Say you have a view component. You can control which subcomponents it displays for maximum reuse. One day, you end up configuring the available effects, or actions, of the view component. Let’s say it’s something like this, a made-up example: The delete case with its associated value sticks out a bit.
Joe Fabsevich (@mergesort) proposes to call data to configure UI elements “View Data” and keep the objects dumb. From part 1: In my experience, things become harder to maintain when they start becoming a crutch, as a place to put your code if it doesn’t neatly fall into the Model, View, or Controller label.
Criticism targeting MVVM (Model–View–View-Model) from late last year essentially points out it’s not the silver bullet some take it for. Most of the stuff is missing the point. How are you supposed to make sense of it? What’s good advice for your project? I want to raise awareness about the underlying issues that often go undiscussed: the use and limits of patterns like MVVM, and understanding the problems you try to solve with it.
The location of a piece of code always matters. I was fiddling with the Charts library today and found out that if you set a chart’s data to nil, it renders some informative text by default. My data source doesn’t pass nil but an empty array around, though, so I had to convert empty arrays to nil to make use of this feature.
“Using a private function means having a hardwired link to an anonymous collaborator. Over time, this will slowly hurt more.” (@jbrains) I was thinking about this the other day when I wrote tests for a presenter. It receives a date, formats it, and makes the view update a label with the result. Simple. (The real thing actually does a bit more, but that doesn’t matter much.)
Reflecting on a recent change of the Word Counter’s file monitoring module, I think I re-discovered a commonly advised pattern in my code: to separate state from state changes. There’s an object that knows how to handle files based on extension: plain text files’s words are counted differently than Word or Scrivener files. Call it Registry. Previously, this was set up once and didn’t change. Now I wanted to make this configurable so users can add custom plain text extensions. This means changing that object’s state.