Core: add location method for cross-frame creatives and update creatives

creative/constants.js

@@ -1,6 +1,7 @@
 // eslint-disable-next-line prebid/validate-imports
-import { AD_RENDER_FAILED_REASON, EVENTS, MESSAGES } from '../src/constants.js';
+import {AD_RENDER_FAILED_REASON, EVENTS, MESSAGES} from '../src/constants.js';
 
+export {PB_LOCATOR} from '../src/constants.js';
 export const MESSAGE_REQUEST = MESSAGES.REQUEST;
 export const MESSAGE_RESPONSE = MESSAGES.RESPONSE;
 export const MESSAGE_EVENT = MESSAGES.EVENT;

creative/crossDomain.js

@@ -1,9 +1,11 @@
 import {
   ERROR_EXCEPTION,
-  EVENT_AD_RENDER_FAILED, EVENT_AD_RENDER_SUCCEEDED,
+  EVENT_AD_RENDER_FAILED,
+  EVENT_AD_RENDER_SUCCEEDED,
   MESSAGE_EVENT,
   MESSAGE_REQUEST,
-  MESSAGE_RESPONSE
+  MESSAGE_RESPONSE,
+  PB_LOCATOR
 } from './constants.js';
 
 const mkFrame = (() => {
@@ -24,14 +26,24 @@ const mkFrame = (() => {
   };
 })();
 
+function isPrebidWindow(win) {
+  return !!win.frames[PB_LOCATOR];
+}
+
 export function renderer(win) {
+  let target = win.parent;
+  while (target !== win.top && !isPrebidWindow(target)) {
+    target = target.parent;
+  }
+  if (!isPrebidWindow(target)) target = win.parent;
+
   return function ({adId, pubUrl, clickUrl}) {
     const pubDomain = new URL(pubUrl, window.location).origin;
 
     function sendMessage(type, payload, responseListener) {
       const channel = new MessageChannel();
       channel.port1.onmessage = guard(responseListener);
-      win.parent.postMessage(JSON.stringify(Object.assign({message: type, adId}, payload)), pubDomain, [channel.port2]);
+      target.postMessage(JSON.stringify(Object.assign({message: type, adId}, payload)), pubDomain, [channel.port2]);
     }
 
     function onError(e) {
@@ -77,7 +89,7 @@ export function renderer(win) {
           W.Promise.resolve(W.render(data, {sendMessage, mkFrame}, win)).then(
             () => sendMessage(MESSAGE_EVENT, {event: EVENT_AD_RENDER_SUCCEEDED}),
             onError
-          )
+          );
         });
         win.document.body.appendChild(renderer);
       }

