class SpreadsheetApp method .showModelessDialog()

SpreadsheetApp is the Apps Script service.

.showModelessDialog() is the method name you will see after a dot in your code.

What it does

Opens a dialog the user can use while still working in the sheet.

Why it's used

  • Keep a helper window open while the user still edits the sheet.
  • Show live search or preview without blocking the grid.

Common errors

  • Forgetting parentheses on showModelessDialog. Write SpreadsheetApp.showModelessDialog(), not SpreadsheetApp.showModelessDialog or showModelessDialog by itself.
  • Skipping dots between chained calls. Each step needs a dot, like SpreadsheetApp.getActiveSpreadsheet().getSheetByName('Data').showModelessDialog().
  • Adding spaces where they do not belong. Write SpreadsheetApp.showModelessDialog(), not SpreadsheetApp .showModelessDialog(), SpreadsheetApp.showModelessDialog (), or SpreadsheetApp . showModelessDialog().
  • Wrong capitalization. Use SpreadsheetApp and showModelessDialog, not spreadsheetapp or showmodelessdialog.

Explore

Related methods

  • .showModalDialog()

    Opens a modal dialog that blocks interaction with the sheet.

  • .prompt()

    Shows a dialog that asks the user for text input.

  • .alert()

    Shows a simple alert box with an OK button.

  • .activate()

    Makes a sheet or range the active selection.

  • .toast()

    Shows a short message in the bottom corner of the spreadsheet.

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