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Shinyu Murakami edited this page Dec 20, 2019 · 31 revisions


Vivliostyle Viewer consists of two components:

  • Core: Page layout engine.
  • Viewer: UI for Vivliostyle Core.

Setting up a development environment

Make sure that the following is installed:

Clone vivliostyle.

git clone
cd vivliostyle

@vivliostyle/core is listed as a dependency for @vivliostyle/viewer in package.json. During development, you want to use the local copy of @vivliostyle/core, rather than a package installed from npm. For this purpose, use yarn bootstrap to make a symbolic link:

yarn install # install dependencies
yarn bootstrap # setup development environment

Build and serve

yarn build-dev # build a development version of both Core and Viewer.
yarn dev # start watching source files and open browser.

With yarn dev, a web server starts (Browsersync with live-reload enabled), and Google Chrome should automatically open. If no browser opens, open http://localhost:3000/core/test/files/. On saving any source file, the browser automatically reloads.

Viewer and test files

Viewer HTML file (in development mode) is located at packages/viewer/lib/vivliostyle-viewer-dev.html. You can open an (X)HTML file with a URL (relative to the viewer HTML file) specified to x hash parameter. For example, http://localhost:3000/viewer/lib/vivliostyle-viewer-dev.html#x=../../core/test/files/print_media/index.html opens a test file for print media located at packages/core/test/files/print_media/index.html. You can also open an EPUB directory (unzipped EPUB file) by b parameter. For example, http://localhost:3000/viewer/lib/vivliostyle-viewer-dev.html#b=../../core/scripts/package-artifacts/samples/niimi/ opens a sample EPUB directory located at packages/core/scripts/package-artifacts/samples/niimi/. Note that you cannot omit the trailing slash. The b parameter also accepts Web publications (multi-HTML documents). See the PR: Support Web Publications and similar multi-HTML documents with TOC navigation.

Test HTML files, intended to be used during development, are located at packages/core/test/files/. You are encouraged to add test files useful for implementing and verifying features.

packages/core/scripts/package-artifacts/samples/ directory holds a public sample files, which are deployed to the sample page on


You need to run npm install in the root directory before running the following.

The TypeScript source files are compiled and minified by Rollup. To build the minified version of JavaScript files, run yarn build (in the root directory). The sources are type-checked and the minified file will be generated under packages/core/lib/ and packages/viewer/lib directories.

Jasmine is used for unit testing. Spec files are located under packages/core/test/spec/. To run unit tests on a local machine, run npm run test-local.

A forked version of CSSWG reftests can be run with vivliostyle. See files under packages/core/test/wpt/ for details. (Currently not working, need fix!)

The unit tests and reftests (listed in packages/core/test/wpt/metadata/MANIFEST.json) is automatically invoked in Travis CI when pushing to GitHub. When pushed to master, after all tests pass, the code will be automatically deployed to github pages and can be accessed from the sample page on, so please be careful when pushing to master (merging PR).

Building production version

You can build a production version of Vivliostyle by running yarn build under both packages/core and packages/viewer directories. All JS files of packages/core and packages/viewer are concatenated to a single file.

Development mode

In development mode (yarn build-dev), the compiled JS file vivliostyle.js and source map file (both located under packages/core/lib) are loaded by the browser and you can debug TypeScript code in the browser's developer tools.

Maintaining documents

Please update the following documents as developing.


Lint and code formatting

Run npm run lint for lint and code format check (using ESLint with eslint-plugin-prettier) for the vivliostyle.js source code.

Run npm run lint-fix to fix fixable errors.

We use the default options of Prettier for code formatting. Use npm run lint-fix to keep the code pretty.

Source files

Source files under src/vivliostyle are briefly described below.

Exposed interface of vivliostyle-core. To use vivliostyle-core, instantiate Vivliostyle.CoreViewer, set options, register event listeners by addListener method, and call loadDocument or loadPublication method.
Defines constants used throughout the library.
Task scheduling.
Definitions for expressions of Adaptive Layout.
Definitions for various CSS values.
CSS parser.
Classes for selector matching and cascading calculation.
View tree data structures.
Apply CSS cascade to a document incrementally.
Web font handling.
Classes for page masters of Adaptive Layout.
Page floats.
Generation of view tree.
Content layout inside regions, including column breaking etc.
Support for CSS Paged Media.
Select page master, layout regions (columns) one by one etc.
Handling EPUB metadata, rendering pages etc.
(There are more files... See the `src/ts` directory)

Other dev documents

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