RSSHub/lib/v2/freecomputerbooks/index.js

95 lines
3.5 KiB
JavaScript

const cheerio = require('cheerio');
const path = require('path');
const got = require('@/utils/got');
const { art } = require('@/utils/render');
const { parseDate } = require('@/utils/parse-date');
const baseURL = 'https://freecomputerbooks.com/';
async function cheerioLoad(url) {
return cheerio.load((await got(url)).data);
}
module.exports = async (ctx) => {
const categoryId = ctx.params.category?.trim();
const requestURL = categoryId ? new URL(`${categoryId}.html`, baseURL).href : baseURL;
const $ = await cheerioLoad(requestURL);
// As observation has shown that each page only has one element of the
// class, thus to simplify the processing the text is directly extracted.
// Needing more robust processing if some day more such elements show up.
const categoryTitle = $('.maintitlebar').text();
ctx.state.data = {
title: 'Free Computer Books - ' + categoryTitle,
link: requestURL,
description: $('title').text(),
// For a "Selected New Books" page, the <ul> element's id. is
// `newBooksG`; for an ordinary category page, it's `newBooksL`.
item: await Promise.all(
$('ul[id^=newBooks] > li')
.toArray()
.map((elem) => buildPostItem($(elem), categoryTitle, ctx.cache))
),
};
};
function buildPostItem(listItem, categoryTitle, cache) {
const $ = cheerio.load(''); // the only use below doesn't care about the content
const postLink = listItem.find('a:first');
const postInfo = listItem.find('p:contains("Post under")');
const postItem = {
title: postLink.text(),
link: new URL(postLink.attr('href'), baseURL).href,
// Only a "Selected New Books" page has exclicit categorization info.
// for posts; an ordinary category page hasn't, then in which case the
// category title is used (after all, it's already a *category page*).
category: postInfo.length
? postInfo
.find('a')
.toArray()
.map((elem) => $(elem).text())
: categoryTitle,
};
const pubDateText = postInfo.find('span:last').text().replace(/^on /, '');
if (pubDateText) {
// Pretty much the same situation: Only a "Selected New Books" page has
// explicit publication dates for posts; even on each post's details
// page, there seems to be only the publication date for the book, but
// the post's creation date is still missing.
postItem.pubDate = parseDate(pubDateText);
}
return cache.tryGet(postItem.link, () => insertDescriptionInto(postItem));
}
async function insertDescriptionInto(item) {
const $ = await cheerioLoad(item.link);
// Eliminate all comment nodes to avoid their being selected and rendered in
// the final output (I know this is actually unnecessary, but please forgive
// my mysophobia).
$.root()
.find('*')
.contents()
.filter((_, node) => node.type === 'comment')
.remove();
const imageURL = $('#bookdesc img[title]').attr('src');
const metadata = $('#booktitle ul').removeAttr('style');
const content = $('#bookdesccontent').removeAttr('id');
metadata.find('li:contains(Share This)').remove();
content.find('img[src$="/hot.gif"]').remove();
content.find(':contains(Similar Books)').nextAll().addBack().remove();
item.description = art(path.join(__dirname, 'templates/desc.art'), { imageURL, metadata, content });
return item;
}