4 * The filter/plugin API is located in this file, which allows for creating filters
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5 * and hooking functions, and methods. The functions or methods will be run when
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6 * the filter is called.
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8 * Any of the syntaxes explained in the PHP documentation for the
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9 * {@link http://us2.php.net/manual/en/language.pseudo-types.php#language.types.callback 'callback'}
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12 * This API is heavily inspired by the one I implemented in Zenphoto 1.3, which was heavily inspired by the one used in WordPress.
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18 $yourls_filters = array();
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19 /* This global var will collect filters with the following structure:
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20 * $yourls_filters['hook']['array of priorities']['serialized function names']['array of ['array (functions, accepted_args)]']
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24 * Registers a filtering function
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27 * yourls_add_filter('some_hook', 'function_handler_for_hook');
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29 * @global array $yourls_filters Storage for all of the filters
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30 * @param string $hook the name of the YOURLS element to be filtered or YOURLS action to be triggered
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31 * @param callback $function_name the name of the function that is to be called.
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32 * @param integer $priority optional. Used to specify the order in which the functions associated with a particular action are executed (default=10, lower=earlier execution, and functions with the same priority are executed in the order in which they were added to the filter)
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33 * @param int $accepted_args optional. The number of arguments the function accept (default is the number provided).
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35 function yourls_add_filter( $hook, $function_name, $priority = 10, $accepted_args = NULL, $type = 'filter' ) {
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36 global $yourls_filters;
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37 // At this point, we cannot check if the function exists, as it may well be defined later (which is OK)
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38 $id = yourls_filter_unique_id( $hook, $function_name, $priority );
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40 $yourls_filters[ $hook ][ $priority ][ $id ] = array(
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41 'function' => $function_name,
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42 'accepted_args' => $accepted_args,
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48 * Hooks a function on to a specific action.
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50 * Actions are the hooks that YOURLS launches at specific points
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51 * during execution, or when specific events occur. Plugins can specify that
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52 * one or more of its PHP functions are executed at these points, using the
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55 * @param string $hook The name of the action to which the $function_to_add is hooked.
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56 * @param callback $function_name The name of the function you wish to be called.
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57 * @param int $priority optional. Used to specify the order in which the functions associated with a particular action are executed (default: 10). Lower numbers correspond with earlier execution, and functions with the same priority are executed in the order in which they were added to the action.
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58 * @param int $accepted_args optional. The number of arguments the function accept (default 1).
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60 function yourls_add_action( $hook, $function_name, $priority = 10, $accepted_args = 1 ) {
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61 return yourls_add_filter( $hook, $function_name, $priority, $accepted_args, 'action' );
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67 * Build Unique ID for storage and retrieval.
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69 * Simply using a function name is not enough, as several functions can have the same name when they are enclosed in classes.
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71 * @global array $yourls_filters storage for all of the filters
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72 * @param string $hook hook to which the function is attached
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73 * @param string|array $function used for creating unique id
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74 * @param int|bool $priority used in counting how many hooks were applied. If === false and $function is an object reference, we return the unique id only if it already has one, false otherwise.
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75 * @param string $type filter or action
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76 * @return string unique ID for usage as array key
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78 function yourls_filter_unique_id( $hook, $function, $priority ) {
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79 global $yourls_filters;
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81 // If function then just skip all of the tests and not overwrite the following.
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82 if ( is_string( $function ) )
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84 // Object Class Calling
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85 else if ( is_object( $function[0] ) ) {
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86 $obj_idx = get_class( $function[0] ) . $function[1];
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87 if ( !isset( $function[0]->_yourls_filters_id ) ) {
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88 if ( false === $priority )
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90 $count = isset( $yourls_filters[ $hook ][ $priority ]) ? count( (array)$yourls_filters[ $hook ][ $priority ] ) : 0;
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91 $function[0]->_yourls_filters_id = $count;
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95 $obj_idx .= $function[0]->_yourls_filters_id;
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99 else if ( is_string( $function[0] ) )
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100 return $function[0].$function[1];
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105 * Performs a filtering operation on a YOURLS element or event.
