Why You Should Read the .NET Core Source Code

In the first five years that I was working as a developer I didn’t once bother to read the .NET framework source code. I’m going to go out on a limb and say that this is probably the case for most software developers. We work with the .NET framework and associated tools and libraries every day, but we seldom care about how they really work or what’s contained within. Now, don’t get me wrong, the whole point of a framework is to shield you from having to know the underlying implementation details and knowing the entire framework is not necessary. I would argue though that knowing parts of the framework and how they work opens up opportunities and affords certain benefits.
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Paging in Entity Framework Core

If you’re using Entity Framework Core and building any non-trivial enterprise application then using data tables with paging is almost a certainty. There are two ways to do this: server side and client side. Which one you choose depends on your design and your needs. There are pros and cons associated with both so you need to choose the correct approach for what you want to accomplish. Continue reading “Paging in Entity Framework Core”

Query Filters and Automated Audit Columns

I wanted to write a quick post about using query filters and automatically populating audit columns in Entity Framework Core since I see a lot of people doing this manually still. A common scenario in most applications is to do soft deletes on everything, typically with a column like “IsDeleted”. Another common scenario that is found almost universally in every system are audit columns like “DateCreated” and “DateUpdated”. This is actually very simple to implement, so this is going to be a fairly short post.
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Maximizing Entity Framework Core Query Performance

Entity Framework Core query performance is something that comes up often when working on projects that rely on it heavily. I have often heard that Entity Framework is not performant enough which then leads to everything being written as a stored procedure. Usually this happens for two main reasons: developers aren’t familiar with how to write queries in a performant manner and developers that are more comfortable with SQL want to develop everything in their technology of choice. Entity Framework is not a silver bullet for everything. There are times when it simply can’t deliver the performance needed or when it is simply functionally incapable of doing what is necessary due to limitations of the framework. That being said, there is no reason you can’t write the vast majority of your application with it and reap all the benefits it provides.
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IdentityServer4 in ASP.NET Core Part 1

If you’ve worked with APIs at all in .NET Core then you have probably had the need to work with tokens for security. You could roll your own set up just using the underlying functionality in ASP.NET Identity, or you could enable easy mode and use something like IdentityServer4. There are other options out there for you to choose from, but this post will focus on IdentityServer4. Our application is going to consist of an API, a web application for IdentityServer4 and a Javascript based client. The source code for this post can be found here.
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Think Before You Use The DTO Pattern

Let me preface this blog post by saying that there are still times when a DTO makes sense. Also, this post is written from a .NET perspective, so some things may be different on your platform. What I want to address though is the tendency of many developers to just automatically create a set of DTOs for each layer for each domain model. As I mentioned in other blog posts, you should always think about why you are doing something before you are doing it. Continue reading “Think Before You Use The DTO Pattern”

Dealing with Validation – Domain vs Contextual

I’ve always found validation to be one of the most difficult and tedious aspects of writing enterprise software. No matter how you organize your rules, you are going to usually end up with duplication. To make matters worse, the rules aren’t written by developers, they are created by the business. This causes a disconnect between knowledge and domain experts, and the people who are implementing the validation in the code. As the rules change over time, and as the developers who originally worked on the system move on, the validation becomes increasingly difficult to manage. As the system matures, it ultimately ends up becoming a significant source of pain for all those involved. That’s assuming, of course, that you even have validation in the first place.
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