Getting the value of a cell the user didn't exit - google-apps-script

Question

I have created a sheet in Google Sheets that is basically a form users fill out. They fill in the blanks, then press a button to run a script based on the data. However, no matter how I warn them, they don't exit the last field before clicking the button, and the script perceives that the last field is empty. I have tried letting the script activate another field on the screen, but it doesn't seal in the value before doing that. Is there another command that can force the value to be written to the field?

Answer 1

As an additional option to what Troy123 mentioned you can try the following script to detect blank values and display an alert if there is one before running the code you are using to submit the form.
Script:
function alertMessage() {
let ss = SpreadsheetApp.getActive().getSheetByName("Sheet2");
let lR = ss.getLastRow();
let lRValues = ss.getRange(lR, 1, 1, 3).getValues();
let x = false;
for(let i=0; i<3; i++) // Used 3 because I am just saving 3 values from code line 4
{
console.log(lRValues[0][i]);
if (lRValues[0][i]=="")
{
x = true;
}
}
if(x == true)
{
SpreadsheetApp.getUi().alert("Make sure there are no blank fields");
}
else
{
/*
Insert the form submission function or script here
*/
}
}
Example:
References:
alert(prompt)

Answer 2

Use a checkbox at the end of your form and have them click it. This checkbox does nothing, but it changes focus from the last field to the checkbox.

Answer 3

As suggested in a previous answer by Troy123, use a checkbox. IMHO this is the simplest option and by adding a very simple statement you could make your script to "reset" the checkbox, so it could "emulate" the button states, checked means pressed, unchecked means unpressed.
If order to make this able to work with scripts that requires more than 30 seconds to run, use an on edit installable trigger to call the a function responsible to responde to check/uncheck events.
function respondToCheckUncheck(e){
// Assing to a1Notation the reference of the cell containing the checkbox
const a1Notation = 'H10';
if(e.range.getA1Notation() === a1Notation && e.range.isChecked()){
// call here your function
myFunction();
// once the funcion finish, uncheck the checkbox
e.range.uncheck();
} else {
// do nothing
}
}
If you would like to take your script to a more sophisticated solution, your script could protect the cell having the checkbox and use the Lock Service to prevent other risks.
Using drawings to trigger Google Apps Script functions have several caveats like the one that was mentioned in this question
having a data entered in a cell and clicking the drawing when the cell is still in edit mode, will make that the value read from the cell doesn't match the value wrote.
While the workaround to check that the cell is not empty (see a previously posted answer by Fernando Lara) might help this still could lead to errors, i.e., if the user entered a value, pressed enter, but before clicking the button, edits the cell...
Considering the above, I suggest using other kind of element of the Google Sheets user interface, i.e. the Recorded Macros menu, a custom menu, a checkbox or cell with other data validation using a drowdown, a sidebar (requires the use of the HtmlService).
Other options to have in mind are to use a dialog for data entering created using the HtmlService, a Google Form or an AppSheet app.