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109 * 1) Modify a variable if a function is attached to hook 'yourls_hook'
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110 * $yourls_var = "default value";
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111 * $yourls_var = yourls_apply_filter( 'yourls_hook', $yourls_var );
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113 * 2) Trigger functions is attached to event 'yourls_event'
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114 * yourls_apply_filter( 'yourls_event' );
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115 * (see yourls_do_action() )
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117 * Returns an element which may have been filtered by a filter.
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119 * @global array $yourls_filters storage for all of the filters
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120 * @param string $hook the name of the YOURLS element or action
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121 * @param mixed $value the value of the element before filtering
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124 function yourls_apply_filter( $hook, $value = '' ) {
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125 global $yourls_filters;
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126 if ( !isset( $yourls_filters[ $hook ] ) )
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129 $args = func_get_args();
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131 // Sort filters by priority
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132 ksort( $yourls_filters[ $hook ] );
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134 // Loops through each filter
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135 reset( $yourls_filters[ $hook ] );
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137 foreach( (array) current( $yourls_filters[ $hook ] ) as $the_ ) {
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138 if ( !is_null( $the_['function'] ) ){
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140 $count = $the_['accepted_args'];
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141 if ( is_null( $count ) ) {
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142 $_value = call_user_func_array( $the_['function'], array_slice( $args, 1 ) );
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144 $_value = call_user_func_array( $the_['function'], array_slice( $args, 1, (int) $count ) );
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147 if( $the_['type'] == 'filter' )
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151 } while ( next( $yourls_filters[ $hook ] ) !== false );
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153 if( $the_['type'] == 'filter' )
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157 function yourls_do_action( $hook, $arg = '' ) {
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159 if ( is_array( $arg ) && 1 == count( $arg ) && isset( $arg[0] ) && is_object( $arg[0] ) ) // array(&$this)
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160 $args[] =& $arg[0];
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163 for ( $a = 2; $a < func_num_args(); $a++ )
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164 $args[] = func_get_arg( $a );
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166 yourls_apply_filter( $hook, $args );
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171 * Removes a function from a specified filter hook.
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173 * This function removes a function attached to a specified filter hook. This
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174 * method can be used to remove default functions attached to a specific filter
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175 * hook and possibly replace them with a substitute.
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177 * To remove a hook, the $function_to_remove and $priority arguments must match
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178 * when the hook was added.
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180 * @global array $yourls_filters storage for all of the filters
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181 * @param string $hook The filter hook to which the function to be removed is hooked.
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182 * @param callback $function_to_remove The name of the function which should be removed.
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183 * @param int $priority optional. The priority of the function (default: 10).
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184 * @param int $accepted_args optional. The number of arguments the function accepts (default: 1).
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185 * @return boolean Whether the function was registered as a filter before it was removed.
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187 function yourls_remove_filter( $hook, $function_to_remove, $priority = 10, $accepted_args = 1 ) {
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188 global $yourls_filters;
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190 $function_to_remove = yourls_filter_unique_id( $hook, $function_to_remove, $priority );
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192 $remove = isset( $yourls_filters[ $hook ][ $priority ][ $function_to_remove ] );
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194 if ( $remove === true ) {
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195 unset ( $yourls_filters[$hook][$priority][$function_to_remove] );
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196 if ( empty( $yourls_filters[$hook][$priority] ) )
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197 unset( $yourls_filters[$hook] );
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204 * Check if any filter has been registered for a hook.
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206 * @global array $yourls_filters storage for all of the filters
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207 * @param string $hook The name of the filter hook.
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208 * @param callback $function_to_check optional. If specified, return the priority of that function on this hook or false if not attached.
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209 * @return int|boolean Optionally returns the priority on that hook for the specified function.
