wps-cleaner / autoload.php

autoload.php in WPS Cleaner trunk, at autoload.php

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1	<?php
2	namespace WPS\WPS_Cleaner;
3
4	/**
5	* An example of a general-purpose implementation that includes the optional
6	* functionality of allowing multiple base directories for a single namespace
7	* prefix.
8	*
9	* Given a foo-bar package of classes in the file system at the following
10	* paths ...
11	*
12	* /path/to/packages/foo-bar/
13	* src/
14	* Baz.php # Foo\Bar\Baz
15	* Qux/
16	* Quux.php # Foo\Bar\Qux\Quux
17	* tests/
18	* BazTest.php # Foo\Bar\BazTest
19	* Qux/
20	* QuuxTest.php # Foo\Bar\Qux\QuuxTest
21	*
22	* ... add the path to the class files for the \Foo\Bar\ namespace prefix
23	* as follows:
24	*
25	* <?php
26	* // instantiate the loader
27	* $loader = new \Example\Psr4AutoloaderClass;
28	*
29	* // register the autoloader
30	* $loader->register();
31	*
32	* // register the base directories for the namespace prefix
33	* $loader->addNamespace('Foo\Bar', '/path/to/packages/foo-bar/src');
34	* $loader->addNamespace('Foo\Bar', '/path/to/packages/foo-bar/tests');
35	*
36	* The following line would cause the autoloader to attempt to load the
37	* \Foo\Bar\Qux\Quux class from /path/to/packages/foo-bar/src/Qux/Quux.php:
38	*
39	* <?php
40	* new \Foo\Bar\Qux\Quux;
41	*
42	* The following line would cause the autoloader to attempt to load the
43	* \Foo\Bar\Qux\QuuxTest class from /path/to/packages/foo-bar/tests/Qux/QuuxTest.php:
44	*
45	* <?php
46	* new \Foo\Bar\Qux\QuuxTest;
47	*/
48	class Autoloader {
49	/**
50	* An associative array where the key is a namespace prefix and the value
51	* is an array of base directories for classes in that namespace.
52	*
53	* @var array
54	*/
55	protected $prefixes = array();
56
57	/**
58	* Register loader with SPL autoloader stack.
59	*
60	* @return void
61	*/
62	public function register() {
63	spl_autoload_register( array( $this, 'loadClass' ) );
64	}
65
66	/**
67	* Adds a base directory for a namespace prefix.
68	*
69	* @param string $prefix The namespace prefix.
70	* @param string $base_dir A base directory for class files in the
71	* namespace.
72	* @param bool $prepend If true, prepend the base directory to the stack
73	* instead of appending it; this causes it to be searched first rather
74	* than last.
75	*
76	* @return void
77	*/
78	public function addNamespace( $prefix, $base_dir, $prepend = false ) {
79	// normalize namespace prefix
80	$prefix = trim( $prefix, '\\' ) . '\\';
81
82	// normalize the base directory with a trailing separator
83	$base_dir = rtrim( $base_dir, DIRECTORY_SEPARATOR ) . '/';
84
85	// initialize the namespace prefix array
86	if ( isset( $this->prefixes[ $prefix ] ) === false ) {
87	$this->prefixes[ $prefix ] = array();
88	}
89
90	// retain the base directory for the namespace prefix
91	if ( $prepend ) {
92	array_unshift( $this->prefixes[ $prefix ], $base_dir );
93	} else {
94	array_push( $this->prefixes[ $prefix ], $base_dir );
95	}
96	}
97
98	/**
99	* Loads the class file for a given class name.
100	*
101	* @param string $class The fully-qualified class name.
102	*
103	* @return mixed The mapped file name on success, or boolean false on
104	* failure.
105	*/
106	public function loadClass( $class ) {
107	// the current namespace prefix
108	$prefix = $class;
109
110	// work backwards through the namespace names of the fully-qualified
111	// class name to find a mapped file name
112	while( false !== $pos = strrpos( $prefix, '\\' ) ) {
113
114	// retain the trailing namespace separator in the prefix
115	$prefix = substr( $class, 0, $pos + 1 );
116
117	// the rest is the relative class name
118	$relative_class = substr( $class, $pos + 1 );
119
120	// try to load a mapped file for the prefix and relative class
121	$mapped_file = $this->loadMappedFile( $prefix, $relative_class );
122	if ( $mapped_file ) {
123	return $mapped_file;
124	}
125
126	// remove the trailing namespace separator for the next iteration
127	// of strrpos()
128	$prefix = rtrim( $prefix, '\\' );
129	}
130
131	// never found a mapped file
132	return false;
133	}
134
135	/**
136	* Load the mapped file for a namespace prefix and relative class.
137	*
138	* @param string $prefix The namespace prefix.
139	* @param string $relative_class The relative class name.
140	*
141	* @return mixed Boolean false if no mapped file can be loaded, or the
142	* name of the mapped file that was loaded.
143	*/
144	protected function loadMappedFile( $prefix, $relative_class ) {
145	// are there any base directories for this namespace prefix?
146	if ( isset( $this->prefixes[ $prefix ] ) === false ) {
147	return false;
148	}
149
150	// look through base directories for this namespace prefix
151	foreach ( $this->prefixes[ $prefix ] as $base_dir ) {
152
153	// replace the namespace prefix with the base directory,
154	// replace namespace separators with directory separators
155	// in the relative class name, append with .php
156	$file = $base_dir . strtolower( str_replace( array( '\\', '_' ), array(
157	'/',
158	'-'
159	), $relative_class ) ) . '.php';
160
161	// if the mapped file exists, require it
162	if ( $this->requireFile( $file ) ) {
163	// yes, we're done
164	return $file;
165	}
166	}
167
168	// never found it
169	return false;
170	}
171
172	/**
173	* If a file exists, require it from the file system.
174	*
175	* @param string $file The file to require.
176	*
177	* @return bool True if the file exists, false if not.
178	*/
179	protected function requireFile( $file ) {
180	if ( file_exists( $file ) ) {
181	require $file;
182
183	return true;
184	}
185
186	return false;
187	}
188	}
189
190	// instantiate the loader
191	$loader = new \WPS\WPS_Cleaner\Autoloader;
192
193	// register the autoloader
194	$loader->register();
195
196	// register the base directories for the namespace prefix
197	$loader->addNamespace( 'WPS\WPS_Cleaner', WPS_CLEANER_DIR . 'classes' );
198
199	/**
200	* Vendor autoload
201	* @since 2.1.0
202	*/
203	if ( file_exists( WPS_CLEANER_DIR . 'vendor/autoload.php' ) ) {
204	require WPS_CLEANER_DIR . 'vendor/autoload.php';
205	}