path: root/Zotlabs/Render/SimpleTemplate.php

<?php

namespace Zotlabs\Render;

define ("KEY_NOT_EXISTS", '^R_key_not_Exists^');

class SimpleTemplate implements TemplateEngine {

	static $name ="internal";

	var $r;
	var $search;
	var $replace;
	var $stack = array();
	var $nodes = array();
	var $done = false;
	var $d = false;
	var $lang = null;
	var $debug=false;

	private function _preg_error() {
		switch(preg_last_error()) {
			case PREG_INTERNAL_ERROR: echo('PREG_INTERNAL_ERROR'); break;
			case PREG_BACKTRACK_LIMIT_ERROR: echo('PREG_BACKTRACK_LIMIT_ERROR'); break;
			case PREG_RECURSION_LIMIT_ERROR: echo('PREG_RECURSION_LIMIT_ERROR'); break;
			case PREG_BAD_UTF8_ERROR: echo('PREG_BAD_UTF8_ERROR'); break;
// This is only valid for php > 5.3, not certain how to code around it for unit tests
//			case PREG_BAD_UTF8_OFFSET_ERROR: echo('PREG_BAD_UTF8_OFFSET_ERROR'); break;
			default:
				//die("Unknown preg error.");
				return;
		}
		echo "<hr><pre>";
		debug_print_backtrace();
		die();
	}

	private function _push_stack() {
		$this->stack[] = array($this->r, $this->nodes);
	}

	private function _pop_stack(){
		list($this->r, $this->nodes) = array_pop($this->stack);
	}

	private function _get_var($name, $retNoKey=false) {
		$keys = array_map('trim',explode(".",$name));
		if ($retNoKey && !array_key_exists($keys[0], $this->r))
			return KEY_NOT_EXISTS;

		$val = $this->r;
		foreach($keys as $k) {
			$val = (isset($val[$k]) ? $val[$k] : null);
		}

		return template_escape($val);
	}

	/**
	 * IF node
	 * \code
	 * {{ if <$var> }}...[{{ else }} ...] {{ endif }}
	 * {{ if <$var>==<val|$var> }}...[{{ else }} ...]{{ endif }}
	 * {{ if <$var>!=<val|$var> }}...[{{ else }} ...]{{ endif }}
	 * \endcode
	 */
	private function _replcb_if($args) {
		if (strpos($args[2],"==")>0){
			list($a,$b) = array_map("trim",explode("==",$args[2]));
			$a = $this->_get_var($a);
			if ($b[0]=="$") $b =  $this->_get_var($b);
			$val = ($a == $b);
		} else if (strpos($args[2],"!=")>0){
			list($a,$b) = array_map("trim", explode("!=",$args[2]));
			$a = $this->_get_var($a);
			if ($b[0]=="$") $b =  $this->_get_var($b);
			$val = ($a != $b);
		} else {
			$val = $this->_get_var($args[2]);
		}
		$x = preg_split("|{{ *else *}}|", $args[3]);

		return ( ($val) ? $x[0] : (isset($x[1]) ? $x[1] : ""));
	}

	/**
	 * FOR node
	 * \code
	 * {{ for <$var> as $name }}...{{ endfor }}
	 * {{ for <$var> as $key=>$name }}...{{ endfor }}
	 * \endcode
	 */
	private function _replcb_for($args) {
		$m = array_map('trim', explode(" as ", $args[2]));
		$x = explode("=>",$m[1]);
		if (count($x) == 1) {
			$varname = $x[0];
			$keyname = "";
		} else {
			list($keyname, $varname) = $x;
		}
		if ($m[0]=="" || $varname=="" || is_null($varname)) die("template error: 'for ".$m[0]." as ".$varname."'") ;
		//$vals = $this->r[$m[0]];
		$vals = $this->_get_var($m[0]);
		$ret="";
		if (!is_array($vals)) return $ret;

		foreach ($vals as $k=>$v){
			$this->_push_stack();
			$r = $this->r;
			$r[$varname] = $v;
			if ($keyname!='') $r[$keyname] = (($k === 0) ? '0' : $k);
			$ret .=  $this->replace($args[3], $r);
			$this->_pop_stack();
		}

		return $ret;
	}

	/**
	 * INC node
	 * \code
	 * {{ inc <templatefile> [with $var1=$var2] }}{{ endinc }}
	 * \endcode
	 */
	private function _replcb_inc($args) {
		if (strpos($args[2],"with")) {
			list($tplfile, $newctx) = array_map('trim', explode("with",$args[2]));
		} else {
			$tplfile = trim($args[2]);
			$newctx = null;
		}

		if ($tplfile[0]=="$") $tplfile = $this->_get_var($tplfile);

