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+<?php
+/**
+ * PathRouter class.
+ * This class can take patterns such as /wiki/$1 and use them to
+ * parse query parameters out of REQUEST_URI paths.
+ *
+ * $router->add( "/wiki/$1" );
+ * - Matches /wiki/Foo style urls and extracts the title
+ * $router->add( array( 'edit' => "/edit/$1" ), array( 'action' => '$key' ) );
+ * - Matches /edit/Foo style urls and sets action=edit
+ * $router->add( '/$2/$1',
+ * array( 'variant' => '$2' ),
+ * array( '$2' => array( 'zh-hant', 'zh-hans' )
+ * );
+ * - Matches /zh-hant/Foo or /zh-hans/Foo
+ * $router->addStrict( "/foo/Bar", array( 'title' => 'Baz' ) );
+ * - Matches /foo/Bar explicitly and uses "Baz" as the title
+ * $router->add( '/help/$1', array( 'title' => 'Help:$1' ) );
+ * - Matches /help/Foo with "Help:Foo" as the title
+ * $router->add( '/$1', array( 'foo' => array( 'value' => 'bar$2' ) );
+ * - Matches /Foo and sets 'foo' to 'bar$2' without $2 being replaced
+ * $router->add( '/$1', array( 'data:foo' => 'bar' ), array( 'callback' => 'functionname' ) );
+ * - Matches /Foo, adds the key 'foo' with the value 'bar' to the data array
+ * and calls functionname( &$matches, $data );
+ *
+ * Path patterns:
+ * - Paths may contain $# patterns such as $1, $2, etc...
+ * - $1 will match 0 or more while the rest will match 1 or more
+ * - Unless you use addStrict "/wiki" and "/wiki/" will be expanded to "/wiki/$1"
+ *
+ * Params:
+ * - In a pattern $1, $2, etc... will be replaced with the relevant contents
+ * - If you used a keyed array as a path pattern, $key will be replaced with
+ * the relevant contents
+ * - The default behavior is equivalent to `array( 'title' => '$1' )`,
+ * if you don't want the title parameter you can explicitly use `array( 'title' => false )`
+ * - You can specify a value that won't have replacements in it
+ * using `'foo' => array( 'value' => 'bar' );`
+ *
+ * Options:
+ * - The option keys $1, $2, etc... can be specified to restrict the possible values
+ * of that variable. A string can be used for a single value, or an array for multiple.
+ * - When the option key 'strict' is set (Using addStrict is simpler than doing this directly)
+ * the path won't have $1 implicitly added to it.
+ * - The option key 'callback' can specify a callback that will be run when a path is matched.
+ * The callback will have the arguments ( &$matches, $data ) and the matches array can
+ * be modified.
+ *
+ * @since 1.19
+ * @author Daniel Friesen
+ */
+class PathRouter {
+
+ /**
+ * Protected helper to do the actual bulk work of adding a single pattern.
+ * This is in a separate method so that add() can handle the difference between
+ * a single string $path and an array() $path that contains multiple path
+ * patterns each with an associated $key to pass on.
+ */
+ protected function doAdd( $path, $params, $options, $key = null ) {
+ // Make sure all paths start with a /
+ if ( $path[0] !== '/' ) {
+ $path = '/' . $path;
+ }
+
+ if ( !isset( $options['strict'] ) || !$options['strict'] ) {
+ // Unless this is a strict path make sure that the path has a $1
+ if ( strpos( $path, '$1' ) === false ) {
+ if ( substr( $path, -1 ) !== '/' ) {
+ $path .= '/';
+ }
+ $path .= '$1';
+ }
+ }
+
+ // If 'title' is not specified and our path pattern contains a $1
+ // Add a default 'title' => '$1' rule to the parameters.
+ if ( !isset( $params['title'] ) && strpos( $path, '$1' ) !== false ) {
+ $params['title'] = '$1';
+ }
+ // If the user explicitly marked 'title' as false then omit it from the matches
+ if ( isset( $params['title'] ) && $params['title'] === false ) {
+ unset( $params['title'] );
+ }
+
+ // Loop over our parameters and convert basic key => string
+ // patterns into fully descriptive array form
+ foreach ( $params as $paramName => $paramData ) {
+ if ( is_string( $paramData ) ) {
+ if ( preg_match( '/\$(\d+|key)/u', $paramData ) ) {
+ $paramArrKey = 'pattern';
+ } else {
+ // If there's no replacement use a value instead
+ // of a pattern for a little more efficiency
+ $paramArrKey = 'value';
+ }
+ $params[$paramName] = array(
+ $paramArrKey => $paramData
+ );
+ }
+ }
+
+ // Loop over our options and convert any single value $# restrictions
+ // into an array so we only have to do in_array tests.
