Laravel 5.1 defer service provider until another is loaded - laravel

I'm using the FormBuilder in Laravel 5.1. The HtmlServiceProvider states the Html and Form facades should defer loading until they are actually needed, which is fine.
However, I have created a FormServiceProvider which registers several macros that I will use in my views. This provider doesn't run any bindings, it simply records a few macros within the FormBuilder class.
However, by storing these macros using the boot method on my own service provider, it's loading the Form binding instantly (making the deferred loading pointless).
Question
Is there any way to defer the boot method in one service provider until another service provider has binded facades?
OR, is there a way to listen for specific binding (or aliasing) events, then manually run a service provider?

you can listen when container resolves object of any type or when container resolves objects of type XXX as below,
$this->app->resolving(function ($object, $app) {
// Called when container resolves object of any type...
});
$this->app->resolving(FooBar::class, function (FooBar $fooBar, $app) {
// Called when container resolves objects of type "FooBar"...
});
here is the DOC

You should refer here.
your service provider should provide Form:class and Html::class.

Related

MediatR Autofac Handler registration in Container

I'm running into an issue in my first IMediatR, Autofac MVC project. Help is much appreciated.. Thanks in advance !!!
Handler was not found for request of type
SliceProject.Services.Query.GetUserListQuery. Container or service
locator not configured properly or handlers not registered with your
container.
Autofac Container Code:
builder
.RegisterAssemblyTypes(typeof(IRequest<>).Assembly)
.Where(t => t.IsClosedTypeOf(typeof(IRequest<>)))
.AsImplementedInterfaces();
builder
.RegisterAssemblyTypes(typeof(IRequestHandler<,>).Assembly)
.Where(t => t.IsClosedTypeOf(typeof(IRequestHandler<,>)))
.AsImplementedInterfaces();
That's because you're telling Autofac to look in the assembly that contains the IRequestHandler<TRequest, TResponse> type. That type lives in the MediatR assembly, so there's no chance your handlers live in that assembly.
You have to chance the registration so it look in the assembly(ies) where your handlers are defined. If they're all defined in one single assembly, pick one handler and use it as a marker type. I tried to guess the name of one of your handlers here:
builder
.RegisterAssemblyTypes(typeof(GetUserListQueryHandler).Assembly)
.Where(t => t.IsClosedTypeOf(typeof(IRequestHandler<,>)))
.AsImplementedInterfaces();
Please also note that the registration can be made simpler with a funciton provided by Autofac, AsClosedTypesOf. It does exactly the same thing.
builder
.RegisterAssemblyTypes(typeof(GetUserListQueryHandler).Assembly)
.AsClosedTypesOf(typeof(IRequestHandler<,>)));
Finally, and this is a bit unrelated, but why do you try to register your requests in the container? Requests are usually created by custom code and not resolved from the container. In your case, it also has no effect since you made the same mistake as for handlers, that is looking for requests in the MediatR assembly, which doesn't contain any implementations of IRequest<TResponse>.

Laravel 5 binding other object to contracts

I started using Laravel 5 and tried to learn things about contracts but i still have some questions about them.
For example I want to alter the Illuminate\Contracts\Auth\PasswordBroker contract (used in App\Http\Controllers\Auth\PasswordController )
The contract is an Interface but somehow Laravel knows what implementation belongs to that contract..
I want to change the implementation to my custom one.
But what is the correct way of loading my custom PasswordBroker class?
Should i bind my custom class in the AppServiceProvider?
$this->app->bind(
'Illuminate\Contracts\Auth\PasswordBroker',
'App\Services\MyPasswordBroker'
);
Where does Laravel itself bind the default implementations?
It's in 'Illuminate/Foundation/Application.php'
'auth.password' => ['Illuminate\Auth\Passwords\PasswordBroker', 'Illuminate\Contracts\Auth\PasswordBroker'],
Can I just overwrite the default bindings?
According to the official documentations: Yes.
You can easily extend and override this class within your own application by overriding this binding.
But remember to replace the original service provider in the config/app.php
Note that this class extends the HashServiceProvider, not the default ServiceProvider base class. Once you have extended the service provider, swap out the HashServiceProvider in your config/app.php configuration file with the name of your extended provider.
Your case
So, in your case, you need to extend the 'Illuminate\Auth\Passwords\PasswordResetServiceProvider' to remain other things happened in the service provider.
Take a look at the default service provider.
Let me know if you have other questions.

Laravel 4 - when to use service providers?

