Tagged

Xcode

A collection of 47 posts

iOS

Drag and Drop on iOS using Swift

Hello folks, it's been a while since I wrote my last article. Today we're going to learn how to implement drag and drop feature on iOS using Swift. To see in advance what we're going to achieve by the end of this tutorial, please watch the following video, To summarize

Xcode

Xcode symbolic breakpoints - Break at method call

Today I am going to write about the big advanced debugging feature of LLDB. I am calling it advanced because I myself didn't know about it for a long time. It allows you to add a symbolic breakpoint which will halt the execution at a specific point so that you

iOS

How to get the iOS App Metadata in Swift

Working on a new app could be exciting. However, there are certain things or information which you might want to get as a part of the core feature. One of them is the app metadata. This may contain numerous values - Some of them essential some - not so useful.

Swift

When to weakify

Today I am going to talk about one of the discussion prone topics on iOS platforms. Detecting memory leaks and when to apply weakify. The topic came up while I was recently performing a code review and there were some discussions on whether there is a memory leak or not.

Monty-Hall problem

Implementing Monty-Hall problem

Today, I am going to write about the Monty-Hall problem simulation I ran programmatically. What is this Monty-Hall problem you may ask? According to Wikipedia, The Monty Hall problem is a brain teaser, in the form of a probability puzzle, loosely based on the American television game show Let's Make

Swift

Closure Trick in Swift

Today I learned a closure trick in Swift. Usually when expression is assigned to a variable on left, it is evaluated instantly. For example, let value = complexCalculation() func complexCalculation() -> String { return "Something useful" } In this example, when value is assigned a result of complexCalculation() method, it

MVVM

Comparing VIPER vs. MVVM

Recently I started playing with VIPER architecture. Although I was quite hesitant trying it out, it turns out it's not all that bad as I expected. It'e certainly better than traditional MVC iOS architecture in terms of testability and separation of concerns. However, I found it consistently annoying to have

Apple

Indirect enums - Swift 3.0

Enums are one of my favorite parts in any language. With Swift they've got extra functionality such as adding functions, associated values and Indirect Enums. So what are indirect enums? I have learned enums in other language, but never came across any language which offers similar functionality. At least not

Swift 3.0

Equality and Comparison with custom objects in Swift (Equatable protocol)

Few weeks ago I ran into frustrating problem. I was dealing with custom objects in Swift. (Actually struct with properties). They were being stored in an array. Now, this array was going to undergo frequent activity due to user action such as adding new elements and avoiding duplicates. So while

iOS

Making a crater in UIView with CALayer

Although title sounds horrible, believe me - It's not that bad. This is a trick I learned from StackOverflow post. Although seemingly innocuous, it took me a while to figure out given the view, how to puncture any shape into it. To make it more interesting let's not only add

Swift 3.0

Pass data with iOS Notifications - Swift 3.0

We all have used Notifications on iOS. (I would not call them NSNotifications though, since this post is about Swift 3.0). I used them long ago when I was yet a newcomer. They were easy way to transport information among different parts of program. Although easy, Notifications can have

Swift

Swift - Testing singletons

In this post we will see how you can test swift singletons easily. Disclaimer: I haven't discovered it myself, but I found it a while back on StackOverflow while looking for how to test Swift singletons. So thanks to the anonymous person for the wonderful solution Say, I want to

Swift

Swift testing with protocols

In this post, we shall see how protocols work with unit testing. Say, you have a downloader class DownloadFileClass for fetching network data. It follows the protocol DownloadFileProtocol. The whole class and protocol looks like this. protocol DownloadFileProtocol { func downloadFile(with name: String, completion: (String) -> ()) } class DownloadFileClass { var downloadedFile:

Xcode

Search and Replace in Xcode with Regular Expressions

Recently I ran into problem where I wanted to search a pattern in the Xcode project and replace the found string with another one. In the past I had had  hard time dealing with Regular expressions. This time I decided I was going to learn more about them and if

iOS

Manually scrolling UIScrollView (iOS/Swift)

Recently while working with one of my libraries, I realized that I wanted to manually scroll UIScrollView in any direction. (Viz. Top, Right, Bottom, Left). It took me quite time to find examples online. But I take this moment to compile them together. Since Swift is a hot word in

Swift

iOS - Autolayout and Resizing UILabel (iOS/Swift)

Last week I had weird issue while applying autolayout rules to UITableViewCell. TableViewCell has two components attached to it. An UIImageView Two variable length UILabels stacked vertically on the top of each other And I wanted tableView cells to look like this, Nice, isn't it? Let's look at the way

Objective-C

Thinking MVVM way with Objective-C

Today I am going to write about one of my most favorite iOS patterns lately. MVVM (Model-View-ViewModel). They say MVC has been in iOS realm for quite a bit. However, if you ask me, MVVM is going to be a big. Advantage being, you can create viewModel once and then

Tutorial

Simulate View Controller Transitions - iOS/Objective-C

We all have dealt with push transition of UINavigationController as well as presentViewController and dismissViewController transitions of typical UIViewController. However, today we will learn how to emulate the transition from one viewController to another without moving to a new viewController. The technique is quite simple and I will only explain

iOS

iOS Add spacing to line of text - Swift

This week while working on one of our internal apps (Again), I came across an interesting problem to add spacing to line labels. I never knew iOS could do it. My first and very naive solution was to have multiple UILabels and arrange them vertically. But this would cause a

iOS

Add image to UILabel with Swift (iOS)

This week while working on one of our client apps I came across interesting problem of embedding images with text. To give a little idea, we wanted to display text somewhat like emojis embedded in the message. Doesn't that look cool? It definitely does. Initially I drew the conclusion of

Xcode

Xcode - Quickly fix the fixable errors

Today I am going to write about a neat trick I learned about automatically fixing fixable error in Xcode. We usually come across the error which are easily fixable. These include typo'ed method/parameter names, missing semicolons, failure to close brackets. Speaking of Swift, they are also errors when we

Xcode

Swifty UITableViewController with generics and structs

Disclaimer - This post along with code supporting is inspired by Chris Eidhof's talk at trySwift. I took the liberty to slightly update the code as per my own logic. There is no difference from the original source as long as user facing functionality is concerned. This code is open

iOS

iOS Testing - Testing asynchronous code (Part 4)

This is the part 4 in the series of articles on 'Unit Testing on iOS'. Below is the list of all articles and respective links to them. iOS Unit Tests - Testing models creation (Part 1) iOS Unit Testing - Testing View Controller (Part 2) iOS Unit Testing - Switching

iOS

iOS Unit Testing - Switching method implementations with OCMock (Part 3)

This is the part 3 in the series of articles on 'Unit Testing on iOS'. Below is the list of all articles and respective links to them. iOS Unit Tests - Testing models creation (Part 1) iOS Unit Testing - Testing View Controller (Part 2) iOS Unit Testing - Switching

AutoLayout

Debugging Autolayout issues in the Xcode

With the release of new iPhone devices in addition to older models iPhone4 and iPhone5, developers are forced to switch to autolayout instead of using manual frames to update our view layouts. As we extensively use autolayout, goof-ups are very much likely to happen. I always miss something or add