+ foreach ( $options as $optionName => $optionData ) {
+ if ( preg_match( '/^\$\d+$/u', $optionName ) ) {
+ if ( !is_array( $optionData ) ) {
+ $options[$optionName] = array( $optionData );
+ }
+ }
+ }
+
+ $pattern = (object)array(
+ 'path' => $path,
+ 'params' => $params,
+ 'options' => $options,
+ 'key' => $key,
+ );
+ $pattern->weight = self::makeWeight( $pattern );
+ $this->patterns[] = $pattern;
+ }
+
+ /**
+ * Add a new path pattern to the path router
+ *
+ * @param $path The path pattern to add
+ * @param $params The params for this path pattern
+ * @param $options The options for this path pattern
+ */
+ public function add( $path, $params = array(), $options = array() ) {
+ if ( is_array( $path ) ) {
+ foreach ( $path as $key => $onePath ) {
+ $this->doAdd( $onePath, $params, $options, $key );
+ }
+ } else {
+ $this->doAdd( $path, $params, $options );
+ }
+ }
+
+ /**
+ * Add a new path pattern to the path router with the strict option on
+ * @see self::add
+ */
+ public function addStrict( $path, $params = array(), $options = array() ) {
+ $options['strict'] = true;
+ $this->add( $path, $params, $options );
+ }
+
+ /**
+ * Protected helper to re-sort our patterns so that the most specific
+ * (most heavily weighted) patterns are at the start of the array.
+ */
+ protected function sortByWeight() {
+ $weights = array();
+ foreach( $this->patterns as $key => $pattern ) {
+ $weights[$key] = $pattern->weight;
+ }
+ array_multisort( $weights, SORT_DESC, SORT_NUMERIC, $this->patterns );
+ }
+
+ protected static function makeWeight( $pattern ) {
+ # Start with a weight of 0
+ $weight = 0;
+
+ // Explode the path to work with
+ $path = explode( '/', $pattern->path );
+
+ # For each level of the path
+ foreach( $path as $piece ) {
+ if ( preg_match( '/^\$(\d+|key)$/u', $piece ) ) {
+ # For a piece that is only a $1 variable add 1 points of weight
+ $weight += 1;
+ } elseif ( preg_match( '/\$(\d+|key)/u', $piece ) ) {
+ # For a piece that simply contains a $1 variable add 2 points of weight
+ $weight += 2;
+ } else {
+ # For a solid piece add a full 3 points of weight
+ $weight += 3;
+ }
+ }
+
+ foreach ( $pattern->options as $key => $option ) {
+ if ( preg_match( '/^\$\d+$/u', $key ) ) {
+ # Add 0.5 for restrictions to values
+ # This way given two separate "/$2/$1" patterns the
+ # one with a limited set of $2 values will dominate
+ # the one that'll match more loosely
+ $weight += 0.5;
+ }
+ }
+
+ return $weight;
+ }
+
+ /**
+ * Parse a path and return the query matches for the path
+ *
+ * @param $path The path to parse
+ * @return Array The array of matches for the path
+ */
+ public function parse( $path ) {
+ // Make sure our patterns are sorted by weight so the most specific
+ // matches are tested first
+ $this->sortByWeight();
+
+ $matches = null;
+
+ foreach ( $this->patterns as $pattern ) {
+ $matches = self::extractTitle( $path, $pattern );
+ if ( !is_null( $matches ) ) {
+ break;
+ }
+ }
+
+ // We know the difference between null (no matches) and
+ // array() (a match with no data) but our WebRequest caller
+ // expects array() even when we have no matches so return
+ // a array() when we have null
+ return is_null( $matches ) ? array() : $matches;
+ }
+
+ protected static function extractTitle( $path, $pattern ) {
+ // Convert the path pattern into a regexp we can match with
+ $regexp = preg_quote( $pattern->path, '#' );
+ // .* for the $1
+ $regexp = preg_replace( '#\\\\\$1#u', '(?P<par1>.*)', $regexp );
+ // .+ for the rest of the parameter numbers
+ $regexp = preg_replace( '#\\\\\$(\d+)#u', '(?P<par$1>.+?)', $regexp );
+ $regexp = "#^{$regexp}$#";
+
+ $matches = array();
+ $data = array();
+
+ // Try to match the path we were asked to parse with our regexp
+ if ( preg_match( $regexp, $path, $m ) ) {
+ // Ensure that any $# restriction we have set in our {$option}s
+ // matches properly here.
