feat: allow generating accessible pdf with printToPDF (electron#39563)

* feat: allow generating accessible pdf with printToPDF

* docs: mark generateTaggedPDF experimental

docs/api/web-contents.md

@@ -1626,6 +1626,7 @@ win.webContents.print(options, (success, errorType) => {
   * `headerTemplate` string (optional) - HTML template for the print header. Should be valid HTML markup with following classes used to inject printing values into them: `date` (formatted print date), `title` (document title), `url` (document location), `pageNumber` (current page number) and `totalPages` (total pages in the document). For example, `<span class=title></span>` would generate span containing the title.
   * `footerTemplate` string (optional) - HTML template for the print footer. Should use the same format as the `headerTemplate`.
   * `preferCSSPageSize` boolean (optional) - Whether or not to prefer page size as defined by css. Defaults to false, in which case the content will be scaled to fit the paper size.
+  * `generateTaggedPDF` boolean (optional) _Experimental_ - Whether or not to generate a tagged (accessible) PDF. Defaults to false. As this property is experimental, the generated PDF may not adhere fully to PDF/UA and WCAG standards.
 
 Returns `Promise<Buffer>` - Resolves with the generated PDF data.
 

docs/api/webview-tag.md

@@ -607,6 +607,7 @@ Prints `webview`'s web page. Same as `webContents.print([options])`.
   * `headerTemplate` string (optional) - HTML template for the print header. Should be valid HTML markup with following classes used to inject printing values into them: `date` (formatted print date), `title` (document title), `url` (document location), `pageNumber` (current page number) and `totalPages` (total pages in the document). For example, `<span class=title></span>` would generate span containing the title.
   * `footerTemplate` string (optional) - HTML template for the print footer. Should use the same format as the `headerTemplate`.
   * `preferCSSPageSize` boolean (optional) - Whether or not to prefer page size as defined by css. Defaults to false, in which case the content will be scaled to fit the paper size.
+  * `generateTaggedPDF` boolean (optional) _Experimental_ - Whether or not to generate a tagged (accessible) PDF. Defaults to false. As this property is experimental, the generated PDF may not adhere fully to PDF/UA and WCAG standards.
 
 Returns `Promise<Uint8Array>` - Resolves with the generated PDF data.
 

lib/browser/api/web-contents.ts

@@ -206,7 +206,8 @@ WebContents.prototype.printToPDF = async function (options) {
     marginLeft: 0.4,
     marginRight: 0.4,
     pageRanges: '',
-    preferCSSPageSize: false
+    preferCSSPageSize: false,
+    shouldGenerateTaggedPDF: false
   };
 
   if (options.landscape !== undefined) {
@@ -322,6 +323,13 @@ WebContents.prototype.printToPDF = async function (options) {
     printSettings.preferCSSPageSize = options.preferCSSPageSize;
   }
 
+  if (options.generateTaggedPDF !== undefined) {
+    if (typeof options.generateTaggedPDF !== 'boolean') {
+      throw new Error('generateTaggedPDF must be a Boolean');
+    }
+    printSettings.shouldGenerateTaggedPDF = options.generateTaggedPDF;
+  }
+
   if (this._printToPDF) {
     if (pendingPromise) {
       pendingPromise = pendingPromise.then(() => this._printToPDF(printSettings));

spec/api-web-contents-spec.ts

@@ -2081,6 +2081,28 @@ describe('webContents module', () => {
       // Check that correct # of pages are rendered.
       expect(doc.numPages).to.equal(3);
     });
+
+    it('does not tag PDFs by default', async () => {
+      await w.loadFile(path.join(__dirname, 'fixtures', 'api', 'print-to-pdf-small.html'));
+
+      const data = await w.webContents.printToPDF({});
+      const doc = await pdfjs.getDocument(data).promise;
+      const markInfo = await doc.getMarkInfo();
+      expect(markInfo).to.be.null();
+    });
+
+    it('can generate tag data for PDFs', async () => {
+      await w.loadFile(path.join(__dirname, 'fixtures', 'api', 'print-to-pdf-small.html'));
+
+      const data = await w.webContents.printToPDF({ generateTaggedPDF: true });
+      const doc = await pdfjs.getDocument(data).promise;
+      const markInfo = await doc.getMarkInfo();
+      expect(markInfo).to.deep.equal({
+        Marked: true,
+        UserProperties: false,
+        Suspects: false
+      });
+    });
   });
 
   describe('PictureInPicture video', () => {

spec/package.json

@@ -25,7 +25,7 @@
     "mocha": "^10.0.0",
     "mocha-junit-reporter": "^1.18.0",
     "mocha-multi-reporters": "^1.1.7",
-    "pdfjs-dist": "^2.2.228",
+    "pdfjs-dist": "^2.16.105",
     "ps-list": "^7.0.0",
     "q": "^1.5.1",
     "send": "^0.16.2",

spec/yarn.lock

@@ -129,21 +129,6 @@ abstract-socket@^2.0.0:
     bindings "^1.2.1"
     nan "^2.12.1"
 
