Tips for Training 'Building Dashboard Applications'

Had two classes this week: one I was attending for certification purposes (Building Dashboard Applications), and one I was instructing (Developing Rich Client Application.) I'll have a post about the second class in a few days, but let's talk first about Building Dashboard Applications.

Overall, it is a relatively short class. It is scheduled as a two-day class, but if you are dealing with a class that has programming experience, especially Flex experience, I can't see it taking more than a day and a half. The reason I say this is because I was just part of a class of students that had ZERO Flex experience, and we were done with the class materials just after 12pm on the second day. Granted, these students had programming experience, but the lack of Flex know-how required a few stops to explain some of the basic language aspects of MXML and AS that wouldn't have been necessary otherwise.

And, still, we finished four hours early.

So, if you are going to be teaching this class, don't get worried if you seem to be running fast. Even a relatively conservative pace should guarantee you finish early on Day 2.

As for the class itself, there were a few things I noticed that could be useful to other instructors in the future. Granted, this is from the aspect of someone taking part in a class in which no one had any Flex experience, but these should translate to any instance of the class.

1. What do you do with a Pie Chart that has a hole in it (aka a Doughnut Chart)? This question was raised during the class, and one of the students came up with an obvious solution: fill it will another Pie Chart, of course! If you provide your Pie Chart with two PieSeries, each one with a different data field, Flex will automatically make a Doughnut Chart of one of your PieSeries, and fill that Doughnut with the second PieSeries. Strangely, the first PieSeries added is the one that is placed in the middle of the Doughnut, with the second PieSeries wrapped around it. When using multiple PieSeries like this on the PieChart, the innerRadius property is ignored - Flex sets it automatically based on the number of Series included. And, yes, the PieChart will continue to wrap PieSeries as you add them. Past three, however, it gets a little hard to read...

2. In the bottom, left-hand corner of the dashboard application, a dynamic chart is included from some of the earliest demos of the app. Then, students are guided through creating this chart, which dynamically adds Series to a chart. However, what it doesn't do appropriately is update the Legend for the chart. The reason is simple: when dynamically creating the Series for this chart, we are not appropriately defining the displayName on our Series. If, when the yField and name properties are defined on the ColumnSeries (Walkthrough 5, Steps 24-25, 'Understanding Advanced Charting Techniques'), we need to define the displayName property appropriately for each Series. If we do this, the Legend will work properly.

3. There are lots of typos, but none of them mislead any of the walkthroughs. However, in Walkthrough 2 of the "Formatting Charts" unit, all of the images are incorrect. They are supposed to be images of an HLOC chart, but instead show a LineChart. Don't worry about it: the Walkthrough still performs its function correctly. Further, the effects of the Walkthrough can still be seen in the images - it is only the forms themselves that are incorrect.

4. When talking about Candlestick charts, there is never any mention as to what the color in the chart actually means. From the documentation:

"If the closeField is lower than the openField, Flex applies a solid fill to the candle. The color of this solid fill defaults to the color of the box's outline. It is defined by the declineFill style property. If the closeField is higher than the openField, Flex fills the candle with white by default."

Knowing this ahead of time could save you some searching if a curious student wants more information.

That's it for now. Stay tuned for my next post: Developing Rich Client Applications.