路由和视图原理与实现

路由原理与实现

主流路由解决方案：pathinfo

<?php
require __DIR__ . '/../helper.php';
//路由
//!方案一,主流路由解决方案：pathinfo
$url = 'http://php.edu/0507/router/demo2.php?c=user&a=hello&id=20&name=liyufeng';
p(pathinfo($url));
//显示如下：
// Array
// (
//     [dirname] => http://php.edu/0507/router
//     [basename] => demo2.php?c=user&a=hello&id=20&name=liyufeng
//     [extension] => php?c=user&a=hello&id=20&name=liyufeng
//     [filename] => demo2
// )
//!获取查询字符串：键值对：c=user&a=hello
$url = 'http://php.edu/0507/router/demo2.php/one/two/three?c=user&a=hello';
p(pathinfo($url));
// $_SERVER['PATH_INFO']
//获取参数：/one/two/three
// p($_SERVER['PATH_INFO']);
//单入口：index.php?m=模块,例如前台home,后台admin
//模块/控制器/方法
//index.php/module/controller/action
//多入口
// 前台：index.php,不需要模块，/controller/action
// 后台：admin.php,不需要模块，/controller/action
$url = 'http://php.edu/0507/router/demo2.php/admin/user/index';
p($_SERVER['PATH_INFO']);
//explode：把“/admin/user/index”转为数组
p(explode('/',$_SERVER['PATH_INFO']));
//第一种方法：array_filter过滤空数组
// p(array_filter(explode('/',$_SERVER['PATH_INFO'])));
//第一种方法：trim
// p(explode('/', trim($_SERVER['PATH_INFO'],'/')));
$request = explode('/', trim($_SERVER['PATH_INFO'],'/'));
//数组解构:将模块、控制器、方法都解析出来
[$module,$controller,$action] = $request;
//参数解析格式
//按顺序传参
//id = 1
//name = admin
$url = 'http://php.edu/0507/router/demo2.php/admin/user/index/1/admin';
//按键名进行传参
//id = 1
//name = admin
$url = 'http://php.edu/0507/router/demo2.php/admin/user/index/id/1/name/admin/qq';
require __DIR__ . '/User.php';
//调用: admin\User::index()
//1.先获取类名
$className = $module . '\\' . ucfirst($controller);
p($className);
//2.获取参数
$params = array_splice($request,3);
// //按顺序传参处理如下：
// echo call_user_func_array([$className,$action],$params);
//按键名进行传参还需要如下处理
// p($params);
//把索引数组转为关联数组
//array_chunk():分组取出
$arr = array_chunk($params,2);
$result = [];
foreach($arr as $item){
    [$key,$value] = $item;
    $result[$key] = $value;
}
p($result);
//3.过滤空值
$result = array_filter($result);
p($result);
//4.调用
echo call_user_func_array([$className,$action],$result);

视图原理与实现

<?php
namespace phpcn;
class View
{
    //约定：控制器方法的模板，默认控制器为目录名，方法为文件名
    protected $controller;
    protected $action;
    protected $path;
    //模板容器
    protected $data = [];
    //初始化创建模板的路径
    public function __construct($controller,$action,$path='/view/')
    {
        $this->controller = $controller;
        $this->action = $action;
        $this->path = $path;
    }
    //模板赋值
    public function assign($name,$value)
    {
        //$name 是外部变量在模板文件中的变量名
        //$value 模板变量的值
        $this->data[$name] = $value;
    }
    //模板渲染
    public function render($path = '')
    {
        //展开模板变量数组
        extract($this->data);
        if(empty($path)){
            //生成路径
            $file = __DIR__ . $this->path . $this->controller . '/' . $this->action . '.php';
        }else{
            $file = $path;
        }
        //加载
        // include $file or die('视图不存在');
        file_exists($file) ? include $file : die('视图不存在');
    }
}
//调用
$controller = 'User';
$action = 'hello';
$view = new View($controller,$action);
//模板赋值：变量
$view->assign('username','李先生');
//模板赋值：数组
$items = [
    ['name'=>'李龙','gongzi'=>5000],
    ['name'=>'刘强','gongzi'=>6000],
    ['name'=>'杨旭','gongzi'=>7000],
];
$view->assign('items',$items);
//渲染模板
$view->render();

