<?php
/*
* This file is part of Mustache.php.
*
* (c) 2010-2017 Justin Hileman
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
/**
* Mustache Template rendering Context.
*/
class Mustache_Context
{
private $stack = array();
private $blockStack = array();
/**
* Mustache rendering Context constructor.
*
* @param mixed $context Default rendering context (default: null)
*/
public function __construct($context = null)
{
if ($context !== null) {
$this->stack = array($context);
}
}
/**
* Push a new Context frame onto the stack.
*
* @param mixed $value Object or array to use for context
*/
public function push($value)
{
array_push($this->stack, $value);
}
/**
* Push a new Context frame onto the block context stack.
*
* @param mixed $value Object or array to use for block context
*/
public function pushBlockContext($value)
{
array_push($this->blockStack, $value);
}
/**
* Pop the last Context frame from the stack.
*
* @return mixed Last Context frame (object or array)
*/
public function pop()
{
return array_pop($this->stack);
}
/**
* Pop the last block Context frame from the stack.
*
* @return mixed Last block Context frame (object or array)
*/
public function popBlockContext()
{
return array_pop($this->blockStack);
}
/**
* Get the last Context frame.
*
* @return mixed Last Context frame (object or array)
*/
public function last()
{
return end($this->stack);
}
/**
* Find a variable in the Context stack.
*
* Starting with the last Context frame (the context of the innermost section), and working back to the top-level
* rendering context, look for a variable with the given name:
*
* * If the Context frame is an associative array which contains the key $id, returns the value of that element.
* * If the Context frame is an object, this will check first for a public method, then a public property named
* $id. Failing both of these, it will try `__isset` and `__get` magic methods.
* * If a value named $id is not found in any Context frame, returns an empty string.
*
* @param string $id Variable name
*
* @return mixed Variable value, or '' if not found
*/
public function find($id)
{
return $this->findVariableInStack($id, $this->stack);
}
/**
* Find a 'dot notation' variable in the Context stack.
*
* Note that dot notation traversal bubbles through scope differently than the regular find method. After finding
* the initial chunk of the dotted name, each subsequent chunk is searched for only within the value of the previous
* result. For example, given the following context stack:
*
* $data = array(
* 'name' => 'Fred',
* 'child' => array(
* 'name' => 'Bob'
* ),
* );
*
* ... and the Mustache following template:
*
* {{ child.name }}
*
* ... the `name` value is only searched for within the `child` value of the global Context, not within parent
* Context frames.
*
* @param string $id Dotted variable selector
*
* @return mixed Variable value, or '' if not found
*/
public function findDot($id)
{
$chunks = explode('.', $id);
$first = array_shift($chunks);
$value = $this->findVariableInStack($first, $this->stack);
foreach ($chunks as $chunk) {
if ($value === '') {
return $value;
}
$value = $this->findVariableInStack($chunk, array($value));
}
return $value;
}
/**
* Find an 'anchored dot notation' variable in the Context stack.
*
* This is the same as findDot(), except it looks in the top of the context
* stack for the first value, rather than searching the whole context stack
* and starting from there.
*
* @see Mustache_Context::findDot
*
* @throws Mustache_Exception_InvalidArgumentException if given an invalid anchored dot $id
*
* @param string $id Dotted variable selector
*
* @return mixed Variable value, or '' if not found
*/
public function findAnchoredDot($id)
{
$chunks = explode('.', $id);
$first = array_shift($chunks);
if ($first !== '') {
throw new Mustache_Exception_InvalidArgumentException(sprintf('Unexpected id for findAnchoredDot: %s', $id));
}
$value = $this->last();
foreach ($chunks as $chunk) {
if ($value === '') {
return $value;
}
$value = $this->findVariableInStack($chunk, array($value));
}
return $value;
}
/**
* Find an argument in the block context stack.
*
* @param string $id
*
* @return mixed Variable value, or '' if not found
*/
public function findInBlock($id)
{
foreach ($this->blockStack as $context) {
if (array_key_exists($id, $context)) {
return $context[$id];
}
}
return '';
}
/**
* Helper function to find a variable in the Context stack.
*
* @see Mustache_Context::find
*
* @param string $id Variable name
* @param array $stack Context stack
*
* @return mixed Variable value, or '' if not found
*/
private function findVariableInStack($id, array $stack)
{
for ($i = count($stack) - 1; $i >= 0; $i--) {
$frame = &$stack[$i];
switch (gettype($frame)) {
case 'object':
if (!($frame instanceof Closure)) {
// Note that is_callable() *will not work here*
// See https://github.com/bobthecow/mustache.php/wiki/Magic-Methods
if (method_exists($frame, $id)) {
return $frame->$id();
}
if (isset($frame->$id)) {
return $frame->$id;
}
if ($frame instanceof ArrayAccess && isset($frame[$id])) {
return $frame[$id];
}
}
break;
case 'array':
if (array_key_exists($id, $frame)) {
return $frame[$id];
}
break;
}
}
return '';
}
}
