1 files changed, 148 insertions, 0 deletions
diff --git a/lib/phptal/PHPTAL/Php/Attribute/METAL/FillSlot.php b/lib/phptal/PHPTAL/Php/Attribute/METAL/FillSlot.php
new file mode 100644
index 0000000..2dfda3a
--- /dev/null
+++ b/lib/phptal/PHPTAL/Php/Attribute/METAL/FillSlot.php
@@ -0,0 +1,148 @@
+<?php
+/**
+ * PHPTAL templating engine
+ *
+ * PHP Version 5
+ *
+ * @category HTML
+ * @package  PHPTAL
+ * @author   Laurent Bedubourg <lbedubourg@motion-twin.com>
+ * @author   Kornel Lesiński <kornel@aardvarkmedia.co.uk>
+ * @license  http://www.gnu.org/licenses/lgpl.html GNU Lesser General Public License
+ * @version  SVN: $Id$
+ * @link     http://phptal.org/
+ */
+
+/**
+ *  METAL Specification 1.0
+ *
+ *      argument ::= Name
+ *
+ * Example:
+ *
+ *       <table metal:use-macro="here/doc1/macros/sidebar">
+ *        <tr><th>Links</th></tr>
+ *        <tr><td metal:fill-slot="links">
+ *          <a href="http://www.goodplace.com">Good Place</a><br>
+ *          <a href="http://www.badplace.com">Bad Place</a><br>
+ *          <a href="http://www.otherplace.com">Other Place</a>
+ *        </td></tr>
+ *      </table>
+ *
+ * PHPTAL:
+ *
+ * 1. evaluate slots
+ *
+ * <?php ob_start(); ? >
+ * <td>
+ *   <a href="http://www.goodplace.com">Good Place</a><br>
+ *   <a href="http://www.badplace.com">Bad Place</a><br>
+ *   <a href="http://www.otherplace.com">Other Place</a>
+ * </td>
+ * <?php $tpl->slots->links = ob_get_contents(); ob_end_clean(); ? >
+ *
+ * 2. call the macro (here not supported)
+ *
+ * <?php echo phptal_macro($tpl, 'master_page.html/macros/sidebar'); ? >
+ *
+ *
+ * @package PHPTAL
+ * @subpackage Php.attribute.metal
+ * @author Laurent Bedubourg <lbedubourg@motion-twin.com>
+ */
+class PHPTAL_Php_Attribute_METAL_FillSlot extends PHPTAL_Php_Attribute
+{
+    private static $uid = 0;
+    private $function_name;
+
+    public function before(PHPTAL_Php_CodeWriter $codewriter)
+    {
+        if ($this->shouldUseCallback()) {
+            $function_base_name = 'slot_'.preg_replace('/[^a-z0-9]/', '_', $this->expression).'_'.(self::$uid++);
+            $codewriter->doFunction($function_base_name, 'PHPTAL $_thistpl, PHPTAL $tpl');
+            $this->function_name = $codewriter->getFunctionPrefix().$function_base_name;
+
+            $codewriter->doSetVar('$ctx', '$tpl->getContext()');
+            $codewriter->doInitTranslator();
+        } else {
+            $codewriter->pushCode('ob_start()');
+            $this->function_name = null;
+        }
+    }
+
+    public function after(PHPTAL_Php_CodeWriter $codewriter)
+    {
+        if ($this->function_name !== null) {
+            $codewriter->doEnd();
+            $codewriter->pushCode('$ctx->fillSlotCallback('.$codewriter->str($this->expression).', '.$codewriter->str($this->function_name).', $_thistpl, clone $tpl)');
+        } else {
+            $codewriter->pushCode('$ctx->fillSlot('.$codewriter->str($this->expression).', ob_get_clean())');
+        }
+    }
+
+    // rough guess
+    const CALLBACK_THRESHOLD = 10000;
+
+    /**
+     * inspects contents of the element to decide whether callback makes sense
+     */
+    private function shouldUseCallback()
+    {
+        // since callback is slightly slower than buffering,
+        // use callback only for content that is large to offset speed loss by memory savings
+        return $this->estimateNumberOfBytesOutput($this->phpelement, false) > self::CALLBACK_THRESHOLD;
+    }
+
+    /**
+     * @param bool $is_nested_in_repeat true if any parent element has tal:repeat
+     *
+     * @return rough guess
+     */
+    private function estimateNumberOfBytesOutput(PHPTAL_Dom_Element $element, $is_nested_in_repeat)
+    {
+        // macros don't output anything on their own
+        if ($element->hasAttributeNS('http://xml.zope.org/namespaces/metal', 'define-macro')) {
+            return 0;
+        }
+
+        $estimated_bytes = 2*(3+strlen($element->getQualifiedName()));
+
+        foreach ($element->getAttributeNodes() as $attr) {
+            $estimated_bytes += 4+strlen($attr->getQualifiedName());
+            if ($attr->getReplacedState() === PHPTAL_Dom_Attr::NOT_REPLACED) {
+                $estimated_bytes += strlen($attr->getValueEscaped()); // this is shoddy for replaced attributes
+            }
+        }
+
+        $has_repeat_attr = $element->hasAttributeNS('http://xml.zope.org/namespaces/tal', 'repeat');
+
+        if ($element->hasAttributeNS('http://xml.zope.org/namespaces/tal', 'content') ||
+            $element->hasAttributeNS('http://xml.zope.org/namespaces/tal', 'replace')) {
+            // assume that output in loops is shorter (e.g. table rows) than outside (main content)
+            $estimated_bytes += ($has_repeat_attr || $is_nested_in_repeat) ? 500 : 2000;
+        } else {
+            foreach ($element->childNodes as $node) {
+                if ($node instanceof PHPTAL_Dom_Element) {
+                    $estimated_bytes += $this->estimateNumberOfBytesOutput($node, $has_repeat_attr || $is_nested_in_repeat);
+                } else {
+                    $estimated_bytes += strlen($node->getValueEscaped());
+                }
+            }
+        }
+
+        if ($element->hasAttributeNS('http://xml.zope.org/namespaces/metal', 'use-macro')) {
+            $estimated_bytes += ($has_repeat_attr || $is_nested_in_repeat) ? 500 : 2000;
+        }
+
+        if ($element->hasAttributeNS('http://xml.zope.org/namespaces/tal', 'condition')) {
+            $estimated_bytes /= 2; // naively assuming 50% chance, that works well with if/else pattern
+        }
+
+        if ($element->hasAttributeNS('http://xml.zope.org/namespaces/tal', 'repeat')) {
+            // assume people don't write big nested loops
+            $estimated_bytes *= $is_nested_in_repeat ? 5 : 10;
+        }
+
+        return $estimated_bytes;
+    }
+}