Headless validation

Two tools cover validation outside the normal UI flow.

In-app: api.validateData()

For a rendered view, validate programmatically through the API service:

const result = await this.api.validateData({
  emitValidationEvent: true,
  includeHidden: false,
  includeDisabled: false,
});
// result: { isValid: boolean, issues: [{ elementName, dataPath, errors[] }] }

Standalone: <ngx-view-builder-validator>

A component with no visible UI that loads a structure + data, runs the full runtime validation (including expressions), and emits the result. Designed for validation services — e.g. a small Angular app rendered server-side or in a headless browser that your backend calls to verify submissions with the same rules the form used.

<ngx-view-builder-validator
  [pageJson]="structure"
  [dataJson]="submittedData"
  [autoValidateOnInit]="true"
  (validated)="onValidated($event)"
  (validationError)="onError($event)"
/>

Input	Default	Purpose
pageJson / dataJson	—	Structure and data to validate
autoValidateOnInit	true	Validate immediately
backendUrl / validatePath	http://127.0.0.1:8010 / /validate	Remote validation endpoint mode
waitMs / timeoutMs	300 / 45000	Stabilisation delay and timeout
headlessApiKey	__NGX_VIEW_BUILDER__	Global API key for headless drivers
sessionHeaderName / sessionKey / requestHeaders	—	Auth headers for the remote mode

You can also call validate() on the component instance for on-demand runs.

Global headless API

For E2E tests and headless automation, expose a global validation API at startup:

inject(ForgeInitializerService).load({
  exposeHeadlessValidationApi: true,
  headlessValidationApiKey: '__NGX_VIEW_BUILDER__',
});

The driver (Playwright, Puppeteer…) can then invoke validation through window.__NGX_VIEW_BUILDER__.

Why server-side validation matters

Client-side rules protect UX, not integrity. Re-run the same structure + data through the validator on trusted infrastructure before persisting anything — the definitions are identical, so rules never drift between client and server.