Function extractSlideData

pptx/scripts/html2pptx.js:244–894

(page)

// Helper: Extract slide data from HTML page
async function extractSlideData(page) {
  return await page.evaluate(() => {
    const PT_PER_PX = 0.75;
    const PX_PER_IN = 96;

    // Fonts that are single-weight and should not have bold applied
    // (applying bold causes PowerPoint to use faux bold which makes text wider)
    const SINGLE_WEIGHT_FONTS = ['impact'];

    // Helper: Check if a font should skip bold formatting
    const shouldSkipBold = (fontFamily) => {
      if (!fontFamily) return false;
      const normalizedFont = fontFamily.toLowerCase().replace(/['"]/g, '').split(',')[0].trim();
      return SINGLE_WEIGHT_FONTS.includes(normalizedFont);
    };

    // Unit conversion helpers
    const pxToInch = (px) => px / PX_PER_IN;
    const pxToPoints = (pxStr) => parseFloat(pxStr) * PT_PER_PX;
    const rgbToHex = (rgbStr) => {
      // Handle transparent backgrounds by defaulting to white
      if (rgbStr === 'rgba(0, 0, 0, 0)' || rgbStr === 'transparent') return 'FFFFFF';

      const match = rgbStr.match(/rgba?\((\d+),\s*(\d+),\s*(\d+)/);
      if (!match) return 'FFFFFF';
      return match.slice(1).map(n => parseInt(n).toString(16).padStart(2, '0')).join('');
    };

    const extractAlpha = (rgbStr) => {
      const match = rgbStr.match(/rgba\((\d+),\s*(\d+),\s*(\d+),\s*([\d.]+)\)/);
      if (!match || !match[4]) return null;
      const alpha = parseFloat(match[4]);
      return Math.round((1 - alpha) * 100);
    };

    const applyTextTransform = (text, textTransform) => {
      if (textTransform === 'uppercase') return text.toUpperCase();
      if (textTransform === 'lowercase') return text.toLowerCase();
      if (textTransform === 'capitalize') {
        return text.replace(/\b\w/g, c => c.toUpperCase());
      }
      return text;
    };

    // Extract rotation angle from CSS transform and writing-mode
    const getRotation = (transform, writingMode) => {
      let angle = 0;

      // Handle writing-mode first
      // PowerPoint: 90° = text rotated 90° clockwise (reads top to bottom, letters upright)
      // PowerPoint: 270° = text rotated 270° clockwise (reads bottom to top, letters upright)
      if (writingMode === 'vertical-rl') {
        // vertical-rl alone = text reads top to bottom = 90° in PowerPoint
        angle = 90;
      } else if (writingMode === 'vertical-lr') {
        // vertical-lr alone = text reads bottom to top = 270° in PowerPoint
        angle = 270;
      }