-ajv-keywords@^3.1.0:
-  version "3.4.1"
-  resolved "https://registry.yarnpkg.com/ajv-keywords/-/ajv-keywords-3.4.1.tgz#ef916e271c64ac12171fd8384eaae6b2345854da"
-  integrity sha512-RO1ibKvd27e6FEShVFfPALuHI3WjSVNeK5FIsmme/LYRNxjKuNj+Dt7bucLa6NdSv3JcVTyMlm9kGR84z1XpaQ==
-
-ajv@^6.1.0:
-  version "6.12.6"
-  resolved "https://registry.yarnpkg.com/ajv/-/ajv-6.12.6.tgz#baf5a62e802b07d977034586f8c3baf5adf26df4"
-  integrity sha512-j3fVLgvTo527anyYyJOGTYJbG+vnnQYvE0m5mmkc1TK+nxAppkCLMIL0aZ4dblVCNoGShhm+kzE4ZUykBoMg4g==
-  dependencies:
-    fast-deep-equal "^3.1.1"
-    fast-json-stable-stringify "^2.0.0"
-    json-schema-traverse "^0.4.1"
-    uri-js "^4.2.2"
-
 ansi-colors@4.1.1:
   version "4.1.1"
   resolved "https://registry.yarnpkg.com/ansi-colors/-/ansi-colors-4.1.1.tgz#cbb9ae256bf750af1eab344f229aa27fe94ba348"
@@ -196,11 +181,6 @@ basic-auth@^2.0.1:
   dependencies:
     safe-buffer "5.1.2"
 
-big.js@^5.2.2:
-  version "5.2.2"
-  resolved "https://registry.yarnpkg.com/big.js/-/big.js-5.2.2.tgz#65f0af382f578bcdc742bd9c281e9cb2d7768328"
-  integrity sha512-vyL2OymJxmarO8gxMr0mhChsO9QGwhynfuu4+MHTAW6czfq9humCB7rKpUjDd9YUiDPU4mzpyupFSvOClAwbmQ==
-
 binary-extensions@^2.0.0:
   version "2.2.0"
   resolved "https://registry.yarnpkg.com/binary-extensions/-/binary-extensions-2.2.0.tgz#75f502eeaf9ffde42fc98829645be4ea76bd9e2d"
@@ -443,6 +423,11 @@ dirty-chai@^2.0.1:
   resolved "https://registry.yarnpkg.com/dirty-chai/-/dirty-chai-2.0.1.tgz#6b2162ef17f7943589da840abc96e75bda01aff3"
   integrity sha512-ys79pWKvDMowIDEPC6Fig8d5THiC0DJ2gmTeGzVAoEH18J8OzLud0Jh7I9IWg3NSk8x2UocznUuFmfHCXYZx9w==
 
+dommatrix@^1.0.3:
+  version "1.0.3"
+  resolved "https://registry.yarnpkg.com/dommatrix/-/dommatrix-1.0.3.tgz#e7c18e8d6f3abdd1fef3dd4aa74c4d2e620a0525"
+  integrity sha512-l32Xp/TLgWb8ReqbVJAFIvXmY7go4nTxxlWiAFyhoQw9RKEOHBZNnyGvJWqDVSPmq3Y9HlM4npqF/T6VMOXhww==
+
 duplexer@^0.1.1, duplexer@~0.1.1:
   version "0.1.2"
   resolved "https://registry.yarnpkg.com/duplexer/-/duplexer-0.1.2.tgz#3abe43aef3835f8ae077d136ddce0f276b0400e6"
@@ -458,11 +443,6 @@ emoji-regex@^8.0.0:
   resolved "https://registry.yarnpkg.com/emoji-regex/-/emoji-regex-8.0.0.tgz#e818fd69ce5ccfcb404594f842963bf53164cc37"
   integrity sha512-MSjYzcWNOA0ewAHpz0MxpYFvwg6yjy1NG3xteoqz644VCo/RPgnr1/GGt+ic3iJTzQ8Eu3TdM14SawnVUmGE6A==
 
