Google sheet script submit specific value - google-sheets

Question

I'm trying to send form details to a google sheets script working. Currently the following code submits a form field to a google sheet perfectly.
var sheetName = 'Sheet1'
var scriptProp = PropertiesService.getScriptProperties()
function intialSetup () {
var activeSpreadsheet = SpreadsheetApp.getActiveSpreadsheet()
scriptProp.setProperty('key', activeSpreadsheet.getId())
}
function doPost (e) {
var lock = LockService.getScriptLock()
lock.tryLock(10000)
try {
var doc = SpreadsheetApp.openById(scriptProp.getProperty('key'))
var sheet = doc.getSheetByName(sheetName)
var headers = sheet.getRange(1, 1, 1, sheet.getLastColumn()).getValues()[0]
var nextRow = sheet.getLastRow() + 1
var newRow = headers.map(function(header) {
return header === 'timestamp' ? new Date() : e.parameter[header]
})
sheet.getRange(nextRow, 1, 1, newRow.length).setValues([newRow])
return ContentService
.createTextOutput(JSON.stringify({ 'result': 'success', 'row': nextRow }))
.setMimeType(ContentService.MimeType.JSON)
}
catch (e) {
return ContentService
.createTextOutput(JSON.stringify({ 'result': 'error', 'error': e }))
.setMimeType(ContentService.MimeType.JSON)
}
finally {
lock.releaseLock()
}
}
But I'm trying to only submit a specific field value, and if submitted, only once. So it would error if it existed in the google sheet. I can't figure it out.
Here is the JS
const scriptURL = 'HIDDEN'
const form = document.forms['submit-to-google-sheet']
const loading = document.querySelector('.js-loading')
const successMessage = document.querySelector('.js-success-message')
const errorMessage = document.querySelector('.js-error-message')
form.addEventListener('submit', e => {
e.preventDefault()
showLoadingIndicator()
fetch(scriptURL, { method: 'POST', body: new FormData(form)})
.then(response => showSuccessMessage(response))
.catch(error => showErrorMessage(error))
})
function showLoadingIndicator () {
form.classList.add('is-hidden')
loading.classList.remove('is-hidden')
}
function showSuccessMessage (response) {
console.log('Submitted', response)
setTimeout(() => {
successMessage.classList.remove('is-hidden')
loading.classList.add('is-hidden')
}, 500)
}
function showErrorMessage (error) {
console.error('Error!', error.message)
setTimeout(() => {
errorMessage.classList.remove('is-hidden')
loading.classList.add('is-hidden')
}, 500)
}
Here is the HTML
<div class="form-container">
<form name="submit-to-google-sheet">
<input name="code" type="text" placeholder="Enter Code" required>
<button type="submit">Submit</button>
</form>
<div class="loading js-loading is-hidden">
<div class="loading-spinner">
<svg><circle cx="25" cy="25" r="20" fill="none" stroke-width="2" stroke-miterlimit="10"/></svg>
</div>
</div>
<p class="js-success-message is-hidden">You're not a winner, better luck next time.</p>
<p class="js-error-message is-hidden">Error: Something wen't wrong, please try again later.</p>
</div>

Answer 1

Assuming you want to check for duplicates for the content of newRow[1] in column 2:
Retrieve the values from column B and convert them into a 1D array with flat()
Verify with indexOf() either the content of newRow is already contained in column B (indexOf() will return -1 if a value is not contained in an array)
A sample where newRow[1] was manually set to 123 for testing purposes:
function doPost (e) {
var lock = LockService.getScriptLock()
lock.tryLock(10000)
try {
var doc = SpreadsheetApp.openById(scriptProp.getProperty('key'))
var sheet = doc.getSheetByName(sheetName)
var headers = sheet.getRange(1, 1, 1, sheet.getLastColumn()).getValues()[0]
var nextRow = sheet.getLastRow() + 1
var newRow = headers.map(function(header) {
return header === 'timestamp' ? new Date() : e.parameter[header]
})
newRow[1] = 123;
var columnTwo = sheet.getRange(1,2, sheet.getLastRow(), 1).getValues().flat();
if (columnTwo.indexOf(newRow[1]) == - 1){
sheet.getRange(nextRow, 1, 1, newRow.length).setValues([newRow])
return ContentService
.createTextOutput(JSON.stringify({ 'result': 'success', 'row': nextRow }))
.setMimeType(ContentService.MimeType.JSON)
}
}
catch (e) {
return ContentService
.createTextOutput(JSON.stringify({ 'result': 'error', 'error': e }))
.setMimeType(ContentService.MimeType.JSON)
}
finally {
lock.releaseLock()
}
}
UPDATE
indexOf() only works correctly for values of the same content AND data type.
If your spreadsheet values are numbers, but the incoming posted value is recognized string, you need to convert it to a number for correct comparison. This can be done by comparing with
if (columnTwo.indexOf(Number(newRow[1])) == - 1){...