foliate-js/README.md

foliate-js

Library for rendering e-books in the browser.

Features:

• Supports EPUB, MOBI, KF8, FB2, CBZ
• Pure JavaScript
• Small and modular
• No dependencies
• Does not depend on or include any library for unzipping; bring your own Zip library
• Does not require loading whole file into memory
• Does not care about older browsers
• No tests :(
• No continuous scrolling mode :(

Demo

Serve the files with a server, and open reader.html. Or visit https://johnfactotum.github.io/foliate-js/reader.html.

Overview

The project is designed to be modular. It has two renderers, one for paginating reflowable books, and one for fixed layout. The View class defined in view.js is the one that strings everything together.

Processors for each book format returns an object that implement the following interface:

• .sections: an array of sections in the book. Each item has the following properties:
  • .load(): returns a string of the URL that will be rendered. May be async.
  • .unload(): returns nothing. If present, can be used to free the section.
  • .createDocument(): returns a Document object of the section. Used for searching. May be async.
  • .size: a number of the byte size of the section. Used for showing reading progress.
  • .linear: a string. If it is "no", the section is not part of the linear reading sequence.
  • .cfi: base CFI string of the section. The part that goes before the ! in CFIs.
  • .id: an identifier for the section, used for getting TOC item (see below). Can be anything, as long as they can be used as keys for the Map object.
• .dir: a string representing the page progression direction of the book ("rtl" or "ltr").
• .toc: an array representing the table of contents of the book. Each item has
  • .label: a string label for the item
  • .href: a string representing the destination of the item. Does not have to be a valid URL.
  • .subitems: a array that contains TOC items
• .pageList: same as the TOC, but for the Page List.
• .metadata: an object representing the metadata of the book.
• .rendition: an object that contains properties similar to the EPUB rendition properties. If .layout is "pre-paginated", the book is rendered with the fixed layout renderer.
• .resolveHref(href): given an href string, returns an object representing the destination referenced by the href, which has the following properties:
  • .index: the index of the referenced section in the .section array
  • .anchor(doc): given a Document object, returns the document fragment referred to by the href (can either be an Element or a Range), or null
• .resolveCFI(cfi): same as above, but with a CFI string instead of href
• .isExternal(href): returns a boolean. If true, the link should be opened externally.

The following methods are used for getting the correct TOC and Page List item when navigating:

• .splitTOCHref(href): given an href string (from the TOC), returns an array, the first element is the id of the section (see above), and the second element is the fragment identifier (can be any type; see below)
• .getTOCFragment(doc, id): given a Document object and a fragment identifier (the one provided by .splitTOCHref(); see above), returns a Node representing the target linked by the TOC item

Almost all of the properties and methods are optional. At minimum it needs .sections and the .load() method for the sections, as otherwise there won't be anything to render.