-emojis-list@^3.0.0:
-  version "3.0.0"
-  resolved "https://registry.yarnpkg.com/emojis-list/-/emojis-list-3.0.0.tgz#5570662046ad29e2e916e71aae260abdff4f6a78"
-  integrity sha512-/kyM18EfinwXZbno9FyUGeFh87KC8HRQBQGildHZbEuRyWFOmv1U10o9BBp8XVZDVNNuQKyIGIu5ZYAAXJ0V2Q==
-
 encodeurl@~1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/encodeurl/-/encodeurl-1.0.2.tgz#ad3ff4c86ec2d029322f5a02c3a9a606c95b3f59"
@@ -508,16 +488,6 @@ event-stream@^4.0.0:
     stream-combiner "^0.2.2"
     through "^2.3.8"
 
-fast-deep-equal@^3.1.1:
-  version "3.1.3"
-  resolved "https://registry.yarnpkg.com/fast-deep-equal/-/fast-deep-equal-3.1.3.tgz#3a7d56b559d6cbc3eb512325244e619a65c6c525"
-  integrity sha512-f3qQ9oQy9j2AhBe/H9VC91wLmKBCCU/gDOnKNAYG5hswO7BLKj09Hc5HYNz9cGI++xlpDCIgDaitVs03ATR84Q==
-
-fast-json-stable-stringify@^2.0.0:
-  version "2.1.0"
-  resolved "https://registry.yarnpkg.com/fast-json-stable-stringify/-/fast-json-stable-stringify-2.1.0.tgz#874bf69c6f404c2b5d99c481341399fd55892633"
-  integrity sha512-lhd/wF+Lk98HZoTCtlVraHtfh5XYijIjalXck7saUtuanSDyLMxnHhSXEDJqHxD7msR8D0uCmqlkwjCV8xvwHw==
-
 file-uri-to-path@1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/file-uri-to-path/-/file-uri-to-path-1.0.0.tgz#553a7b8446ff6f684359c445f1e37a05dacc33dd"
@@ -757,18 +727,6 @@ json-buffer@3.0.1:
   resolved "https://registry.yarnpkg.com/json-buffer/-/json-buffer-3.0.1.tgz#9338802a30d3b6605fbe0613e094008ca8c05a13"
   integrity sha512-4bV5BfR2mqfQTJm+V5tPPdf+ZpuhiIvTuAB5g8kcrXOZpTT/QwwVRWBywX1ozr6lEuPdbHxwaJlm9G6mI2sfSQ==
 
-json-schema-traverse@^0.4.1:
-  version "0.4.1"
-  resolved "https://registry.yarnpkg.com/json-schema-traverse/-/json-schema-traverse-0.4.1.tgz#69f6a87d9513ab8bb8fe63bdb0979c448e684660"
-  integrity sha512-xbbCH5dCYU5T8LcEhhuh7HJ88HXuW3qsI3Y0zOZFKfZEHcpWiHU/Jxzk629Brsab/mMiHQti9wMP+845RPe3Vg==
-
-json5@^1.0.1:
-  version "1.0.2"
-  resolved "https://registry.yarnpkg.com/json5/-/json5-1.0.2.tgz#63d98d60f21b313b77c4d6da18bfa69d80e1d593"
-  integrity sha512-g1MWMLBiz8FKi1e4w0UyVL3w+iJceWAFBAaBnnGKOpNa5f8TLktkbre1+s6oICydWAm+HRUGTmI+//xv2hvXYA==
-  dependencies:
-    minimist "^1.2.0"
-
 just-extend@^4.0.2:
   version "4.1.0"
   resolved "https://registry.yarnpkg.com/just-extend/-/just-extend-4.1.0.tgz#7278a4027d889601640ee0ce0e5a00b992467da4"
@@ -781,15 +739,6 @@ keyv@^4.0.0:
   dependencies:
     json-buffer "3.0.1"
 
-loader-utils@^1.0.0:
-  version "1.4.2"
-  resolved "https://registry.yarnpkg.com/loader-utils/-/loader-utils-1.4.2.tgz#29a957f3a63973883eb684f10ffd3d151fec01a3"
-  integrity sha512-I5d00Pd/jwMD2QCduo657+YM/6L3KZu++pmX9VFncxaxvHcru9jx1lBaFft+r4Mt2jK0Yhp41XlRAihzPxHNCg==
-  dependencies:
-    big.js "^5.2.2"
-    emojis-list "^3.0.0"
-    json5 "^1.0.1"
-
 locate-path@^6.0.0:
   version "6.0.0"
   resolved "https://registry.yarnpkg.com/locate-path/-/locate-path-6.0.0.tgz#55321eb309febbc59c4801d931a72452a681d286"
@@ -875,7 +824,7 @@ minimatch@^3.0.4, minimatch@^3.1.1:
   dependencies:
     brace-expansion "^1.1.7"
 
