How to refresh jqplot bar chart without redrawing the chart - jquery-plugins

Question

I have a jqplot bar chart and I want the chart data to be changed when the user changes the value on a drop-down list. That works, but the problem is the bar chart redraws, one over another, each time the user changes the values.
How can I update or reload the bars without drawing the whole thing again? Is there any property value to be set?
Chart data changes according to an ajax call:
$.ajax({
url: '/Home/ChartData',
type: 'GET',
data: { Id: Id },
dataType: 'json',
success: function (data) {
$.jqplot('chartDiv', [a, b], CreateBarChartOptions(xAxis));
}});
function CreateBarChartOptions(xAxis) {
var optionsObj = {
title: 'Stat',
axes: {
xaxis: {
renderer: $.jqplot.CategoryAxisRenderer,
ticks: xAxis
},
yaxis: { min: 0 }
},
series: [{ label: 'A' }, { label: 'B'}],
seriesDefaults: {
shadow: true,
renderer: $.jqplot.BarRenderer,
rendererOptions: {
barPadding: 8,
barMargin: 10
}
},
};
return optionsObj;
}
A reply would be highly appreciated. Thanks.

Answer 1

What you want to do is call jqPlot's .replot() method when you draw the new chart. Change your ajax call to look like this:
$.ajax({
url: '/Home/ChartData',
type: 'GET',
data: { Id: Id },
dataType: 'json',
success: function (data) {
$.jqplot('chartDiv', [a, b], CreateBarChartOptions(xAxis)).replot();
}});

Answer 2

Try having your chart object as a global variable in your script as:
var plot1 = $.jqplot('chartDiv', [a, b], CreateBarChartOptions(xAxis));
Then on success reset the data, axesScale and replot as:
var newData = [['a',1],['b',2],['c',3]];
plot1.series[0].data = newData;
plot1.resetAxesScale();
plot1.replot();
Ref: https://groups.google.com/group/jqplot-users/browse_thread/thread/59df82899617242b?pli=1

Answer 3

Each time before redrawing the graph, just destroy the existing1.
$.ajax({
url: '/Home/ChartData',
type: 'GET',
data: { Id: Id },
dataType: 'json',
success: function (data) {
if(plot)
{
plot.destroy();
}
var plot=$.jqplot('chartDiv', [a, b], CreateBarChartOptions(xAxis));
}});

Answer 4

Took me a while to find an answer for the script generated data, so I'm going to post this right here. I used a combination of the above code.
I created a global var, named plot3 within my script file. Then created the below function. When this is called with a redraw boolean, it determines if I need to destroy and redraw or draw for the first time.
What first bit of code does is gets data from my jqgrid, (which is being updated in a different function), and updates the arrays. The second bit, determines my interval ticks, on the x-axis dependent upon my length of data.
function DrawGraph(bRedraw){
var testTimes = [];
testTimes = $('#polarizationTable').jqGrid('getCol', 'TestTime', testTimes, false);
var RdgA = $('#polarizationTable').jqGrid('getCol', 'RdgA', RdgA, false);
var RdgB = $('#polarizationTable').jqGrid('getCol', 'RdgB', RdgB, false);
var readingLineA = [];
for (var i=0; i<testTimes.length; i++){
readingLineA.push([testTimes[i], RdgA[i]]);
}
var readingLineB = [];
for (var i=0; i<testTimes.length; i++){
readingLineB.push([testTimes[i], RdgB[i]]);
}
var maxX = $("#testLength").val();
var lengthX = testTimes.length;
var tickIntervalX = Math.round(maxX/10);
if(bRedraw == true)
{
plot3.destroy();
bRedraw = false;
}
if(bRedraw == false)
{
plot3 = $.jqplot('chart3', [readingLineA, readingLineB],
{
title:'Graph',
series:[{label:'Reading - A'}, {label:'Reading - B'} ],
legend:{show:true, location:'se'},
// You can specify options for all axes on the plot at once with
// the axesDefaults object. Here, we're using a canvas renderer
// to draw the axis label which allows rotated text.
axes:{
xaxis:{
label:'Minutes',
syncTicks: true,
min: 0,
numberTicks: 10,
tickInterval: tickIntervalX,
max: maxX*1.1,
labelRenderer: $.jqplot.CanvasAxisLabelRenderer,
labelOptions: {
fontSize: '12pt'
},
},
yaxis:{
label:'Data',
min: 0,
numberTicks: 10,
labelRenderer: $.jqplot.CanvasAxisLabelRenderer,
labelOptions: {
fontSize: '12pt'
}
},
}
});
}
}

Answer 5

Here is a full example of how to dynamically update the plot with new data without reloading the page:
<div id="chart1" style="height: 300px; width: 500px; position: relative;"></div>
<button>New data point</button>
<script type="text/javascript">
var storedData = [3, 7];
var plot1;
renderGraph();
$('button').click( function() {
doUpdate();
});
function renderGraph() {
if (plot1) {
plot1.destroy();
}
plot1 = $.jqplot('chart1', [storedData]);
}
function doUpdate() {
var newVal = Math.random();
storedData.push(newVal);
renderGraph();
}
</script>
It's a simplified version of this guy's post: JQPlot auto refresh chart with dynamic ajax data

Answer 6

$('#chart).html('');
chart is the DIV where chart is created.
this does the trick, nothing fancy by effective.

Answer 7

Maybe this will help. I on the other hand is having problem with getting replot to work at all, but i'am using a dataRenderer.
$.ajax({
url: '/Home/ChartData',
type: 'GET',
data: { Id: Id },
dataType: 'json',
success: function (data) {
$('chartDiv').empty();
$.jqplot('chartDiv', [a, b], CreateBarChartOptions(xAxis));
}});

Answer 8

hope this helps
jQuery(document).ready(function(){
jQuery.ajax({
url: '/review_graphs/show',
type: 'GET',
success: function (data) {
var plot1 = jQuery.jqplot('chartDiv', [data,data],
{
title: 'Bianual Reviews percentage',
series:[
{
renderer:jQuery.jqplot.BarRenderer,
label:'Average',
stackSeries: true,
dragable: {color: '#ff3366',constrainTo: 'x'},
trendline:{show: false}
},
{
label:'Trend Line',trendline:{show: false}}
],
legend: {
show: true,
placement: 'outsideGrid'
},
axesDefaults: {
tickRenderer: jQuery.jqplot.CanvasAxisTickRenderer ,
tickOptions: {
angle: -30,
fontSize: '10pt'
}
},
axes: {
xaxis: {
renderer: jQuery.jqplot.CategoryAxisRenderer
}
}
});
}});
});

Answer 9

The best method I got is, the div in which you're drawing, clear that before you draw your new graph.
$('#graph_area).children().remove();