Read all emails from a Gmail Label, parse using Regex and store it to a Google Spreadsheet

parse_gmail_data.gs

/**
 * method for parsing the data
 **/
function parseEmail() {
    var emails = readGmailLabel("your label here");
    var parsedData = [];
    var data, parsedRegex;
    for (var i = 0; i < emails.length; i++) {
        data = []

        // extract order number
        parsedRegex = extractDate(emails.body, "2Checkout.com Order Number : ([0-9]+)");
        data.push(parsedRegex[1]);

        // extract total payment
        parsedRegex = extractDate(emails.body, "Base Price : ([(0-9)|\.]+)");
        data.push(parsedRegex[1]);

        // extract more data as needed
        parsedData.push(data);
    }
    // write this data (parsedData) to the spreadsheet
}

/**
 * label: gmail label to be read
 **/
function readGmailLabel(label) {

    var emails = [];
    var label = GmailApp.getUserLabelByName(label);
    var threads = label.getThreads();
    for (var j = threads.length - 1; j >= 0; j--) {
        emails.push({
            body: threads[j].getMessages()[0].getPlainBody(),
            date: threads[j].getMessages()[0].getDate()
        });
    }
    label.removeFromThreads(threads);
    return emails;
}

/**
 * text: data from which data needs to be parsed
 * regularExpression: Regular expression
 **/
function extractData(text, regularExpression) {
    var regex = new RegExp(regularExpression);
    var res = body.match(regex);
    return res;
}