opencart源码解析之 index.php

//访问index.php，安全过滤、加载配置文件、核心启动文件、函数库、类库
//转载请注明: http://blog.csdn.net/dabao1989/article/details/21223585
//new注册表
$registry = new Registry();

//$registry里保存的config是根据当前店店铺(`oc_store`)获取`store_id`,然后到`oc_setting`里取出该店的配置信息，跟配置文件config.php无关
$query = $db->query("SELECT * FROM " . DB_PREFIX . "setting WHERE store_id = '0' OR store_id = '" . (int)$config->get('config_store_id') . "' ORDER BY store_id ASC");
foreach ($query->rows as $setting) {
    if (!$setting['serialized']) {
        $config->set($setting['key'], $setting['value']);
    } else {
        $config->set($setting['key'], unserialize($setting['value']));
    }
}



//依次new核心类，压入$registry,最后几个类需要当前$registry作为参数,new之后再重新压入$registry
$registry->set('customer', new Customer($registry));

//new Front();加载前置Action
$controller = new Front($registry);
$controller->addPreAction(new Action('common/seo_url'));    
$controller->addPreAction(new Action('common/maintenance'));
    
//根据当前URL,加载指定Action,默认加载Action('common/home');
if (isset($request->get['route'])) {
    $action = new Action($request->get['route']);
} else {
    $action = new Action('common/home');
}

//new Action()所进行的操作,根据URL路由，判断是否是一个控制器文件，如果是，break
//保存此控制器文件路径、当前需要执行的方法、参数等，假如方法名为空则要执行的方法名保存为index
function __construct($route, $args = array()) {
        $path = '';

        $parts = explode('/', str_replace('../', '', (string)$route));

        foreach ($parts as $part) { 
                $path .= $part;

                if (is_dir(DIR_APPLICATION . 'controller/' . $path)) {
                        $path .= '/';

                        array_shift($parts);

                        continue;
                }

                if (is_file(DIR_APPLICATION . 'controller/' . str_replace(array('../', '..\', '..'), '', $path) . '.php')) {
                        $this->file = DIR_APPLICATION . 'controller/' . str_replace(array('../', '..\', '..'), '', $path) . '.php';

                        $this->class = 'Controller' . preg_replace('/[^a-zA-Z0-9]/', '', $path);

                        array_shift($parts);

                        break;
                }
        }

        if ($args) {
                $this->args = $args;
        }

        $method = array_shift($parts);

        if ($method) {
                $this->method = $method;
        } else {
                $this->method = 'index';//默认index
        }
}

//Front执行控制器, 先执行之前压入的前置控制器， 然后执行当前请求的控制器， 失败则执行控制器error/not_found
//前置控制器有seo_url,maintenance，后台应该可配置SEO，可能会根据SEO创建新的控制器并返回，覆盖，执行
//Front->dispatch()会调用$this->execute()执行控制器
//execute()内部通过调用is_callable()判断控制器方法是否可以调用，所以可以在子Controller中将index()定义为protected，防止直接调用
//当直接调用时child Controller中的protected方法时，将会转到error/not_found
$controller->dispatch($action, new Action('error/not_found'));
function dispatch($action, $error) {
        $this->error = $error;

        foreach ($this->pre_action as $pre_action) {
                $result = $this->execute($pre_action);

                if ($result) {
                        $action = $result;//重置

                        break;
                }
        }

        while ($action) {
                $action = $this->execute($action);
        }
}
function execute($action) {
        if (file_exists($action->getFile())) {
                require_once($action->getFile());

                $class = $action->getClass();

                $controller = new $class($this->registry);

                if (is_callable(array($controller, $action->getMethod()))) {
                        $action = call_user_func_array(array($controller, $action->getMethod()), $action->getArgs());
                } else {
                        $action = $this->error;//当不可用时，会调用$this->error

                        $this->error = '';
                }
        } else {
                $action = $this->error;

                $this->error = '';
        }

        return $action;
}

//假设执行的控制器是common/home, 没有指定方法， 则执行index()
class ControllerCommonHome extends Controller {
    public function index() {
        $this->document->setTitle($this->config->get('config_title'));
        $this->document->setDescription($this->config->get('config_meta_description'));

        $this->data['heading_title'] = $this->config->get('config_title');
        
        if (file_exists(DIR_TEMPLATE . $this->config->get('config_template') . '/template/common/home.tpl')) {
            $this->template = $this->config->get('config_template') . '/template/common/home.tpl';
        } else {
            $this->template = 'default/template/common/home.tpl';
        }
        