数据库操作:增删查改

<?php
namespace phpcn;
use PDO;
class Db
{
    protected $db;
    protected $table;
    protected $field;
    protected $limit;
    protected $opt = [];
    public function __construct($dsn,$username,$password)
    {
        $this->db = new PDO($dsn, $username, $password);
    }
    public function table($table){
        $this->table = $table;
        return $this;
    }
    public function field($field){
        $this->field = $field;
        return $this;
    }
    public function limit($limit = 10){
        $this->limit = $limit;
        $this->opt['limit'] = " LIMIT $limit";
        return $this;
    }
    public function page($page = 1)
    {
        //偏移量：offset = (page - 1) * limit
        $this->opt['offset'] = ' OFFSET ' . ($page - 1) * $this->limit;
        return $this;
    }
    //查询条件
    public function where($where = '')
    {
        $this->opt['where'] = " WHERE $where";
        return $this;
    }
    //查询
    public function select()
    {
        //拼装sql
        $sql = 'SELECT ' . $this->field . ' FROM ' . $this->table;
        $sql .= $this->opt['where'] ?? null;
        $sql .= $this->opt['limit'] ?? null;
        $sql .= $this->opt['offset'] ?? null;
        echo $sql . '<br>';
        //预处理
        $stmt = $this->db->prepare($sql);
        $stmt->execute();
        //清空条件
        $this->opt['where'] = null;
        return $stmt->fetchAll();
    }
    //插入
    public function insert($data)
    {
        // [a=>1,b=2] => 'a=1,b=2'
        $str ='';
        foreach($data as $key=>$value){
            $str .= $key . '="' . $value . '",';
        }
        $sql = 'INSERT ' . $this->table . ' SET ' . rtrim($str,',');
        echo $sql .'<br>';
        //预处理
        $stmt = $this->db->prepare($sql);
        $stmt->execute();
        //清空条件
        $this->opt['where'] = null;
        return $stmt->rowCount();
    }
    //更新
    public function update($data)
    {
        // [a=>1,b=2] => 'a=1,b=2'
        $str ='';
        foreach($data as $key=>$value){
            $str .= $key . '="' . $value . '",';
        }
        $sql = 'UPDATE ' . $this->table . ' SET ' . rtrim($str,',');
        echo $sql .'<br>';
        //禁止无条件更新
        $sql .= $this->opt['where'] ?? die('禁止无条件更新');
        //预处理
        $stmt = $this->db->prepare($sql);
        $stmt->execute();
        //清空条件
        $this->opt['where'] = null;
        return $stmt->rowCount();
    }
    //删除
    public function delete()
    {
        $sql = 'DELETE FROM ' . $this->table;
        echo $sql .'<br>';
        //禁止无条件更新
        $sql .= $this->opt['where'] ?? die('禁止无条件删除');
        //预处理
        $stmt = $this->db->prepare($sql);
        $stmt->execute();
        //清空条件
        $this->opt['where'] = null;
        return $stmt->rowCount();
    }
}
//测试
//查询
$db = new Db('mysql:dbname=phpedu','root','phpedu');
// $result = $db->table('staff')->field('id,name,email')->select();
// $result = $db->table('staff')
//             ->field('id,name,email')
//             ->where('id > 1')
//             ->limit(2)
//             ->page(2)
//             ->select();
// require __DIR__ . '/helper.php';
// p($result);
//新增
// $n = $db->table('staff')->insert(['name'=>'李先生','sex'=>0,'email'=>'li@qq.com']);
// 打印结果：INSERT staff SET name=李先生,email=li@qq.com,sex=0,
// echo $n > 0 ? '新增成功' . $n . '条<br>' : '新增失败'. $n . '条<br>';
//更新
// $n = $db->table('staff')->where('id = 18')->update(['name'=>'刘女士','sex'=>1]);
// echo $n > 0 ? '更新成功' . $n . '条<br>' : '更新失败'. $n . '条<br>';
//删除
$n = $db->table('staff')->where('id = 14')->delete();
echo $n > 0 ? '删除成功' . $n . '条<br>' : '删除失败'. $n . '条<br>';