如果文件夹不存在如何创建？

Question

如果文件夹不存在，我会尝试创建它，但代码每次运行时都会创建一个新文件夹。我不知道我的代码是否正确。

这是我的代码：

var alumnopath = DocsList.getFolderById ('0Bzgw8SlR34pUbFl5a2tzU2F0SUk');
var alumno2 = alumno.toString();
Logger.log(alumno2);
try {
  var folderalumno =  alumnopath.getFolder(alumno2);
  if (folderalumno == undefined){
    var folderalumno =  alumnopath.createFolder(alumno2);
  }
  else {
    var folderalumno =  alumnopath.getFolder(alumno2);
  }
}
catch(e) {
  var folderalumno =  alumnopath.createFolder(alumno2);
}
folderalumno.createFile(pdf.getAs('application/pdf')).rename(  alumno +  " , " + fechafor);

感谢您的帮助！！

Answer 1

截至 2016 年 8 月的 Google Apps 脚本代码

var par_fdr = DriveApp.getFolderById(123456789A); // replace the ID
var fdr_name = "child_fdr";

try {
  var newFdr = par_fdr.getFoldersByName(fdr_name).next();
}
catch(e) {
  var newFdr = par_fdr.createFolder(fdr_name);
}

Answer 2

当您使用 try/catch 结构时，您实际上不需要 if 条件。 try/catch 结构处理文件夹本身不存在的情况。

试试这样：

var alumnopath = DocsList.getFolderById ('0Bzgw8SlR34pUbFl5a2tzU2F0SUk');
var alumno2 = alumno.toString();
Logger.log(alumno2);
try{
  var folderalumno =  alumnopath.getFolder(alumno2);
}
catch(e) {
  var folderalumno =  alumnopath.createFolder(alumno2);
}
folderalumno.createFile(pdf.getAs('application/pdf')).rename(  alumno +  " , " + fechafor);

Answer 3

如果其他人遇到此问题，您可以像这样使用三元运算符（根据需要替换“Name_of_Folder”字符串）：

var alumnopath = DriveApp.getFoldersByName("Name_of_Folder");
var folderalumno = alumnopath.hasNext() ? 
    alumnopath.next() : DriveApp.createFolder("Name_of_Folder");

Answer 4

Google 已更改其脚本。我知道这是一篇旧帖子，但这是我能想到的当前最佳答案：

function getFolder(parent_folder,folder_name){
  var folders = parent_folder.getFolders();     
  while (folders.hasNext()) {
    var folder = folders.next();
    if(folder_name == folder.getName()) {         
      return folder;
    }
  }
  return false;
}

var parent_folder = DriveApp.getFolderById(//id\\);
var folderName = getFolders(parent_folder,name);
if (folderName === false){
  folderName =  outputfolderId.createFolder(name);
}

希望这对其他人有帮助！

Answer 5

如果有人仍在寻找这个问题的答案并且想要创建文件夹（如果它不存在）这里是我创建的函数。

这个函数接受两个输入值：

• base_folder - 在其中执行搜索的文件夹 ID 或 false 以搜索驱动器根文件夹中的文件夹
• folder_name - 您正在搜索的文件夹名称

有些东西是可以调整的，但是我已经用这个来创建文件夹结构基本文件夹->年->月->日。

function checkFolders(base_folder, folder_name) {
  if (base_folder){ //Checks if is specified main folder
    var folders = DriveApp.getFolderById(base_folder).getFolders(); //Getting folder list from specified location
  } else { //If not specified folder we take all Drive folders
   var folders = DriveApp.getFolders(); //Getting all folders in Drive
  }

  var folder_exist = false, folder; //By default folder don`t exists till we check and confirm that it exists

  while(folders.hasNext()){ //Looping through all folders in specified location while we have folders which to check
    folder = folders.next(); //Taking next folder to check if it is folder that we are looking for
    if(folder.getName() == folder_name){ //Checking it`s name
     folder_exist = folder.getId(); //If folder is found we assign its ID to our return variable
    } //If folder don`t exists we have already assigned false to return value
  }

  if (!folder_exist) { //Checks if folder don`t exists than we need to create it
    if(base_folder){ //Checking where we should create folder
      DriveApp.getFolderById(base_folder).createFolder(folder_name); //If base folder is specified than we create there folder
    } else {
      DriveApp.createFolder(folder_name); //If base folder not specified than we create folder in Drive root folder
    }
   folder_exist = checkFolders(base_folder, folder_name); //Now run self again to check if folder was created and if it is created than we get folder ID
  }

  return folder_exist; //Returning false if our folder is not created or folder ID if folder exists and is created
}

这就是我使用这个功能的方式：

function createFolderStructure() {
 var base_folder_id, year_folder_id, month_folder_id, day_folder_id, date, day, month, year;

 date = new Date(); //Creates new Date object
 day = date.getDate(); //Extract day number in month
 month = date.getMonth(); //Extract month number, first month number is 0
 year = date.getFullYear(); //Extract year number

 base_folder_id = checkFolders(false, "My base folder"); //Check if base folder is created, if created return folder ID, if not, than create it and return it ID
 year_folder_id = checkFolders(base_folder_id, year); //Check if year folder is created, if created return folder ID, if not, than create it and return it ID
 month_folder_id = checkFolders(year_folder_id, month); //Check if month folder is created, if created return folder ID, if not, than create it and return it ID
 day_folder_id = checkFolders(month_folder_id, day); //Check if day folder is created, if created return folder ID, if not, than create it and return it ID, ID can be used to save files in this folder
}