+ foreach ( $pattern->options as $key => $option ) {
+ if ( preg_match( '/^\$\d+$/u', $key ) ) {
+ $n = intval( substr( $key, 1 ) );
+ $value = rawurldecode( $m["par{$n}"] );
+ if ( !in_array( $value, $option ) ) {
+ // If any restriction does not match return null
+ // to signify that this rule did not match.
+ return null;
+ }
+ }
+ }
+
+ // Give our $data array a copy of every $# that was matched
+ foreach ( $m as $matchKey => $matchValue ) {
+ if ( preg_match( '/^par\d+$/u', $matchKey ) ) {
+ $n = intval( substr( $matchKey, 3 ) );
+ $data['$'.$n] = rawurldecode( $matchValue );
+ }
+ }
+ // If present give our $data array a $key as well
+ if ( isset( $pattern->key ) ) {
+ $data['$key'] = $pattern->key;
+ }
+
+ // Go through our parameters for this match and add data to our matches and data arrays
+ foreach ( $pattern->params as $paramName => $paramData ) {
+ $value = null;
+ // Differentiate data: from normal parameters and keep the correct
+ // array key around (ie: foo for data:foo)
+ if ( preg_match( '/^data:/u', $paramName ) ) {
+ $isData = true;
+ $key = substr( $paramName, 5 );
+ } else {
+ $isData = false;
+ $key = $paramName;
+ }
+
+ if ( isset( $paramData['value'] ) ) {
+ // For basic values just set the raw data as the value
+ $value = $paramData['value'];
+ } elseif ( isset( $paramData['pattern'] ) ) {
+ // For patterns we have to make value replacements on the string
+ $value = $paramData['pattern'];
+ $replacer = new PathRouterPatternReplacer;
+ $replacer->params = $m;
+ if ( isset( $pattern->key ) ) {
+ $replacer->key = $pattern->key;
+ }
+ $value = $replacer->replace( $value );
+ if ( $value === false ) {
+ // Pattern required data that wasn't available, abort
+ return null;
+ }
+ }
+
+ // Send things that start with data: to $data, the rest to $matches
+ if ( $isData ) {
+ $data[$key] = $value;
+ } else {
+ $matches[$key] = $value;
+ }
+ }
+
+ // If this match includes a callback, execute it
+ if ( isset( $pattern->options['callback'] ) ) {
+ call_user_func_array( $pattern->options['callback'], array( &$matches, $data ) );
+ }
+ } else {
+ // Our regexp didn't match, return null to signify no match.
+ return null;
+ }
+ // Fall through, everything went ok, return our matches array
+ return $matches;
+ }
+
+}
+
+class PathRouterPatternReplacer {
+
+ public $key, $params, $error;
+
+ /**
+ * Replace keys inside path router patterns with text.
+ * We do this inside of a replacement callback because after replacement we can't tell the
+ * difference between a $1 that was not replaced and a $1 that was part of
+ * the content a $1 was replaced with.
+ */
+ public function replace( $value ) {
+ $this->error = false;
+ $value = preg_replace_callback( '/\$(\d+|key)/u', array( $this, 'callback' ), $value );
+ if ( $this->error ) {
+ return false;
+ }
+ return $value;
+ }
+
+ protected function callback( $m ) {
+ if ( $m[1] == "key" ) {
+ if ( is_null( $this->key ) ) {
+ $this->error = true;
+ return '';
+ }
+ return $this->key;
+ } else {
+ $d = $m[1];
+ if ( !isset( $this->params["par$d"] ) ) {
+ $this->error = true;
+ return '';
+ }
+ return rawurldecode( $this->params["par$d"] );
+ }
+ }
+
+} \ No newline at end of file