* @author Kornel Lesiński * @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: * * * * *

Links
* Good Place * Bad Place * Other Place *

* * PHPTAL: * * 1. evaluate slots * * * * Good Place
* Bad Place
* Other Place * * slots->links = ob_get_contents(); ob_end_clean(); ? > * * 2. call the macro (here not supported) * * * * * @package PHPTAL * @subpackage Php.attribute.metal * @author Laurent Bedubourg */ 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; } }