CodeIgniter

CodeIgniter\n\nCodeIgniter 是轻量级 PHP MVC 框架，由 EllisLab 于 2006 年创建，现由 BCIT 维护。它以极小的内存占用（~1.2MB）和出色的性能著称，几乎零配置即可运行。\n\n### 核心特性\n\n- 超轻量：下载仅 ~1.2MB，无强制 CLI 依赖\n- 出色性能：基准测试表现优异\n- 简洁 MVC：松散的 MVC 模式，可按需使用\n- 零配置：几乎开箱即用，极少配置文件\n- 丰富类库：Email、Session、Cache、Upload 等\n- 查询构建器：安全直观的数据库操作\n- 表单验证：内置强大的验证库\n- CodeIgniter 4：完全重写的现代化版本

1. 环境准备

• OS：Linux / macOS / Windows
• PHP：>= 7.4（CI3），>= 8.1（CI4）
• PHP 扩展：intl, mbstring, json, mysqlnd（数据库可选）
• Composer：最新稳定版（CI4）或手动下载（CI3）
• 数据库：MySQL 5.1+ / PostgreSQL / SQLite3

2. 安装命令

CodeIgniter 4（推荐）

# 通过 Composer
composer create-project codeigniter4/appstarter my-app

# 或手动下载
wget https://github.com/codeigniter4/CodeIgniter4/archive/refs/tags/v4.4.5.zip
unzip v4.4.5.zip

CodeIgniter 3

# 手动下载
wget https://github.com/bcit-ci/CodeIgniter/archive/refs/tags/3.1.13.zip
unzip 3.1.13.zip

启动开发服务器

cd my-app
php spark serve
# 访问 http://localhost:8080

3. 常见安装问题

CI4 环境文件

# 开发模式下复制 .env
cp env .env
# 设置为 development 模式
# CI_ENVIRONMENT = development

# 生成密钥
php spark key:generate

目录权限

chmod -R 775 writable/

"No input file specified"

确保 public/.htaccess 存在且 mod_rewrite 已启用。

国内镜像

composer config -g repo.packagist composer https://mirrors.aliyun.com/composer/

Hello World：CodeIgniter 4 控制器

目标

创建 CI4 控制器，展示路由定义和 JSON 响应。

完整代码

1. 编辑 app/Controllers/Hello.php

<?php

namespace App\Controllers;

use CodeIgniter\HTTP\ResponseInterface;

class Hello extends BaseController
{
    public function index(): ResponseInterface
    {
        return $this->response->setJSON([
            'message' => 'Hello, Vibe!',
            'framework' => 'CodeIgniter',
            'php_version' => PHP_VERSION,
            'timestamp' => date('c'),
        ]);
    }

    public function greet(string $name): ResponseInterface
    {
        return $this->response->setJSON([
            'message' => "Hello, {$name}!",
            'powered_by' => 'CodeIgniter 4',
        ]);
    }
}

2. 编辑 app/Config/Routes.php

<?php

use CodeIgniter\Router\RouteCollection;

/** @var RouteCollection $routes */
$routes->get('hello', 'Hello::index');
$routes->get('hello/(:segment)', 'Hello::greet/$1');

运行步骤

php spark serve
# 访问 http://localhost:8080/hello

预期输出

curl http://localhost:8080/hello
# {"message":"Hello, Vibe!","framework":"CodeIgniter","php_version":"8.2.0","timestamp":"2024-01-01T00:00:00+00:00"}

curl http://localhost:8080/hello/World
# {"message":"Hello, World!","powered_by":"CodeIgniter 4"}

CodeIgniter 4 入门教程：CRUD 新闻应用

1. 背景

CodeIgniter 以轻量和速度著称。本教程带你构建完整的新闻 CRUD 应用，掌握 CI4 的 MVC 模式、模型、查询构建器和表单。

2. 前置概念

概念	说明
Model	CodeIgniter\Model，内置 CRUD 方法
Entity	实体对象，属性可自动转换类型
Validation	模型内 $validationRules 定义
Routing	自动/手动路由映射

3. 分步操作

步骤一：创建数据库

CREATE TABLE news (
    id INT AUTO_INCREMENT PRIMARY KEY,
    title VARCHAR(255) NOT NULL,
    slug VARCHAR(255) NOT NULL UNIQUE,
    body TEXT NOT NULL,
    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
    updated_at DATETIME DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
);

配置 app/Config/Database.php：

public $default = [
    'DSN'      => '',
    'hostname' => 'localhost',
    'username' => 'root',
    'password' => '',
    'database' => 'codeigniter_demo',
    'DBDriver' => 'MySQLi',
];

步骤二：创建模型

php spark make:model News

编辑 app/Models/NewsModel.php：

<?php

namespace App\Models;

use CodeIgniter\Model;

class NewsModel extends Model
{
    protected $table = 'news';
    protected $primaryKey = 'id';
    protected $useAutoIncrement = true;
    protected $returnType = 'array';
    protected $allowedFields = ['title', 'slug', 'body'];

    protected $useTimestamps = true;
    protected $createdField = 'created_at';
    protected $updatedField = 'updated_at';

    protected $validationRules = [
        'title' => 'required|min_length[3]|max_length[255]',
        'body'  => 'required|min_length[10]',
    ];
}

步骤三：创建控制器

php spark make:controller News

<?php

namespace App\Controllers;

use App\Models\NewsModel;
use CodeIgniter\HTTP\ResponseInterface;

class News extends BaseController
{
    public function index(): string
    {
        $model = new NewsModel();
        $data['news'] = $model->orderBy('id', 'DESC')->findAll();
        return view('news/index', $data);
    }

    public function create(): string
    {
        return view('news/create');
    }

    public function store(): ResponseInterface
    {
        $model = new NewsModel();

        $data = [
            'title' => $this->request->getPost('title'),
            'slug'  => url_title($this->request->getPost('title'), '-', true),
            'body'  => $this->request->getPost('body'),
        ];

        if ($model->insert($data)) {
            return redirect()->to('/news')->with('success', 'News created!');
        }

        return redirect()->back()->withInput()->with('errors', $model->errors());
    }

    public function edit(int $id): string
    {
        $model = new NewsModel();
        $data['news'] = $model->find($id);
        return view('news/edit', $data);
    }

    public function update(int $id): ResponseInterface
    {
        $model = new NewsModel();

        $data = [
            'title' => $this->request->getPost('title'),
            'body'  => $this->request->getPost('body'),
        ];

        $model->update($id, $data);
        return redirect()->to('/news')->with('success', 'Updated!');
    }

    public function delete(int $id): ResponseInterface
    {
        (new NewsModel())->delete($id);
        return redirect()->to('/news')->with('success', 'Deleted!');
    }
}

步骤四：路由

app/Config/Routes.php：

$routes->get('news', 'News::index');
$routes->get('news/create', 'News::create');
$routes->post('news', 'News::store');
$routes->get('news/edit/(:num)', 'News::edit/$1');
$routes->post('news/(:num)', 'News::update/$1');
$routes->get('news/delete/(:num)', 'News::delete/$1');

4. 验证

php spark serve

curl -X POST http://localhost:8080/news \
  -d "title=CI4 News&body=CodeIgniter 4 is amazing!"

curl http://localhost:8080/news

5. 思考题

1. 如何使用 Entity 类为 News 添加 getExcerpt() 方法？
2. 如何启用 CI4 的自动路由简化路由定义？
3. 如何为 News 添加分页功能？