python/php/sdk/google/appengine/util/string_util.php

   1 <?php
   2 /**
   3  * Copyright 2007 Google Inc.
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17 /**
  18  * Various utilities for working with Strings.
  19  *
  20  */
  21 namespace google\appengine\util;
  22
  23 final class StringUtil {
  24   /**
  25    * Return true if the first paramater contains the second parameter at the
  26    * end.
  27    *
  28    * @param string $input The input string which may contain the suffix.
  29    * @param string $suffix The string to look for at the end of the input.
  30    *
  31    * @return boolean <code>true</code> iff the input contains the suffix at the
  32    * end.
  33    */
  34   public static function endsWith($input, $suffix) {
  35     return substr($input, -strlen($suffix)) === $suffix;
  36   }
  37
  38   /**
  39    * @param string $input The string which may contain the prefix at the start.
  40    * @param string $prefix The string to look for at the start of the input.
  41    *
  42    * @return boolean <code>true</code> iff the input contains the prefix at the
  43    * start.
  44    */
  45   public static function startsWith($input, $prefix) {
  46     return substr($input, 0, strlen($prefix)) === $prefix;
  47   }
  48
  49   /**
  50    * @param string $input The string which may not be url safe.
  51    *
  52    * @return string A Base64 encoded url safe string.
  53    */
  54   public static function base64UrlEncode($input) {
  55     return strtr(base64_encode($input), '+/=', '-_,');
  56   }
  57
  58   /**
  59    * @param string $input The url safe Base64 encoded string.
  60    *
  61    * @return string The original string which may not be url safe.
  62    */
  63   public static function base64UrlDecode($input) {
  64     return base64_decode(strtr($input, '-_,', '+/='));
  65   }
  66 }