integrationExamples/gpt/x-domain/creative.html

@@ -2,7 +2,7 @@
 // creative will be rendered, e.g. GAM delivering a SafeFrame
 
 // this code is autogenerated, also available in 'build/creative/creative.js'
-<script>!function(){"use strict";const e="Prebid Event",n=(()=>{const e={frameBorder:0,scrolling:"no",marginHeight:0,marginWidth:0,topMargin:0,leftMargin:0,allowTransparency:"true"};return(n,t)=>{const r=n.createElement("iframe");return Object.entries(Object.assign({},t,e)).forEach((([e,n])=>r.setAttribute(e,n))),r}})();var t;window.pbRender=(t=window,function({adId:r,pubUrl:s,clickUrl:o}){const i=new URL(s,window.location).origin;function a(e,n,s){const o=new MessageChannel;o.port1.onmessage=d(s),t.parent.postMessage(JSON.stringify(Object.assign({message:e,adId:r},n)),i,[o.port2])}function c(n){a(e,{event:"adRenderFailed",info:{reason:n?.reason||"exception",message:n?.message}}),n?.stack&&console.error(n)}function d(e){return function(){try{return e.apply(this,arguments)}catch(e){c(e)}}}a("Prebid Request",{options:{clickUrl:o}},(function(s){let o;try{o=JSON.parse(s.data)}catch(e){return}if("Prebid Response"===o.message&&o.adId===r){const r=n(t.document,{width:0,height:0,style:"display: none",srcdoc:`<script>${o.renderer}<\/script>`});r.onload=d((function(){const s=r.contentWindow;s.Promise.resolve(s.render(o,{sendMessage:a,mkFrame:n},t)).then((()=>a(e,{event:"adRenderSucceeded"})),c)})),t.document.body.appendChild(r)}}))})}();</script>
+<script>(()=>{"use strict";const e="Prebid Event",n=(()=>{const e={frameBorder:0,scrolling:"no",marginHeight:0,marginWidth:0,topMargin:0,leftMargin:0,allowTransparency:"true"};return(n,t)=>{const r=n.createElement("iframe");return Object.entries(Object.assign({},t,e)).forEach((([e,n])=>r.setAttribute(e,n))),r}})();function t(e){return!!e.frames.__pb_locator__}window.pbRender=function(r){let o=r.parent;for(;o!==r.top&&!t(o);)o=o.parent;return t(o)||(o=r.parent),function({adId:t,pubUrl:s,clickUrl:i}){const a=new URL(s,window.location).origin;function c(e,n,r){const s=new MessageChannel;s.port1.onmessage=l(r),o.postMessage(JSON.stringify(Object.assign({message:e,adId:t},n)),a,[s.port2])}function d(n){c(e,{event:"adRenderFailed",info:{reason:n?.reason||"exception",message:n?.message}}),n?.stack&&console.error(n)}function l(e){return function(){try{return e.apply(this,arguments)}catch(e){d(e)}}}c("Prebid Request",{options:{clickUrl:i}},(function(o){let s;try{s=JSON.parse(o.data)}catch(e){return}if("Prebid Response"===s.message&&s.adId===t){const t=n(r.document,{width:0,height:0,style:"display: none",srcdoc:`<script>${s.renderer}<\/script>`});t.onload=l((function(){const o=t.contentWindow;o.Promise.resolve(o.render(s,{sendMessage:c,mkFrame:n},r)).then((()=>c(e,{event:"adRenderSucceeded"})),d)})),r.document.body.appendChild(t)}}))}}(window)})();</script>
 
 <script>
     pbRender({

src/adRendering.js

@@ -1,6 +1,15 @@
-import {createIframe, deepAccess, inIframe, insertElement, logError, logWarn, replaceMacros} from './utils.js';
+import {
+  createIframe,
+  createInvisibleIframe,
+  deepAccess,
+  inIframe,
+  insertElement,
+  logError,
+  logWarn,
+  replaceMacros
+} from './utils.js';
 import * as events from './events.js';
-import { AD_RENDER_FAILED_REASON, BID_STATUS, EVENTS, MESSAGES } from './constants.js';
+import {AD_RENDER_FAILED_REASON, BID_STATUS, EVENTS, MESSAGES, PB_LOCATOR} from './constants.js';
 import {config} from './config.js';
 import {executeRenderer, isRendererRequired} from './Renderer.js';
 import {VIDEO} from './mediaTypes.js';
@@ -235,3 +244,17 @@ export function renderAdDirect(doc, adId, options) {
     fail(EXCEPTION, e.message);
   }
 }
+
+/**
+ * Insert an invisible, named iframe that can be used by creatives to locate the window Prebid is running in
+ * (by looking for one that has `.frames[PB_LOCATOR]` defined).
+ * This is necessary because in some situations creatives may be rendered inside nested iframes - Prebid is not necessarily
+ * in the immediate parent window.
+ */
+export function insertLocatorFrame() {
+  if (!window.frames[PB_LOCATOR]) {
+    const frame = createInvisibleIframe();
+    frame.name = PB_LOCATOR;
+    document.body.appendChild(frame);
+  }
+}

src/constants.js

@@ -193,3 +193,5 @@ export const MESSAGES = {
   NATIVE: 'Prebid Native',
   EVENT: 'Prebid Event'
 };
+
+export const PB_LOCATOR = '__pb_locator__';

src/prebid.js

@@ -39,7 +39,7 @@ import {newMetrics, useMetrics} from './utils/perfMetrics.js';
 import {defer, GreedyPromise} from './utils/promise.js';
 import {enrichFPD} from './fpd/enrichment.js';
 import {allConsent} from './consentHandler.js';
-import {renderAdDirect} from './adRendering.js';
+import {insertLocatorFrame, renderAdDirect} from './adRendering.js';
 import {getHighestCpm} from './utils/reducers.js';
 import {fillVideoDefaults} from './video.js';
 
