Reploting a JQplot chart using ajax - ajax

Question

I have been trying to solve this in different ways, but haven't make it work as expected, I feel it isn't so big deal (I really hope so) but my experience and skills with Ajax and jQuery are kind of limited that's why I am appealing to your expertise!
I am working on a chart similar to the one here http://www.jqplot.com/tests/data-renderers.php. but in my case the json file is generated depending on a value that the user choses from a select box. I am using 2 files and ajax calls to accomplish this:
-AnnualB.html is the file where the select box is located and the chart should be displayed.
-Index.php is the file where the query to the database is made (using the value obtained from the selectbox in AnnualB.html) and the json array is generated.
In AnnualB.html I use the GET method to retrieve the value from the selectbox and send it to Index.php, which generates the json data. Based on that json data the chart has to be created in AnnualB... Here is where my problem comes. The function to generate the chart is working fine and the call to send the select value and return the json is also working (have checked with Firebug), but I know am missing something (but don't know what yet) because I don't manage to pass the json data to the function that generates the chart.
My codes in AnnualB.html goes like this (abbreviating some irrelevant information with ...):
Function to generate the chart (Is working ok if the json data is passed)
function CreateGraph() {
$(document).ready(function(){
var ajaxDataRenderer = function(url, plot) {
var ret = null;
$.ajax({
async: false,
url: url,
dataType:'json',
success: function(data) {
ret = data; }
});
return ret; };
$.jqplot.config.enablePlugins = true;
var jsonurl = "./index.php";
var plotData = ajaxDataRenderer(jsonurl);
var series = ...
plot1 = $.jqplot('Chart1', series,{...}}
Ajax Call (PROBABLY WHERE MY MISTAKE/OMISSION IS)
function LoadGraph(int)
{
if (window.XMLHttpRequest)
{xmlhttp=new XMLHttpRequest();}
else
{xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");}
xmlhttp.open("GET","index.php?tasel="+int,true);
xmlhttp.send();
xmlhttp.onreadystatechange=function()
{
CreateGraph(int)
}
}
Select box
<select name="tasel" size="1" onchange="LoadGraph(this.value)">
<option value="">Select accounts type:</option>
<option value="3">Tuloslaskelma</option>
<option value="2">Tasevastattava</option>
<option value="1">Tasevastaava</option>
</select>
The related code in Index.php goes like this (Is working ok when the value of the select box (tasel) is passed)):
$tasel = $_REQUEST['tasel'];
if ($tasel == ...2)
{...}
.
.
.
echo "[",$selite, ",";// These 2 variables create the json array
echo $finaljson, "]";
Thanks in advance for your patience and help!

Answer 1

I realized the answer to this question was simpler than what I was expecting.
Instead of making the whole function LoadGraph(int) ajax call, I just needed to call the tasel value ?tasel="+int in the function to generate the chart like this (which is already doing an ajax call):
function CreateGraph() {
$(document).ready(function(){
var ajaxDataRenderer = function(url, plot) {
var ret = null;
$.ajax({
async: false,
url: url,
dataType:'json',
success: function(data) {
ret = data;
}
});
return ret;
};
$.jqplot.config.enablePlugins = true;
var jsonurl = "./index.php?tasel="+int;
var plotData = ajaxDataRenderer(jsonurl);
var series = ...
plot1 = $.jqplot('Chart1', series,{...}
}

Answer 2

var plot1 = undefined;
var plotOptions = undefined;
function CreateGraph() {
$.ajax({
async: false,
url: "./index.php",
dataType:'json',
success: function(data) {
var series = fn... // Convert your json Data to array
if(plot1 != undefined)
{
plot1.destroy();
}
plot1 = $.jqplot('Chart1', series, plotOptions);
}
});
}
$(function(){
$.jqplot.config.enablePlugins = true;
plotOptions = {...}; // jqPlot options
CreateGraph();
});
Hope this might help you..