require_once('code/wfpl/misc.php');
-# Public functions
-# ----------------
+# Top-Level Functions
+# -------------------
function template($template, $data) {
return fill_template(parse_template($template), $data);
return parse_template(file_get_contents($filename));
}
-# First we take the template string and convert it into a tree of
-# strings and sub-templates. A template is a hash with a name string,
-# a pieces array, and possibly an args array.
+# We parse the template string into a tree of strings and sub-templates.
+# A template is a hash with a name string, a pieces array, and possibly
+# an args array.
function parse_template($string) {
- # Don't mess with the $stack/$tem assignments! Since
- # PHP references point to the variable, not the data,
- # it really does have to be written exactly like this.
- $stack[] = array('name' => 'root', 'pieces' => array());
- $tem = &last($stack);
+ $tem =& tem_push();
+ $tem['pieces'] = array();
# note: for some reason this captures '<!--' but not '-->'.
$matches = preg_split("/(<!--)?(~[^~]*~)(?(1)-->)/", $string, -1, PREG_SPLIT_DELIM_CAPTURE);
foreach($matches as $match) {
if(last($args) == '{') { # open block
array_pop($args);
- $stack[] = array('name' => $name, 'pieces' => array(), 'args' => $args);
- $tem['pieces'][] = &last($stack);
- $tem = &last($stack);
+ # create a new sub-template
+ # and add it to the parent.
+ $tem =& tem_push($tem);
+ $tem['parent']['pieces'][] =& $tem;
+ $tem['name'] = $name;
+ $tem['pieces'] = array();
+ $tem['args'] = $args;
} elseif(last($args) == '}') { # close block
array_pop($args);
- $cur = $stack[count($stack)-1]['name'];
+ $cur = $tem['name'];
if($name && $name != $cur) {
die("Invalid template: tried to close '$name', but '$cur' is current.");
}
- array_pop($stack); $tem = &last($stack);
+ $tem =& $tem['parent'];
} else { # value slot
$tem['pieces'][] = array('name' => $name, 'args' => $args);
}
return $tem;
}
+function fill_template($template, &$data, &$context = NULL) {
+ if(!$context) {
+ $context =& tem_push($context);
+ $context['data'] =& $data;
+ }
+
+ foreach($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) {
+ $context =& tem_push($context);
+ $context['data'] =& $row;
+ $context['rows'] =& $rows;
+ $output .= fill_template($tem, $row, $context);
+ $context =& $context['parent'];
+
+ }
+ } else { # variable
+ $output .= tem_get_enc($tem, $context);
+ }
+ }
+ return $output;
+}
+
+
+# Implementation
+# --------------
+
+
+# To track our position in the template and in the data, we use a linked
+# stack structure. Each node is a hash with a reference to the parent
+# node along with whatever other data you want to add. For each stack,
+# you simply keep a variable with a reference to the top element. Then
+# the push and pop operations are:
+
+# $top =& tem_push($top);
+# $top =& $top['parent'];
+
+function &tem_push(&$stack = NULL) {
+ static $refs = array();
+
+ # Since a PHP reference is *not* a pointer to data, but a pointer to
+ # a variable (or array slot), we *have* to first put the new node in
+ # $refs, and then reference it from $new.
+
+ $refs[] = array();
+ $new =& $refs[count($refs)-1];
+ if($stack) $new['parent'] =& $stack;
+ return $new;
+}
+
# To fill out a template, we do a depth-first traversal of the template
# tree, replacing all tags with the data values.
}
}
-
-
-# We use dynamic scoping, so we keep a stack of namespaces.
-# Each scope references a hash and the parent scope.
-
-function &tem_scope(&$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.
return array('parent' => $context);
}
-function tem_get($key, $context) {
+function tem_find_value($key, $context) {
$scope = tem_find_scope($key, $context);
if($scope) return $scope['data'][$key];
}
function tem_get_enc($tag, $context)
{
$key = $tag['name'];
- $value = tem_get($key, $context);
+ $value = tem_find_value($key, $context);
foreach($tag['args'] as $encoding) {
$func = "enc_$encoding";
if(function_exists($func)) $value = $func($value, $key);
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 $output;
-}
-
# Return a hash containing the top-level sub-templates of tem.
# else we are on the last row (cursor has hit the end and reset).
}
-# 'once' sections will be shown once unless the corresponding data value
+# 'show' sections will be shown unless the corresponding data value
# is false. We check only for false; 0 or '' will not work.
-function tem_auto_once($key, $context) {
+function tem_auto_show($key, $context) {
if($context['data'][$key] !== false)
return tem_data_as_rows(true);
}