Take a look at the LoggingAspect class. This interface has one method; the Intercept method:. This method allows us to intercept calls to our objects, e. We can use the invocation parameter to access the invocation context. This context includes information such as the intercepted method arguments, the return value of the method, the method metadata, etc.
We can use it for example to get the method description from the MethodDescriptionAttribute that we used to annotate the GetDocuments method in the FakeDocumentSource class. In the LoggingAspect class, we first collect information about the method itself, such as the method description from the MethodDescription attribute.
Then we collect logging data from the method arguments, and finally invoke the original method. If an exception is thrown, we log the logging data we obtained so far along with the exception itself.
If no exception is thrown, we extract logging data from the return value and record all logging data. Net framework to generate new classes at runtime. For an example on how this can be done, take a look at the example provided by Microsoft in the documentation of the TypeBuilder class.
We can log context information as we did before. There is no difference. CastleDynamicProxy application and the AsLoggable extension method for more details. We have relied on Reflection to extract logging information. Basically, we searched for parameters or properties that are annotated with specific attributes, and then read their values.
This takes more time than directly accessing parameters or properties. The details of this approach is beyond the scope of this article, but we may cover this subject in a future one. Another method for doing AOP is via compile-time weaving. But this time, a post-compilation process starts, searches for these attributes, and adds extra IL code to our methods inside the compiled assemblies to make the aspects work.
One of the popular compile-time AOP tools in. NET is PostSharp. It contains a lot of built-in aspects such as the logging aspect, and can be used to create our own aspect. One thing to note here is that aspects are applied to classes, not objects. As far as I know, there is no easy way to configure aspects to work differently for different instances. Text Template Transformation Toolkit T4 is a template based text generation framework from Microsoft. We can use this tool to generate code at design-time.
Basically, we can create a T4 template that represents an aspect, and then use it to generate many classes that each represent the customized application of that aspect to a specific unit. This is basically the same as AOP via decorators, but now the decorators are generated automatically from a template at design time. AOP allows us to remove code duplication and enhances code readability by moving code related to cross-cutting concerns into a single place where it can be easily maintained.
This article provided some options for doing AOP. It also discussed the challenge posed by context-independence in SOLID code base, and provided a solution for such a challenge. Download the entire source code of this article over here Github. This article has been editorially reviewed by Suprotim Agarwal. C and.
Organized around concepts, this Book aims to provide a concise, yet solid foundation in C and. NET, covering C 6. NET Core, with chapters on the latest. NET Core 3. NET Standard and C 8. Use these concepts to deepen your existing knowledge of C and. NET, to have a solid grasp of the latest in C and.
NET OR to crack your next. NET Interview. Now, next, and beyond: Tracking need-to-know trends at the intersection of business and technology. Few technologies have the potential to change the nature of work and how we live as artificial intelligence AI and machine learning ML.
Game Development Develop 2D and 3D games for the most popular desktops, phones, and consoles. Languages You can write your. Learn about. NET languages. One Platform Your skills, code, and favorite libraries apply anywhere you use. NET can do with these free videos. Watch Now. For the best experience on our site, be sure to turn on Javascript in your browser.
Advance your knowledge in tech. Get all the quality content you'll ever need to stay ahead with a Packt subscription — unlimited. When you visit any website, it may store or retrieve information on your browser,usually in the form of cookies. This information does not usually identify you, but it does help companies to learn how their users are interacting with the site.
We respect your right to privacy, so you can choose not to accept some of these cookies. Choose from the different category headers to find out more and change your default settings. Please note if you have arrived at our site via a cashback website, turning off targeting or performance cookies will mean we cannot verify your transaction with the referrer and you may not receive your cashback.
0コメント