From: Josh Grams <josh@qualdan.com>
Date: Tue, 4 Aug 2009 18:29:39 +0000 (-0400)
Subject: * template.php: changed arg order, new context stack implementation.
X-Git-Url: https://jasonwoof.com/gitweb/?p=wfpl.git;a=commitdiff_plain;h=ea7f4763f4ee51f22091aa6e75cd4c59cea55bc0

* template.php: changed arg order, new context stack implementation.
---

diff --git a/run.php b/run.php
index 26a8b36..4e56e98 100644
--- a/run.php
+++ b/run.php
@@ -137,7 +137,7 @@ function run_php($dest = false) {
 	} elseif($html_exists) {
 		$template = parse_template_file("$html_file");
 	}
-	if($template) print fill_template($data, $template);
+	if($template) print fill_template($template, $data);
 }
 
 run_php();
diff --git a/template.php b/template.php
index da05621..0e1688c 100644
--- a/template.php
+++ b/template.php
@@ -45,12 +45,12 @@ require_once('code/wfpl/misc.php');
 # Public functions
 # ----------------
 
-function template($data, $template) {
-	return fill_template($data, parse_template($template));
+function template($template, $data) {
+	return fill_template(parse_template($template), $data);
 }
 
-function template_file($data, $filename) {
-	return fill_template($data, parse_template_file($filename));
+function template_file($filename, $data) {
+	return fill_template(parse_template_file($filename), $data);
 }
 
 function parse_template_file($filename) {
@@ -98,32 +98,143 @@ function parse_template($string) {
 	return $tem;
 }
 
-# Then we do a depth-first traversal of the template tree,
-# replacing all tags with the data values.
-
-function fill_template($data, $template, $context = NULL, $keychain = NULL) {
-	$context[] = $data;
-	foreach($template['pieces'] as $piece) {
-		if(is_string($piece)) $output .= $piece;
-		else {
-			if($piece['pieces']) {  # sub-template
-				$keychain[] = $piece['name'];
-				$rows = tem_get_rows($piece, $context, $keychain);
-				foreach($rows as $key => $row) {
-					$keychain[] = $key;
-					$output .= fill_template($row, $piece, $context, $keychain);
-					array_pop($keychain);
-				}
-				array_pop($keychain);
-			} else {  # variable
-				$output .= tem_get_enc($piece, $context);
+# To fill out a template, we do a depth-first traversal of the template 
+# tree, replacing all tags with the data values.
+
+# The data starts out as a nested set of key/value pairs, where the 
+# values can be:
+
+	# a string to fill a value slot
+	# a hash to fill one instance of a sub-template
+	# an array of hashes to fill multiple instances of a sub-template
+
+# The middle form will be converted to the last form as we use it.
+
+function tem_data_as_rows($value) {
+	if(is_array($value)) {
+		# numeric keys, is already array of arrays -- expand sub-template for each.
+		if(array_key_exists(0, $value)) return $value;
+		# key/value pairs -- expand sub-template once.
+		else return array($value);
+	} elseif($value) {
+		# value -- expand sub-template once using only parent values
+		return array(array());
+	} else {
+		# empty value -- don't expand sub-template
+		return array();
+	}
+}
+
+
+
+# We use dynamic scoping, so we keep a stack of namespaces.
+# Each scope references a hash and the parent scope.
+
+function &tem_scope(&$data, $push = true) {
+	static $stack = array();
+
+	if($push) {
+		$parent =& last($stack);
+		$stack[] = array();
+
+		$scope =& last($stack);
+		$scope['data'] =& $data;
+		if($parent) $scope['parent'] =& $parent;
+	} else { # pop
+		array_pop($stack);
+	}
+	return last($stack);
+}
+
+function &tem_end_scope() { return tem_scope($x, false); }
+
+# To look up a key, we check each namespace (starting with the
+# innermost one) until a value is found.
+
+function tem_find_scope($key, $context) {
+	$scope = $context;
+	do{
+		if(array_key_exists($key, $scope['data'])) {
+			return $scope;
+		}
+	} while($scope = $scope['parent']);
+
+	# not found; return empty scope.
+	return array('parent' => $context);
+}
+
+function tem_get($key, $context) {
+	$scope = tem_find_scope($key, $context);
+	if($scope) return $scope['data'][$key];
+}
+
+# Return the value for a tag as a set of rows to fill a sub-template.
+# If $tag has an arg, call the tem_auto function to munge the data.
+function &tem_get_rows($tag, $context)
+{
+	$key = $tag['name'];
+	if(count($tag['args'])) {
+		$func = "tem_auto_" . $tag['args'][0];
+		function_exists($func)
+		   	or die("ERROR: template auto function '$func' not found.<br>\n");
+	}
+	$scope = tem_find_scope($key, $context);
+
+	if($func) $value = $func($key, $scope);
+	else $value = $scope['data'][$key];
+
+	$rows = tem_data_as_rows($value);
+	if(is_array($value)) $scope['data'][$key] = $rows;
+
+	return $rows;
+}
+
+# Return the value for a tag as an encoded string.
+function tem_get_enc($tag, $context)
+{
+	$key = $tag['name'];
+	$value = tem_get($key, $context);
+	foreach($tag['args'] as $encoding) {
+		$func = "enc_$encoding";
+		if(function_exists($func)) $value = $func($value, $key);
+		else die("ERROR: encoder function '$func' not found.<br>\n");
+	}
+	return $value;
+}
+
+function fill_template($template, &$data, &$context = NULL) {
+	if(!$context) $context =& tem_scope($data);
+	foreach($template['pieces'] as $tem) {
+		if(is_string($tem)) $output .= $tem;
+		elseif($tem['pieces']) {  # sub-template
+			$rows =& tem_get_rows($tem, $context);
+			foreach($rows as $key => &$row) {
+				$context =& tem_scope($row);
+				$context['rows'] =& $rows;
+					$output .= fill_template($tem, $row, $context);
+				$context =& tem_end_scope();
+
 			}
+		} else {  # variable
+			$output .= tem_get_enc($tem, $context);
 		}
 	}
 	return $output;
 }
 