@@ -976,6 +976,7 @@ function processQueue(queue) {
  * @alias module:pbjs.processQueue
  */
 pbjsInstance.processQueue = function () {
+  insertLocatorFrame();
   hook.ready();
   processQueue(pbjsInstance.que);
   processQueue(pbjsInstance.cmd);

test/spec/creative/crossDomainCreative_spec.js

@@ -9,12 +9,18 @@ import {
 
 describe('cross-domain creative', () => {
   const ORIGIN = 'https://example.com';
-  let win, renderAd, messages, mkIframe;
+  let win, top, renderAd, messages, mkIframe;
 
   beforeEach(() => {
     messages = [];
     mkIframe = sinon.stub();
+    top = {
+      frames: {}
+    };
+    top.top = top;
     win = {
+      top,
+      frames: {},
       document: {
         body: {
           appendChild: sinon.stub(),
@@ -30,12 +36,14 @@ describe('cross-domain creative', () => {
         })
       },
       parent: {
+        parent: top,
+        frames: {'__pb_locator__': {}},
         postMessage: sinon.stub().callsFake((payload, targetOrigin, transfer) => {
           messages.push({payload: JSON.parse(payload), targetOrigin, transfer});
         })
       }
     };
-    renderAd = renderer(win);
+    renderAd = (...args) => renderer(win)(...args);
   })
 
   function waitFor(predicate, timeout = 1000) {
@@ -64,6 +72,34 @@ describe('cross-domain creative', () => {
     expect(messages[0].targetOrigin).to.eql('https://domain.com:123')
   });
 
+  it('posts to first parent if no __pb_locator__ can be found', () => {
+    delete win.parent.frames['__pb_locator__'];
+    renderAd({pubUrl: 'https://www.example.com'});
+    expect(messages.length).to.eql(1);
+  })
+
+  describe('when there are multiple ancestors', () => {
+    let target;
+    beforeEach(() => {
+      target = win.parent;
+      win.parent = {
+        top,
+        frames: {},
+        parent: {
+          ...target,
+          parent: {
+            frames: {'__pb_locator__': {}},
+            top
+          }
+        }
+      }
+    })
+    it('posts message to the first ancestor with __pb_locator__ child', () => {
+      renderAd({pubUrl: 'https://www.example.com'});
+      expect(messages.length).to.eql(1);
+    });
+  })
+
   it('generates request message with adId and clickUrl', () => {
     renderAd({adId: '123', clickUrl: 'https://click-url.com', pubUrl: ORIGIN});
     expect(messages[0].payload).to.eql({

test/spec/unit/pbjs_api_spec.js

@@ -26,7 +26,7 @@ import {enrichFPD} from '../../../src/fpd/enrichment.js';
 import {mockFpdEnrichments} from '../../helpers/fpd.js';
 import {generateUUID} from '../../../src/utils.js';
 import {getCreativeRenderer} from '../../../src/creativeRenderers.js';
-import { BID_STATUS, EVENTS, GRANULARITY_OPTIONS, TARGETING_KEYS } from 'src/constants.js';
+import {BID_STATUS, EVENTS, GRANULARITY_OPTIONS, PB_LOCATOR, TARGETING_KEYS} from 'src/constants.js';
 import {getBidToRender} from '../../../src/adRendering.js';
 
 var assert = require('chai').assert;
@@ -236,6 +236,11 @@ describe('Unit: Prebid Module', function () {
     getBidToRender.getHooks({hook: getBidToRenderHook}).remove();
   });
 
+  it('should insert a locator frame on the page', () => {
+    $$PREBID_GLOBAL$$.processQueue();
+    expect(window.frames[PB_LOCATOR]).to.exist;
+  })
+
   describe('and global adUnits', () => {
     const startingAdUnits = [
       {