Improve __uspapi behavior in iframe

modules/consentManagementUsp.js

@@ -44,6 +44,35 @@ function lookupStaticConsentData(cmpSuccess, cmpError, hookConfig) {
  * @param {object} hookConfig contains module related variables (see comment in requestBidsHook function)
  */
 function lookupUspConsent(uspSuccess, uspError, hookConfig) {
+ function findUsp() {
+ let f = window;
+ let uspapiFrame;
+ let uspapiFunction;
+
+ while (!uspapiFrame) {
+ try {
+ if (typeof f.__uspapi === 'function') {
+ uspapiFunction = f.__uspapi;
+ uspapiFrame = f;
+ break;
+ }
+ } catch (e) {}
+
+ try {
+ if (f.frames['__uspapiLocator']) {
+ uspapiFrame = f;
+ break;
+ }
+ } catch (e) {}
+ if (f === window.top) break;
+ f = f.parent;
+ }
+ return {
+ uspapiFrame,
+ uspapiFunction,
+ };
+ }
+
  function handleUspApiResponseCallbacks() {
  const uspResponse = {};
 
@@ -61,41 +90,43 @@ function lookupUspConsent(uspSuccess, uspError, hookConfig) {
  uspResponse.usPrivacy = consentResponse.uspString;
  }
  afterEach();
- }
+ },
  };
  }
 
  let callbackHandler = handleUspApiResponseCallbacks();
  let uspapiCallbacks = {};
 
+ let { uspapiFrame, uspapiFunction } = findUsp();
+
+ if (!uspapiFrame) {
+ return uspError('USP CMP not found.', hookConfig);
+ }
+
  // to collect the consent information from the user, we perform a call to USPAPI
  // to collect the user's consent choices represented as a string (via getUSPData)
 
  // the following code also determines where the USPAPI is located and uses the proper workflow to communicate with it:
- // - use the USPAPI locator code to see if USP's located in the current window or an ancestor window. This works in friendly or cross domain iframes
+ // - use the USPAPI locator code to see if USP's located in the current window or an ancestor window.
+ // - else assume prebid is in an iframe, and use the locator to see if the CMP is located in a higher parent window. This works in cross domain iframes.
  // - if USPAPI is not found, the iframe function will call the uspError exit callback to abort the rest of the USPAPI workflow
- // - try to call the __uspapi() function directly, otherwise use the postMessage() api
- // find the CMP frame/window
-
- try {
- // try to call __uspapi directly
- window.__uspapi('getUSPData', USPAPI_VERSION, callbackHandler.consentDataCallback);
- } catch (e) {
- // must not have been accessible, try using postMessage() api
- let f = window;
- let uspapiFrame;
- while (!uspapiFrame) {
- try {
- if (f.frames['__uspapiLocator']) uspapiFrame = f;
- } catch (e) { }
- if (f === window.top) break;
- f = f.parent;
- }
 
- if (!uspapiFrame) {
- return uspError('USP CMP not found.', hookConfig);
- }
- callUspApiWhileInIframe('getUSPData', uspapiFrame, callbackHandler.consentDataCallback);
+ if (utils.isFn(uspapiFunction)) {
+ utils.logInfo('Detected USP CMP is directly accessible, calling it now...');
+ uspapiFunction(
+ 'getUSPData',
+ USPAPI_VERSION,
+ callbackHandler.consentDataCallback
+ );
+ } else {
+ utils.logInfo(
+ 'Detected USP CMP is outside the current iframe where Prebid.js is located, calling it now...'
+ );
+ callUspApiWhileInIframe(
+ 'getUSPData',
+ uspapiFrame,
+ callbackHandler.consentDataCallback
+ );
  }
 
  function callUspApiWhileInIframe(commandName, uspapiFrame, moduleCallback) {
@@ -107,19 +138,19 @@ function lookupUspConsent(uspSuccess, uspError, hookConfig) {
  __uspapiCall: {
  command: cmd,
  version: ver,
- callId: callId
- }
+ callId: callId,
+ },
  };
 
  uspapiCallbacks[callId] = callback;
  uspapiFrame.postMessage(msg, '*');
- }
+ };
 
  /** when we get the return message, call the stashed callback */
  window.addEventListener('message', readPostMessageResponse, false);
 
  // call uspapi
- window.__uspapi(commandName, USPAPI_VERSION, uspapiCallback);
+ window.__uspapi(commandName, USPAPI_VERSION, moduleCallback);
 
  function readPostMessageResponse(event) {
  const res = event && event.data && event.data.__uspapiReturn;
@@ -130,11 +161,6 @@ function lookupUspConsent(uspSuccess, uspError, hookConfig) {
  }
  }
  }
-
- function uspapiCallback(consentObject, success) {
- window.removeEventListener('message', readPostMessageResponse, false);
- moduleCallback(consentObject, success);
- }
  }
 }