		$this->_push_stack();
		$r = $this->r;
		if (!is_null($newctx)) {
			list($a,$b) = array_map('trim', explode("=",$newctx));
			$r[$a] = $this->_get_var($b); 
		}
		$this->nodes = Array();
		$tpl = get_markup_template($tplfile);
		$ret = $this->replace($tpl, $r);
		$this->_pop_stack();

		return $ret;
	}

	/**
	 * DEBUG node
	 * \code
	 * {{ debug $var [$var [$var [...]]] }}{{ enddebug }}
	 * \endcode
	 * replace node with <pre>var_dump($var, $var, ...);</pre>
	 */
	private function _replcb_debug($args) {
		$vars = array_map('trim', explode(" ",$args[2]));
		$vars[] = $args[1];

		$ret = "<pre>";
		foreach ($vars as $var){
			$ret .= htmlspecialchars(var_export( $this->_get_var($var), true ));
			$ret .= "\n";
		}
		$ret .= "</pre>";

		return $ret;
	}

	private function _replcb_node($m) {
		$node = $this->nodes[$m[1]];
		if (method_exists($this, "_replcb_".$node[1])){
			$s = call_user_func(array($this, "_replcb_".$node[1]),  $node);
		} else {
			$s = "";
		}
		$s = preg_replace_callback('/\|\|([0-9]+)\|\|/', array($this, "_replcb_node"), $s);

		return $s;
	}

	private function _replcb($m) {
		//var_dump(array_map('htmlspecialchars', $m));
		$this->done = false;
		$this->nodes[] = (array) $m;

		return "||". (count($this->nodes)-1) ."||";
	}

	private function _build_nodes($s) {
		$this->done = false;
		while (!$this->done) {
			$this->done=true;
			$s = preg_replace_callback('|{{ *([a-z]*) *([^}]*)}}([^{]*({{ *else *}}[^{]*)?){{ *end\1 *}}|', array($this, "_replcb"), $s);
			if ($s==Null) $this->_preg_error();
		}
		//({{ *else *}}[^{]*)?
		krsort($this->nodes);

		return $s;
	}

	private function var_replace($s) {
		$m = array();
		/** regexp:
		 * \$ 						literal $
		 * (\[)?					optional open square bracket
		 * ([a-zA-Z0-9-_]+\.?)+		var name, followed by optional
		 * 							dot, repeated at least 1 time
		 * (?(1)\])					if there was opened square bracket
		 * 							(subgrup 1), match close bracket
		 */
		if (preg_match_all('/\$(\[)?([a-zA-Z0-9-_]+\.?)+(?(1)\])/', $s,$m)) {
			foreach ($m[0] as $var) {
				$exp = str_replace(array("[", "]"), array("", ""), $var);
				$exptks = explode("|", $exp);

				$varn = $exptks[0];
				unset($exptks[0]);
				$val = $this->_get_var($varn, true);
				if ($val != KEY_NOT_EXISTS) {
					/* run filters */
					/*
					 * Filter are in form of:
					 * filtername:arg:arg:arg
					 *
					 * "filtername" is function name
					 * "arg"s are optional, var value is appended to the end
					 *          if one "arg"==='x' , is replaced with var value
					 *
					 * examples:
					 * $item.body|htmlspecialchars              // escape html chars
					 * $item.body|htmlspecialchars|strtoupper   // escape html and uppercase result
					 * $item.created|date:%Y %M %j              // format date (created is a timestamp)
					 * $item.body|str_replace:cat:dog           // replace all "cat" with "dog"
					 * $item.body|str_replace:cat:dog:x:1       // replace one "cat" with "dog"
					 */
					foreach ($exptks as $filterstr) {
						$filter = explode(":", $filterstr);
						$filtername = $filter[0];
						unset($filter[0]);
						$valkey = array_search("x", $filter);
						if ($valkey === false) {
							$filter[] = $val;
						} else {
							$filter[$valkey] = $val;
						}
						if (function_exists($filtername)) {
							$val = call_user_func_array($filtername, $filter);
						}
					}
					$s = str_replace($var, $val, $s);
				}
			}
		}

		return $s;
	}

	private function replace($s, $r) {
		$this->replace_macros($s, $r);
	}

	// TemplateEngine interface

	public function replace_macros($s, $r) {
		$this->r = $r;

		$s = $this->_build_nodes($s);

		$s = preg_replace_callback('/\|\|([0-9]+)\|\|/', array($this, "_replcb_node"), $s);
		if ($s == Null)
			$this->_preg_error();

		// remove comments block
		$s = preg_replace('/{#[^#]*#}/', "" , $s);

		//$t2 = dba_timer();

		// replace strings recursively (limit to 10 loops)
		$os = "";
		$count=0;
		while (($os !== $s) && $count<10) {
			$os=$s;
			$count++;
			$s = $this->var_replace($s);
		}

		return $s;
	}

	public function get_markup_template($file, $root='') {
		$template_file = theme_include($file, $root);
		if ($template_file) {
			$content = file_get_contents($template_file);
		}

		return $content;
	}
}


function template_escape($s) {
	return str_replace(array('$','{{'),array('!_Doll^Ars1Az_!','!_DoubLe^BraceS4Rw_!'),$s);
}

function template_unescape($s) {
	return str_replace(array('!_Doll^Ars1Az_!','!_DoubLe^BraceS4Rw_!'),array('$','{{'),$s);
}