wp_parse_url

A wrapper for PHP's parse_url() function that handles consistency in the return values across PHP versions.

Description

wp_parse_url( (string) $url, (int) $component = -1 ); 

PHP 5.4.7 expanded parse_url(…)'s ability to handle non-absolute url's, including schemeless and relative url's with :// in the path. This function works around those limitations providing a standard output on PHP 5.2~5.4+.

Secondly, across various PHP versions, schemeless URLs starting containing a : in the query are being handled inconsistently. This function works around those differences as well.

Error suppression is used as prior to PHP 5.3.3, an E_WARNING would be generated when URL parsing failed.

Parameters (2)

0. $url (string)
The URL to parse.
1. $component — Optional. (int) => -1
The specific component to retrieve. Use one of the PHP predefined constants to specify which one. Defaults to -1 (= return all parts as an array). @see http://php.net/manual/en/function.parse-url.php

Usage

  1. if ( !function_exists( 'wp_parse_url' ) ) { 
  2.     require_once ABSPATH . WPINC . '/http.php'; 
  3. } 
  4.   
  5. // The URL to parse. 
  6. $url = ''; 
  7. $component = -1; 
  8.   
  9. // NOTICE! Understand what this does before running. 
  10. $result = wp_parse_url($url, $component); 
  11.     

Defined (1)

The function is defined in the following location(s).

/wp-includes/http.php  
  1. function wp_parse_url( $url, $component = -1 ) { 
  2.     $to_unset = array(); 
  3.     $url = strval( $url ); 
  4.  
  5.     if ( '//' === substr( $url, 0, 2 ) ) { 
  6.         $to_unset[] = 'scheme'; 
  7.         $url = 'placeholder:' . $url; 
  8.     } elseif ( '/' === substr( $url, 0, 1 ) ) { 
  9.         $to_unset[] = 'scheme'; 
  10.         $to_unset[] = 'host'; 
  11.         $url = 'placeholder://placeholder' . $url; 
  12.     } 
  13.  
  14.     $parts = @parse_url( $url ); 
  15.  
  16.     if ( false === $parts ) { 
  17.         // Parsing failure. 
  18.         return $parts; 
  19.     } 
  20.  
  21.     // Remove the placeholder values. 
  22.     foreach ( $to_unset as $key ) { 
  23.         unset( $parts[ $key ] ); 
  24.     } 
  25.  
  26.     return _get_component_from_parsed_url_array( $parts, $component ); 
  27. }