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url_to_absolute.inc in TMGMT Translator Smartling 8

Edited by Nitin Kr. Gupta, publicmind.in

A library with some url-related functions.

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includes/url_to_absolute.inc
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<?php

/**
 * @file
 * Edited by Nitin Kr. Gupta, publicmind.in
 *
 * A library with some url-related functions.
 */

/**
 * Copyright (c) 2008, David R. Nadeau, NadeauSoftware.com.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials provided
 *     with the distribution.
 *
 *   * Neither the names of David R. Nadeau or NadeauSoftware.com, nor
 *     the names of its contributors may be used to endorse or promote
 *     products derived from this software without specific prior
 *     written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 */

/*
 * This is a BSD License approved by the Open Source Initiative (OSI).
 * See:  http://www.opensource.org/licenses/bsd-license.php
 */

/**
 * Combine a base URL and a relative URL to produce a new
 * absolute URL.  The base URL is often the URL of a page,
 * and the relative URL is a URL embedded on that page.
 *
 * This function implements the "absolutize" algorithm from
 * the RFC3986 specification for URLs.
 *
 * This function supports multi-byte characters with the UTF-8 encoding,
 * per the URL specification.
 *
 * Parameters:
 *    baseUrl      the absolute base URL.
 *
 *    url      the relative URL to convert.
 *
 * Return values:
 *    An absolute URL that combines parts of the base and relative
 *    URLs, or FALSE if the base URL is not absolute or if either
 *    URL cannot be parsed.
 */
function url_to_absolute($base_url, $relative_url) {

  // If relative URL has a scheme, clean path and return.
  $r = split_url($relative_url);
  if ($r === FALSE) {
    return FALSE;
  }
  if (!empty($r['scheme'])) {
    if (!empty($r['path']) && $r['path'][0] == '/') {
      $r['path'] = url_remove_dot_segments($r['path']);
    }
    return join_url($r);
  }

  // Make sure the base URL is absolute.
  $b = split_url($base_url);
  if ($b === FALSE || empty($b['scheme']) || empty($b['host'])) {
    return FALSE;
  }
  $r['scheme'] = $b['scheme'];

  // If relative URL has an authority, clean path and return.
  if (isset($r['host'])) {
    if (!empty($r['path'])) {
      $r['path'] = url_remove_dot_segments($r['path']);
    }
    return join_url($r);
  }
  unset($r['port']);
  unset($r['user']);
  unset($r['pass']);

  // Copy base authority.
  $r['host'] = $b['host'];
  if (isset($b['port'])) {
    $r['port'] = $b['port'];
  }
  if (isset($b['user'])) {
    $r['user'] = $b['user'];
  }
  if (isset($b['pass'])) {
    $r['pass'] = $b['pass'];
  }

  // If relative URL has no path, use base path
  if (empty($r['path'])) {
    if (!empty($b['path'])) {
      $r['path'] = $b['path'];
    }
    if (!isset($r['query']) && isset($b['query'])) {
      $r['query'] = $b['query'];
    }
    return join_url($r);
  }

  // If relative URL path doesn't start with /, merge with base path
  if (isset($b['path']) && $r['path'][0] != '/') {
    $base = mb_strrchr($b['path'], '/', TRUE, 'UTF-8');
    if ($base === FALSE) {
      $base = '';
    }
    $r['path'] = $base . '/' . $r['path'];
  }
  $r['path'] = url_remove_dot_segments($r['path']);
  return join_url($r);
}

/**
 * Filter out "." and ".." segments from a URL's path and return
 * the result.
 *
 * This function implements the "remove_dot_segments" algorithm from
 * the RFC3986 specification for URLs.
 *
 * This function supports multi-byte characters with the UTF-8 encoding,
 * per the URL specification.
 *
 * Parameters:
 *    path   the path to filter
 *
 * Return values:
 *    The filtered path with "." and ".." removed.
 */
function url_remove_dot_segments($path) {

  // multi-byte character explode
  $in_segs = preg_split('!/!u', $path);
  $out_segs = array();
  foreach ($in_segs as $seg) {
    if ($seg == '' || $seg == '.') {
      continue;
    }
    if ($seg == '..') {
      array_pop($out_segs);
    }
    else {
      array_push($out_segs, $seg);
    }
  }
  $out_path = implode('/', $out_segs);
  if ($path[0] == '/') {
    $out_path = '/' . $out_path;
  }

