concept library in category asp.net
This is an excerpt from Manning's book ASP.NET Core in Action.
With .NET Core alone, it’s possible to build console applications that run cross-platform. Microsoft created ASP.NET Core to be an additional layer on top of console applications, such that converting to a web application involves adding and composing libraries, as shown in figure 1.3.
Figure 1.3. The ASP.NET Core application model. The .NET Core platform provides a base console application model for running command-line apps. Adding a web server library converts this into an ASP.NET Core web app. Additional features, such as configuration and logging, are added by way of additional libraries.
By adding an ASP.NET Core web server to your .NET Core app, your application can run as a web application. ASP.NET Core is composed of many small libraries that you can choose from to provide your application with different features. You’ll rarely need all the libraries available to you and you only add what you need. Some of the libraries are common and will appear in virtually every application you create, such as the ones for reading configuration files or performing logging. Other libraries build on top of these base capabilities to provide application-specific functionality, such as third-party logging-in via Facebook or Google.
Most of the libraries you’ll use in ASP.NET Core can be found on GitHub, in the Microsoft ASP.NET Core organization repositories at https://github.com/aspnet. You can find the core libraries here, such as the Kestrel web server and logging libraries, as well as many more peripheral libraries, such as the third-party authentication libraries.
Each of these platforms uses a slightly different set of APIs (classes and methods) in their BCL. Platforms have a certain number of similar APIs between them in their BCLs, but the intersection is patchy. On top of that, the libraries that make up the BCL of a platform are fundamentally not interoperable. Any source code written for a given set of APIs must be specifically recompiled for each target platform.
PCLs were introduced to make the process of compiling and sharing code between multiple platforms simpler. When creating a library, developers could specify the platforms they wanted to support, and the project would only have access to the set of APIs common among all of them. Each additional platform supported would reduce the API surface to only those APIs available in all the selected platforms, as shown in figure A.2.
Figure A.2. Each additional framework that must be supported by a PCL reduces the APIs available to your application.
To create a PCL library, you’d create a library that targeted a specific PCL profile. This profile contained a precomputed list of APIs known to be available on the associated platforms. That way, you could create one library that you could share across your selected platforms. You could have a single project and a single resulting package—no copy and paste or duplicate projects required.
This is an excerpt from Manning's book ASP.NET AJAX in Action.
As we stated previously, the heart of the client framework is the Microsoft Ajax Library, also known as the core library. The library consists of a set of JavaScript files that can be used independently from the server features. We’ll ease into the core library by explaining the intentions of each of its pieces or layers, beginning with its foundation: the type system.
The Microsoft Ajax Library provides a rich set of tools for managing nearly every aspect of client development. The library isn’t just a simple framework for sending asynchronous requests using the XMLHttpRequest object. Instead, one of its main goals is to bring to the client side many coding patterns familiar to .NET developers. Such .NET flavors include the possibility of exposing multicast events in JavaScript objects and leveraging a component model on the client side. The library also enhances the JavaScript language’s type system and lets you write client code using object-oriented constructs like classes and interfaces. In addition, you can easily access local web services using JavaScript and deal with the ASP.NET application services, such as membership and profile, from the client side. Nonetheless, this is just a taste of the goodies provided by the library.
Ajax— The library isn’t exempt from providing a communication layer for sending asynchronous HTTP requests using the XMLHttpRequest object. Chapter 5 is entirely dedicated to the networking layer.