Injectable Scripts

Pre-built script strings for WebView injection. Import from @snapfill/core or @snapfill/core/injectable.

snapfillScript

const snapfillScript: string

Combined injectable containing form detection, cart detection, and value capture. Inject this single string into a WebView for full autofill support.

When evaluated, the script:

1. Scans the DOM for form fields and posts a formDetected message
2. Scans for shopping cart data and posts a cartDetected message
3. Attaches listeners to detected fields and posts valuesCaptured on change
4. Watches for DOM mutations and re-scans automatically

// Inject once after page load
webview.evaluateJavaScript(snapfillScript);

The script is idempotent — injecting it multiple times has no effect.

buildFillScript(mappings)

function buildFillScript(mappings: AutofillMappings): string

Builds a fill script string for WebView injection. The returned string fills form fields using the field map created by snapfillScript.

Parameters:

• mappings — Object mapping field types to values

Returns: A JavaScript string to evaluate in the WebView

const script = buildFillScript({
  firstName: 'Jane',
  lastName: 'Doe',
  email: 'jane@example.com',
});

webview.evaluateJavaScript(script);

The fill script posts a formFillComplete message with the result.

WARNING

snapfillScript must be injected first — the fill script depends on the field map it creates.

fillScriptTemplate

const fillScriptTemplate: string

Raw fill script with a __SNAPFILL_MAPPINGS__ placeholder. Used internally by buildFillScript and by native libraries (Android/iOS) that perform their own JSON serialization.

// Native usage (Kotlin/Swift)
val script = fillScriptTemplate.replace("__SNAPFILL_MAPPINGS__", jsonMappings)
webView.evaluateJavascript(script, null)

Individual Scripts

You can also inject detection scripts individually:

formDetectorScript

const formDetectorScript: string

Only form detection — no cart detection or value capture. Posts formDetected messages.

cartDetectorScript

const cartDetectorScript: string

Only cart detection. Posts cartDetected messages.

valueCaptureScript

const valueCaptureScript: string

Only value capture. Requires formDetectorScript to be injected first. Posts valuesCaptured messages.