Reading Consent from an airgap.js WebView

When your mobile app embeds a WebView that loads a page with airgap.js running, consent choices the user makes in the browser context can be retrieved by calling airgap.getConsent(). This guide walks through extracting that consent and forwarding it to the Transcend native SDK so your app-side tracking respects the same preferences.

The overall flow has four steps:

1. Establish a JavaScript bridge between your native app and the WebView.

2. Retrieve consent by calling airgap.getConsent() from within the WebView's JavaScript context, and sent the consent's purposes object back across the bridge to native code.

3. Call setConsent on the Transcend SDK with the purposes map.

• Your app already loads a WebView whose page includes the airgap.js script.
• The Transcend SDK is initialized in your native app via TranscendAPI.init().

If your app does not already have a JavaScript-to-native bridge, add one. The bridge gives JavaScript running inside the WebView a way to send data back to your native code.

First, you'll need to ensure that your getConsent code runs after airgap has finished initializing; this is accomplished by attaching a callback to airgap.ready.

If your bridge code already interacts with airgap.js in some way, then it likely already waits for the airgap ready signal, otherwise you will need to wrap your getConsent call within the ready callback, as shown below:

airgap.ready(() => {
  const purposes = airgap.getConsent().purposes;
  const purposesString = JSON.stringify(purposes);
  window.ConsentBridge.receiveConsent(purposesString);
});

Either way, you will need to make your bridge code invoke airgap.getConsent() and pass the stringified purposes object back through to the native context.

When the bridge callback fires, deserialize the JSON string into a <String, Boolean> map and call the SDK's setConsent method with it.

private fun handlePurposes(purposesJson: String) {
    try {
        val gson = Gson()
        val type = object : TypeToken<Map<String, Boolean>>() {}.type
        val purposes: Map<String, Boolean> = gson.fromJson(purposesJson, type)

        val success = TranscendAPI.setConsent(purposes)
        if (success) {
            Log.d("Consent", "Consent synced from WebView")
        } else {
            Log.e("Consent", "Failed to set consent")
        }
    } catch (e: Exception) {
        Log.e("Consent", "Failed to sync consent from Webview", e)
    }
}

private func handlePurposes(_ purposesJson: String) {
    guard let data = purposesJson.data(using: .utf8) else {
        NSLog("[Consent] Failed to sync consent from WebView: invalid data")
        return
    }
    do {
        guard let purposes = try JSONSerialization.jsonObject(with: data) as? [String: Bool] else {
            NSLog("[Consent] Failed to sync consent from WebView: invalid JSON structure")
            return
        }
        let success = TranscendAPI.setConsent(purposes)
        if success {
            NSLog("[Consent] Consent synced from WebView")
        } else {
            NSLog("[Consent] Failed to set consent")
        }
    } catch {
        NSLog("[Consent] Failed to sync consent from WebView: %@", error.localizedDescription)
    }
}