mdpdf/src/utils.js

Markdown to PDF command line converter

import { resolve } from 'path';
import { readFileSync } from 'fs';
import { parse } from 'url';
import fileUrl from 'file-url';
import cheerio from 'cheerio';
const { load } = cheerio;

export function getStyleBlock(stylesheets) {
  // Read in all stylesheets and format them into HTML to
  // be placed in the header. We do this because the normal
  // <link...> doesn't work for the headers and footers.
  let styleHtml = '';
  for (const i in stylesheets) {
    if (Object.prototype.hasOwnProperty.call(stylesheets, i)) {
      const style = readFileSync(stylesheets[i], 'utf8');
      styleHtml += '<style>' + style + '</style>';
    }
  }

  return styleHtml;
}

export function getStyles(stylesheets) {
  let styleHtml = '';
  for (const i in stylesheets) {
    if (Object.prototype.hasOwnProperty.call(stylesheets, i)) {
      const style = readFileSync(stylesheets[i], 'utf8');
      styleHtml += style;
    }
  }

  return styleHtml;
}

export function hasAcceptableProtocol(src) {
  const acceptableProtocols = ['http:', 'https:'].join('|');

  const theUrl = parse(src);

  if (!theUrl.protocol) {
    return false;
  }
  return new RegExp(acceptableProtocols).test(src);
}

export function processSrc(src, options) {
  if (hasAcceptableProtocol(src)) {
    // The protocol is great and okay!
    return src;
  }

  // We need to convert it
  const resolvedSrc = resolve(options.assetDir, src);
  return fileUrl(resolvedSrc);
}

export function qualifyImgSources(html, options) {
  const $ = load(html);

  $('img').each((i, img) => {
    img.attribs.src = processSrc(img.attribs.src, options);
  });

  return $.html();
}