Question

我试图在yii2控制器中创建简单的单例。也许我误解了这种模式，但我决定尝试。所以我有一个CRUD。当我在db中获得该类的一个实例并且我决定更新它时，$instance变量为空（null）。是因为在创建实例后重新加载页面，以及为什么我的静态变量再次设置为null？甚至有可能让它像这样，或者我真的，真的在错误的方式？提前谢谢！

<?php

namespace backend\controllers;

use backend\models\DeliveryTime;
use yii\data\ActiveDataProvider;
use Yii;

class DeliveryTimeController extends \yii\web\Controller
{

    public static $instance = null;

    public function actionIndex()
    {
        $delivery = new ActiveDataProvider([
            'query' => DeliveryTime::find()->where('id>0')
        ]);
        return $this->render('index', ['delivery' => $delivery]);
    }

    public static function setInstance()
    {
        if(self::$instance == null){
            self::$instance = new DeliveryTime();
        }
        return self::$instance;
    }

    public static function getInstance(){
        return self::$instance;
    }

    public function actionCreate()
    {
        $delivery = DeliveryTimeController::setInstance();

        if($delivery->load(Yii::$app->request->post()) && $delivery->save()){
            self::$instance = $delivery;
            return $this->redirect(['index']);
        }

        return $this->render('create', ['model' => $delivery]);
    }

    public function actionUpdate()
    {
        $delivery = DeliveryTimeController::getInstance();

        if($delivery->load(Yii::$app->request->post()) && $delivery->save()){
            return $this->render(['index']);
        }
        return $this->render('update', ['model' => $delivery]);
    }

    public function actionDelete(){
        $delivery = DeliveryTimeController::getInstance();
        if($delivery != null){
            $delivery->delete();
            return $this->redirect(['index']);
        }
    }

}

Answer 1

对于设计模式，我建议您查看

https://github.com/kamranahmedse/design-patterns-for-humans
https://github.com/edin/php-design-patterns（我的github repo :)

对于您正在尝试的内容，最好只创建新实例。

Yii2创建简单的单例

1 个答案: