如何将Google Apps Script模态对话框改为Alert并保留PDF新标签打开功能？

一、修复模态对话框大小问题 #

原代码中通过HTML div的style设置宽高无法生效，因为Google Apps Script的模态对话框尺寸由HtmlOutput实例的方法控制，而非内部HTML样式。只需在创建HtmlOutput后调用setWidth()和setHeight()即可指定弹窗大小：

// 替换原HtmlOutput创建代码
var html = '<div>' + message + '</div><script>window.open("' + pdfUrl + '", "_blank");</script>';
var userInterface = HtmlService.createHtmlOutput(html)
  .setWidth(300) // 设置弹窗宽度
  .setHeight(150); // 设置弹窗高度

SpreadsheetApp.getUi().showModalDialog(userInterface, "Generate CPD Certificate");

二、替换模态框为Alert后打开PDF的方案 #

原生alert()是浏览器原生弹窗，不支持执行JavaScript代码，因此无法直接触发window.open()。推荐以下两种替代方案：

方案1：用侧边栏（Sidebar）替代Alert #

侧边栏支持执行JS脚本，既能展示提示信息，又能自动打开PDF：

// 替换原模态框代码部分
var pdfUrl = pdfFileInDrive.getUrl();
var message = "证书已生成，PDF将在新标签页打开。";
var html = '<div style="padding: 15px;">' + message + '</div><script>window.open("' + pdfUrl + '", "_blank");google.script.host.close();</script>';
var sidebar = HtmlService.createHtmlOutput(html)
  .setTitle("CPD证书生成完成");

SpreadsheetApp.getUi().showSidebar(sidebar);

方案2：复制PDF链接到剪贴板+Alert提示 #

如果必须使用Alert，可以将PDF链接复制到用户剪贴板，再提示用户手动打开：

// 替换原模态框代码部分
var pdfUrl = pdfFileInDrive.getUrl();
// 复制链接到剪贴板的HTML
var html = '<script>navigator.clipboard.writeText("' + pdfUrl + '").then(() => {google.script.host.close();});</script>';
// 先执行复制操作
SpreadsheetApp.getUi().showModalDialog(HtmlService.createHtmlOutput(html), "正在复制链接");
// 延迟后弹出Alert提示
Utilities.sleep(1000);
SpreadsheetApp.getUi().alert("证书已生成，PDF链接已复制到剪贴板，请粘贴到浏览器打开:\n" + pdfUrl);

完整修改后的代码（修复模态框大小版本） #

function generateCPDCertificate() {
  var spreadsheet = SpreadsheetApp.getActiveSpreadsheet();
  var certificateSheet = spreadsheet.getSheetByName("Certificate");
  
  // Check if AG cell needs to be updated
  var sheetName = certificateSheet.getRange("D4").getValue();
  var targetSheet = spreadsheet.getSheetByName(sheetName);
  var targetCell = targetSheet.getRange("D:D").createTextFinder(certificateSheet.getRange("D6").getValue()).findNext();
  var agCell = targetCell.offset(0, 28); // Assuming AG is 28 columns to the right of D

  if (agCell.isBlank()) {
    // Define the range to be included in the PDF
    var range = certificateSheet.getRange("A1:A30");

    // Define the filename
    var filename = certificateSheet.getRange("D4").getValue() + "_" + certificateSheet.getRange("B6").getValue() + "_" + certificateSheet.getRange("D6").getValue() + ".pdf";

    // Export the range as a PDF
    var url = spreadsheet.getUrl();
    var exportUrl = url.replace(/\/edit.*$/, '') + '/export?format=pdf&size=A4&portrait=true&fitw=true&sheetnames=false&printtitle=false&pagenum=false&gridlines=false&horizontal_alignment=CENTER&vertical_alignment=TOP';

    var options = {
      headers: {
        'Authorization': 'Bearer ' + ScriptApp.getOAuthToken()
      }
    };

    var response = UrlFetchApp.fetch(exportUrl + "&gid=" + certificateSheet.getSheetId() + "&range=A1:A30", options);
    var blob = response.getBlob().setName(filename);

    // Create or get the "CPD Certificate" folder
    var folderName = "CPD Certificate";
    var folderIterator = DriveApp.getFoldersByName(folderName);
    var folder;
    if (folderIterator.hasNext()) {
      folder = folderIterator.next();
    } else {
      folder = DriveApp.createFolder(folderName);
    }

    // Delete existing files in the "CPD Certificate" folder
    var files = folder.getFiles();
    while (files.hasNext()) {
      var file = files.next();
      file.setTrashed(true);
    }

    // Save the PDF file to "CPD Certificate" folder
    var pdfFileInDrive = folder.createFile(blob);

    // Set permissions to 'anyone can view'
    pdfFileInDrive.setSharing(DriveApp.Access.ANYONE_WITH_LINK, DriveApp.Permission.VIEW);
  
    // Open the PDF file using the Mozilla PDF Viewer
    var pdfUrl = pdfFileInDrive.getUrl();
    var message = "The PDF file is now open in the new tab.";
    var html = '<div>' + message + '</div><script>window.open("' + pdfUrl + '", "_blank");</script>';
    var userInterface = HtmlService.createHtmlOutput(html)
      .setWidth(300)
      .setHeight(150);

    // Show the modal dialog
    SpreadsheetApp.getUi().showModalDialog(userInterface, "Generate CPD Certificate");
    
    // Update AG cell with today's date
    agCell.setValue(new Date());
  } else {
    // Display message if AG cell is not blank
    SpreadsheetApp.getUi().alert("This certificate is already printed: " + agCell.getValue());
  }
}

内容的提问来源于stack exchange，提问作者Angelei