Make an API call

With our Box and iOS applications created and configured with the Box iOS SDK we can now make our first call to Box APIs.

Using our blank iOS application, we will create a button to trigger a request to Box to fetch the name of the currently authenticated user.

Using a blocking actions as we use in these examples is slow. In a production app these blocking actions would need to be replaced with proper task delegation and non-blocking actions.

Create a button

Within your Swift application in Xcode, load ContentView.swift. At the top of the file you will see a struct for ContentView, within which is a basic string that will be output to your iOS application if you run the app in an emulator.

import SwiftUI

struct ContentView: View {
  var body: some View {
    Text("Hello, World!")
  }
}

We’ll first replace the Text output line with a button to be able to trigger off the call to get the current user. Replace that line with the below button.

Button(action: {
  // Perform some action
}) {
  Text("Click to get current user")
}
.padding(10)
.cornerRadius(20)
.foregroundColor(.white)
.background(Color.blue)

Our next step is to add an an action for the button which will fetch a user’s details from Box.

Add an API call button action

When a user clicks the button, we want to fetch the user’s details. To achieve this we need to do two things, add the import for the Box iOS SDK and add the button action to make the call.

At the top of the ContentView.swift file, add import BoxSDK with the other import statement.

Next, within the button action, where we currently have a comment placeholder, add a call to the iOS SDK to fetch the current user. When the API call completes it will print an authentication message to the developer console. For ease of implementation, we have a blocking sleep(5) call in place in order to test that the iOS SDK can make calls from our iOS SDK by providing enough time for the request to complete.

Replace {{YOUR DEVELOPER TOKEN}} with your developer token.

let client = BoxSDK.getClient(token: "{{YOUR DEVELOPER TOKEN}}")

client.users.getCurrent(fields:["name", "login"]) { (result: Result<User,
  BoxSDKError>) in
  guard case let .success(user) = result else {
      print("Error getting user information")
      return
  }
  print("Authenticated as \(user.name)")
}

sleep(5)

Build and run your sample application in the iOS emulator.

If you run this code an hour or more after you created the developer token in the last step, you will need to revoke and generate a new developer token using the same method in the as the developer token will only persist for 60 minutes.

Once the application loads in the emulator you should see the button we created. Click it to start the API request.

Within the Xcode developer console you should see the API request and response, with the last line showing the user print statement that we specified.

◁ Status code: 200: no error
◁ Headers:
    ◁ Cache-Control, Value: no-cache, no-store
    ◁ BOX-REQUEST-ID, Value: 1c55151238444132eca16b4c2346d005
    ◁ Transfer-Encoding, Value: Identity
    ◁ content-type, Value: application/json
    ◁ Connection, Value: keep-alive
    ◁ Strict-Transport-Security, Value: max-age=31536000
◁ Body: {"type":"user","id":"123456789","name":"Test
          User","login":"[e-mail]"}

Authenticated as Optional("Test User")

If you don’t see the Xcode developer console, from the menu click View -> Debug Area -> Activate Console

Congratulations, you’ve now configured the Box iOS SDK and have made your first call to the Box API.

Summary

• You added a button to your blank iOS application
• You added a request to fetch the current user using the iOS SDK