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211 function yourls_has_filter( $hook, $function_to_check = false ) {
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212 global $yourls_filters;
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214 $has = !empty( $yourls_filters[ $hook ] );
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215 if ( false === $function_to_check || false == $has ) {
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218 if ( !$idx = yourls_filter_unique_id( $hook, $function_to_check, false ) ) {
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222 foreach ( (array) array_keys( $yourls_filters[ $hook ] ) as $priority ) {
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223 if ( isset( $yourls_filters[ $hook ][ $priority ][ $idx ] ) )
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229 function yourls_has_action( $hook, $function_to_check = false ) {
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230 return yourls_has_filter( $hook, $function_to_check );
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234 * Return number of active plugins
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236 * @return integer Number of activated plugins
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238 function yourls_has_active_plugins( ) {
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241 if( !property_exists( $ydb, 'plugins' ) || !$ydb->plugins )
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242 $ydb->plugins = array();
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244 return count( $ydb->plugins );
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249 * List plugins in /user/plugins
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251 * @global $ydb Storage of mostly everything YOURLS needs to know
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252 * @return array Array of [/plugindir/plugin.php]=>array('Name'=>'Ozh', 'Title'=>'Hello', )
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254 function yourls_get_plugins( ) {
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257 $plugins = (array) glob( YOURLS_PLUGINDIR .'/*/plugin.php');
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262 foreach( $plugins as $key => $plugin ) {
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263 $_plugin = yourls_plugin_basename( $plugin );
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264 $plugins[ $_plugin ] = yourls_get_plugin_data( $plugin );
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265 unset( $plugins[ $key ] );
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272 * Check if a plugin is active
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274 * @param string $file Physical path to plugin file
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277 function yourls_is_active_plugin( $plugin ) {
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278 if( !yourls_has_active_plugins( ) )
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282 $plugin = yourls_plugin_basename( $plugin );
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284 return in_array( $plugin, $ydb->plugins );
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289 * Parse a plugin header
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291 * @param string $file Physical path to plugin file
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292 * @return array Array of 'Field'=>'Value' from plugin comment header lines of the form "Field: Value"
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294 function yourls_get_plugin_data( $file ) {
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295 $fp = fopen( $file, 'r' ); // assuming $file is readable, since yourls_load_plugins() filters this
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296 $data = fread( $fp, 8192 ); // get first 8kb
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299 // Capture all the header within first comment block
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300 if( !preg_match( '!.*?/\*(.*?)\*/!ms', $data, $matches ) )
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303 // Capture each line with "Something: some text"
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305 $lines = preg_split( "[\n|\r]", $matches[1] );
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308 $plugin_data = array();
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309 foreach( $lines as $line ) {
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310 if( !preg_match( '!(.*?):\s+(.*)!', $line, $matches ) )
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313 list( $null, $field, $value ) = array_map( 'trim', $matches);
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314 $plugin_data[ $field ] = $value;
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317 return $plugin_data;
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320 // Include active plugins
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321 function yourls_load_plugins() {
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323 $ydb->plugins = array();
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324 $active_plugins = yourls_get_option( 'active_plugins' );
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326 // Don't load plugins when installing or updating
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327 if( !$active_plugins OR ( defined( 'YOURLS_INSTALLING' ) AND YOURLS_INSTALLING ) OR yourls_upgrade_is_needed() )
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330 foreach( (array)$active_plugins as $key=>$plugin ) {
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331 if( yourls_validate_plugin_file( YOURLS_PLUGINDIR.'/'.$plugin ) ) {
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332 include_once( YOURLS_PLUGINDIR.'/'.$plugin );
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333 $ydb->plugins[] = $plugin;
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334 unset( $active_plugins[$key] );
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338 // $active_plugins should be empty now, if not, a plugin could not be find: remove it
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339 if( count( $active_plugins ) ) {
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340 $missing = '<strong>'.join( '</strong>, <strong>', $active_plugins ).'</strong>';
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341 yourls_update_option( 'active_plugins', $ydb->plugins );
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342 $message = 'Could not find and deactivated '. yourls_plural( 'plugin', count( $active_plugins ) ) .' '. $missing;
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343 yourls_add_notice( $message );
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348 * Check if a file is safe for inclusion (well, "safe", no guarantee)
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350 * @param string $file Full pathname to a file
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352 function yourls_validate_plugin_file( $file ) {
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354 false !== strpos( $file, '..' )
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356 false !== strpos( $file, './' )
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358 'plugin.php' !== substr( $file, -10 ) // a plugin must be named 'plugin.php'
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360 !is_readable( $file )
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368 * Activate a plugin
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370 * @param string $plugin Plugin filename (full or relative to plugins directory)
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371 * @return mixed string if error or true if success
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373 function yourls_activate_plugin( $plugin ) {
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375 $plugin = yourls_plugin_basename( $plugin );
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376 $plugindir = yourls_sanitize_filename( YOURLS_PLUGINDIR );
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377 if( !yourls_validate_plugin_file( $plugindir.'/'.$plugin ) )
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378 return 'Not a valid plugin file';
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380 // check not activated already
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382 if( yourls_has_active_plugins() && in_array( $plugin, $ydb->plugins ) )
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383 return 'Plugin already activated';
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385 // attempt activation. TODO: uber cool fail proof sandbox like in WP.
