OptionalContentConfig
I happened to notice that the way the `OptionalContentConfig`-data handled in the PR that implements worker-rendering leaves a lot to be desired:
- The way that the optional content state is handled is not correct, since that PR collects the "effective visibility" of the optional content groups rather than their *actual* internal state.
- The necessary `OptionalContentConfig`-data is collected piecemeal in the API, which leads to quite frankly very messy code that's hard to read and will be even harder to maintain.
The solution to all of these issues seem really simple though, just add a couple of `OptionalContentConfig` methods that serialize/de-serialize the necessary data.
In the API calling `optionalContentConfig.serializable` will get *all* of the needed data for transferring to the worker-renderer, and once received there calling `OptionalContentConfig.fromSerializable(/* transferred data here */)` will create an `OptionalContentConfig` instance with the correct internal state.
As part of this patch, to avoid increasing bundle-size unnecessarily, a couple of existing methods are stubbed out when the `OptionalContentConfig` class ends up in a worker-file (since they're unused there).
This part assumes that the new worker-renderer is built correctly, note how the existing `pdf.worker.mjs` is handled in 03eda70d7e/gulpfile.mjs (L539-L545)
(*Note:* Submitting a PR was a lot faster than trying to provide review comments, since writing this commit message took longer than writing the patch.)
PDF.js

PDF.js is a Portable Document Format (PDF) viewer that is built with HTML5.
PDF.js is community-driven and supported by Mozilla. Our goal is to create a general-purpose, web standards-based platform for parsing and rendering PDFs.
Contributing
PDF.js is an open source project and always looking for more contributors. To get involved, visit:
- Issue Reporting Guide
- Code Contribution Guide
- Frequently Asked Questions
- Good Beginner Bugs
- Projects
Feel free to stop by our Matrix room for questions or guidance.
Getting Started
Online demo
Please note that the "Modern browsers" version assumes native support for the latest JavaScript features; please also see this wiki page.
-
Modern browsers: https://mozilla.github.io/pdf.js/web/viewer.html
-
Older browsers: https://mozilla.github.io/pdf.js/legacy/web/viewer.html
Browser Extensions
Firefox
PDF.js is built into version 19+ of Firefox.
Chrome
- The official extension for Chrome can be installed from the Chrome Web Store. This extension is maintained by @Rob--W.
- Build Your Own - Get the code as explained below and issue
npx gulp chromium. Then open Chrome, go toTools > Extensionand load the (unpackaged) extension from the directorybuild/chromium.
PDF debugger
Browser the internal structure of a PDF document with https://mozilla.github.io/pdf.js/internal-viewer/web/debugger.html
Getting the Code
To get a local copy of the current code, clone it using git:
$ git clone https://github.com/mozilla/pdf.js.git
$ cd pdf.js
Next, install Node.js via the official package or via nvm. If everything worked out, install all dependencies for PDF.js:
$ npm install
Finally, you need to start a local web server as some browsers do not allow opening
PDF files using a file:// URL. Run:
$ npx gulp server
and then you can open:
Please keep in mind that this assumes the latest version of Mozilla Firefox; refer to Building PDF.js for non-development usage of the PDF.js library.
It is also possible to view all test PDF files on the right side by opening:
Building PDF.js
In order to bundle all src/ files into two production scripts and build the generic
viewer, run:
$ npx gulp generic
If you need to support older browsers, run:
$ npx gulp generic-legacy
This will generate pdf.js and pdf.worker.js in the build/generic/build/ directory (respectively build/generic-legacy/build/).
Both scripts are needed but only pdf.js needs to be included since pdf.worker.js will
be loaded by pdf.js. The PDF.js files are large and should be minified for production.
Using PDF.js in a web application
To use PDF.js in a web application you can choose to use a pre-built version of the library
or to build it from source. We supply pre-built versions for usage with NPM under
the pdfjs-dist name. For more information and examples please refer to the
wiki page on this subject.
Including via a CDN
PDF.js is hosted on several free CDNs:
- https://www.jsdelivr.com/package/npm/pdfjs-dist
- https://cdnjs.com/libraries/pdf.js
- https://unpkg.com/pdfjs-dist/
Learning
You can play with the PDF.js API directly from your browser using the live demos below:
More examples can be found in the examples folder. Some of them are using the pdfjs-dist package, which can be built and installed in this repo directory via npx gulp dist-install command.
For an introduction to the PDF.js code, check out the presentation by our contributor Julian Viereck:
More learning resources can be found at:
The API documentation can be found at:
Questions
Check out our FAQs and get answers to common questions:
Talk to us on Matrix:
File an issue: