Laravel:为什么在实例化其提供的类时未调用注册服务提供者?
问题描述:
This is my service provider:
<?php
namespace App\Providers;
use Illuminate\Support\Facades\Config;
use Illuminate\Support\ServiceProvider;
class ESServiceProvider extends ServiceProvider
{
/**
* Bootstrap the application services.
*
* @return void
*/
public function boot()
{
//
}
/**
* Register the application services.
*
* @return void
*/
public function register()
{
$this->app->singleton('\Elastica\Search', function ($app) {
$client = new \Elastica\Client(array(
'host' => env('ES_HOST'),
'port' => env('ES_PORT')));
$search = new \Elastica\Search($client);
$search->addIndex(Config::get('constants.es_index'))->addType(Config::get('constants.es_type'));
return $search;
});
}
}
When injecting instances of \Elastica\Search\
the closure (2nd param to singleton()
) doesn't get called (verified using var_dump()
/ dd()
). The provider is registered correctly - verified as above. Why?
答
The reason, in Laravel 5.4 and above, is that the first param to singleton()
(and similar binding functions) must not have a leading slash. So, changing it to 'Elastica\Search'
fixes the problem. It took me about an hour of debugging to realize this - hopefully this post saves someone this time...
Laravel website post explaining this change: http://laravel-guide.readthedocs.io/en/latest/upgrade/ - search for Binding Classes With Leading Slashes
.