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387 include( YOURLS_PLUGINDIR.'/'.$plugin );
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388 if ( ob_get_length() > 0 ) {
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389 // there was some output: error
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390 $output = ob_get_clean();
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391 return 'Plugin generated expected output. Error was: <br/><pre>'.$output.'</pre>';
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394 // so far, so good: update active plugin list
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395 $ydb->plugins[] = $plugin;
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396 yourls_update_option( 'active_plugins', $ydb->plugins );
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397 yourls_do_action( 'activated_plugin', $plugin );
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398 yourls_do_action( 'activated_' . $plugin );
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404 * Dectivate a plugin
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406 * @param string $plugin Plugin filename (full relative to plugins directory)
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407 * @return mixed string if error or true if success
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409 function yourls_deactivate_plugin( $plugin ) {
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410 $plugin = yourls_plugin_basename( $plugin );
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412 // Check plugin is active
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413 if( !yourls_is_active_plugin( $plugin ) )
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414 return 'Plugin not active';
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416 // Deactivate the plugin
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418 $key = array_search( $plugin, $ydb->plugins );
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419 if( $key !== false ) {
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420 array_splice( $ydb->plugins, $key, 1 );
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423 yourls_update_option( 'active_plugins', $ydb->plugins );
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424 yourls_do_action( 'deactivated_plugin', $plugin );
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425 yourls_do_action( 'deactivated_' . $plugin );
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431 * Return the path of a plugin file, relative to the plugins directory
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433 function yourls_plugin_basename( $file ) {
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434 $file = yourls_sanitize_filename( $file );
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435 $plugindir = yourls_sanitize_filename( YOURLS_PLUGINDIR );
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436 $file = str_replace( $plugindir, '', $file );
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437 return trim( $file, '/' );
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441 * Return the URL of the directory a plugin
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443 function yourls_plugin_url( $file ) {
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444 $url = YOURLS_PLUGINURL . '/' . yourls_plugin_basename( $file );
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445 if( yourls_is_ssl() or yourls_needs_ssl() )
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446 $url = str_replace( 'http://', 'https://', $url );
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447 return yourls_apply_filter( 'plugin_url', $url, $file );
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451 * Display list of links to plugin admin pages, if any
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453 function yourls_list_plugin_admin_pages() {
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456 if( !property_exists( $ydb, 'plugin_pages' ) || !$ydb->plugin_pages )
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459 $plugin_links = array();
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460 foreach( (array)$ydb->plugin_pages as $plugin => $page ) {
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461 $plugin_links[ $plugin ] = array(
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462 'url' => yourls_admin_url( 'plugins.php?page='.$page['slug'] ),
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463 'anchor' => $page['title'],
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466 return $plugin_links;
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470 * Register a plugin administration page
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472 function yourls_register_plugin_page( $slug, $title, $function ) {
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475 if( !property_exists( $ydb, 'plugin_pages' ) || !$ydb->plugin_pages )
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476 $ydb->plugin_pages = array();
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478 $ydb->plugin_pages[ $slug ] = array(
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481 'function' => $function,
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486 * Handle plugin administration page
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489 function yourls_plugin_admin_page( $plugin_page ) {
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492 // Check the plugin page is actually registered
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493 if( !isset( $ydb->plugin_pages[$plugin_page] ) ) {
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494 yourls_die( 'This page does not exist. Maybe a plugin you thought was activated is inactive?', 'Invalid link' );
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497 // Draw the page itself
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498 yourls_do_action( 'load-' . $plugin_page);
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499 yourls_html_head( 'plugin_page_' . $plugin_page, $ydb->plugin_pages[$plugin_page]['title'] );
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500 yourls_html_logo();
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501 yourls_html_menu();
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503 call_user_func( $ydb->plugin_pages[$plugin_page]['function'] );
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505 yourls_html_footer();
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