-minimist@1.2.7, minimist@^1.2.0, minimist@^1.2.6, minimist@~0.0.1:
+minimist@1.2.7, minimist@^1.2.6, minimist@~0.0.1:
   version "1.2.7"
   resolved "https://registry.yarnpkg.com/minimist/-/minimist-1.2.7.tgz#daa1c4d91f507390437c6a8bc01078e7000c4d18"
   integrity sha512-bzfL1YUZsP41gmu/qjrEk0Q6i2ix/cVeAhbCbqH9u3zYutS1cLg00qhrD0M2MVdCcx4Sc0UpP2eBWo9rotpq6g==
@@ -968,11 +917,6 @@ nise@^4.0.1:
     just-extend "^4.0.2"
     path-to-regexp "^1.7.0"
 
-node-ensure@^0.0.0:
-  version "0.0.0"
-  resolved "https://registry.yarnpkg.com/node-ensure/-/node-ensure-0.0.0.tgz#ecae764150de99861ec5c810fd5d096b183932a7"
-  integrity sha1-7K52QVDemYYexcgQ/V0Jaxg5Mqc=
-
 normalize-path@^3.0.0, normalize-path@~3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/normalize-path/-/normalize-path-3.0.0.tgz#0dcd69ff23a1c9b11fd0978316644a0388216a65"
@@ -1053,13 +997,13 @@ pause-stream@^0.0.11:
   dependencies:
     through "~2.3"
 
-pdfjs-dist@^2.2.228:
-  version "2.2.228"
-  resolved "https://registry.yarnpkg.com/pdfjs-dist/-/pdfjs-dist-2.2.228.tgz#777b068a0a16c96418433303807c183058b47aaa"
-  integrity sha512-W5LhYPMS2UKX0ELIa4u+CFCMoox5qQNQElt0bAK2mwz1V8jZL0rvLao+0tBujce84PK6PvWG36Nwr7agCCWFGQ==
+pdfjs-dist@^2.16.105:
+  version "2.16.105"
+  resolved "https://registry.yarnpkg.com/pdfjs-dist/-/pdfjs-dist-2.16.105.tgz#937b9c4a918f03f3979c88209d84c1ce90122c2a"
+  integrity sha512-J4dn41spsAwUxCpEoVf6GVoz908IAA3mYiLmNxg8J9kfRXc2jxpbUepcP0ocp0alVNLFthTAM8DZ1RaHh8sU0A==
   dependencies:
-    node-ensure "^0.0.0"
-    worker-loader "^2.0.0"
+    dommatrix "^1.0.3"
+    web-streams-polyfill "^3.2.1"
 
 picomatch@^2.0.4, picomatch@^2.2.1:
   version "2.3.1"
@@ -1079,11 +1023,6 @@ pump@^3.0.0:
     end-of-stream "^1.1.0"
     once "^1.3.1"
 
-punycode@^2.1.0:
-  version "2.1.1"
-  resolved "https://registry.yarnpkg.com/punycode/-/punycode-2.1.1.tgz#b58b010ac40c22c5657616c8d2c2c02c7bf479ec"
-  integrity sha512-XRsRjdf+j5ml+y/6GKHPZbrF/8p2Yga0JPtdqTIY2Xe5ohJPD9saDJJLPvp9+NSBprVvevdXZybnj2cv8OEd0A==
-
 q@^1.5.1:
   version "1.5.1"
   resolved "https://registry.yarnpkg.com/q/-/q-1.5.1.tgz#7e32f75b41381291d04611f1bf14109ac00651d7"
@@ -1152,14 +1091,6 @@ sax@>=0.6.0:
   resolved "https://registry.yarnpkg.com/sax/-/sax-1.2.4.tgz#2816234e2378bddc4e5354fab5caa895df7100d9"
   integrity sha512-NqVDv9TpANUjFm0N8uM5GxL36UgKi9/atZw+x7YFnQ8ckwFGKrl4xX4yWtrey3UJm5nP1kUbnYgLopqWNSRhWw==
 
