Question

I’m trying to use a BarChart in Flex. I’d like it to order the bars according to the order of the ArrayCollection I fed it. i.e. data at index 0 should be the first bar on top. However, Flex is giving me the exact reverse order. i.e. data at index 0 is not the last bar in bottom.

How could I tell the BarChart to reverse the order other than reversing the order of my ArrayCollection? Thanks!!

Here’s the block of code in my script tag:

[Bindable]
private var optionsArray:ArrayCollection = new ArrayCollection([
        new VotingOption('Yes, it rocks!', 'yes', 5),
        new VotingOption('Meh, it is okay!', 'ok', 10),
        new VotingOption('No, it sucks!', 'no', 15)
]);

And here’s my BarChart code:

<mx:BarChart x="9.1" y="8" id="barchart1" width="563.0303" height="454.01514" maxBarWidth="30" 
    type="overlaid" dataProvider="{optionsArray}" showAllDataTips="true">

    <mx:verticalAxis>
        <mx:CategoryAxis id="vertAxis" categoryField="optionSMSCode"/>
    </mx:verticalAxis>

    <mx:verticalAxisRenderers>
        <mx:AxisRenderer axis="{vertAxis}" showLabels="false"/>     
    </mx:verticalAxisRenderers>

    <mx:series>
        <mx:BarSeries xField="optionResult" showDataEffect="morph"/>
    </mx:series>
</mx:BarChart>  

Answer 1

The output that you are getting is correct according to how Flex BarCharts work, and this is also the output you should be expecting. The origin is at the bottom_left, and as such objects/lists start at the bottom_left and continue outward towards the the top and to the right.
http://livedocs.adobe.com/flex/3/html/help.html?content=charts_types_03.html

I do understand visually how you would interpret it the reverse way. So let’s say that someone gave you that dataProvider/ArrayCollection in that order, but you wanted to visualize in the reverse order.
I would either 1)

//public var data:ArrayCollection;
data.source.reverse();

http://livedocs.adobe.com/flex/3/langref/Array.html

or 2)
reverse the labels on the vertical axis using the AxisRenderer.labelFunction property.
Flex: Inverting LinearAxis values