unpack the array into an argument list.
	 * Sadly there is no way to conditionally include a syntax construct like
	 * a new operator in a way that allows older versions of PHP to still
	 * parse the file. Instead, we will try a loop unrolling technique that
	 * works for 0-10 arguments. If we are passed 11 or more arguments we will
	 * take the performance penalty of using
	 * `ReflectionClass::newInstanceArgs()` to construct the desired object.
	 *
	 * @param string $clazz Class name
	 * @param array $args Constructor arguments
	 * @return mixed Constructed instance
	 */
	public static function constructClassInstance( $clazz, $args ) {
		// $args should be a non-associative array; show nice error if that's not the case
		if ( $args && array_keys( $args ) !== range( 0, count( $args ) - 1 ) ) {
			throw new InvalidArgumentException( __METHOD__ . ': $args cannot be an associative array' );
		}

		// TODO: when PHP min version supported is >=5.6.0 replace this
		// with `return new $clazz( ... $args );`.
		$obj = null;
$myVar = 'Value';
$higher = false;

if (rand(1, 6) > 3) {
    $higher = true;
} else {
    $higher = false;
}
		switch ( count( $args ) ) {
			case 0:
				$obj = new $clazz();
				break;
			case 1:
				$obj = new $clazz( $args[0] );
				break;
			case 2:
				$obj = new $clazz( $args[0], $args[1] );
				break;
			case 3:
				$obj = new $clazz( $args[0], $args[1], $args[2] );
				break;
			case 4:
				$obj = new $clazz( $args[0], $args[1], $args[2], $args[3] );
				break;
			case 5:
				$obj = new $clazz(
					$args[0], $args[1], $args[2], $args[3], $args[4]
				);
				break;
			case 6:
				$obj = new $clazz(
					$args[0], $args[1], $args[2], $args[3], $args[4],
					$args[5]
				);
				break;
			case 7:
				$obj = new $clazz(
					$args[0], $args[1], $args[2], $args[3], $args[4],
					$args[5], $args[6]
				);
				break;
			case 8:
				$obj = new $clazz(
					$args[0], $args[1], $args[2], $args[3], $args[4],
					$args[5], $args[6], $args[7]
				);
				break;
			case 9:
				$obj = new $clazz(
					$args[0], $args[1], $args[2], $args[3], $args[4],
					$args[5], $args[6], $args[7], $args[8]
				);
				break;
			case 10:
				$obj = new $clazz(
					$args[0], $args[1], $args[2], $args[3], $args[4],
					$args[5], $args[6], $args[7], $args[8], $args[9]
				);
				break;
			default:
				// Fall back to using ReflectionClass and curse the developer
				// who decided that 11+ args was a reasonable method
				// signature.
				$ref = new ReflectionClass( $clazz );
				$obj = $ref->newInstanceArgs( $args );
		}
		return $obj;
	}
}