  // compare last multi-byte character against '/'
  if ($out_path != '/' && mb_strlen($path) - 1 == mb_strrpos($path, '/', 'UTF-8')) {
    $out_path .= '/';
  }
  return $out_path;
}

/**
 * This function parses an absolute or relative URL and splits it
 * into individual components.
 *
 * RFC3986 specifies the components of a Uniform Resource Identifier (URI).
 * A portion of the ABNFs are repeated here:
 *
 *   URI-reference   = URI
 *         / relative-ref
 *
 *   URI      = scheme ":" hier-part [ "?" query ] [ "#" fragment ]
 *
 *   relative-ref   = relative-part [ "?" query ] [ "#" fragment ]
 *
 *   hier-part   = "//" authority path-abempty
 *         / path-absolute
 *         / path-rootless
 *         / path-empty
 *
 *   relative-part   = "//" authority path-abempty
 *         / path-absolute
 *         / path-noscheme
 *         / path-empty
 *
 *   authority   = [ userinfo "@" ] host [ ":" port ]
 *
 * So, a URL has the following major components:
 *
 *   scheme
 *      The name of a method used to interpret the rest of
 *      the URL.  Examples:  "http", "https", "mailto", "file'.
 *
 *   authority
 *      The name of the authority governing the URL's name
 *      space.  Examples:  "example.com", "user@example.com",
 *      "example.com:80", "user:password@example.com:80".
 *
 *      The authority may include a host name, port number,
 *      user name, and password.
 *
 *      The host may be a name, an IPv4 numeric address, or
 *      an IPv6 numeric address.
 *
 *   path
 *      The hierarchical path to the URL's resource.
 *      Examples:  "/index.htm", "/scripts/page.php".
 *
 *   query
 *      The data for a query.  Examples:  "?search=google.com".
 *
 *   fragment
 *      The name of a secondary resource relative to that named
 *      by the path.  Examples:  "#section1", "#header".
 *
 * An "absolute" URL must include a scheme and path.  The authority, query,
 * and fragment components are optional.
 *
 * A "relative" URL does not include a scheme and must include a path.  The
 * authority, query, and fragment components are optional.
 *
 * This function splits the $url argument into the following components
 * and returns them in an associative array.  Keys to that array include:
 *
 *   "scheme"   The scheme, such as "http".
 *   "host"      The host name, IPv4, or IPv6 address.
 *   "port"      The port number.
 *   "user"      The user name.
 *   "pass"      The user password.
 *   "path"      The path, such as a file path for "http".
 *   "query"      The query.
 *   "fragment"   The fragment.
 *
 * One or more of these may not be present, depending upon the URL.
 *
 * Optionally, the "user", "pass", "host" (if a name, not an IP address),
 * "path", "query", and "fragment" may have percent-encoded characters
 * decoded.  The "scheme" and "port" cannot include percent-encoded
 * characters and are never decoded.  Decoding occurs after the URL has
 * been parsed.
 *
 * Parameters:
 *    url      the URL to parse.
 *
 *    decode      an optional boolean flag selecting whether
 *          to decode percent encoding or not.  Default = TRUE.
 *
 * Return values:
 *    the associative array of URL parts, or FALSE if the URL is
 *    too malformed to recognize any parts.
 */
function split_url($url, $decode = FALSE) {
  $parts = array();

  // Character sets from RFC3986.
  $xunressub = 'a-zA-Z\\d\\-._~\\!$&\'()*+,;=';
  $xpchar = $xunressub . ':@% ';

  // Scheme from RFC3986.
  $xscheme = '([a-zA-Z][a-zA-Z\\d+-.]*)';

  // User info (user + password) from RFC3986.
  $xuserinfo = '(([' . $xunressub . '%]*)' . '(:([' . $xunressub . ':%]*))?)';

  // IPv4 from RFC3986 (without digit constraints).
  $xipv4 = '(\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3})';

  // IPv6 from RFC2732 (without digit and grouping constraints).
  $xipv6 = '(\\[([a-fA-F\\d.:]+)\\])';

  // Host name from RFC1035.  Technically, must start with a letter.
  // Relax that restriction to better parse URL structure, then
  // leave host name validation to application.
  $xhost_name = '([a-zA-Z\\d-.%]+)';

