* Copyright 2013 Google Inc.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* Implementation of levels 1-3 of the URI Template spec.
* @see http://tools.ietf.org/html/rfc6570
class Google_Utils_URITemplate
* These are valid at the start of a template block to
* modify the way in which the variables inside are
private $operators = array(
* These are the characters which should not be URL encoded in reserved
private $reserved = array(
"=", ",", "!", "@", "|", ":", "/", "?", "#",
"[", "]",'$', "&", "'", "(", ")", "*", "+", ";"
private $reservedEncoded = array(
"%3D", "%2C", "%21", "%40", "%7C", "%3A", "%2F", "%3F",
"%23", "%5B", "%5D", "%24", "%26", "%27", "%28", "%29",
public function parse($string, array $parameters)
return $this->resolveNextSection($string, $parameters);
* This function finds the first matching {...} block and
* executes the replacement. It then calls itself to find
* subsequent blocks, if any.
private function resolveNextSection($string, $parameters)
$start = strpos($string, "{");
$end = strpos($string, "}");
$string = $this->replace($string, $start, $end, $parameters);
return $this->resolveNextSection($string, $parameters);
private function replace($string, $start, $end, $parameters)
// We know a data block will have {} round it, so we can strip that.
$data = substr($string, $start + 1, $end - $start - 1);
// If the first character is one of the reserved operators, it effects
// the processing of the stream.
if (isset($this->operators[$data[0]])) {
$op = $this->operators[$data[0]];
$data = substr($data, 1);
$prefix_on_missing = false;
// Reserved means certain characters should not be URL encoded
$data = $this->replaceVars($data, $parameters, ",", null, true);
// Comma separated with fragment prefix. Bare values only.
$prefix_on_missing = true;
$data = $this->replaceVars($data, $parameters, ",", null, true);
// Slash separated data. Bare values only.
$data =$this->replaceVars($data, $parameters, "/");
// Dot separated data. Bare values only.
$prefix_on_missing = true;
$data = $this->replaceVars($data, $parameters, ".");
// Semicolon prefixed and separated. Uses the key name
$data = $this->replaceVars($data, $parameters, ";", "=", false, true, false);
// Standard URL format. Uses the key name
$data = $this->replaceVars($data, $parameters, "&", "=");
// Standard URL, but with leading ampersand. Uses key name.
$data = $this->replaceVars($data, $parameters, "&", "=");
// Add the initial prefix character if data is valid.
if ($data || ($data !== false && $prefix_on_missing)) {
// If no operator we replace with the defaults.
$data = $this->replaceVars($data, $parameters);
// This is chops out the {...} and replaces with the new section.
return substr($string, 0, $start) . $data . substr($string, $end + 1);
private function replaceVars(
if (strpos($section, ",") === false) {
// If we only have a single value, we can immediately process.
// If we have multiple values, we need to split and loop over them.
// Each is treated individually, then glued together with the
$vars = explode(",", $section);
return $this->combineList(
false, // Never emit empty strings in multi-param replacements
$skip_final_combine = false;
// Check for length restriction.
if (strpos($key, ":") !== false) {
list($key, $length) = explode(":", $key);
// Check for explode parameter.
if ($key[strlen($key) - 1] == "*") {
$key = substr($key, 0, -1);
$skip_final_combine = true;
// Define the list separator.
$list_sep = $explode ? $sep : ",";
if (isset($parameters[$key])) {
$data_type = $this->getDataType($parameters[$key]);
$value = $this->getValue($parameters[$key], $length);
foreach ($parameters[$key] as $pkey => $pvalue) {
$pvalue = $this->getValue($pvalue, $length);
if ($combine && $explode) {
$values[$pkey] = $key . $combine . $pvalue;
$values[$pkey] = $pvalue;
$value = implode($list_sep, $values);
foreach ($parameters[$key] as $pkey => $pvalue) {
$pvalue = $this->getValue($pvalue, $length);
$pkey = $this->getValue($pkey, $length);
$values[] = $pkey . "=" . $pvalue; // Explode triggers = combine.
$value = implode($list_sep, $values);
// If we are just indicating empty values with their key name, return that.
// Otherwise we can skip this variable due to not being defined.
$value = str_replace($this->reservedEncoded, $this->reserved, $value);
// If we do not need to include the key name, we just return the raw
if (!$combine || $skip_final_combine) {
// Else we combine the key name: foo=bar, if value is not the empty string.
return $key . ($value != '' || $combine_on_empty ? $combine . $value : '');
* Return the type of a passed in value
private function getDataType($data)
return self::TYPE_SCALAR;
* Utility function that merges multiple combine calls
* for multi-key templates.
private function combineList(
foreach ($vars as $var) {
$response = $this->combine(
if ($response === false) {
return implode($sep, $ret);
* Utility function to encode and trim values
private function getValue($value, $length)
$value = substr($value, 0, $length);
$value = rawurlencode($value);
It is recommended that you Edit text format, this type of Fix handles quite a lot in one request
