如何在Google App脚本中创建一个弹出框？

Question

Basicly this is my question:

How do I, using Google App script w/ HTML service create a Pop up or dialog box.

I am doing lots of validation in a Google Script file (as appose to HTML file) and I just need to quickly tell the user the error, then they can adjust their form and carry on... this is my attempt at validation so far. I've tried to just use the javascript alert() function but it does nothing.

if(date == ""){
     alert("please select a date");
   }else if(teacher == ""){
     alert("please put your name");
   }else if(group == ""){
     alert("Please enter a group");
   }else if(notes == ""){
     alert("Please write where the tech is being used in the notes");
   }else if(events.length != 0){
     window.alert("It appears that the slot your trying to book is taken");
   }else{

Im hoping I can do this validation this way and not have to do a whole new method of validation (most likely from within the HTML file)

Answer 1

If your validation script (if elseif statements) is in the Code.gs file, the alert function will not work.

What you want to do is to throw that error message to your google.script.run function in your html script using the .withSuccessHandler, then do the alert from there.
Since the alert is called from within html (not in the .gs file), it will work.

Lets assume that the script you have above is in a function called validateForm() and you are calling that on your form submit button, the code will looke like something like this:

HTML file

// some codes and scripts here

Google.script.run.withSuccessHandler(showAlert).validateForm(this.form);

function showAlert(stringFromCodeGs) {
  if (stringFromCodeGs != false) {
   alert(stringFromCodeGs);
}

GS file

function validateForm(formObject) {
if(formObject.date == ""){
     return "please select a date";
   }else if(formObject.teacher == ""){
     return "please put your name";
   }
   // your other else if here
   }else{
     //your code to process form here
      return false;
   }

What it does is that it throws (return) the error message back to your google.script.run, which will then use it as a parameter for the success handler - in this example, the showAlert() function, automatically called by the .withSuccessHandler().

Hope this helps.