  // Authority from RFC3986.  Skip IP future.
  $xhost = '(' . $xhost_name . '|' . $xipv4 . '|' . $xipv6 . ')';
  $xport = '(\\d*)';
  $xauthority = '((' . $xuserinfo . '@)?' . $xhost . '?(:' . $xport . ')?)';

  // Path from RFC3986.  Blend absolute & relative for efficiency.
  $xslash_seg = '(/[' . $xpchar . ']*)';
  $xpath_authabs = '((//' . $xauthority . ')((/[' . $xpchar . ']*)*))';
  $xpath_rel = '([' . $xpchar . ']+' . $xslash_seg . '*)';
  $xpath_abs = '(/(' . $xpath_rel . ')?)';
  $xapath = '(' . $xpath_authabs . '|' . $xpath_abs . '|' . $xpath_rel . ')';

  // Query and fragment from RFC3986.
  $xqueryfrag = '([' . $xpchar . '/?' . ']*)';

  // URL.
  $xurl = '^(' . $xscheme . ':)?' . $xapath . '?' . '(\\?' . $xqueryfrag . ')?(#' . $xqueryfrag . ')?$';

  // Split the URL into components.
  if (!preg_match('!' . $xurl . '!', $url, $m)) {
    return FALSE;
  }
  if (!empty($m[2])) {
    $parts['scheme'] = strtolower($m[2]);
  }
  if (!empty($m[7])) {
    if (isset($m[9])) {
      $parts['user'] = $m[9];
    }
    else {
      $parts['user'] = '';
    }
  }
  if (!empty($m[10])) {
    $parts['pass'] = $m[11];
  }
  if (!empty($m[13])) {
    $h = $parts['host'] = $m[13];
  }
  else {
    if (!empty($m[14])) {
      $parts['host'] = $m[14];
    }
    else {
      if (!empty($m[16])) {
        $parts['host'] = $m[16];
      }
      else {
        if (!empty($m[5])) {
          $parts['host'] = '';
        }
      }
    }
  }
  if (!empty($m[17])) {
    $parts['port'] = $m[18];
  }
  if (!empty($m[19])) {
    $parts['path'] = $m[19];
  }
  else {
    if (!empty($m[21])) {
      $parts['path'] = $m[21];
    }
    else {
      if (!empty($m[25])) {
        $parts['path'] = $m[25];
      }
    }
  }
  if (!empty($m[27])) {
    $parts['query'] = $m[28];
  }
  if (!empty($m[29])) {
    $parts['fragment'] = $m[30];
  }
  if (!$decode) {
    return $parts;
  }
  if (!empty($parts['user'])) {
    $parts['user'] = rawurldecode($parts['user']);
  }
  if (!empty($parts['pass'])) {
    $parts['pass'] = rawurldecode($parts['pass']);
  }
  if (!empty($parts['path'])) {
    $parts['path'] = rawurldecode($parts['path']);
  }
  if (isset($h)) {
    $parts['host'] = rawurldecode($parts['host']);
  }
  if (!empty($parts['query'])) {
    $parts['query'] = rawurldecode($parts['query']);
  }
  if (!empty($parts['fragment'])) {
    $parts['fragment'] = rawurldecode($parts['fragment']);
  }
  return $parts;
}

