Hi all,

I'm trying to experiment with the new generally available Visualforce charting in one of my sandboxes, and I've found myself stumped.  Here's the situation:

I've got an object called Teacher Implementation that has a master-detail relationship with an object called Class Implementation.  The Class Implementation object has a field called "# of students in class".  I would like to display a line graph on the Teacher Implementation record showing the number of students in the related classes, ordered by the created dates of the classes.

Here's my controller:

public class testTIControllerExtension {

private final Teacher_Implementation__c TI;

public testTIControllerExtension(ApexPages.StandardController stdController) {
this.TI = (Teacher_Implementation__c)stdController.getRecord();
}

//Create a method that retrieves the related classes
public List<Class_Implementation__c> getClasses() {
        return [SELECT name, createddate, Teacher_Implementation__c, of_Students_in_Class__c FROM Class_Implementation__c WHERE Teacher_Implementation__c = :ApexPages.currentPage().getParameters().get('id')];
}
}

and here is my VF page:

<apex:page standardController="Teacher_Implementation__c" extensions="testTIControllerExtension">
<apex:chart data="{!classes}" width="600" height="400">
<apex:axis type="Category" position="left" fields="createddate" title="Created Date"/>
<apex:axis type="Numeric" position="bottom" fields="of_Students_in_Class__c" title="Students"/>
<apex:lineSeries title="Closed-Lost" axis="left" xField="createddate" yField="of_Students_in_Class__c"
markerType="circle" markerSize="4" markerFill="#8E35EF"/>
</apex:chart>
<apex:dataTable value="{!classes}" var="c">
<apex:column headerValue="Created Date" value="{!c.createddate}"/>
<apex:column headerValue="Students" value="{!c.of_Students_in_Class__c}"/>
</apex:dataTable>
</apex:page>

Currently, this displays only a table of data, no chart.  This makes me think that my controller's working okay, but that there is something amiss with my VF page.  Then again, I don't feel like I have a great grasp of controller extensions, so something could certainly be wrong there, too.

I'd greatly appreciate any insight!