foliate-js
Version:
Render e-books in the browser
65 lines (62 loc) • 2.52 kB
JavaScript
export const makeComicBook = async ({ entries, loadBlob, getSize, getComment }, file) => {
const cache = new Map()
const urls = new Map()
const load = async name => {
if (cache.has(name)) return cache.get(name)
const src = URL.createObjectURL(await loadBlob(name))
const page = URL.createObjectURL(
new Blob([`<body style="margin: 0"><img src="${src}">`], { type: 'text/html' }))
urls.set(name, [src, page])
cache.set(name, page)
return page
}
const unload = name => {
urls.get(name)?.forEach?.(url => URL.revokeObjectURL(url))
urls.delete(name)
cache.delete(name)
}
const exts = ['.jpg', '.jpeg', '.png', '.gif', '.bmp', '.webp', '.svg', '.jxl', '.avif']
const files = entries
.map(entry => entry.filename)
.filter(name => exts.some(ext => name.endsWith(ext)))
.sort()
if (!files.length) throw new Error('No supported image files in archive')
const book = {}
try {
const jsonComment = JSON.parse(await getComment() || '')
const info = jsonComment['ComicBookInfo/1.0']
if (info) {
const year = info.publicationYear
const month = info.publicationMonth
const mm = month && month >= 1 && month <= 12 ? String(month).padStart(2, '0') : null
book.metadata = {
title: info.title || file.name,
publisher: info.publisher,
language: info.language || info.lang,
author: info.credits ? info.credits.map(c => `${c.person} (${c.role})`).join(', ') : '',
published: year && month ? `${year}-${mm}` : undefined,
}
} else {
book.metadata = { title: file.name }
}
} catch {
book.metadata = { title: file.name }
}
book.getCover = () => loadBlob(files[0])
book.sections = files.map(name => ({
id: name,
load: () => load(name),
unload: () => unload(name),
size: getSize(name),
}))
book.toc = files.map(name => ({ label: name, href: name }))
book.rendition = { layout: 'pre-paginated' }
book.resolveHref = href => ({ index: book.sections.findIndex(s => s.id === href) })
book.splitTOCHref = href => [href, null]
book.getTOCFragment = doc => doc.documentElement
book.destroy = () => {
for (const arr of urls.values())
for (const url of arr) URL.revokeObjectURL(url)
}
return book
}