1		<?php
2		/**
3		* This program is free software; you can redistribute it and/or modify
4		* it under the terms of the GNU General Public License as published by
5		* the Free Software Foundation; either version 2 of the License, or
6		* (at your option) any later version.
7		*
8		* This program is distributed in the hope that it will be useful,
9		* but WITHOUT ANY WARRANTY; without even the implied warranty of
10		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11		* GNU General Public License for more details.
12		*
13		* You should have received a copy of the GNU General Public License along
14		* with this program; if not, write to the Free Software Foundation, Inc.,
15		* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
16		* http://www.gnu.org/copyleft/gpl.html
17		*
18		* @file
19		*/
20
21		/**
22		* Construct objects from configuration instructions.
23		*
24		* @author Bryan Davis <[email protected]>
25		* @copyright © 2014 Bryan Davis and Wikimedia Foundation.
26		*/
27		class ObjectFactory {
28
29		/**
30		* Instantiate an object based on a specification array.
31		*
32		* The specification array must contain a 'class' key with string value
33		* that specifies the class name to instantiate or a 'factory' key with
34		* a callable (is_callable() === true). It can optionally contain
35		* an 'args' key that provides arguments to pass to the
36		* constructor/callable.
37		*
38		* Values in the arguments collection which are Closure instances will be
39		* expanded by invoking them with no arguments before passing the
40		* resulting value on to the constructor/callable. This can be used to
41		* pass IDatabase instances or other live objects to the
42		* constructor/callable. This behavior can be suppressed by adding
43		* closure_expansion => false to the specification.
44		*
45		* The specification may also contain a 'calls' key that describes method
46		* calls to make on the newly created object before returning it. This
47		* pattern is often known as "setter injection". The value of this key is
48		* expected to be an associative array with method names as keys and
49		* argument lists as values. The argument list will be expanded (or not)
50		* in the same way as the 'args' key for the main object.
51		*
52		* @param array $spec Object specification
53		* @return object
54		* @throws InvalidArgumentException when object specification does not
55		* contain 'class' or 'factory' keys
56		* @throws ReflectionException when 'args' are supplied and 'class'
57		* constructor is non-public or non-existent
58		*/
59		public static function getObjectFromSpec( $spec ) {
60		$args = isset( $spec['args'] ) ? $spec['args'] : [];
61		$expandArgs = !isset( $spec['closure_expansion'] ) \|\|
62		$spec['closure_expansion'] === true;
63
64		if ( $expandArgs ) {
65		$args = static::expandClosures( $args );
66		}
67
68		if ( isset( $spec['class'] ) ) {
69		$clazz = $spec['class'];
70		if ( !$args ) {
71		$obj = new $clazz();
72		} else {
73		$obj = static::constructClassInstance( $clazz, $args );
74		}
75		} elseif ( isset( $spec['factory'] ) ) {
76		$obj = call_user_func_array( $spec['factory'], $args );
77		} else {
78		throw new InvalidArgumentException(
79		'Provided specification lacks both factory and class parameters.'
80		);
81		}
82
83		if ( isset( $spec['calls'] ) && is_array( $spec['calls'] ) ) {
84		// Call additional methods on the newly created object
85		foreach ( $spec['calls'] as $method => $margs ) {
86		if ( $expandArgs ) {
87		$margs = static::expandClosures( $margs );
88		}
89		call_user_func_array( [ $obj, $method ], $margs );
90		}
91		}
92
93		return $obj;
94		}
95
96		/**
97		* Iterate a list and call any closures it contains.
98		*
99		* @param array $list List of things
100		* @return array List with any Closures replaced with their output
101		*/
102		protected static function expandClosures( $list ) {
103		return array_map( function ( $value ) {
104		if ( is_object( $value ) && $value instanceof Closure ) {
105		// If $value is a Closure, call it.
106		return $value();
107		} else {
108		return $value;
109		}
110		}, $list );
111		}
112
113		/**
114		* Construct an instance of the given class using the given arguments.
115		*
116		* PHP's `call_user_func_array()` doesn't work with object construction so
117		* we have to use other measures. Starting with PHP 5.6.0 we could use the
118		* "splat" operator (`...`) to unpack the array into an argument list.
119		* Sadly there is no way to conditionally include a syntax construct like
120		* a new operator in a way that allows older versions of PHP to still
121		* parse the file. Instead, we will try a loop unrolling technique that
122		* works for 0-10 arguments. If we are passed 11 or more arguments we will
123		* take the performance penalty of using
124		* `ReflectionClass::newInstanceArgs()` to construct the desired object.
125		*
126		* @param string $clazz Class name
127		* @param array $args Constructor arguments
128		* @return mixed Constructed instance
129		*/
130		public static function constructClassInstance( $clazz, $args ) {
131		// $args should be a non-associative array; show nice error if that's not the case
132		if ( $args && array_keys( $args ) !== range( 0, count( $args ) - 1 ) ) {
133		throw new InvalidArgumentException( __METHOD__ . ': $args cannot be an associative array' );
134		}
135
136		// TODO: when PHP min version supported is >=5.6.0 replace this
137		// with `return new $clazz( ... $args );`.
138		$obj = null;
		0 ignored issues – show Unused Code introduced 2016-01-16 18:00 UTC by Report Bug Copy Issue Report `$obj` is not used, you could remove the assignment. This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently. $myVar = 'Value'; $higher = false; if (rand(1, 6) > 3) { $higher = true; } else { $higher = false; } Both the `$myVar` assignment in line 1 and the `$higher` assignment in line 2 are dead. The first because `$myVar` is never used and the second because `$higher` is always overwritten for every possible time line. Loading history...
139		switch ( count( $args ) ) {
140		case 0:
141		$obj = new $clazz();
142		break;
143		case 1:
144		$obj = new $clazz( $args[0] );
145		break;
146		case 2:
147		$obj = new $clazz( $args[0], $args[1] );
148		break;
149		case 3:
150		$obj = new $clazz( $args[0], $args[1], $args[2] );
151		break;
152		case 4:
153		$obj = new $clazz( $args[0], $args[1], $args[2], $args[3] );
154		break;
155		case 5:
156		$obj = new $clazz(
157		$args[0], $args[1], $args[2], $args[3], $args[4]
158		);
159		break;
160		case 6:
161		$obj = new $clazz(
162		$args[0], $args[1], $args[2], $args[3], $args[4],
163		$args[5]
164		);
165		break;
166		case 7:
167		$obj = new $clazz(
168		$args[0], $args[1], $args[2], $args[3], $args[4],
169		$args[5], $args[6]
170		);
171		break;
172		case 8:
173		$obj = new $clazz(
174		$args[0], $args[1], $args[2], $args[3], $args[4],
175		$args[5], $args[6], $args[7]
176		);
177		break;
178	View Code Duplication	case 9:
179		$obj = new $clazz(
180		$args[0], $args[1], $args[2], $args[3], $args[4],
181		$args[5], $args[6], $args[7], $args[8]
182		);
183		break;
184	View Code Duplication	case 10:
185		$obj = new $clazz(
186		$args[0], $args[1], $args[2], $args[3], $args[4],
187		$args[5], $args[6], $args[7], $args[8], $args[9]
188		);
189		break;
190		default:
191		// Fall back to using ReflectionClass and curse the developer
192		// who decided that 11+ args was a reasonable method
193		// signature.
194		$ref = new ReflectionClass( $clazz );
195		$obj = $ref->newInstanceArgs( $args );
196		}
197		return $obj;
198		}
199		}
200

wikimedia / mediawiki

ObjectFactory::constructClassInstance() C last analyzed 2016-11-13 17:42 UTC

Complexity

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Duplication

Importance

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ObjectFactory::constructClassInstance() C
last analyzed 2016-11-13 17:42 UTC