Form container in iOS Swift - Mini App: Build & Ship

Build: User Info Form

A simple form screen where users can enter their name and email, then submit the form.

Target UI

-------------------------
| User Info Form        |
|-----------------------|
| Name: [___________]   |
| Email: [___________]  |
|                       |
|       [Submit]        |
-------------------------

Add two text fields: one for Name and one for Email.

Add a Submit button below the text fields.

When Submit is tapped, print the entered Name and Email to the console.

Use a vertical stack to arrange the fields and button with spacing.

Add padding around the form content.

Starter Code

iOS Swift

import SwiftUI

struct UserInfoForm: View {
    // TODO: Add @State properties for name and email

    var body: some View {
        VStack {
            // TODO: Add TextFields for name and email

            // TODO: Add Submit button
        }
        .padding()
    }
}

struct UserInfoForm_Previews: PreviewProvider {
    static var previews: some View {
        UserInfoForm()
    }
}

Task 1

Task 2

Task 3

Task 4

Solution

iOS Swift

import SwiftUI

struct UserInfoForm: View {
    @State private var name: String = ""
    @State private var email: String = ""

    var body: some View {
        VStack(spacing: 20) {
            TextField("Name", text: $name)
                .textFieldStyle(RoundedBorderTextFieldStyle())

            TextField("Email", text: $email)
                .keyboardType(.emailAddress)
                .textFieldStyle(RoundedBorderTextFieldStyle())

            Button("Submit") {
                print("Name: \(name), Email: \(email)")
            }
            .buttonStyle(.borderedProminent)
        }
        .padding()
    }
}

struct UserInfoForm_Previews: PreviewProvider {
    static var previews: some View {
        UserInfoForm()
    }
}

We use @State properties to store the user's input for name and email. The VStack arranges the two TextField views and the Button vertically with spacing. Each TextField uses a rounded border style for clarity. The email field uses the email keyboard type for better user experience. The Submit button prints the current values to the console when tapped. Padding around the stack keeps the form content away from screen edges.

Final Result

Completed Screen

-------------------------
| User Info Form        |
|-----------------------|
| Name: [John Doe    ]  |
| Email: [john@example] |
|                       |
|       [Submit]        |
-------------------------

User taps the Name field and types their name.

User taps the Email field and types their email address.

User taps the Submit button, and the app prints the entered name and email to the console.

Stretch Goal

Add validation to disable the Submit button unless both fields are not empty and the email contains '@'.

💡 Hint

Use a computed property to check if name and email are valid, then bind the button's disabled state to it.

Practice

1. What is the main purpose of using a Form container in SwiftUI?

easy

A. To handle network requests

B. To create animations for buttons

C. To display images in a grid

D. To group input fields vertically for easy data entry

Solution

1. Step 1: Understand the role of Form in SwiftUI

   The Form container is designed to group input fields vertically, making data entry easier and more organized.

2. Step 2: Compare with other options

   Options B, C, and D describe unrelated functionalities like animations, image grids, and networking, which are not the purpose of Form.

3. Final Answer:

   To group input fields vertically for easy data entry -> Option D

4. Quick Check:

   Form groups inputs vertically = A [OK]

Hint: Form groups inputs vertically for easy data entry [OK]

Common Mistakes:

• Confusing Form with layout containers like VStack
• Thinking Form handles animations or images
• Assuming Form manages network tasks

2. Which of the following is the correct syntax to create a simple form with a text field in SwiftUI?

easy

A. Form { TextField("Name", text: $name) }

B. Form() -> TextField("Name", text: $name)

C. Form: TextField("Name", text: $name)

D. Form(TextField("Name", text: $name))

Solution

1. Step 1: Recall SwiftUI Form syntax

   The correct way to declare a form with a text field is using a closure: Form { ... } with the input inside the braces.

2. Step 2: Analyze each option

   Form { TextField("Name", text: $name) } uses the correct closure syntax. Options A, B, and C use invalid syntax or incorrect punctuation.