/**
 * This function joins together URL components to form a complete URL.
 *
 * RFC3986 specifies the components of a Uniform Resource Identifier (URI).
 * This function implements the specification's "component recomposition"
 * algorithm for combining URI components into a full URI string.
 *
 * The $parts argument is an associative array containing zero or
 * more of the following:
 *
 *   "scheme"   The scheme, such as "http".
 *   "host"      The host name, IPv4, or IPv6 address.
 *   "port"      The port number.
 *   "user"      The user name.
 *   "pass"      The user password.
 *   "path"      The path, such as a file path for "http".
 *   "query"      The query.
 *   "fragment"   The fragment.
 *
 * The "port", "user", and "pass" values are only used when a "host"
 * is present.
 *
 * The optional $encode argument indicates if appropriate URL components
 * should be percent-encoded as they are assembled into the URL.  Encoding
 * is only applied to the "user", "pass", "host" (if a host name, not an
 * IP address), "path", "query", and "fragment" components.  The "scheme"
 * and "port" are never encoded.  When a "scheme" and "host" are both
 * present, the "path" is presumed to be hierarchical and encoding
 * processes each segment of the hierarchy separately (i.e., the slashes
 * are left alone).
 *
 * The assembled URL string is returned.
 *
 * Parameters:
 *    parts      an associative array of strings containing the
 *          individual parts of a URL.
 *
 *    encode      an optional boolean flag selecting whether
 *          to do percent encoding or not.  Default = true.
 *
 * Return values:
 *    Returns the assembled URL string.  The string is an absolute
 *    URL if a scheme is supplied, and a relative URL if not.  An
 *    empty string is returned if the $parts array does not contain
 *    any of the needed values.
 */
function join_url($parts, $encode = FALSE) {
  if ($encode) {
    if (isset($parts['user'])) {
      $parts['user'] = rawurlencode($parts['user']);
    }
    if (isset($parts['pass'])) {
      $parts['pass'] = rawurlencode($parts['pass']);
    }
    if (isset($parts['host']) && !preg_match('!^(\\[[\\da-f.:]+\\]])|([\\da-f.:]+)$!ui', $parts['host'])) {
      $parts['host'] = rawurlencode($parts['host']);
    }
    if (!empty($parts['path'])) {
      $parts['path'] = preg_replace('!%2F!ui', '/', rawurlencode($parts['path']));
    }
    if (isset($parts['query'])) {
      $parts['query'] = rawurlencode($parts['query']);
    }
    if (isset($parts['fragment'])) {
      $parts['fragment'] = rawurlencode($parts['fragment']);
    }
  }
  $url = '';
  if (!empty($parts['scheme'])) {
    $url .= $parts['scheme'] . ':';
  }
  if (isset($parts['host'])) {
    $url .= '//';
    if (isset($parts['user'])) {
      $url .= $parts['user'];
      if (isset($parts['pass'])) {
        $url .= ':' . $parts['pass'];
      }
      $url .= '@';
    }
    if (preg_match('!^[\\da-f]*:[\\da-f.:]+$!ui', $parts['host'])) {
      $url .= '[' . $parts['host'] . ']';
    }
    else {
      $url .= $parts['host'];
    }

    // IPv4 or name
    if (isset($parts['port'])) {
      $url .= ':' . $parts['port'];
    }
    if (!empty($parts['path']) && $parts['path'][0] != '/') {
      $url .= '/';
    }
  }
  if (!empty($parts['path'])) {
    $url .= $parts['path'];
  }
  if (isset($parts['query'])) {
    $url .= '?' . $parts['query'];
  }
  if (isset($parts['fragment'])) {
    $url .= '#' . $parts['fragment'];
  }
  return $url;
}

/**
 * This function encodes URL to form a URL which is properly
 * percent encoded to replace disallowed characters.
 *
 * RFC3986 specifies the allowed characters in the URL as well as
 * reserved characters in the URL. This function replaces all the
 * disallowed characters in the URL with their repective percent
 * encodings. Already encoded characters are not encoded again,
 * such as '%20' is not encoded to '%2520'.
 *
 * Parameters:
 *    url      the url to encode.
 *
 * Return values:
 *    Returns the encoded URL string.
 */
function encode_url($url) {
  $reserved = array(
    ":" => '!%3A!ui',
    "/" => '!%2F!ui',
    "?" => '!%3F!ui',
    "#" => '!%23!ui',
    "[" => '!%5B!ui',
    "]" => '!%5D!ui',
    "@" => '!%40!ui',
    "!" => '!%21!ui',
    "\$" => '!%24!ui',
    "&" => '!%26!ui',
    "'" => '!%27!ui',
    "(" => '!%28!ui',
    ")" => '!%29!ui',
    "*" => '!%2A!ui',
    "+" => '!%2B!ui',
    "," => '!%2C!ui',
    ";" => '!%3B!ui',
    "=" => '!%3D!ui',
    "%" => '!%25!ui',
  );
  $url = rawurlencode($url);
  $url = preg_replace(array_values($reserved), array_keys($reserved), $url);
  return $url;
}

Functions

Namesort descending Description
encode_url This function encodes URL to form a URL which is properly percent encoded to replace disallowed characters.
join_url This function joins together URL components to form a complete URL.
split_url This function parses an absolute or relative URL and splits it into individual components.
url_remove_dot_segments Filter out "." and ".." segments from a URL's path and return the result.
url_to_absolute Combine a base URL and a relative URL to produce a new absolute URL. The base URL is often the URL of a page, and the relative URL is a URL embedded on that page.