DevFright

There are two categories of notifications on iOS devices. One type is a push notification sent by a server, and the other is a local notification scheduled on-device that appears at a particular time or location.

This tutorial focuses on local notifications. An example of a local notification can be seen in your calendar. You add an appointment, set it to remind you 15 minutes before, and 15 minutes before the meeting begins, you see a notification on your lock screen. Let’s take a look at how these work.

For the last few weeks, I have been making plans for a new iPad/iPhone, and potentially macOS application. I haven’t used SwiftUI much in development so wasn’t sure how best to sort out the navigation on both mobile devices.

The app I am building, which is in very early stages, is for note-taking and meeting planning. My plan was to use a two-column layout, much like master/detail, but it seems that one good option is the three-column layout that has a menu on the far left column, a list view in the centre column, and then details on the rest of the view, as seen below.

If you are getting an error saying that you cannot preview this file (while using SwiftUI), then perhaps like my experience, a reboot might fix it. That’s the short version to possibly get you going before reading on.

I created a new project today and switched the default ContentView.swift to use an iPad Pro 11 inch for the preview. An error appeared in right pane saying “Cannot preview in this file – Unable to boot device due to insufficient system resources”. Clicking the diagnostics button provided the following:

We recently wrote about Swift structs. In this tutorial, we’ll look at classes. Classes and structures have a lot in common, although there are some important differences. Let’s take a look at what a class is and what you use them for.

• A class is initialised as an object.
• You need to create an initialiser for your class.
• Classes can also inherit from other classes which bring to your class the abilities and properties of the other class. You can also override the default behaviour of a method of the parent class.
• Unlike structs which are passed around by value, classes are passed by reference.

A struct, or structure, is a custom data type in Swift that allows you to add many properties to it. If you think of a regular string, you can store just one string in the variable, as follows:

var firstName = "Matthew"

What if we wanted to add Matthews height:

var firstName = "Matthew"
var height = 190

This rapidly becomes complicated because we now have two variables to manage and think about. Imagine if we needed to add their last name, and so on, and then have the need to pass this information somewhere else within the program. This is one benefit of using a struct.