 
+
+# Return a hash containing the top-level sub-templates of tem.
+function top_sub_templates($tem) {
+	$subs = array();
+	foreach($tem['pieces'] as $piece) {
+		if(is_array($piece) and $piece['pieces']) {
+		   	$subs[$piece['name']] = $piece;
+		}
+	}
+	return $subs;
+}
+
 # Replace top-level values in $main with top-level templates from $tem.
 function merge_templates($main, $tem) {
 	$out = array('name' => $main['name'], 'pieces' => array());
@@ -156,102 +267,32 @@ function merge_templates($main, $tem) {
 # 		<!--~row~-->
 # 	<!--~rows~-->
 #
-function tem_auto_sep($piece, $context, $keychain) {
-	list($name, $index, $this_name) = array_slice($keychain, -3);
-	$array = tem_get($name, $context);
-	if($index != count($array)-1) return true;
+function tem_auto_sep($key, $context) {
+	$rows =& $context['parent']['rows'];
+	if(key($rows)) return true;
+	# else we are on the last row (cursor has hit the end and reset).
 }
 
 # 'once' sections will be shown once unless the corresponding data value
 # is false.  We check only for false; 0 or '' will not work.
 
-function tem_auto_once($piece, $context, $keychain) {
-	$value = tem_get(array_pop($keychain), $context);
-	if($value !== false) return true;
+function tem_auto_once($key, $context) {
+	if($context['data'][$key] !== false)
+	   	return tem_data_as_rows(true);
 }
 
 # 'evenodd' sections are given an 'evenodd' attribute whose value
 # alternates between 'even' and 'odd'.
 
-function tem_auto_evenodd($piece, $context, $keychain) {
-	$rows = tem_get(array_pop($keychain), $context);
+function tem_auto_evenodd($key, $context) {
+	$rows = $context['data'][$key];
 	$even = 0;
 	$text = array('even', 'odd');
 	foreach($rows as $key => $value) {
 		$rows[$key]['evenodd'] = $text[$even];
 		$even = 1 - $even;
 	}
-	return $rows;
-}
-
-
-
-# Internal functions
-# ------------------
-#
-# Of course, nothing stops you from using these, but I don't know
-# why you would want to...
-
-
-# Convert value to array of hashes for use in sub-template expansion.
-# This adds flexibility to how you represent your data.
-function tem_value_as_rows($value) {
-	if(is_array($value)) {
-		# numeric keys, is already array of arrays -- expand sub-template for each.
-		if(array_key_exists(0, $value)) return $value;
-		# key/value pairs -- expand sub-template once.
-		else return array($value);
-	} elseif($value) {
-		# value -- expand sub-template once using only parent values
-		return array(array());
-	} else {
-		# empty value -- don't expand sub-template
-		return array();
-	}
-}
-
-# Search the current context and return the value for key.
-function tem_get($key, $context) {
-	while($context) {
-		$data = array_pop($context);
-		if(array_key_exists($key, $data)) return $data[$key];
-	}
-}
-
-# Return the value for a tag as a set of rows to fill a sub-template.
-# If $tag has an arg, call the tem_auto function to munge the data.
-function tem_get_rows($tag, $context, $keychain)
-{
-	if(count($tag['args'])) {
-		$func = "tem_auto_" . $tag['args'][0];
-		if(function_exists($func)) $value = $func($tag, $context, $keychain);
-		else die("ERROR: template auto function '$func' not found.<br>\n");
-	} else $value = tem_get($tag['name'], $context);
-
-	return tem_value_as_rows($value);
-}
-
-# Return the value for a tag as an encoded string.
-function tem_get_enc($tag, $context)
-{
-	$key = $tag['name'];
-	$value = tem_get($key, $context);
-	foreach($tag['args'] as $encoding) {
-		$func = "enc_$encoding";
-		if(function_exists($func)) $value = $func($value, $key);
-		else die("ERROR: encoder function '$func' not found.<br>\n");
-	}
-	return $value;
-}
-
-function top_sub_templates($tem) {
-	$subs = array();
-	foreach($tem['pieces'] as $piece) {
-		if(is_array($piece) and $piece['pieces']) {
-		   	$subs[$piece['name']] = $piece;
-		}
-	}
-	return $subs;
+	return tem_data_as_rows($rows);
 }
 
 ?>