Quick Start

Build a complete Course Enrollment form in 5 minutes using the FormBuilder DSL.

The Scenario

We will create an LMS enrollment form that:

1. Collects student name, email, and phone number
2. Lets the student select a course and enrollment type
3. Shows payment fields only when "Paid Enrollment" is selected
4. Validates all inputs with appropriate rules
5. Groups preferences into a collapsible section

1. 1

   Import the DSL

   The DSL import gives you FormBuilder, all field builders, and the When class for conditional rules.
2. 2

   Build the Form

   Chain field builders fluently — starting a new field auto-finalizes the previous one, so no .done() calls are needed.

   enrollment_form.dart
3. 3

   Use the Form

   The build() method returns a Form object with a fully wired FormGroup. You can render it or work with it programmatically.
4. 4

   Render in Flutter

   Use the form's content builder system to render it. The default vertical layout renders fields in order; explicit side-by-side layout uses row blocks.

   enrollment_page.dart

What You Built

In under 50 lines of DSL code, you created a form with:

• 6 fields across 3 types (text, select, date)
• Validation -- required, email, min length
• Conditional visibility -- payment method appears only for paid enrollment
• Sequential layout -- fields render in the order declared by the DSL
• Collapsible section -- preferences grouped and collapsible
• Reactive state -- FormGroup-backed values with MobX observability

Key Patterns

Pattern	How
Auto-finalize	Starting a new field commits the previous one -- no .done() needed
Fluent validation	.required().email().minLength(2) chains naturally
Conditional rules	.showWhen(When.fieldEquals(...)) for declarative visibility
Rows	Use FormRowBlock in the runtime model or Row blocks in the visual editor for side-by-side fields
Sections	.section('Title', (s) => s.field(...)) for visual grouping

Next Steps

• Philosophy -- Understand the 6 design principles
• Form Model -- Deep dive into Form, FormRowBlock, FormSection, and StepForm
• Field Types -- All 12 field types with configuration options
• Validation Patterns -- Real-world validation examples