Google Charts Standard ToolTip Update after datachange - google-visualization

Question

I'm using ASGALLANT'S Hide/Show method shown here:
http://jsfiddle.net/asgallant/6gz2Q/
Except I have fourth data series called average. When a series is hidden or shown, I recalculate the average... by adjusting the fiddle above:
function showHideSeries () {
var sel = chart.getChart().getSelection();
var view = chart.getView() || {};
// if selection length is 0, we deselected an element
if (sel.length > 0) {
// if row is undefined, we clicked on the legend
if (sel[0].row == null) {
var col = sel[0].column;
if (typeof(columns[col]) == 'number') {
var src = columns[col];
// hide the data series
columns[col] = {
label: datatable.getColumnLabel(src),
type: datatable.getColumnType(src),
sourceColumn: src,
calc: function () {
return null;
}
};
//record as hidden
hiddenSeries[col] = true;
// grey out the legend entry
series[columnsMap[src]].color = '#CCCCCC';
chart.setOption('series', series);
//If Exists a columnLabel called "Average", check if last column (average column is currently shown), recalculate average
if ((datatable.getColumnLabel(datatable.getNumberOfColumns() - 1) == 'Average') && (hiddenSeries[datatable.getNumberOfColumns() - 1] == false)){
for(var r = 0; r < datatable.getNumberOfRows(); ++r) {
sum = 0;
k = 0
for(var c = 1; c < datatable.getNumberOfColumns()-1; ++c) {
if(hiddenSeries[c] == false){
if(datatable.getValue(r, c) > 0){
sum = sum + datatable.getValue(r, c);
k = k + 1;
}
}
}
if (k == 0) k = 1;
datatable.setValue(r, datatable.getNumberOfColumns() - 1, sum/k);
}
}
var tmpColumn = new Array();
// Add each data value to the array with push()
for(var i = 0; i < datatable.getNumberOfRows(); ++i) {
tmpColumn.push(datatable.getValue(i, col));
}
}
else {
var src = columns[col].sourceColumn;
// show the data series
columns[col] = src;
series[columnsMap[src]].color = null;
//record as shown
hiddenSeries[col] = false;
//If Exists a columnLabel called "Average", check if last column (average column is currently shown), recalculate average
if ((datatable.getColumnLabel(datatable.getNumberOfColumns() - 1) == 'Average') && (hiddenSeries[datatable.getNumberOfColumns() - 1] == false)){
for(var r = 0; r < datatable.getNumberOfRows(); ++r) {
sum = 0;
k = 0;
for(var c = 1; c < datatable.getNumberOfColumns() - 1; ++c) {
if(hiddenSeries[c] == false){
if(datatable.getValue(r, c) > 0){
sum = sum + datatable.getValue(r, c);
k = k + 1;
}
}
}
if (k == 0) k = 1;
datatable.setValue(r, datatable.getNumberOfColumns() - 1, sum/k);
}
}
//chart.setOption('series.' + i + '.type', 'bars');
if(datatable.getColumnLabel(src) == 'Average' || datatable.getColumnLabel(src) == 'Peak Demand [kVA]'){
chart.getOptions().series[columnsMap[src]].type = 'line';
if(c.second_axis == true){
chart.getOptions().series[columnsMap[src]].targetAxisIndex = 1;
}
}
}
chart.setDataTable(datatable);
view.columns = columns;
chart.setView(view);
google.visualization.events.addListener(chart, 'ready', function() {
document.getElementById('chartImg').href = chart.getChart().getImageURI();
});
chart.draw();
}
}
}
It works great, except that the Standard tooltip is not being updated on the re-draw of the chart. I would like to avoid using custom tooltips as a solution. I would think that the ToolTip values should automatically update on each draw of the chart... if not, there must be a way to force it?

Answer 1

The issue here is that I was using formatted numbers as shown below:
var formatter = new google.visualization.NumberFormat(
{negativeColor: 'red', negativeParens: true, pattern: '###,###'});
formatter.format(datatable, i);
Therefore, not only did I have to use datatable.setValue(row, column, value) but I also have to use datatable.setFormattedValue(row, column, *String* value).