Completed
Pull Request — master (#22)
by
unknown
09:23
created

Psr4Autoloader::loadClass()   B

Complexity

Conditions 3
Paths 3

Size

Total Lines 29
Code Lines 10

Duplication

Lines 0
Ratio 0 %

Importance

Changes 1
Bugs 0 Features 0
Metric Value
c 1
b 0
f 0
dl 0
loc 29
rs 8.8571
cc 3
eloc 10
nc 3
nop 1
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<?php
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namespace BigBlueButton\Autoloader;
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/**
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 * Class Psr4Autoloader
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 * @see https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-4-autoloader-examples.md#class-example
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 *
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 * @package BigBlueButton\Autoloader
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 */
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class Psr4Autoloader
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{
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    /**
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     * An associative array where the key is a namespace prefix and the value
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     * is an array of base directories for classes in that namespace.
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     *
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     * @var array
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     */
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    protected $prefixes = array();
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    /**
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     * Register loader with SPL autoloader stack.
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     *
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     * @return void
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     */
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    public function register()
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    {
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        spl_autoload_register(array($this, 'loadClass'));
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    }
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    /**
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     * Adds a base directory for a namespace prefix.
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     *
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     * @param string $prefix The namespace prefix.
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     * @param string $baseDir A base directory for class files in the
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     * namespace.
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     * @param bool $prepend If true, prepend the base directory to the stack
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     * instead of appending it; this causes it to be searched first rather
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     * than last.
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     * @return void
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     */
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    public function addNamespace($prefix, $baseDir, $prepend = false)
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    {
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        // normalize namespace prefix
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        $prefix = trim($prefix, '\\') . '\\';
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        // normalize the base directory with a trailing separator
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        $baseDir = rtrim($baseDir, DIRECTORY_SEPARATOR) . '/';
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        // initialize the namespace prefix array
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        if (isset($this->prefixes[$prefix]) === false) {
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            $this->prefixes[$prefix] = array();
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        }
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        // retain the base directory for the namespace prefix
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        if ($prepend) {
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            array_unshift($this->prefixes[$prefix], $baseDir);
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        } else {
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            array_push($this->prefixes[$prefix], $baseDir);
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        }
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    }
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    /**
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     * Loads the class file for a given class name.
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     *
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     * @param string $class The fully-qualified class name.
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     * @return mixed The mapped file name on success, or boolean false on
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     * failure.
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     */
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    public function loadClass($class)
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    {
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        // the current namespace prefix
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        $prefix = $class;
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        // work backwards through the namespace names of the fully-qualified
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        // class name to find a mapped file name
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        while (false !== $pos = strrpos($prefix, '\\')) {
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            // retain the trailing namespace separator in the prefix
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            $prefix = substr($class, 0, $pos + 1);
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            // the rest is the relative class name
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            $relativeClass = substr($class, $pos + 1);
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            // try to load a mapped file for the prefix and relative class
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            $mappedFile = $this->loadMappedFile($prefix, $relativeClass);
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            if ($mappedFile !== false) {
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                return $mappedFile;
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            }
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            // remove the trailing namespace separator for the next iteration
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            // of strrpos()
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            $prefix = rtrim($prefix, '\\');
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        }
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        // never found a mapped file
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        return false;
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    }
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    /**
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     * Load the mapped file for a namespace prefix and relative class.
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     *
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     * @param string $prefix The namespace prefix.
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     * @param string $relativeClass The relative class name.
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     * @return mixed Boolean false if no mapped file can be loaded, or the
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     * name of the mapped file that was loaded.
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     */
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    protected function loadMappedFile($prefix, $relativeClass)
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    {
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        // are there any base directories for this namespace prefix?
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        if (isset($this->prefixes[$prefix]) === false) {
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            return false;
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        }
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        // look through base directories for this namespace prefix
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        foreach ($this->prefixes[$prefix] as $baseDir) {
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            // replace the namespace prefix with the base directory,
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            // replace namespace separators with directory separators
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            // in the relative class name, append with .php
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            $file = $baseDir
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                  . str_replace('\\', '/', $relativeClass)
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                  . '.php';
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            // if the mapped file exists, require it
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            if ($this->requireFile($file)) {
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                // yes, we're done
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                return $file;
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            }
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        }
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        // never found it
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        return false;
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    }
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    /**
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     * If a file exists, require it from the file system.
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     *
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     * @param string $file The file to require.
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     * @return bool True if the file exists, false if not.
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     */
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    protected function requireFile($file)
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    {
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        if (file_exists($file)) {
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            require $file;
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            return true;
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        }
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        return false;
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    }
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}
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