# Pre-fill field options from Google Sheets

## Overview

This rule runs as the first step of the form is loaded. It queries a Google Sheet that has a **Class Name** header and several class names defined below, within the same column. The class names are then set as options of the `CoursesDropdown` field.

## Rule Logic

```
function fetchSheetData(spreadsheetId, sheetName, apiKey, callback) {
    // API endpoint URL
    const url = `https://sheets.googleapis.com/v4/spreadsheets/${spreadsheetId}/values/${sheetName}?key=${apiKey}`;

    // Fetch data from Google Sheets
    fetch(url)
        .then(response => response.json())
        .then(data => callback(data.values)); // Return the sheet values
}

function convertToJSON(data) {
    const [headers, ...rows] = data;
    return rows.map(row => {
        let obj = {};
        headers.forEach((header, index) => obj[header] = row[index]);
        return obj;
    });
}

// Usage
const API_KEY = 'DUMMY_KEY'; // Replace with your Google Sheets API Key
const SPREADSHEET_ID = 'DUMMY_ID'; // Replace with your spreadsheet ID
const SHEET_NAME = 'Sheet1'; // Replace with your sheet name

fetchSheetData(SPREADSHEET_ID, SHEET_NAME, API_KEY, (data) => {
    const jsonData = convertToJSON(data)
    const classes = jsonData.map(account => account["Class Name"])
    CoursesDropdown.options = classes
    
})
```