3. Final Answer:

   Form { TextField("Name", text: $name) } -> Option A

4. Quick Check:

   Form uses braces for content = D [OK]

Hint: Use braces { } to wrap form content in SwiftUI [OK]

Common Mistakes:

• Using parentheses instead of braces for Form content
• Trying to call Form like a function with arrow syntax
• Misplacing colons or parentheses

3. What will be the visible result of this SwiftUI code?

Form {
  Section(header: Text("User Info")) {
    TextField("Username", text: $username)
    Toggle("Enable Notifications", isOn: $notifications)
  }
}

medium

A. A form with no visible header and only a text field

B. A form with a section titled 'User Info' containing a text field and a toggle switch

C. A form with two separate sections, one for text field and one for toggle

D. A form that crashes due to missing bindings

Solution

1. Step 1: Understand Section usage inside Form

   The Section groups the text field and toggle under the header "User Info" inside the form.

2. Step 2: Visualize the UI output

   The form will show a titled section with the header text, containing the two input controls vertically stacked.

3. Final Answer:

   A form with a section titled 'User Info' containing a text field and a toggle switch -> Option B

4. Quick Check:

   Section header groups inputs = C [OK]

Hint: Section header groups inputs visually inside Form [OK]

Common Mistakes:

• Thinking each input creates a separate section
• Expecting no header to appear
• Assuming code crashes without seeing binding declarations

4. Identify the error in this SwiftUI form code snippet:

Form {
  TextField("Email", text: email)
  Toggle("Subscribe", isOn: $subscribe)
}

medium

A. Form cannot contain both TextField and Toggle

B. Toggle label should be a Text view

C. Missing $ before email binding in TextField

D. TextField requires a placeholder parameter

Solution

1. Step 1: Check binding usage in TextField

   The TextField requires a binding to a state variable, which must be prefixed with $. Here, email lacks the $.

2. Step 2: Verify other parts

   The Toggle uses $subscribe correctly. The label can be a string. Form can contain both controls. Placeholder is the first parameter.

3. Final Answer:

   Missing $ before email binding in TextField -> Option C

4. Quick Check:

   Bindings need $ prefix = A [OK]

Hint: Always prefix state bindings with $ in input controls [OK]

Common Mistakes:

• Forgetting $ before state variables in bindings
• Thinking Toggle label must be Text view
• Assuming Form restricts input types

5. You want to create a form with two sections: one for personal info with a text field for name, and one for settings with a toggle for dark mode. Which code snippet correctly implements this?

hard

A. Form {
Section(header: Text("Personal Info")) {
TextField("Name", text: $name)
}
Section(header: Text("Settings")) {
Toggle("Dark Mode", isOn: $darkMode)
}
}

B. Form {
TextField("Name", text: $name)
Toggle("Dark Mode", isOn: $darkMode)
Section(header: Text("Personal Info")) {}
Section(header: Text("Settings")) {}
}

C. Form {
Section {
TextField("Name", text: $name)
Toggle("Dark Mode", isOn: $darkMode)
}
}

D. Form {
Section(header: Text("Personal Info")) {
Toggle("Dark Mode", isOn: $darkMode)
}
Section(header: Text("Settings")) {
TextField("Name", text: $name)
}
}

Solution

1. Step 1: Understand section grouping requirements

   Each section should group related inputs with the correct header. Personal info section must contain the name text field, settings section the dark mode toggle.

2. Step 2: Analyze each option's structure

   Form { Section(header: Text("Personal Info")) { TextField("Name", text: $name) } Section(header: Text("Settings")) { Toggle("Dark Mode", isOn: $darkMode) } } correctly places inputs inside their respective sections with headers. Form { TextField("Name", text: $name) Toggle("Dark Mode", isOn: $darkMode) Section(header: Text("Personal Info")) {} Section(header: Text("Settings")) {} } places inputs outside sections and empty sections after. Form { Section { TextField("Name", text: $name) Toggle("Dark Mode", isOn: $darkMode) } } puts both inputs in one section without headers. Form { Section(header: Text("Personal Info")) { Toggle("Dark Mode", isOn: $darkMode) } Section(header: Text("Settings")) { TextField("Name", text: $name) } } swaps inputs between sections incorrectly.

3. Final Answer:

   Form with two sections correctly grouping inputs by header -> Option A

4. Quick Check:

   Inputs grouped by section headers = B [OK]

Hint: Group related inputs inside Section with header inside Form [OK]

Common Mistakes:

• Placing inputs outside sections
• Mixing inputs between wrong sections
• Leaving sections empty or without headers