<?php
namespace GuzzleHttp;
/**
* Expands URI templates. Userland implementation of PECL uri_template.
*
* @link http://tools.ietf.org/html/rfc6570
*/
class UriTemplate
{
/** @var string URI template */
private $template;
/** @var array Variables to use in the template expansion */
private $variables;
/** @var array Hash for quick operator lookups */
private static $operatorHash = [
'' => ['prefix' => '', 'joiner' => ',', 'query' => false],
'+' => ['prefix' => '', 'joiner' => ',', 'query' => false],
'#' => ['prefix' => '#', 'joiner' => ',', 'query' => false],
'.' => ['prefix' => '.', 'joiner' => '.', 'query' => false],
'/' => ['prefix' => '/', 'joiner' => '/', 'query' => false],
';' => ['prefix' => ';', 'joiner' => ';', 'query' => true],
'?' => ['prefix' => '?', 'joiner' => '&', 'query' => true],
'&' => ['prefix' => '&', 'joiner' => '&', 'query' => true]
];
/** @var array Delimiters */
private static $delims = [':', '/', '?', '#', '[', ']', '@', '!', '$',
'&', '\'', '(', ')', '*', '+', ',', ';', '='];
/** @var array Percent encoded delimiters */
private static $delimsPct = ['%3A', '%2F', '%3F', '%23', '%5B', '%5D',
'%40', '%21', '%24', '%26', '%27', '%28', '%29', '%2A', '%2B', '%2C',
'%3B', '%3D'];
public function expand($template, array $variables)
{
if (false === strpos($template, '{')) {
return $template;
}
$this->template = $template;
$this->variables = $variables;
return preg_replace_callback(
'/\{([^\}]+)\}/',
[$this, 'expandMatch'],
$this->template
);
}
/**
* Parse an expression into parts
*
* @param string $expression Expression to parse
*
* @return array Returns an associative array of parts
*/
private function parseExpression($expression)
{
$result = [];
if (isset(self::$operatorHash[$expression[0]])) {
$result['operator'] = $expression[0];
$expression = substr($expression, 1);
} else {
$result['operator'] = '';
}
foreach (explode(',', $expression) as $value) {
$value = trim($value);
$varspec = [];
if ($colonPos = strpos($value, ':')) {
$varspec['value'] = substr($value, 0, $colonPos);
$varspec['modifier'] = ':';
$varspec['position'] = (int) substr($value, $colonPos + 1);
} elseif (substr($value, -1) === '*') {
$varspec['modifier'] = '*';
$varspec['value'] = substr($value, 0, -1);
} else {
$varspec['value'] = (string) $value;
$varspec['modifier'] = '';
}
$result['values'][] = $varspec;
}
return $result;
}
/**
* Process an expansion
*
* @param array $matches Matches met in the preg_replace_callback
*
* @return string Returns the replacement string
*/
private function expandMatch(array $matches)
{
static $rfc1738to3986 = ['+' => '%20', '%7e' => '~'];
$replacements = [];
$parsed = self::parseExpression($matches[1]);
$prefix = self::$operatorHash[$parsed['operator']]['prefix'];
$joiner = self::$operatorHash[$parsed['operator']]['joiner'];
$useQuery = self::$operatorHash[$parsed['operator']]['query'];
foreach ($parsed['values'] as $value) {
if (!isset($this->variables[$value['value']])) {
continue;
}
$variable = $this->variables[$value['value']];
$actuallyUseQuery = $useQuery;
$expanded = '';
if (is_array($variable)) {
$isAssoc = $this->isAssoc($variable);
$kvp = [];
foreach ($variable as $key => $var) {
if ($isAssoc) {
$key = rawurlencode($key);
$isNestedArray = is_array($var);
} else {
$isNestedArray = false;
}
if (!$isNestedArray) {
$var = rawurlencode($var);
if ($parsed['operator'] === '+' ||
$parsed['operator'] === '#'
) {
$var = $this->decodeReserved($var);
}
}
if ($value['modifier'] === '*') {
if ($isAssoc) {
if ($isNestedArray) {
// Nested arrays must allow for deeply nested
// structures.
$var = strtr(
http_build_query([$key => $var]),
$rfc1738to3986
);
} else {
$var = $key . '=' . $var;
}
} elseif ($key > 0 && $actuallyUseQuery) {
$var = $value['value'] . '=' . $var;
}
}
$kvp[$key] = $var;
}
if (empty($variable)) {
$actuallyUseQuery = false;
} elseif ($value['modifier'] === '*') {
$expanded = implode($joiner, $kvp);
if ($isAssoc) {
// Don't prepend the value name when using the explode
// modifier with an associative array.
$actuallyUseQuery = false;
}
} else {
if ($isAssoc) {
// When an associative array is encountered and the
// explode modifier is not set, then the result must be
// a comma separated list of keys followed by their
// respective values.
foreach ($kvp as $k => &$v) {
$v = $k . ',' . $v;
}
}
$expanded = implode(',', $kvp);
}
} else {
if ($value['modifier'] === ':') {
$variable = substr($variable, 0, $value['position']);
}
$expanded = rawurlencode($variable);
if ($parsed['operator'] === '+' || $parsed['operator'] === '#') {
$expanded = $this->decodeReserved($expanded);
}
}
if ($actuallyUseQuery) {
if (!$expanded && $joiner !== '&') {
$expanded = $value['value'];
} else {
$expanded = $value['value'] . '=' . $expanded;
}
}
$replacements[] = $expanded;
}
$ret = implode($joiner, $replacements);
if ($ret && $prefix) {
return $prefix . $ret;
}
return $ret;
}
/**
* Determines if an array is associative.
*
* This makes the assumption that input arrays are sequences or hashes.
* This assumption is a tradeoff for accuracy in favor of speed, but it
* should work in almost every case where input is supplied for a URI
* template.
*
* @param array $array Array to check
*
* @return bool
*/
private function isAssoc(array $array)
{
return $array && array_keys($array)[0] !== 0;
}
/**
* Removes percent encoding on reserved characters (used with + and #
* modifiers).
*
* @param string $string String to fix
*
* @return string
*/
private function decodeReserved($string)
{
return str_replace(self::$delimsPct, self::$delims, $string);
}
}
