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photo credit: jasoneppink

I’ve been working on a project recently that involves a desktop AIR application running (mostly) offline with a local SQLite database. Occasionally the app will synch collected data remotely with a central server that will have an administrative and reporting web front end. Various parts of the AIR application involve filling out a series of multi-choice questions. Considering that the data will be used by two different systems, and anticipating that questions and answers may want to be updated from the admin portal, it seems a good choice to make things as dynamic as possible based on data from the db. It’s not a difficult problem to solve, and I’ve done it a time or two before, but since it’s fresh in my head and the code is in front of me, I’m going to use a couple blog posts to document the strategy.  The SQL presented is pseudo code and will not actually execute.

Part 1 is getting the database structure in place.

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You have a great application on your hands but you can’t load it up as a part of your brand-spanking-new application because they are not the same version.

Do you rewrite the old stuff? Or you downgrade the version of the app you are currently building? Both are very painful, and all you need to do to avoid the pain is to make the apps talk and coexist. This is a standard problem of any enterprise system, especially the ones with a long lifespan.

Flex framework addresses this problem with the Marshall Plan or at least it’s supposed to. Here at Pathfinder, when we were tasked with a complex multi-versioned  enterprise system that had just such a problem. We gave Marshall Plan a try and in our experience we never got it to work entirely as intended. But we came up with a solution.

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photo credit: Amateugrapher

We recently finished a first release of a data visualization application. The application was written in Flex and needed to draw curves with up to 250,000 points total between them. To do this in less than a half a second took quite a bit of optimization, to the point where we could have written a 3D real-time video game with our rendering code.

I was curious to see what the performance would be on other browsers with HTML5 Canvas. I put together a simple GWT program to run each browser through it’s paces. The target on the Macbook Pro I was using: 400 milliseconds, which is what the Flex app could do for 250,000 points. The results?

• Opera 10.53 – 160 milliseconds.
• Safari 5.0 – 180 milliseconds.
• Firefox 3.6.4 – 180 milliseconds.
• Chrome 5.0 – 200 milliseconds.
• iPad – 2500 milliseconds.
• IE ? – Blech. Don’t ask. Minutes. It likely has something to do with the GWT implementation.

For a long time if you suggested using web technologies for complex graphical operations, you would have been laughed out of the room. When the tools and libraries catch up to Flex/Flash, however, these days nobody will be chuckling at HTML5.

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Do you know every detail in the Flex framework by heart? Do you also know all the other libraries that you use by heart? Well I don’t and I often have to reference some online resource while developing.

For instance, I always have Action Script Language Reference, Wikipedia, some library API site(s), Gmail and a dozen other ones open + the debug version of the app at hand.

So what used to happen when you but a breakpoint in Flex Builder with all these tabs? They would be unavailable and any process happening inside of them could not be relied on. Since not all code runs well on first attempt, if the app crashed while testing ( think 3D, data intensive apps, etc.) the browser and all the tabs went down with it.

My solution so far was to use Firefox as a development browser and Safari ( since I’m Mac based ) as a browser for references and everything else. For crashing resolution, Firefox has a nice “Restore” option but it’s not fun waiting for 15 tabs to reload.

So Google Chrome recently came out for Mac. It didn’t impress me on Vista so I didn’t care much. I guess I was in between of curious and bored so I decided to give it a spin.

What a pleasant surprise to see every tab running in a different process. My workflow feels so much better now that I’m not afraid that a bad line of code is going to take down my whole browser.

I’ve heard that IE8 also runs tabs as different processes but I’m not crazy about returning to development on Windows. I did try out Chrome on Windows 7 as a result of the Mac test and all the issues I’ve seen the first time around have been addressed. Kudos to Chrome development team.

Let’s not forget to mention all the features that are missing on Google Chrome for Mac, primarily the lack of Bookmark Management, but Google Bookmarks or any online bookmarking service will do for now.

