CodeIgniter4 核心类重写(静态文件生成)

CodeIgniter4 基础

官网

https://codeigniter.org.cn/user_guide/database/queries.html

ci4有是轻量、快速和灵活的特点，不过想比较于tp,lavavel和其他框架尚有不足之处，比如参考文档相对较少，社区活跃度等，不过不影响phper使用。

基础安装

你可以从网站手动下载版本,但是对于本教程,我们将使用推荐的方法,通过 Composer 安装 AppStarter 包。 在命令行输入以下命令:

composer create-project codeigniter4/appstarter ci-news

问题集锦

1. 多模版共存时，调用$this->cachePage() 不区分域名，导致页面重复

解决：重写核心类

参考官网：https://codeigniter.org.cn/user_guide/extending/core_classes.html

解析：

• BaseService定义了可以重写的类
  文件路径：vendor\codeigniter4\framework\system\Config\BaseService.php 中的codeigniter 方法
• Config/Service重定义加载自定义类
  文件路径：app\Config\Services.php

添加如下

     public static function codeigniter($config = null, $getShared = true)
     {
         if ($getShared) {
             return static::getSharedInstance('codeigniter');
         }
         return new \App\Libraries\CodeIgniter($config);
     }

• 新建核心类文件
  文件路径：app\Libraries\CodeIgniter.php
  代码如下：

/**
     * Generates the cache name to use for our full-page caching.
     */
    protected function generateCacheName(Cache $config): string
    {
        if ($this->request instanceof CLIRequest) {
            return md5($this->request->getPath());
        }

        $uri = clone $this->request->getUri();

        $query = $config->cacheQueryString
            ? $uri->getQuery(is_array($config->cacheQueryString) ? ['only' => $config->cacheQueryString] : [])
            : '';

        return md5($_SERVER['SERVER_NAME'] . $uri->setFragment('')->setQuery($query));
    }


    /**
     * Determines if a response has been cached for the given URI.
     *
     * @return false|ResponseInterface
     *
     * @throws Exception
     */
    public function displayCache(Cache $config)
    {
        if(isset($_GET['clear']) && $_GET['clear'] == 'true'){
            cache()->delete($this->generateCacheName($config));
        }
        if ($cachedResponse = cache()->get($this->generateCacheName($config))) {
            $cachedResponse = unserialize($cachedResponse);
            if (! is_array($cachedResponse) || ! isset($cachedResponse['output']) || ! isset($cachedResponse['headers'])) {
                throw new Exception('Error unserializing page cache');
            }

            $headers = $cachedResponse['headers'];
            $output  = $cachedResponse['output'];

            // Clear all default headers
            foreach (array_keys($this->response->headers()) as $key) {
                $this->response->removeHeader($key);
            }

            // Set cached headers
            foreach ($headers as $name => $value) {
                $this->response->setHeader($name, $value);
            }

            $this->totalTime = $this->benchmark->getElapsedTime('total_execution');
            $output          = $this->displayPerformanceMetrics($output);
            $this->response->setBody($output);

            return $this->response;
        }

        return false;
    }

generateCacheName 方法中添加$_SERVER[‘SERVER_NAME’]唯一标识

displayCache方法中添加$_GET[‘clear’]，方便前台删除时及时更新。