Nested If statements inside ForEach loop - swiftui

Question

I have created a custom list. Based on the conditions, some objects don't have names. Alternatively, some objects might have more than 1 name. So, the names in my custom list are optional. I want to print out all the names and I used the following codes. The code is working but it is too heavy. Sometimes, the Xcode throws "The compiler is unable to type-check this expression in a reasonable time"
My DataArray Example:
import SwiftUI
struct DataArray: Identifiable {
let id = UUID()
let number: Int
let cities: String
var name1: String?
var name2: String?
var name3: String?
var name4: String?
}
public struct ListDataArray {
static var dot = [
DataArray(number: 1,
cities: "Baltimore"
name1: "A",
name2: "B"),
DataArray(number: 2,
cities: "Frederick"),
DataArray(number: 3,
cities: "Catonsville"
name1: "Aa",
name2: "Bb",
name3: "Cc",
name4: "Dd"),
]
}
import SwiftUI
struct Home: View {
var datas: [DataArray] = ListDataArray.dot
var body: some View {
ScrollView {
LazyVStack(spacing: 10) {
ForEach (datas, id: \.id) { data in
if (data.name1 !=nil) {
HStack {
Image(systemName: "1.circle.fill")
.font(.title2)
.foregroundColor(.red)
Text(data.name1 ?? "")
Spacer()
}
}
if (data.name2 !=nil) {
HStack {
Image(systemName: "2.circle.fill")
.font(.title2)
.foregroundColor(.red)
Text(data.name2 ?? "")
Spacer()
}
}
if (data.name3 !=nil) {
HStack {
Image(systemName: "3.circle.fill")
.font(.title2)
.foregroundColor(.red)
Text(data.name3 ?? "")
Spacer()
}
}
if (data.name4 !=nil) {
HStack {
Image(systemName: "4.circle.fill")
.font(.title2)
.foregroundColor(.red)
Text(data.name4 ?? "")
Spacer()
}
}
}
}
}
}
}
So, for the second approach, I used nested ForEach loop like
ForEach (data, id: \.id) { data in
ForEach ([data.name1, data.name2, data.name3, data.name4], id: .\self) { d in
if (d !=nil) {
HStack {
Image(systemName: "1.circle.fill")
.font(.title2)
.foregroundColor(.red)
Text(d ?? "")
Spacer()
}
}
The issue about this nested ForEach approach is that the LazyVStack always crashes when I scroll to the bottom of the pages. Also, I don't know how to update the system images. I can use regular VStack but these arrays will be a lot so I need LazyVStack. So, please help me to do a better way to shorten the if statements. Please please don't comment if you don't know or if you are not sure what you are doing. I posted similar questions four to five times here already. They all ended up with useless comments and they are worthless for a beginner level who really try to learn something new.

Answer 1

Here's one solution, using my solution mentioned in the comments, using if let = ... to do optional binding (read more on that concept here https://docs.swift.org/swift-book/LanguageGuide/TheBasics.html):
struct Home: View {
var datas: [DataArray] = ListDataArray.dot
var body: some View {
ScrollView {
LazyVStack(spacing: 10) {
ForEach (datas, id: \.id) { data in
if let name1 = data.name1 {
HStack {
Image(systemName: "1.circle.fill")
.font(.title2)
.foregroundColor(.red)
Text(name1)
Spacer()
}
}
if let name2 = data.name2 {
HStack {
Image(systemName: "2.circle.fill")
.font(.title2)
.foregroundColor(.red)
Text(name2)
Spacer()
}
}
if let name3 = data.name3 {
HStack {
Image(systemName: "3.circle.fill")
.font(.title2)
.foregroundColor(.red)
Text(name3)
Spacer()
}
}
if let name4 = data.name4 {
HStack {
Image(systemName: "4.circle.fill")
.font(.title2)
.foregroundColor(.red)
Text(name4)
Spacer()
}
}
}
}
}
}
}
Here's a further refactored version that splits the inner view into a separate function so that the code isn't repeated:
struct Home: View {
var datas: [DataArray] = ListDataArray.dot
#ViewBuilder func segment(imageName: String, text: String) -> some View {
HStack {
HStack {
Image(systemName: imageName)
.font(.title2)
.foregroundColor(.red)
Text(text)
Spacer()
}
}
}
var body: some View {
ScrollView {
LazyVStack(spacing: 10) {
ForEach (datas, id: \.id) { data in
if let name1 = data.name1 {
segment(imageName: "1.circle.fill", text: name1)
}
if let name2 = data.name2 {
segment(imageName: "2.circle.fill", text: name2)
}
if let name3 = data.name3 {
segment(imageName: "3.circle.fill", text: name3)
}
if let name4 = data.name4 {
segment(imageName: "4.circle.fill", text: name4)
}
}
}
}
}
}
I've found that when parsing SwiftUI, the compiler has trouble evaluating what would seem like simple boolean expressions. In other words, your original code should actually work, but the compiler has trouble parsing it.