I can not wait to see more development being done on Google Chrome for Mac and it getting out of beta. I will not uninstall Firefox anytime soon but as a Flex developer I give Google Chrome for Mac high scores for beta.

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[SWF]http://www.pathf.com/sites/pfd/flash/zeitlupe/Zeitlupe.swf, 500, 475, dataLocation=http://www.pathf.com/sites/pfd/flash/zeitlupe/[/SWF]

We’ve been building a lot of mapping/GIS data visualization applications over the last few months, mostly using flex with various back end services (ArcGIS, google and yahoo maps, open source mapping frameworks.) One of the more fun little projects was putting together this flex widget for displaying maps and graphical data together on a timeline. It’s meant to be distributable so that anyone with a blog can display it. We put it together using presidential election data and national debt, not because we thought the correlation was particularly significant, but because the data was available going back a long time. The widget is pretty flexible; it can go against a local data source or a web service, and we can easily modify it to show different kinds of data. We’ll be coming out with a few more of these over the next few months, hopefully with some more 3D maps, drill down on geographic level, as well as more charting and other visualizations. If you’d like to use this one, or have ideas for other data sets and visualizations you’d like to see, let us know.

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The other day, I was trying to get the icon for a button in flex programmatically for a FlexUnit test. The code I was testing set the icon of a button using setStyle('icon', ICON). I attempted the obvious button.getStyle('icon') in the test, but was surprised that this always returned null.

A little bit of digging revealed that the I needed to go through the style declaration for the button. When changing my test to assert on button.styleDeclaration.getStyle('icon'), I was able to successfully access the icon.

I found this a bit non-intuitive, but fortunately it only involved some investigation and minimal code changes.

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We just published a case study on a Hedge Fund Analytics application developed in Flex. It’s an extensible Flex based platform for real time analysis of hedge fund performance data, with dynamically updating charts, graphs and sophisticated filters for cumulative performance, return distribution, alpha, beta and correlations, commissions and fees, credit and sector exposure.

The system is designed as a modular platform which can consume data services from multiple sources, and can integrate multiple custom components. Custom components were designed to conform to a standard API. Components expose standard flex component properties and events so that properties and method references could be passed. This allowed individual dashboard applications to be built, fed data and customized at run time. Take a look at a video demo or read the longer case study on the Pathfinder site.

Hedge Fund Analytics

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After a long time of searching for the right data visualization framework for Flash Platform, some time ago I’ve put my money on Flare which is based on a Java framework called Prefuse. I have been very happy with it and haven’t looked back until a new framework of same purpose crossed my way – Axiis.

Before anything else said, Axiis is a brand new framework so I have to give it some credit if all the bells and whistles are not there. What intrigued me about it in the first place is that Axiis is heavily relying on Degrafa, a well proven declarative graphics framework that I have a lot of good experience with.

After looking at Axiis examples, here are my first impressions of how it stands against Flare.

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photo credit: Paul L. Nettles

We’re starting a software development summer internship in our Chicago office this year. If you’re a college junior, senior or recent graduate who want to learn the agile/OO development ropes while developing really cool products and services and earning $20/hr per hour (you should pay for the privilege, right?), give the internship posting a look here.

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We just launched a new rich internet application for Destinationbeer.com, called Beer Hunter.  It was written in Flex and Ruby on Rails and features mapping and 150 beers from around the world.  We think it’s pretty cool, so check it out, and let us know what you think.  One of the things I really like about it is that the design pattern can be applied anywhere you’re filtering products geographically and on attributes.  Coffee? Wine? Jewelry? Chocolate? Travel Books? I particularly like the way the beer list visually sorts when you change a filter and the zoom interactions on the map.

There’s more information in the case study on the Pathfinder web site, Sasha has written a related post on RubyAMF and Flex from the Flex perspective , and Justin has written one on Rails, AMF and Flex from the Rails perspective.

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