        $this->children = array(
            'common/column_left',
            'common/column_right',
            'common/content_top',
            'common/content_bottom',
            'common/footer',
            'common/header'
        );
                                        
        $this->response->setOutput($this->render());
    }
}

//Controller中的render()方法
//会判断children属性是否赋值,有的话会逐个new child Controller,child Controller仍可以$this->render()，但调用$this->render()必须设定$this->template
//$this->data数组存储的值可在模板中使用
//$this->data[basename[$child]]保存的是子模板，common/home.tpl可以通过调用echo $column_left、$column_right、$content_top、$content_bottom输出
//应注意$this->data数组中的键值不要和子模板名重复！
function render() {
        foreach ($this->children as $child) {
                $this->data[basename($child)] = $this->getChild($child);
        }

        if (file_exists(DIR_TEMPLATE . $this->template)) {
                extract($this->data);//模板中使用

        ob_start();

                require(DIR_TEMPLATE . $this->template);

                $this->output = ob_get_contents();

        ob_end_clean();

                return $this->output;
} else {
                trigger_error('Error: Could not load template ' . DIR_TEMPLATE . $this->template . '!');
                exit();                
}
}

//controller中的getChild()方法
//只有在child Controller中执行了$this->render(),父Controller在$this->data[basename($child)]才能捕获到子模板，否则捕获的是空字符串
//虽然child Controller中的index()被定义为protected, 但是可以被父Controller调用， 因为他们都继承自Controller
function getChild($child, $args = array()) {
        $action = new Action($child, $args);

        if (file_exists($action->getFile())) {
                require_once($action->getFile());

                $class = $action->getClass();

                $controller = new $class($this->registry);

                $controller->{$action->getMethod()}($action->getArgs());

                return $controller->output;
        } else {
                trigger_error('Error: Could not load controller ' . $child . '!');
                exit();                    
        }        
}

//在主Controlle中,this->render()返回的模板需要传送给$this->response->setOutput()才能输出
$this->response->setOutput($this->render());

//Controller中的语言包使用,$this->language保存在$registry中
$this->language->load('common/footer');
$this->data['text_information'] = $this->language->get('text_information');
$this->data['text_service'] = $this->language->get('text_service');

//Controller中session使用,$this->session保存在$registry中
$this->session->data[$key];
$this->session->data[$key] = 'hello';

//Controller中的$this->request数组
$this->get = $_GET;
$this->post = $_POST;
$this->request = $_REQUEST;
$this->cookie = $_COOKIE;
$this->files = $_FILES;
$this->server = $_SERVER;
$this->request->get['route'];//获取方式

//Controller中的$this->response使用
$this->response->setOutput($this->render());
$this->response->setOutput(json_encode($json));
$this->response->addHeader('Content-Type: application/xml');

//Controller中的$this->customer
$this->customer->isLogged();//判断登录状态
$this->customer->logout();//退出操作
$this->customer->login();//登录操作
$this->getId();//获取用户ID,存储在customer表中的customer_id

//Controller中的页面跳转,$url->link()用于生成控制器的链接,如下
$this->redirect($this->url->link('catalog/information', 'token=' . $this->session->data['token'] . $url, 'SSL'));

//Controller中的forward(),用于new 新的控制器，并返回
function forward($route, $args = array()) {
        return new Action($route, $args);
}

//Controller中的模型加载
$this->load->model('catalog/category');
$this->model_catalog_category;//使用格式

//cache使用(原始使用文件缓存)
$this->cache->get($key);
$this->cache->set($key, $value);
$this->cache->delete($key);

//js,css等静态文件加载,通过Document对象加载额外的JS,CSS链接,在common子模板中会自动输出
$registry->document;
$registry->document->addLink($href, $rel);
$registry->addStyle($href, $rel = 'stylesheet', $media = 'screen');
$registry->addScript($script);

//币种


//模型机制
//在index.php创建数据库连接,并保存在$registry,根据DB_DRIVER不同，调用system/database/下指定的数据库引擎
//拥有4个方法：query(),escape(),countAffected(),getLastId()
//当验证外部数据时要用escape()进行安全过滤
$db = new DB(DB_DRIVER, DB_HOSTNAME, DB_USERNAME, DB_PASSWORD, DB_DATABASE);
$registry->set('db', $db);

//数据表解析
//oc_setting 配置
//oc_url_alias 配合apache rewrite，进行商品及分类URL优化