DjVu.js

About / О проекте

DjVu.js is a program library for working with .djvu online. It's written in JavaScript and can be run in a web browser without any connection with a server. DjVu.js can be used for splitting (and concatenation) of .djvu files, rendering pages of a .djvu document, converting (and compressing) images into .djvu documents and for analyzing of metadata of .djvu documents.

DjVu.js Viewer is an app which uses DjVu.js to render DjVu documents. The app may be easily included into any html page. You can look at it and try it out on the official website (the link is below).

DjVu.js Viewer browser extension. By and large, it's a copy of the viewer, but also it allows opening links to .djvu files right in the browser without downloading them explicitly. The links to the extension are below.

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DjVu.js - это программная библиотека написанная на JavaScript и предназначенная для работы с файлами формата .djvu онлайн. DjVu.js ориентирована на исполнение в браузере пользователя без связи с сервером. Библиотека может быть использована для разделения (объединения) файлов .djvu, преобразования картинок в документы .djvu, отрисовки страниц документов .djvu, а также для анализа мета данных и структуры .djvu документов.

DjVu.js Viewer - приложение, которое можно легко встроить в любую html-страницу. Данное приложение служит для просмотра документов DjVu непосредственно в браузере. Вы можете ознакомиться с ним по ссылке ниже.

Расширение для браузера DjVu.js Viewer. По большей части это копия приложения DjVu.js Viewer, однако также расширение позволяет открывать ссылки на .djvu файлы прямо в браузере, не скачивая их явно. Ссылки на расширение доступны ниже.

Translation (localization)

If you want to add a new translation to the viewer read here how to do it.

Tools and supported browsers

You need to have Node.js 18+ (although older versions should work too) and npm 9+ installed to work with the project.

The viewer and the library are supposed to run in a browser. Technically, it should not be difficult to update the library so that it could be used in Node.js projects - the main code is pure JS and doesn't rely on browser specific APIs.

Currently, the following browsers are supported:

Chrome >= 88
Firefox >= 78
Safari >= 14
Edge >= 88

The list above is conditioned by the default Vite settings and the support of the :where CSS pseudo class.

How to build it

Clone the repo and run:

npm run make

in the root folder of the repository. The command will install all dependencies and create bundles of the library and viewer (the build folder should appear).

There is another variant:

npm run remake

It does the same as make, but first it removes all git-ignored files (including dependencies).

How to run it locally

If you want to work with the library you should read the library's README.

As for the viewer, you have to build the library once and start the dev server. It can be achieved with the following commands:

npm run make # run it only once
cd viewer
npm start

A page with the viewer will open automatically.

Tests

Once the dev server has been started, you can run E2E tests via test* npm scripts that you can find in the viewer/package.json file.

How to pack the extension

After the project has been built (npm run make), the extension folder contains all the necessary files. However, there are two manifests: v2 and v3. You should copy and rename one of them to manifest.json.

After it's done, the folder is an unpacked extension - it can be installed in the "developer mode".

If you want to pack the extension, you can either zip it yourself or run:

npm run ext # it uses "npx web-ext", so you will be asked to install the package

It will pack the extension with both v2 and v3 manifests.

Links

• The official website with the DjVu.js Viewer demo is https://djvu.js.org
• You may download the library and the viewer on https://djvu.js.org/downloads
• The browser extension for Mozilla Firefox
• The browser extension for Google Chrome
• The technical documentation of the library is available in the wiki
• CHANGELOG of the library
• CHANGELOG of the viewer

License / Лицензия

The DjVu.js Library is distributed under the terms of GNU GPL v2. Everything else in this repository (including the DjVu.js Viewer and the browser extension) is under The Unlicense. Read more in the LICENSE file.

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Библиотека DjVu.js распространяется под лицензией GNU GPL v2. Все остальное в этом репозитории (включая DjVu.js Viewer и расширение для браузера) является общественным достоянием (The Unlicense). Читайте подробнее в файле лицензии.