Merge pull request #818 from hypothesis/support-newer-pdfjs

Support recent versions of PDF.js

src/annotator/plugin/pdf-metadata.js

@@ -38,13 +38,20 @@ class PDFMetadata {
     this._loaded = new Promise(resolve => {
       const finish = () => {
         window.removeEventListener('documentload', finish);
+        window.removeEventListener('documentloaded', finish);
         resolve(app);
       };
 
-      if (app.documentFingerprint) {
+      if (app.downloadComplete) {
         resolve(app);
       } else {
+        // Listen for either the `documentload` (older PDF.js) or
+        // `documentloaded` (newer PDF.js) events which signal that the document
+        // has been downloaded and the first page has been rendered.
+        //
+        // See https://github.com/mozilla/pdf.js/commit/7bc4bfcc8b7f52b14107f0a551becdf01643c5c2
         window.addEventListener('documentload', finish);
+        window.addEventListener('documentloaded', finish);
       }
     });
   }
@@ -61,7 +68,7 @@ class PDFMetadata {
     return this._loaded.then(app => {
       let uri = getPDFURL(app);
       if (!uri) {
-        uri = fingerprintToURN(app.documentFingerprint);
+        uri = fingerprintToURN(app.pdfDocument.fingerprint);
       }
       return uri;
     });
@@ -86,7 +93,7 @@ class PDFMetadata {
       }
 
       const link = [
-        {href: fingerprintToURN(app.documentFingerprint)},
+        {href: fingerprintToURN(app.pdfDocument.fingerprint)},
       ];
 
       const url = getPDFURL(app);
@@ -97,7 +104,7 @@ class PDFMetadata {
       return {
         title: title,
         link: link,
-        documentFingerprint: app.documentFingerprint,
+        documentFingerprint: app.pdfDocument.fingerprint,
       };
     });
   }

src/annotator/plugin/test/pdf-metadata-test.js

@@ -2,27 +2,107 @@
 
 const PDFMetadata = require('../pdf-metadata');
 
-describe('pdf-metadata', function () {
+/**
+ * Fake implementation of PDF.js `window.PDFViewerApplication.metadata`.
+ */
+class FakeMetadata {
+  /**
+   * Initialize the metadata dictionary.
+   *
+   * @param {Object} metadata - A key/value dictionary of metadata fields.
+   */
+  constructor(metadata) {
+    this._metadata = metadata;
+  }
+
+  get(key) {
+    return this._metadata[key];
+  }
+
+  has(key) {
+    return this._metadata.hasOwnProperty(key);
+  }
+}
+
+/**
+ * Fake implementation of PDF.js `window.PDFViewerApplication.pdfDocument`.
+ */
+class FakePDFDocumentProxy {
+  constructor({ fingerprint }) {
+    this.fingerprint = fingerprint;
+  }
+}
+
+/**
+ * Fake implementation of PDF.js `window.PDFViewerApplication` entry point.
+ *
+ * This fake only implements the parts that concern document metadata.
+ */
+class FakePDFViewerApplication {
+  /**
+   * Initialize the "PDF viewer" as it would be when loading a document or
+   * when a document fails to load.
+   */
+  constructor(url = '') {
+    this.url = url;
+    this.documentInfo = undefined;
+    this.metadata = undefined;
+    this.pdfDocument = null;
+  }
+
+  /**
+   * Simulate completion of PDF document loading.
+   */
+  finishLoading({ url, fingerprint, metadata, title, eventName = 'documentload' }) {
+    const event = document.createEvent('Event');
+    event.initEvent(eventName, false, false);
+    window.dispatchEvent(event);
+
+    this.url = url;
+    this.downloadComplete = true;
+    this.documentInfo = {};
+
+    if (typeof title !== undefined) {
+      this.documentInfo.Title = title;
+    }
+
+    if (metadata) {
+      this.metadata = new FakeMetadata(metadata);
+    }
+
+    this.pdfDocument = new FakePDFDocumentProxy({ fingerprint });
+  }
+}
+
+describe('annotator/plugin/pdf-metadata', function () {
+  [
+    // Event dispatched in older PDF.js versions (pre-7bc4bfcc).
+    'documentload',
+    // Event dispatched in newer PDF.js versions (post-7bc4bfcc).
+    'documentloaded',
+  ].forEach(eventName => {
     it('waits for the PDF to load before returning metadata', function () {
-    const fakeApp = {};
+      const fakeApp = new FakePDFViewerApplication;
       const pdfMetadata = new PDFMetadata(fakeApp);
 
-    const event = document.createEvent('Event');
-    event.initEvent('documentload', false, false);
-    fakeApp.url = 'http://fake.com';
-    fakeApp.documentFingerprint = 'fakeFingerprint';
-    window.dispatchEvent(event);
+      fakeApp.finishLoading({
+        eventName,
+        url: 'http://fake.com',
+        fingerprint: 'fakeFingerprint',
+      });
 
       return pdfMetadata.getUri().then(function (uri) {
         assert.equal(uri, 'http://fake.com/');
       });
     });
+  });
 
   it('does not wait for the PDF to load if it has already loaded', function () {
-    const fakePDFViewerApplication = {
+    const fakePDFViewerApplication = new FakePDFViewerApplication;
+    fakePDFViewerApplication.finishLoading({
       url: 'http://fake.com',
-      documentFingerprint: 'fakeFingerprint',
-    };
+      fingerprint: 'fakeFingerprint',
+    });
     const pdfMetadata = new PDFMetadata(fakePDFViewerApplication);
     return pdfMetadata.getUri().then(function (uri) {
       assert.equal(uri, 'http://fake.com/');
@@ -31,18 +111,15 @@ describe('pdf-metadata', function () {
 
   describe('metadata sources', function () {
     let pdfMetadata;
-    const fakePDFViewerApplication = {
-      documentFingerprint: 'fakeFingerprint',
-      documentInfo: {
-        Title: 'fakeTitle',
-      },
+    const fakePDFViewerApplication = new FakePDFViewerApplication;
+    fakePDFViewerApplication.finishLoading({
+      fingerprint: 'fakeFingerprint',
+      title: 'fakeTitle',
       metadata: {
-        metadata: {
-          'dc:title': 'fakeTitle',
-        },
+        'dc:title': 'dcFakeTitle',
       },
       url: 'http://fake.com/',
-    };
+    });
 
     beforeEach(function () {
       pdfMetadata = new PDFMetadata(fakePDFViewerApplication);
@@ -56,10 +133,11 @@ describe('pdf-metadata', function () {
       });
 
       it('returns the fingerprint as a URN when the PDF URL is a local file', function () {
-        const fakePDFViewerApplication = {
+        const fakePDFViewerApplication = new FakePDFViewerApplication;
+        fakePDFViewerApplication.finishLoading({
           url: 'file:///test.pdf',
-          documentFingerprint: 'fakeFingerprint',
-        };
+          fingerprint: 'fakeFingerprint',
+        });
         const pdfMetadata = new PDFMetadata(fakePDFViewerApplication);
 
         return pdfMetadata.getUri().then(function (uri) {
@@ -68,10 +146,11 @@ describe('pdf-metadata', function () {
       });
 
       it('resolves relative URLs', () => {
-        const fakePDFViewerApplication = {
+        const fakePDFViewerApplication = new FakePDFViewerApplication;
+        fakePDFViewerApplication.finishLoading({
           url: 'index.php?action=download&file_id=wibble',
-          documentFingerprint: 'fakeFingerprint',
-        };
+          fingerprint: 'fakeFingerprint',
+        });
         const pdfMetadata = new PDFMetadata(fakePDFViewerApplication);
 
         return pdfMetadata.getUri().then(uri => {
@@ -85,15 +164,12 @@ describe('pdf-metadata', function () {
     describe('#getMetadata', function () {
       it('gets the title from the dc:title field', function () {
         const expectedMetadata = {
-          title: 'dcTitle',
-          link: [{href: 'urn:x-pdf:' + fakePDFViewerApplication.documentFingerprint},
+          title: 'dcFakeTitle',
+          link: [{href: 'urn:x-pdf:' + fakePDFViewerApplication.pdfDocument.fingerprint},
             {href: fakePDFViewerApplication.url}],
-          documentFingerprint: fakePDFViewerApplication.documentFingerprint,
+          documentFingerprint: fakePDFViewerApplication.pdfDocument.fingerprint,
         };
 
-        fakePDFViewerApplication.metadata.has = sinon.stub().returns(true);
-        fakePDFViewerApplication.metadata.get = sinon.stub().returns('dcTitle');
-
         return pdfMetadata.getMetadata().then(function (actualMetadata) {
           assert.deepEqual(actualMetadata, expectedMetadata);
         });
@@ -102,9 +178,9 @@ describe('pdf-metadata', function () {
       it('gets the title from the documentInfo.Title field', function () {
         const expectedMetadata = {
           title: fakePDFViewerApplication.documentInfo.Title,
-          link: [{href: 'urn:x-pdf:' + fakePDFViewerApplication.documentFingerprint},
+          link: [{href: 'urn:x-pdf:' + fakePDFViewerApplication.pdfDocument.fingerprint},
             {href: fakePDFViewerApplication.url}],
-          documentFingerprint: fakePDFViewerApplication.documentFingerprint,
+          documentFingerprint: fakePDFViewerApplication.pdfDocument.fingerprint,
         };
 
         fakePDFViewerApplication.metadata.has = sinon.stub().returns(false);
@@ -116,12 +192,13 @@ describe('pdf-metadata', function () {
 
       it('does not save file:// URLs in document metadata', function () {
         let pdfMetadata;
-        const fakePDFViewerApplication = {
-          documentFingerprint: 'fakeFingerprint',
+        const fakePDFViewerApplication = new FakePDFViewerApplication;
+        fakePDFViewerApplication.finishLoading({
+          fingerprint: 'fakeFingerprint',
           url: 'file://fake.pdf',
-        };
+        });
         const expectedMetadata = {
-          link: [{href: 'urn:x-pdf:' + fakePDFViewerApplication.documentFingerprint}],
+          link: [{href: 'urn:x-pdf:' + fakePDFViewerApplication.pdfDocument.fingerprint}],
         };
 
         pdfMetadata = new PDFMetadata(fakePDFViewerApplication);