Yii2 - 04配置文件(Application属性)与调试技巧

Yii2的主要配置文件configweb.php:

<?php

$params = require(__DIR__ . "/params.php");

$config = [
    "id" => "basic",
    "basePath" => dirname(__DIR__),
    "bootstrap" => ["log"],
    "components" => [
        "request" => [
            // !!! insert a secret key in the following (if it is empty) - this is required by cookie validation
            "cookieValidationKey" => "aldjaldjaldjaljd",
        ],
        "cache" => [
            "class" => "yiicachingFileCache",
        ],
        "user" => [
            "identityClass" => "appmodelsUser",
            "enableAutoLogin" => true,
        ],
        "errorHandler" => [
            "errorAction" => "site/error",
        ],
        "mailer" => [
            "class" => "yiiswiftmailerMailer",
            // send all mails to a file by default. You have to set
            // "useFileTransport" to false and configure a transport
            // for the mailer to send real emails.
            "useFileTransport" => true,
        ],
        "log" => [
            "traceLevel" => YII_DEBUG ? 3 : 0,
            "targets" => [
                [
                    "class" => "yiilogFileTarget",
                    "levels" => ["error", "warning"],
                ],
            ],
        ],
        "db" => require(__DIR__ . "/db.php"),

        "urlManager" => [
            "enablePrettyUrl" => true,
            "showScriptName" => false,
            "rules" => [
            ],
        ],

    ],
    "params" => $params,
];

if (YII_ENV_DEV) {
    // configuration adjustments for "dev" environment
    $config["bootstrap"][] = "debug";
    $config["modules"]["debug"] = [
        "class" => "yiidebugModule",
    ];

    $config["bootstrap"][] = "gii";
    $config["modules"]["gii"] = [
        "class" => "yiigiiModule",
    ];
}

return $config;

最后返回的一个数组，数组的key都是Application的属性。
我们到控制器中来访问一下：

    public function actionIndex()
    {
        echo Yii::$app->id,"<br>";
        echo Yii::$app->name,"<br>";
        exit;


        return $this->render("index",["username"=>"张三","age"=>22]);

    }

在入口文件web/index.php 里会加载这个config.php 配置文件，来创建一个Application

#...
$config = require(__DIR__ . "/../config/web.php");

(new yiiwebApplication($config))->run();

助手类Yii，服务于整个框架，提供一些基础方法：记录日志、调试等
Yii:warning()日志文件runtime/logs/app.log
Yii::error()
Yii::info()
Yii:trace(‘调试内容’,’test’)