Swift iOS App - No Console Messages Cannot Make URLSession Call to GraphQL Enpoint - swift

Question

I've been trying to get a list of entities from a graphql endpoint but I can't figure it out. Also, the console in my Xcode v13.4 isn't showing anything even though I have some print() statements in the code, so that's not helping - I've found where it is at the bottom of the window but it's always blank.
My View to get the data is below, the DetailView is the link following a link from the main ContentView. the loadData function content, I got the code from Postman after testing the graphql call.
import SwiftUI
import Foundation
#if canImport(FoundationNetworking)
import FoundationNetworking
#endif
//array of properties
struct Response: Codable {
var data: Properties
}
struct Properties: Codable {
var properties: Nodes
}
struct Nodes: Codable {
var nodes: [Result]
}
struct Result: Codable {
var propertyId: Int
var title: String
}
struct DetailView: View {
#State private var results = [Result]()
var body: some View {
List(results, id: \.propertyId) { property in
VStack(alignment: .leading) {
Text(property.title)
.font(.headline)
}
}
.task{
await loadData()
}
}
func loadData() async {
let semaphore = DispatchSemaphore (value: 0)
let parameters = "{\"query\":\"{\\n properties {\\n nodes {\\n title(format: RENDERED)\\n propertyId\\n }\\n }\\n}\",\"variables\":{}}"
let postData = parameters.data(using: .utf8)
var request = URLRequest(url: URL(string: "http://DOMAIN/graphql")!,timeoutInterval: Double.infinity)
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
request.httpMethod = "POST"
request.httpBody = postData
do {
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard let data = data else {
print(String(describing: error))
semaphore.signal()
return
}
if let decodedResponse = try? JSONDecoder().decode(Response.self, from: data) {
results = decodedResponse.data.properties.nodes
}
semaphore.signal()
}
task.resume()
semaphore.wait()
} catch {
print("Invalid data")
}
}
}
The output of the graphql call is
{
"data": {
"properties": {
"nodes": [
{
"title": "MY TITLE",
"propertyId": 00001
}
]
}
}
}
EDIT
Swapped try? for try! as suggested
if let decodedResponse = try! JSONDecoder().decode(Response.self, from: data) {
results = decodedResponse.data.properties.nodes
}
error: Initializer for conditional binding must have Optional type, not 'Response'

Answer 1

I managed to get it all working with the below...
import SwiftUI
import Foundation
#if canImport(FoundationNetworking)
import FoundationNetworking
#endif
//array of properties
struct Response: Codable {
var data: Properties
}
struct Properties: Codable {
var properties: Nodes
}
struct Nodes: Codable {
var nodes: [Result]
}
struct Result: Codable {
var propertyId: Int
var title: String
}
struct DetailView: View {
#State private var results = [Result]()
#State private var test = "one"
var body: some View {
List(results, id: \.propertyId) { property in
VStack(alignment: .leading) {
Text(property.title)
.font(.headline)
}
}.task{
await loadData()
}
}
func loadData() async {
let semaphore = DispatchSemaphore (value: 0)
let parameters = "{\"query\":\"{\\n properties {\\n nodes {\\n title(format: RENDERED)\\n propertyId\\n }\\n }\\n}\",\"variables\":{}}"
let postData = parameters.data(using: .utf8)
var request = URLRequest(url: URL(string: "https://DOMAIN/graphql")!,timeoutInterval: Double.infinity)
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
request.httpMethod = "POST"
request.httpBody = postData
do {
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard let data = data else {
print(String(describing: error))
semaphore.signal()
return
}
let decodedResponse = try! JSONDecoder().decode(Response.self, from: data)
results = decodedResponse.data.properties.nodes
semaphore.signal()
}
task.resume()
semaphore.wait()
} catch {
print("Invalid data \(error)")
}
}
}
Much to learn :)