How to change tooltip text for google chart api?

Question

http://code.google.com/apis/chart/

Answer 1

For custom tooltips, add the tooltip as an extra column:

function drawVisualization() {
    data = new google.visualization.DataTable()
    data.addColumn('string', 'Date');
    data.addColumn('number');
    data.addColumn({type:'string',role:'tooltip'});
    data.addRow();
    base = 10;
    data.setValue(0, 0, 'Datapoint1');
    data.setValue(0, 1, base++);
    data.setValue(0, 2, " This is my tooltip1 ");

    data.addRow();
    data.setValue(1, 0, 'Datapoint2');
    data.setValue(1, 1, base++);
    data.setValue(1, 2, "This is my second tooltip2");

    // Draw the chart.
    var chart = new google.visualization.BarChart(document.getElementById('visualization'));
    chart.draw(data, {legend:'none', width:600, height:400});
}