PBjs Core : add ability to inject tracking in video

src/auction.js

@@ -83,7 +83,7 @@ import {config} from './config.js';
 import {userSync} from './userSync.js';
 import {hook} from './hook.js';
 import {find, includes} from './polyfill.js';
-import {OUTSTREAM} from './video.js';
+import {OUTSTREAM, getVastTrackers, insertVastTrackers} from './video.js';
 import {VIDEO} from './mediaTypes.js';
 import {auctionManager} from './auctionManager.js';
 import {bidderSettings} from './bidderSettings.js';
@@ -582,7 +582,9 @@ function tryAddVideoBid(auctionInstance, bidResponse, afterBidAdded, {index = au
     }), 'video');
   const context = videoMediaType && deepAccess(videoMediaType, 'context');
   const useCacheKey = videoMediaType && deepAccess(videoMediaType, 'useCacheKey');
+  const [hasTrackers, vastTrackers] = getVastTrackers(bidResponse);
 
+  if (hasTrackers) { bidResponse.vastXml = insertVastTrackers(vastTrackers, bidResponse.vastXml); }
   if (config.getConfig('cache.url') && (useCacheKey || context !== OUTSTREAM)) {
     if (!bidResponse.videoCacheKey || config.getConfig('cache.ignoreBidderCacheKey')) {
       addBid = false;

src/video.js

@@ -21,6 +21,8 @@ export const videoBidder = bid => includes(adapterManager.videoAdapters, bid.bid
 export const hasNonVideoBidder = adUnit =>
   adUnit.bids.filter(bid => !videoBidder(bid)).length;
 
+let vastTrackers = [];
+
 /**
  * @typedef {object} VideoBid
  * @property {string} adId id of the bid
@@ -64,3 +66,47 @@ export const checkVideoBidSetup = hook('sync', function(bid, adUnit, videoMediaT
 
   return true;
 }, 'checkVideoBidSetup');
+
+export function registerVASTTrackers(tracker) {
+  vastTrackers.push(tracker);
+}
+
+export function insertVastTrackers(trackers, vastXml) {
+  const doc = new DOMParser().parseFromString(vastXml, 'text/xml');
+  const wrappers = doc.querySelectorAll('VAST Ad Wrapper, VAST Ad InLine');
+  try {
+    if (wrappers.length) {
+      wrappers.forEach(wrapper => {
+        trackers['impressions'].forEach(trackingUrl => {
+          const impression = doc.createElement('Impression');
+          impression.appendChild(doc.createCDATASection(trackingUrl));
+          wrapper.appendChild(impression)
+        });
+      });
+      vastXml = new XMLSerializer().serializeToString(doc);
+    }
+  } catch (error) {
+    logError('an error happened trying to insert trackers in vastXml');
+  }
+  return vastXml;
+}
+
+export function getVastTrackers(bid) {
+  let hasTrackers = false;
+  let trackers = {'impressions': []};
+  vastTrackers.forEach(func => {
+    let tmpTrackers = func(bid);
+    for (const key in tmpTrackers) {
+      if (key in trackers && Array.isArray(tmpTrackers[key])) {
+        // only add not existing trackers
+        tmpTrackers[key].forEach(item => {
+          if (!trackers[key].includes(item)) {
+            trackers[key].push(item);
+            hasTrackers = true;
+          }
+        });
+      }
+    }
+  });
+  return [hasTrackers, trackers];
+}

src/videoCache.js

@@ -12,6 +12,7 @@
 import {ajaxBuilder} from './ajax.js';
 import {config} from './config.js';
 import {auctionManager} from './auctionManager.js';
+import {getVastTrackers} from './video.js';
 
 /**
  * Might be useful to be configurable in the future
@@ -42,17 +43,22 @@ const ttlBufferInSeconds = 15;
  * @param {string} impUrl An impression tracker URL for the delivery of the video ad
  * @return A VAST URL which loads XML from the given URI.
  */
-function wrapURI(uri, impUrl) {
+function wrapURI(uri, impUrl, arrayVastTrackers) {
   // Technically, this is vulnerable to cross-script injection by sketchy vastUrl bids.
   // We could make sure it's a valid URI... but since we're loading VAST XML from the
   // URL they provide anyway, that's probably not a big deal.
-  let vastImp = (impUrl) ? `<![CDATA[${impUrl}]]>` : ``;
+  let impressions = (impUrl) ? `<Impression><![CDATA[${impUrl}]]></Impression>` : ``;
+  if (Array.isArray(arrayVastTrackers) && arrayVastTrackers.length == 2 && arrayVastTrackers[1].hasOwnProperty('impressions')) {
+    arrayVastTrackers[1]['impressions'].forEach(trackingImp => {
+      impressions += `<Impression><![CDATA[${trackingImp}]]></Impression>`;
+    });
+  }
   return `<VAST version="3.0">
     <Ad>
       <Wrapper>
         <AdSystem>prebid.org wrapper</AdSystem>
         <VASTAdTagURI><![CDATA[${uri}]]></VASTAdTagURI>
-        <Impression>${vastImp}</Impression>
+        ${impressions}
         <Creatives></Creatives>
       </Wrapper>
     </Ad>
@@ -67,7 +73,7 @@ function wrapURI(uri, impUrl) {
  * @param index
  */
 function toStorageRequest(bid, {index = auctionManager.index} = {}) {
-  const vastValue = bid.vastXml ? bid.vastXml : wrapURI(bid.vastUrl, bid.vastImpUrl);
+  const vastValue = bid.vastXml ? bid.vastXml : wrapURI(bid.vastUrl, bid.vastImpUrl, getVastTrackers(bid));
   const auction = index.getAuction(bid);
   const ttlWithBuffer = Number(bid.ttl) + ttlBufferInSeconds;
   let payload = {

