Separating ReSwift Actions from UI Events

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Today was the second time during the development of TableFlip that I started to implement a new feature in the wrong way: starting with an explicit event type that is triggered by pressing a button in the user interface. This is a 1:1 mapping of user intent to an event that performs changes in the model. Next time I’ll start from another point of view instead to not rush too many minuscule changes until I hit a roadblock and hate myself. Here’s what went wrong.

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Revisiting the Core Data + Domain Model Architecture

It happens that just yesterday I read about architecture smells in code. Among the examples was “subclasses don’t redefine methods”. In my post about Core Data and expressive domains earlier this week, I did just that: create a Egg subclass of CoreDataEgg to inherit CoreDataEgg’s behavior. That’s not what abstraction to superclasses is meant to do.

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How to Create Flexible Components with Two Levels of Service Objects

Again I was reminded about the value of service objects to encapsulate sequences in two places: the Domain, where business rules are kept, and in client code, where database management and transactions play a role. This distinction helps create clean code and deliver flexible components. I am building a feature for the Word Counter in a separate “library” project until everything runs smoothly. Then I’ll integrate the code into the main application. Since I consider this to be some kind of library, I thought I wouldn’t need many service objects, but I was wrong.

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Where Instead of Using Functional Bind, I Create an Expressive Model

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The other day, I wrote a post about bind() and the >>= operator and how it can help chain function calls together. The example was a bit too contrived and making it fit the requirements left us with really bad code. I came up with an even better implementation: use plain Swift objects and express your intent carefully.

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I'm About to Release a Little E-book on Domain-Driven Design and Mac Application Development

I’m adding a file monitoring feature to the Word Counter. This is a huge change to the application’s source code. To tackle this problem with style, I mulled things over for a while and considered my existing application’s design. I wanted to try out a few new things, so it was a no-brainer to start a sample project from scratch and fiddle with it.

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Core Data Violates DDD Principles by Default

I’m working on a way to make the Word Counter watch files and folders on a user’s disk. This will enable to measure project progress. Until now, I always used .plist files to store records with the end in mind that I’m going to switch to a better alternative in the future. Since I’m adding all-new data tracking, I thought I might as well try different solutions now.

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