Recent articles

Oftentimes when you’re working with Combine, you’ll have publishers that produce a certain output. Sometimes this output is exactly what you need, but often the values that are output by a publisher need to be transformed or manipulated somehow before they are useful to their subscribers. The ability to do this is a huge part […]

So far in my series of posts about Combine, we have focussed on processing values and publishing them. In all of these posts, I used the sink method to subscribe to publishers and to handle their results. Today I would like to show you a different kind of built-in subscriber; assign(to:on:). This subscriber is perfect […]

In Combine, everything is considered a stream of values that are emitted over time. This means that sometimes a publisher can publish many values, and other times it publishes only a single value. And other times it errors and publishes no values at all. When your UI has to respond to changing data, or if […]

When you perform a URL Request in your app, you typically configure the request in your code and when it’s all set up you pass it off to a URLSession data task, and the request should succeed if everything goes as expected. When the request is misconfigured, the server will hopefully return a useful error […]

This post is a short demo of using Swift’s sort() and sort(by:) methods. For a more comprehensive overview of sorting, and some background information on how Swift’s sorting works I recommend you take a look at this updated post The easiest way to sort an Array in Swift is to use the sort method. This […]

In the past two weeks I have introduced you to Combine and I’ve shown you in detail how Publishers and Subscribers work in Combine. This week I want to take a more practical route and explore Combine in a real-world setting. A while ago, I published a post that explained how you can architect and […]

You can use Array’s insert(_:at:) method to insert a new element at the start, or any other arbitrary position of an Array: var array = ["world"] array.insert("hello", at: 0) // array is now ["hello", "world"] Make sure that the position that you pass to the at: argument isn’t larger than the array’s current last index […]

Dates in Swift can be compared to each other. This allows you to check whether one date comes before or after another date: if dateOne > dateTwo { print("dateOne comes after dateTwo") } else if dateOne < dateTwo { print("dateOne comes before dateTwo") } else if dateOne == dateTwo { print("dateOne is equal to dateTwo") […]

As developers, we all get stuck sometimes. When this happens we start searching for solutions on Google, or we ask questions on Stackoverflow, on the Swift forums, the iOS Developers Slack community or other places. Over the past couple of years, I have been actively trying to help people solve problems they were stuck on […]

In my previous post about Combine, I introduced you to Functional Reactive Programming (FRP) and I’ve shown you can subscribe to Combine publishers using the sink(receiveCompletion:receiveValue:) method. I also showed you how you can transform the output of publishers using some of its built-in functions like map and collect. This week I want to focus […]