createFormView

Signature

const view = createFormView(options);

CreateFormViewOptions is the same family of app-facing inputs used by mountForm(), plus headless layout.

Input options

Required:

• schema
• transport

Common optional inputs:

• layout
• registry
• primitiveRegistry
• designSystemRegistry
• initialValues
• validators
• hooks
• inactiveFieldPolicy
• listenerErrorPolicy
• onListenerError

Returned controller

interface FormViewController {
  form: FormController;
  engineRegistry: Registry;
  primitiveRegistry: PrimitiveRegistry;
  designSystemRegistry: DesignSystemRegistry;
  state: FormViewState;
  getSnapshot(): FormViewSnapshot;
  getNodeById(id: string): ResolvedFormLayoutNode | undefined;
  getField(id: string): FormViewFieldItem | undefined;
  getReport(id: string): FormViewReportItem | undefined;
  getExplanation(id: string): FormViewExplanationItem | undefined;
  getVisibleFields(): FormViewFieldItem[];
  getVisibleReports(): FormViewReportItem[];
  getVisibleExplanations(): FormViewExplanationItem[];
  getActiveLayoutNodes(): ResolvedFormLayoutNode[];
  validate(): Promise<FormValidationResult>;
  submit(options?: SubmitOptions): Promise<SubmitResult>;
  reset(): void;
  subscribe(listener): () => void;
  nextStep(): Promise<boolean>;
  prevStep(): void;
  goToStep(stepId: string): Promise<boolean>;
  setActiveTab(tabId: string): void;
  nextTab(): boolean;
  prevTab(): boolean;
  toggleSection(sectionId: string): void;
  openSection(sectionId: string): void;
  closeSection(sectionId: string): void;
  openAllSections(): void;
  closeAllSections(): void;
}

Snapshot shape

getSnapshot() returns:

• form
• layout
• fields
• reports
• explanations
• wizard
• tabs
• accordion

wizard is null unless layout.kind === "wizard". tabs is null unless layout.kind === "tabs". accordion is null unless layout.kind === "accordion".

Item collections

Each field item contains:

• id
• kind
• config
• controller
• state
• descriptor
• stepId
• tabId
• visibleInLayout

The report and explanation collections follow the same pattern.

Navigation semantics

nextStep()

• only meaningful for wizard layouts
• validates fields in the current step
• returns false on validation failure
• returns true when the current step is valid
• does not advance past the last step

prevStep()

• only meaningful for wizard layouts
• never validates
• moves back one step when possible

goToStep(stepId)

• allows free backward navigation
• validates incrementally when moving forward
• throws if used outside a wizard layout

setActiveTab(tabId)

• only meaningful for tabs layouts
• switches tabs without validation
• throws if used outside a tabs layout

nextTab() / prevTab()

• only meaningful for tabs layouts
• never validate
• return false when movement is not possible

Accordion controls

• toggleSection(sectionId) opens or closes one accordion section
• openSection(sectionId) and closeSection(sectionId) are explicit variants
• openAllSections() and closeAllSections() manage the full accordion state
• all accordion control methods throw outside layout.kind === "accordion"

Subscription model

Use subscribe() for host rendering:

const unsubscribe = view.subscribe((snapshot) => {
  render(snapshot);
});

Typical host pattern:

1. create the view once
2. render initial snapshot
3. subscribe
4. on teardown, unsubscribe and abort or unmount host-side resources

Design system note

createFormView() does not attach stylesheets or mutate DOM. Use:

• mountForm() for built-in one-page DOM
• mountWizardForm() for built-in wizard DOM
• mountTabsForm() for built-in tabs DOM
• mountAccordionForm() for built-in accordion DOM
• attachDesignSystem() yourself when your custom host needs it