test/spec/videoCache_spec.js

@@ -1,4 +1,5 @@
 import chai from 'chai';
+import { registerVASTTrackers } from 'src/video.js';
 import { getCacheUrl, store } from 'src/videoCache.js';
 import { config } from 'src/config.js';
 import { server } from 'test/mocks/xhr.js';
@@ -127,7 +128,7 @@ describe('The video cache', function () {
       <Wrapper>
         <AdSystem>prebid.org wrapper</AdSystem>
         <VASTAdTagURI><![CDATA[my-mock-url.com]]></VASTAdTagURI>
-        <Impression></Impression>
+
         <Creatives></Creatives>
       </Wrapper>
     </Ad>
@@ -149,6 +150,39 @@ describe('The video cache', function () {
       assertRequestMade({ vastUrl: 'my-mock-url.com', vastImpUrl: 'imptracker.com', ttl: 25 }, expectedValue)
     });
 
+    it('should include additional impressions trackers on top of vastImpUrl when they exist', function() {
+      registerVASTTrackers(function(bidResponse) {
+        return {
+          'impressions': [`https://vasttracking.mydomain.com/vast?cpm=${bidResponse.cpm}`]
+        };
+      });
+      const expectedValue = `<VAST version="3.0">
+    <Ad>
+      <Wrapper>
+        <AdSystem>prebid.org wrapper</AdSystem>
+        <VASTAdTagURI><![CDATA[my-mock-url.com]]></VASTAdTagURI>
+        <Impression><![CDATA[imptracker.com]]></Impression><Impression><![CDATA[https://vasttracking.mydomain.com/vast?cpm=1.2]]></Impression>
+        <Creatives></Creatives>
+      </Wrapper>
+    </Ad>
+  </VAST>`;
+      assertRequestMade({ vastUrl: 'my-mock-url.com', vastImpUrl: 'imptracker.com', ttl: 25, cpm: 1.2 }, expectedValue)
+    });
+
+    it('should include only additional impressions trackers when they exist', function() {
+      const expectedValue = `<VAST version="3.0">
+    <Ad>
+      <Wrapper>
+        <AdSystem>prebid.org wrapper</AdSystem>
+        <VASTAdTagURI><![CDATA[my-mock-url.com]]></VASTAdTagURI>
+        <Impression><![CDATA[https://vasttracking.mydomain.com/vast?cpm=1.2]]></Impression>
+        <Creatives></Creatives>
+      </Wrapper>
+    </Ad>
+  </VAST>`;
+      assertRequestMade({ vastUrl: 'my-mock-url.com', ttl: 25, cpm: 1.2 }, expectedValue)
+    });
+
     it('should make the expected request when store() is called on an ad with vastXml', function () {
       const vastXml = '<VAST version="3.0"></VAST>';
       assertRequestMade({ vastXml: vastXml, ttl: 25 }, vastXml);

test/spec/video_spec.js

@@ -1,4 +1,4 @@
-import { isValidVideoBid } from 'src/video.js';
+import { isValidVideoBid, registerVASTTrackers, insertVastTrackers, getVastTrackers } from 'src/video.js';
 import {hook} from '../../src/hook.js';
 import {stubAuctionIndex} from '../helpers/indexStub.js';
 
@@ -100,4 +100,24 @@ describe('video.js', function () {
     const valid = isValidVideoBid(bid, {index: stubAuctionIndex({adUnits})});
     expect(valid).to.equal(false);
   });
+
+  it('insert into tracker list', function() {
+    registerVASTTrackers(function(bidResponse) {
+      return {
+        'impressions': [`https://vasttracking.mydomain.com/vast?cpm=${bidResponse.cpm}`]
+      };
+    });
+    const [hasTrackers, trackers] = getVastTrackers({'cpm': 1.0});
+    expect(hasTrackers).to.equal(true);
+    expect(trackers).to.have.property('impressions');
+    expect(trackers.impressions.length).to.equal(1);
+    expect(trackers.impressions[0]).to.equal('https://vasttracking.mydomain.com/vast?cpm=1');
+  });
+
+  it('insert trackers in vastXml', function() {
+    const [hasTrackers, trackers] = getVastTrackers({'cpm': 1.0});
+    let vastXml = '<VAST><Ad><Wrapper></Wrapper></Ad></VAST>';
+    vastXml = insertVastTrackers(trackers, vastXml);
+    expect(vastXml).to.equal('<VAST><Ad><Wrapper><Impression><![CDATA[https://vasttracking.mydomain.com/vast?cpm=1]]></Impression></Wrapper></Ad></VAST>');
+  });
 });