Installation
============

## Getting Composer package

The preferred way to install this extension is through [composer](http://getcomposer.org/download/).

Either run

```
php composer.phar require --prefer-dist yiisoft/yii2-debug
```

or add

```
"yiisoft/yii2-debug": "~2.0.0"
```

to the require section of your `composer.json` file.


## Configuring application

To enable extension, add these lines to your configuration file to enable the debug module:

```php
'bootstrap' => ['debug'],
'modules' => [
    'debug' => [
        'class' => 'yii\debug\Module',
    ],
]
```

By default, the debug module only works when browsing the website from localhost. If you want to use it on a remote (staging)
server, add the parameter `allowedIPs` to the configuration to whitelist your IP:

```php
'bootstrap' => ['debug'],
'modules' => [
    'debug' => [
        'class' => 'yii\debug\Module',
        'allowedIPs' => ['1.2.3.4', '127.0.0.1', '::1']
    ]
]
```

If you are using `enableStrictParsing` URL manager option, add the following to your `rules`:

```php
'urlManager' => [
    'enableStrictParsing' => true,
    'rules' => [
        // ...
        'debug/<controller>/<action>' => 'debug/<controller>/<action>',
    ],
],
```

> Note: the debugger stores information about each request in the `@runtime/debug` directory. If you have problems using
> the debugger, such as weird error messages when using it, or the toolbar not showing up or not showing any requests, check
> whether the web server has enough permissions to access this directory and the files located inside.


### Extra configuration for logging and profiling

Logging and profiling are simple but powerful tools that may help you to understand the execution flow of both the
framework and the application. These tools are useful for development and production environments alike.

While in a production environment, you should log only significantly important  messages manually, as described in
[logging guide section](https://github.com/yiisoft/yii2/blob/master/docs/guide/runtime-logging.md). It hurts performance too much to continue to log all messages in production.

In a development environment, the more logging the better, and it's especially useful to record the execution trace.

In order to see the trace messages that will help you to understand what happens under the hood of the framework, you
need to set the trace level in the configuration file:

```php
return [
    // ...
    'components' => [
        'log' => [
            'traceLevel' => YII_DEBUG ? 3 : 0, // <-- here
```

By default, the trace level is automatically set to `3` if Yii is running in debug mode, as determined by the presence of
the following line in your `index.php` file:

```php
defined('YII_DEBUG') or define('YII_DEBUG', true);
```

> Note: Make sure to disable debug mode in production environments since it may have a significant and adverse performance
effect. Further, the debug mode may expose sensitive information to end users.