exceljs-xlsx-template/src/filters.js

Generate .xlsx file from .xlsx template. Support for Browser and Node.js

const ExcelJS = require("exceljs");
const { fetchUrlFile } = require("./helpers.js");

/**
 *
 * @param {ExcelJS.Cell} cell
 * @param {Array<{start: {row: number; col: number}; end: {row: number; col: number}}>} sheetMerges
 * @param {{width: number; height: number}} size
 * @param {'jpeg'|'png'|'gif'} ext
 */
async function image(cell, sheetMerges, size, ext) {
  if (cell.type === ExcelJS.ValueType.String) {
    let imageId = 0;
    let regx = null;
    const urlRegex = /https?:\/\/[^\s]+(?:\.(jpe?g|png|gif))?/i;
    const base64Regex = /data:image\/(jpeg|gif|png);base64,[^\s]+/i;
    if (urlRegex.test(cell.value)) {
      const matches = cell.value.match(urlRegex);
      const imageUrl = matches[0];
      const imageExt = matches[1] ?? "png";
      let fileContent = null;
      try {
        fileContent = await fetchUrlFile(imageUrl);
      } catch {
        console.warn(`Fail to load image ${imageUrl}`);
        return;
      }
      // 将图片添加到工作簿中
      imageId = cell.workbook.addImage({
        buffer: fileContent,
        extension: ext ?? (imageExt === "jpg" ? "jpeg" : imageExt),
      });
      regx = urlRegex;
    } else if (base64Regex.test(cell.value)) {
      const matches = cell.value.match(base64Regex);
      imageId = cell.workbook.addImage({
        base64: matches[0],
        extension: ext ?? matches[1],
      });
      regx = base64Regex;
    }
    if (!regx) {
      return;
    }
    const merge = sheetMerges.find((merge) => {
      return merge.start.row === cell.fullAddress.row && merge.start.col === cell.fullAddress.col;
    });
    // 坐标系基于零，A1 的左上角将为 {col：0，row：0}，右下角为 {col：1，row：1}
    const range = {
      // 左上角
      tl: {
        col: merge ? merge.start.col - 1 : cell.fullAddress.col - 1,
        row: merge ? merge.start.row - 1 : cell.fullAddress.row - 1,
      },
    };
    if (typeof size === "object" && size.width && size.height) {
      // 宽高(像素)
      range.ext = size;
    } else {
      // 右下角
      range.br = {
        col: merge ? merge.end.col : cell.fullAddress.col,
        row: merge ? merge.end.row : cell.fullAddress.row,
      };
    }
    // 将图片添加到工作表中
    cell.worksheet.addImage(imageId, range);
    // 移除图片地址
    cell.value = cell.value.replace(regx, "");
  }
}

module.exports = { image };