源码小记 Application 初始化 setBasePath

laravel version : 6.20.44
IDE : VsCode
代码追踪组件 : "barryvdh/laravel-ide-helper": "2.8"

这篇分析图片中的这一行代码

__construct 接收一个参数 $basePath ⌈应用的根路径⌉，相对于 ~/bootstrap/app.php 则是 dirname(__DIR__)

 __DIR__: D:\MyCode\study\laravel\laravel6\bootstrap
 dirname(__DIR__): D:\MyCode\study\laravel\laravel6

回到 __construct 方法，第一行调用 $this->setBasePath($basePath);，为了方便查看，我把这行代码有关的代码单独分离了出来放进伪 class 文件里

<?php
class Path
{
  protected $basePath; //根路径 D:\MyCode\study\laravel\laravel6
  protected $appPath; // The custom application path defined by the developer.
  protected $databasePath; // The custom database path defined by the developer.
  protected $storagePath; // The custom storage path defined by the developer.
  protected $environmentPath;// The custom environment path defined by the developer.

  public function __construct($basePath = null)
  {
    if ($basePath) {
      $this->setBasePath($basePath);
    }
  }

  public function setBasePath($basePath)
  {
    $this->basePath = rtrim($basePath, '\/');

    $this->bindPathsInContainer();

    return $this;
  }

  protected function bindPathsInContainer()
  {
    $this->instance('path', $this->path());
    $this->instance('path.base', $this->basePath());
    $this->instance('path.lang', $this->langPath());
    $this->instance('path.config', $this->configPath());
    $this->instance('path.public', $this->publicPath());
    $this->instance('path.storage', $this->storagePath());
    $this->instance('path.database', $this->databasePath());
    $this->instance('path.resources', $this->resourcePath());
    $this->instance('path.bootstrap', $this->bootstrapPath());
  }

  public function path($path = '')
  {
    $appPath = $this->appPath ?: $this->basePath . DIRECTORY_SEPARATOR . 'app';

    return $appPath . ($path ? DIRECTORY_SEPARATOR . $path : $path);
  }
  public function basePath($path = '')
  {
    return $this->basePath . ($path ? DIRECTORY_SEPARATOR . $path : $path);
  }
  public function langPath()
  {
    return $this->resourcePath() . DIRECTORY_SEPARATOR . 'lang';
  }
  public function configPath($path = '')
  {
    return $this->basePath . DIRECTORY_SEPARATOR . 'config' . ($path ? DIRECTORY_SEPARATOR . $path : $path);
  }
  public function publicPath()
  {
    return $this->basePath . DIRECTORY_SEPARATOR . 'public';
  }
  public function storagePath()
  {
    return $this->storagePath ?: $this->basePath . DIRECTORY_SEPARATOR . 'storage';
  }
  public function databasePath($path = '')
  {
    return ($this->databasePath ?: $this->basePath . DIRECTORY_SEPARATOR . 'database') . ($path ? DIRECTORY_SEPARATOR . $path : $path);
  }
  public function resourcePath($path = '')
  {
    return $this->basePath . DIRECTORY_SEPARATOR . 'resources' . ($path ? DIRECTORY_SEPARATOR . $path : $path);
  }
  public function bootstrapPath($path = '')
  {
    return $this->basePath . DIRECTORY_SEPARATOR . 'bootstrap' . ($path ? DIRECTORY_SEPARATOR . $path : $path);
  }


  public function useAppPath($path)
  {
    $this->appPath = $path;

    $this->instance('path', $path);

    return $this;
  }
  public function useStoragePath($path)
  {
    $this->storagePath = $path;

    $this->instance('path.storage', $path);

    return $this;
  }
  public function useDatabasePath($path)
  {
    $this->databasePath = $path;

    $this->instance('path.database', $path);

    return $this;
  }
  public function useEnvironmentPath($path)
  {
    $this->environmentPath = $path;

    return $this;
  }
}

分析

1. 定义了

$basePath，
$appPath，
$databasePath，
$storagePath，
$environmentPath 五个属性

思考：除了 $basePath，为什么只定义这几个目录的属性，而 resources,config 路径却没有定义属性？我们发现属性的注解写着 The custom，说明这几个目录路径是允许自定义的。

2. 定义了

path($path = '')，
basePath($path = '')，
langPath()，
configPath($path = '')，
publicPath()，
storagePath()，
databasePath($path = '')，
resourcePath($path = '')，
bootstrapPath($path = '')
方法

一般情况下，在 $basePath 基础上拼接成路径，而允许自定义的属性是这样获取的：

有的方法接收 $path='' 参数，有的却没有，不太理解，感觉没什么区别，以至于助手函数 helpers 中对是否接收 $path='' 参数的方法调用都不同:
有 $path='' 参数的：

if (! function_exists('database_path')) {

    function database_path($path = '')
    {
        return app()->databasePath($path);
    }
}

没有 $path='' 参数的：

if (! function_exists('public_path')) {

    function public_path($path = '')
    {
        return app()->make('path.public').($path ? DIRECTORY_SEPARATOR.ltrim($path, DIRECTORY_SEPARATOR) : $path);
    }
}

if (! function_exists('storage_path')) {

    function storage_path($path = '')
    {
        return app('path.storage').($path ? DIRECTORY_SEPARATOR.$path : $path);
    }
}

有点意思，什么写法都有了

3. 将路径通过 instance($abstract, $instance) 放进 $instances 属性，打印 $instances 属性：

array:9 [
  "path" => "D:\MyCode\study\laravel\laravel6\app" //custom
  "path.base" => "D:\MyCode\study\laravel\laravel6"
  "path.lang" => "D:\MyCode\study\laravel\laravel6\resources\lang"
  "path.config" => "D:\MyCode\study\laravel\laravel6\config"
  "path.public" => "D:\MyCode\study\laravel\laravel6\public"
  "path.storage" => "D:\MyCode\study\laravel\laravel6\storage" //custom
  "path.database" => "D:\MyCode\study\laravel\laravel6\database" //custom
  "path.resources" => "D:\MyCode\study\laravel\laravel6\resources"
  "path.bootstrap" => "D:\MyCode\study\laravel\laravel6\bootstrap"
];

4. 定义了

useAppPath($path),
useStoragePath($path),
useDatabasePath($path),
useEnvironmentPath($path),

这四个方法也是对应四个可自定义的属性，在论坛中搜索 useAppPath 发现这篇文章
详解 packagit 用了什么黑魔法，并可完全替换 artisan 命令

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