The parameter action is a Lambda function, which can be used to provide extra configurations to the service.
Working with Options pattern in ASP.NET Core - The Complete Guide
In this blog post, we will create a similar service, MyService, that can be registered to the Dependency Injection DI container by calling the services. We will pass options to MyService so that this service can be more flexible with extra parameters at runtime.
We will also take a look at the unit testing for MyService with its options. The complete solution is located at this GitHub repository. NET Core link.
This options pattern covers a variety of topics about the configurations in ASP. The options pattern allows our application to follow two important software engineering principles: the Interface Segregation Principle ISP and Separation of Concerns. We use named options to decouple different configuration settings, so that services classes only depend on the specific configuration settings that they use.
Andrew Lock | .NET Escapades
In this blog post, I will not repeat the same things in the Microsoft Docs article. The settings could have one or more properties, so that we can use a class, MyServiceOptions, to represent the settings.
This type of settings are called named options. We need to install a NuGet package, Microsoft. Optionsto utilize and configure named options. Assuming the service MyService needs three configuration variables, we then write the MyServiceOptions class as follows. Then we can inject the named options to any classes or Razor views in the DI container.
Options pattern in ASP.NET Core
Thanks to the named options, we can use the strongly typed options value to assess all properties in the Options pattern object. Also, we can set up some validations or arrange fallback values if needed.
NET Core which brings up an aggregate of appsettings json file along with several other providers, is simple and useful. However, As the application grows in complexity, so does configuration in most cases: new configurations and sections add up to the size of the appsettings making individual values from the appsettings hard to access. ToString ; As the configuration structure goes diverse with nested sections, its key representation grows lengthy and hard to maintain. In a previous article, we tried to solve this by creating a strongly typed ConfigurationManager class which encapsulates this key access mechanism and also takes care of the datatype casting requirements options pattern non-string properties. An even elegant solution for this is to "configure" these sections against their matching strongly typed classes and let ASP.
Create a ServiceCollection extension method Now, we have the service and options ready. The next thing is to create an extension method to show the services. AddMyService magic.
- Short options reviews
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- NET Core Take advantage of the options pattern to load configuration data directly into your classes at runtime for simple and flexible configuration data management qimono CC0 When working in ASP.
- Options pattern in .NET | Microsoft Docs
The following code snippet shows an example extension method AddMyService. In line 13, the delegate is registered to the service collection, and the options will have a Singleton lifestyle in the DI container. If there are other dependencies in the MyService class, we can add them to the DI container within this extension method as options pattern.
Be careful though, if you want to register some common dependencies that other users might register again in another project, then it would be better to use the serviceCollection. In this way, we can avoid name collisions for common dependencies. Usages Now we can register IMyService and its options in the ConfigureServices method like the following code snippet. In this way, all MyService related stuff is kept in one code block, which is easy to read and manage.
Why the Options Pattern? The options pattern gives us similar possibilities, but it offers a more structured approach and more features like validation, live reloading, and easier testing. The options pattern also provides a good validation mechanism that uses the widely used DataAnotations attributes to check if the configuration abides by the logical rules of our application. The testing of options is also easy because of the helper methods and easy to mock options classes. Now we can modify the HomeController to support the options pattern.
We can utilize the static method Options. The following code snippet shows a demo test method. This is all we need to stub an option.
How to use the IOptions pattern for configuration in themainebarkery.com Core RC2
I hope this short blog post can get you started to understand or write more advanced services or libraries. Again, you can find the full solution in my GitHub repository. Thanks for reading.