组件开发是 Laravel 扩展功能的主要方式，从操作日期的 Carbon，到类似 Behat 这种完整的测试框架，组件可以是任何形式的。
当然，有许多不同类型的组件，有些组件是独立的，意味着它们可以跟任何框架一起使用，而不仅是 Laravel。Carbon 和 Behat 都是独立组件的例子，所有这些组件，只需要将其依赖加入你的 composer.json 文件就可以在 Laravel 中使用。
另一方面，其它一些组件是专门为了在 Laravel 中使用而开发的，这些组件可能包含路由，控制器，视图和配置，是专门为了增加 Laravel 程序而开发的，这份指南主要涵盖这一类组件的开发内容。
服务提供者是 Laravel 和组件的连接点，服务提供者负责将组件绑定到 Laravel 的服务容器中且告知 Laravel 如何加组件的资源，如视图，配置和本地化语言文件。
一个服务提供者继承于 Illuminate\Support\ServiceProvider 类且包含两个方法： register 和 boot，基础类 ServiceProvider 位于 illuminate/support Composer 组件中，你需要将此组件的依赖加入你自己的包依赖中。
要了解更多关于服务提供者的结构与用途，请查看相关文档。
为组件定义路由，你只需在组件服务提供者的 boot 方法中 require 相关的路由配置文件即可，在路由配置文件中，你可以使用 Route facade，和在一般 Laravel 应用程序中一样来注册路由。
/**
* Perform post-registration booting of services.
*
* @return void
*/
public function boot()
{
if (! $this->app->routesAreCached()) {
require __DIR__.'/../../routes.php';
}
}
要将你的组件中的视图注册到 Laravel 中，你需要告诉 Laravel 视图的位置，你可以使用服务容器的 loadViewsFrom 方法来加载视图，这个方法接受两个参数：指向视图模板的路径和你的组件名，例如，如果你的包名是「courier」，将以下代码添加到你的服提供者的 boot 方法中：
/**
* Perform post-registration booting of services.
*
* @return void
*/
public function boot()
{
$this->loadViewsFrom(__DIR__.'/path/to/views', 'courier');
}
组件视图的引用使用的是双冒号 package::view 语法，所以你可以像这样从 courier 组件中加截 admin 视图：
Route::get('admin', function () {
return view('courier::admin');
});
当你使用 loadViewsFrom 方法时，Laravel 实际上为你的视图注册了两个位置：
When you use the loadViewsFrom method, Laravel actually registers two locations for your views: one in the application's resources/views/vendor directory and one in the directory you specify. So, using our courier example: when requesting a package view, Laravel will first check if a custom version of the view has been provided by the developer in resources/views/vendor/courier. Then, if the view has not been customized, Laravel will search the package view directory you specified in your call to loadViewsFrom. This makes it easy for end-users to customize / override your package's views.
If you would like to make your views available for publishing to the application's resources/views/vendor directory, you may use the service provider's publishes method. The publishes method accepts an array of package view paths and their corresponding publish locations.
/**
* Perform post-registration booting of services.
*
* @return void
*/
public function boot()
{
$this->loadViewsFrom(__DIR__.'/path/to/views', 'courier');
$this->publishes([
__DIR__.'/path/to/views' => base_path('resources/views/vendor/courier'),
]);
}
Now, when users of your package execute Laravel's vendor:publish Artisan command, your views package's will be copied to the specified location.
If your package contains translation files, you may use the loadTranslationsFrom method to inform Laravel how to load them. For example, if your package is named "courier", you should add the following to your service provider's boot method:
/**
* Perform post-registration booting of services.
*
* @return void
*/
public function boot()
{
$this->loadTranslationsFrom(__DIR__.'/path/to/translations', 'courier');
}
Package translations are referenced using a double-colon package::file.line syntax. So, you may load the courier package's welcome line from the messages file like so:
echo trans('courier::messages.welcome');
Typically, you will want to publish your package's configuration file to the application's own config directory. This will allow users of your package to easily override your default configuration options. To publish a configuration file, just use the publishes method from the boot method of your service provider:
/**
* Perform post-registration booting of services.
*
* @return void
*/
public function boot()
{
$this->publishes([
__DIR__.'/path/to/config/courier.php' => config_path('courier.php'),
]);
}
Now, when users of your package execute Laravel's vendor:publish command, your file will be copied to the specified location. Of course, once your configuration has been published, it can be accessed like any other configuration file:
$value = config('courier.option');
You may also choose to merge your own package configuration file with the application's copy. This allows your users to include only the options they actually want to override in the published copy of the configuration. To merge the configurations, use the mergeConfigFrom method within your service provider's register method:
/**
* Register bindings in the container.
*
* @return void
*/
public function register()
{
$this->mergeConfigFrom(
__DIR__.'/path/to/config/courier.php', 'courier'
);
}
Your packages may have assets such as JavaScript, CSS, and images. To publish these assets to the application's public directory, use the service provider's publishes method. In this example, we will also add a public asset group tag, which may be used to publish groups of related assets:
/**
* Perform post-registration booting of services.
*
* @return void
*/
public function boot()
{
$this->publishes([
__DIR__.'/path/to/assets' => public_path('vendor/courier'),
], 'public');
}
Now, when your package's users execute the vendor:publish command, your assets will be copied to the specified location. Since you typically will need to overwrite the assets every time the package is updated, you may use the --force flag:
php artisan vendor:publish --tag=public --force
If you would like to make sure your public assets are always up-to-date, you can add this command to the post-update-cmd list in your composer.json file.
You may want to publish groups of package assets and resources separately. For instance, you might want your users to be able to publish your package's configuration files without being forced to publish your package's assets at the same time. You may do this by "tagging" them when calling the publishes method. For example, let's define two publish groups in the boot method of a package service provider:
/**
* Perform post-registration booting of services.
*
* @return void
*/
public function boot()
{
$this->publishes([
__DIR__.'/../config/package.php' => config_path('package.php')
], 'config');
$this->publishes([
__DIR__.'/../database/migrations/' => database_path('/migrations')
], 'migrations');
}
Now your users may publish these groups separately by referencing their tag name when using the vendor:publish Artisan command:
php artisan vendor:publish --provider="Vendor\Providers\PackageServiceProvider" --tag="config"