-schema-utils@^0.4.0:
-  version "0.4.7"
-  resolved "https://registry.yarnpkg.com/schema-utils/-/schema-utils-0.4.7.tgz#ba74f597d2be2ea880131746ee17d0a093c68187"
-  integrity sha512-v/iwU6wvwGK8HbU9yi3/nhGzP0yGSuhQMzL6ySiec1FSrZZDkhm4noOSWzrNFo/jEc+SJY6jRTwuwbSXJPDUnQ==
-  dependencies:
-    ajv "^6.1.0"
-    ajv-keywords "^3.1.0"
-
 send@^0.16.2:
   version "0.16.2"
   resolved "https://registry.yarnpkg.com/send/-/send-0.16.2.tgz#6ecca1e0f8c156d141597559848df64730a6bbc1"
@@ -1301,13 +1232,6 @@ type-detect@4.0.8, type-detect@^4.0.0, type-detect@^4.0.5, type-detect@^4.0.8:
   resolved "https://registry.yarnpkg.com/type-detect/-/type-detect-4.0.8.tgz#7646fb5f18871cfbb7749e69bd39a6388eb7450c"
   integrity sha512-0fr/mIH1dlO+x7TlcMy+bIDqKPsw/70tVyeHW787goQjhmqaZe10uwLujubK9q9Lg6Fiho1KUKDYz0Z7k7g5/g==
 
-uri-js@^4.2.2:
-  version "4.4.1"
-  resolved "https://registry.yarnpkg.com/uri-js/-/uri-js-4.4.1.tgz#9b1a52595225859e55f669d928f88c6c57f2a77e"
-  integrity sha512-7rKUyy33Q1yc98pQ1DAmLtwX109F7TIfWlW1Ydo8Wl1ii1SeHieeh0HHfPeL2fMXK6z0s8ecKs9frCuLJvndBg==
-  dependencies:
-    punycode "^2.1.0"
-
 uuid@^3.3.3:
   version "3.4.0"
   resolved "https://registry.yarnpkg.com/uuid/-/uuid-3.4.0.tgz#b23e4358afa8a202fe7a100af1f5f883f02007ee"
@@ -1318,6 +1242,11 @@ walkdir@^0.3.2:
   resolved "https://registry.yarnpkg.com/walkdir/-/walkdir-0.3.2.tgz#ac8437a288c295656848ebc19981ebc677a5f590"
   integrity sha512-0Twghia4Z5wDGDYWURlhZmI47GvERMCsXIu0QZWVVZyW9ZjpbbZvD9Zy9M6cWiQQRRbAcYajIyKNavaZZDt1Uw==
 
+web-streams-polyfill@^3.2.1:
+  version "3.2.1"
+  resolved "https://registry.yarnpkg.com/web-streams-polyfill/-/web-streams-polyfill-3.2.1.tgz#71c2718c52b45fd49dbeee88634b3a60ceab42a6"
+  integrity sha512-e0MO3wdXWKrLbL0DgGnUV7WHVuw9OUvL4hjgnPkIeEvESk74gAITi5G606JtZPp39cd8HA9VQzCIvA49LpPN5Q==
+
 winreg@^1.2.4:
   version "1.2.4"
   resolved "https://registry.yarnpkg.com/winreg/-/winreg-1.2.4.tgz#ba065629b7a925130e15779108cf540990e98d1b"
@@ -1328,14 +1257,6 @@ wordwrap@~0.0.2:
   resolved "https://registry.yarnpkg.com/wordwrap/-/wordwrap-0.0.3.tgz#a3d5da6cd5c0bc0008d37234bbaf1bed63059107"
   integrity sha512-1tMA907+V4QmxV7dbRvb4/8MaRALK6q9Abid3ndMYnbyo8piisCmeONVqVSXqQA3KaP4SLt5b7ud6E2sqP8TFw==
 
-worker-loader@^2.0.0:
-  version "2.0.0"
-  resolved "https://registry.yarnpkg.com/worker-loader/-/worker-loader-2.0.0.tgz#45fda3ef76aca815771a89107399ee4119b430ac"
-  integrity sha512-tnvNp4K3KQOpfRnD20m8xltE3eWh89Ye+5oj7wXEEHKac1P4oZ6p9oTj8/8ExqoSBnk9nu5Pr4nKfQ1hn2APJw==
-  dependencies:
-    loader-utils "^1.0.0"
-    schema-utils "^0.4.0"
-
 workerpool@6.2.1:
   version "6.2.1"
   resolved "https://registry.yarnpkg.com/workerpool/-/workerpool-6.2.1.tgz#46fc150c17d826b86a008e5a4508656777e9c343"