I tried to google it but did not find detailed information.
Service providers are a great way to group related IoC registrations
in a single location. Think of them as a way to bootstrap components
in your application.
Not understanding from the documentation. Is this only needed when I create packages? So when I am regular developer and not making some packages to release in public - I don't need to care?
One of the keys to building a well architected Laravel application is
learning to use serviceproviders as an organizational tool. When you are
registering many classes with the IoC container, all of those bindings
can start to clutter your app/start files. Instead of doing container
registrations in those files, create serviceproviders that register
related services.
So, this is a way to organize your application's services in one place to keep it more organized. A service provider must have at least one method: register. The register method is where the provider binds classes to the container. When a request enters your application and the framework is booting up, the register method is called on the providers listed in your configuration file
'providers' => array(
'Illuminate\Foundation\Providers\ArtisanServiceProvider',
'Illuminate\Auth\AuthServiceProvider',
'Illuminate\Cache\CacheServiceProvider',
// more ...
'Illuminate\Html\HtmlServiceProvider',
// more ...
)
This is providers array in app.php config file and this is the HtmlServiceProvider stored in 'Illuminate\Html\HtmlServiceProvider.php'
use Illuminate\Support\ServiceProvider;
class HtmlServiceProvider extends ServiceProvider {
//...
public function register()
{
$this->registerHtmlBuilder();
$this->registerFormBuilder();
}
protected function registerHtmlBuilder()
{
$this->app['html'] = $this->app->share(function($app)
{
return new HtmlBuilder($app['url']);
});
}
protected function registerFormBuilder()
{
$this->app['form'] = $this->app->share(function($app)
{
$form = new FormBuilder($app['html'], $app['url'], $app['session']->getToken());
return $form->setSessionStore($app['session']);
});
}
}
When, Laravel boots up, it calls this (register) method and in this method there are two lines, these line calls two methods, registerHtmlBuilder() and registerFormBuilder(), these both methods components to the IoC container using
$this->app['html'] = $this->app->share(...);
$this->app['form'] = $this->app->share(...);
In this case both are anonymous functions which returns an instance of html/form class and that's why, when you use
Html::link(...);
Or, using form
Form::input(...);
You get the bound class from the $app object which is available to your application. In this case 'Html' => 'Illuminate\Support\Facades\Html', is used to alias the main class in the aliases array in the app.php file.
So, in Laravel, service providers are a way to organize things in a nice cleaner way, during the boot up process of your application, Laravel runs all register methods from all the service providers so each component become available (bound) to the IoC container so you can access them in your application.
It's worth mentioning that, after calling of all register methods from service providers all the boot methods from those service providers get called. In that case, if you need to use any service from the application (IoC/Service Container) within the service provider class then you should use that service from the boot method since it's not guranteed that any service is avaiable during the registeration of service providers (within register method) because services are registered through register method of each service provider but within the boot method you may use any service because by then every service is hopefully registered.
Check this answer Laravel 4 : How are Facades resolved? too, it may help you to understand.
There's nothing a service provider can do that you can't just slap into app/start/global.php, but with a service provider you gather all the logic in one place and can develop application in a more modular fashion.
If you're making a package a service provider is pretty much a must.
In Laravel, service providers are directly related to the way in which IoC container works. They allow easier and more modular approach to dependencies. In fact, it is a great pattern for organizing your code in a bootstrap fashion ( even outside of Laravel ). I think If you are regular developer you still need to know the basics of Laravel service providers, because that pattern is integral part of Laravel architecture. I am sure it can make your work easier.
For example, when installing a package, your have to give application access to that package - one of the best solution is through service providers list and a facade. On the other hand, I can't imagine being a Laravel developer without knowing basics of SP-s.

Webapi DefaultHttpControllerSelector does not properly resolve my controller

I have an WebApi application that contains some controllers (they are registered using the extension method RegisterApiControllers). This application references another assembly that contains other controllers that I don't want to expose(I have checked that they are not registered in the container). It happens that both have an OrderController, and when I try to access the /api/Order url, I get an exception "Multiple types were found that match the controller named 'order'." and the stack trace shows that I was in DefaultHttpControllerSelector.
I have seen that AutofacControllerFactory used to exist and there was even a ConfigureWebApi that registered it, but it is not anymore present in the default branch.(you can see it here http://alexmg.com/post/2012/03/09/Autofac-ASPNET-Web-API-(Beta)-Integration.aspx)
It seems also that we can not filter the namespace of the route definition in WebApi (it is possible to MVC).
So any idea on how I can use only the Controller registered in my Autofac container and not use the DefaultHttpControllerSelector that seems to scan all referenced assemblies to discover controller?
Thanks
The problem is that registering the controller with autofac is not really related to the routing process. Only once the routing process has identified which controller to dispatch to will Autofac be called to resolve the type.
It looks like, from digging around in the source, that you would need to write a replacement IHttpControllerSelector in order to handle two controllers with the same name. (which really sucks BTW).
You might be able replace the DefaultHttpControllerTypeResolver with an instance that is passed a predicate that filters out the controllers from the assembly that you want to ignore. It's a bit of a kludgy solution but might work.
Actually, you might be able to replace the DefaultHttpControllerTypeResolver completely with one that is based on registrations in your Autofac container. It is a very simple interface, so as long as Autofac have a some kind of discovery mechanism, you should be golden.
public interface IHttpControllerTypeResolver
{
ICollection<Type> GetControllerTypes(IAssembliesResolver assembliesResolver);
}

Regarding Symfony2 Session

In symfony2 every user created controller extends Controller Class as shown below,
class MyController extends Controller {
thus functions related to session handling are available with $this object, But controllers in Vendor and Core don't extend Controller class thus don't provide access to session related functions. So is there any way to use these functions without extending Controller class.
Presently I am using $_SESSION[], for setting and getting session variables.
Is there any way other than above.
Symfony2 provides a service for sessions, this is what you're trying to retrieve. All services in symfony2 are retrieved using the service container, which is what you're referring to with
$this->get('session');
To properly make use of the service container in your own controllers you can either...
Configure your controllers as services (see: here)
Extend the base Controller class provided by the Symfony2 stack (making the get() method available to your child Controller)
The first option is the correct way to go, you have full control over what services are then injected into your respective controllers (see service container documentation)

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