smarty/libs/sysplugins/smarty_internal_compile_shared_inheritance.php

<?php
/**
 * Smarty Internal Plugin Compile Shared Inheritance
 * Shared methods for {extends} and {block} tags
 *
 * @package    Smarty
 * @subpackage Compiler
 * @author     Uwe Tews
 */

/**
 * Smarty Internal Plugin Compile Shared Inheritance Class
 *
 * @package    Smarty
 * @subpackage Compiler
 */
class Smarty_Internal_Compile_Shared_Inheritance extends Smarty_Internal_CompileBase
{
    /**
     * Register post compile callback to compile inheritance initialization code
     *
     * @param \Smarty_Internal_TemplateCompilerBase $compiler
     * @param bool|false                            $initChildSequence if true force child template
     */
    public function registerInit(Smarty_Internal_TemplateCompilerBase $compiler, $initChildSequence = false)
    {
        if ($initChildSequence || !isset($compiler->_cache['inheritanceInit'])) {
            $compiler->registerPostCompileCallback(array('Smarty_Internal_Compile_Shared_Inheritance', 'postCompile'),
                                                   array($initChildSequence), 'inheritanceInit', $initChildSequence);

            $compiler->_cache['inheritanceInit'] = true;
        }
    }

    /**
     * Compile inheritance initialization code as prefix
     *
     * @param \Smarty_Internal_TemplateCompilerBase $compiler
     * @param bool|false                            $initChildSequence if true force child template
     */
    static function postCompile(Smarty_Internal_TemplateCompilerBase $compiler, $initChildSequence = false)
    {
        $compiler->prefixCompiledCode .= "<?php \$_smarty_tpl->ext->_inheritance->init(\$_smarty_tpl, " .
            var_export($initChildSequence, true) . ");\n?>\n";
    }
}