Bookmarklet to export HSBC statements to CSV

hsbc-csv-statement.js

(function () {
    var months = {
            'Jan': '01',
            'Feb': '02',
            'Mar': '03',
            'Apr': '04',
            'May': '05',
            'Jun': '06',
            'Jul': '07',
            'Aug': '08',
            'Sep': '09',
            'Oct': '10',
            'Nov': '11',
            'Dec': '12'
        };
    function locateTextNode(text) {
        var xPathResult = document.evaluate('//text()[contains(.,\'' + text + '\')]', document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null);
        return xPathResult.singleNodeValue
    }
    function nextElement(elem) {
        do {
            elem = elem.nextSibling
        } while (elem && elem.nodeType !== 1);
        return elem
    }
    var dateFormat = /(.{2}) (.{3})( ..(.{2}))?$/;
    function readStatementDate() {
        var label = locateTextNode('Statement date:');
        var statementDate = nextElement(label.parentNode.parentNode).textContent.trim();
        var result = dateFormat.exec(statementDate);
        return {
            day: result[1],
            month: months[result[2]],
            year: result[4]
        }
    }
    var statementDate = readStatementDate();
    function parseDate(tr) {
        var value = tr.children[0].textContent.trim();
        var tokens = dateFormat.exec(value);
        return [
            tokens[1],
            months[tokens[2]],
            statementDate.year
        ].join('/')
    }
    function parseAmount(tr) {
        var out = tr.children[3].textContent.trim();
        var amountIn = tr.children[4].textContent.trim();
        if (out) {
            return '-' + out
        }
        return amountIn
    }
    function parseDescription(tr) {
        return tr.children[2].textContent.trim()
    }
    function parseRow(tr) {
        var parsed = [
                parseDate(tr),
                parseAmount(tr),
                parseDescription(tr)
            ];
        return parsed
    }
    function formatCSV(result, row) {
        if (row[1]) {
            return result += row.join(',') + '\n'
        } else {
            return result
        }
    }
    function generateFileName() {
        return statementDate.year + statementDate.month + statementDate.day + '.csv'
    }
    function download() {
        var dataURL = 'data:text/csv;charset=utf8;base64,' + btoa(csv);
        var downloadLink = document.createElement('a');
        downloadLink.setAttribute('download', generateFileName());
        downloadLink.href = dataURL;
        var clickEvent = document.createEvent('MouseEvent');
        clickEvent.initEvent('click', true, true);
        downloadLink.dispatchEvent(clickEvent)
    }
    var rows = document.querySelectorAll('[summary] tbody tr');
    var csv = Array.prototype.map.call(rows, parseRow).reduce(formatCSV, '');
    download(csv)
}());