Showing posts from 2018

Review: Rock Your Code: Defensive Programming for Microsoft .NET by David McCarter

I saw a post on Twitter from a guy named David McCarter  promoting his new book.  Rock Your Code: Defensive Programming for Microsoft .NET . I thought the title looked interesting so I bought it. This book (if approximately 50 pages of A5 can count as a book) was packed with bad advice. It is going to be more effort to explain why than the book deserves, but I will do it. TL;DR Source code doesn't compile. When it does, it doesn't do what the author says it does. The author promotes practices long established as poor. Chapter 1: OOP This chapter explains the three pillars of OOP are Encapsulation, Inheritance, and Polymorphism. The author has a tiny 1 or 2 sentence explanation of each. He then goes on to show an example of some poor source code "from a real in production project" (I hope he has permission from the copyright holder). The source code is a single class with lots of public attributes. That's the end of the chapter. Honestly, th

Assigning a piped async result to a variable in an Angular view

If you have an Observable<x> in your component you might find yourself doing something like this {{ ( source$ | async)?.property1 }} {{ ( source$ | async)?.property2 }} This will subscribe to the source$ observable more than once. A commonly used technique to avoid this is to assign the result of the async into a view variable, like so: <ng-container ngif="source$ | async as source">   {{ source?.property1 }}   {{ source?.property2 }} </ng-container> But if you have other UI elements within that ng-container that you want to be displayed whether or not source$ has emitted a value then you might not like the fact that a portion of your UI is excluded until the observable emits a value or when the observable emits a falsey value. If that is the cast, you can try this little trick. <ng-container ngif="(source$ | async) || {} as source">   {{ source.property1 }}   {{ source.property2 }} </ng-container> We utilise *ngIf to a