Category Archives: coldfusion

3 geek events; a summary

It occurs to me I’ve been to three geek events recently, and not mentioned a word about them.


Over the weekend Yahoo, the BBC and a bunch of other companies ran HackDay up at Alexandra Palace. The basic principle being: get a bunch of geeks together, give them large amounts of APIs, ideas, caffeine and pizza, and then see what happens. A few unexpected problems occurred, such as Alexandra Palace getting struck by lightning early in the day, and then the fire alarms thought the building was on fire, so understandably opened the roof vents to deal with the problem. Which meant, that it was now raining on everyone’s laptops. The HackDay staff did a good job of evacuating everyone out into the conservatory before the next storm hit, and a lot of people kept right on hacking.

During the day I hit a couple of road block in my attempted hacking, apart from the obvious inspiration one: firstly a lack of crossdomain policy files meant I couldn’t access a lot of the BBC feeds I wanted to. I’m thinking of making moo cards with important info on them, just to hand out to people who don’t make it easy for Flash. Secondly my attempts to use the HTML object in Adobe Air seemed to hit security problems -aka I could only load up locally saved web pages. So in the end I spent a few hours randomly annoying Aral while he was playing with a wifi Nabaztag/tag by making it flash and waggle its ears at him. As a result of all these difficulties I spent most of my time at the event wandering around catching up with people, looking at geeky things at the O’Reilly Make stand (including a gear system built out of pasta and ginger snaps), seeing a few alpha demos of projects for HackDay, and a fair bit of evangelising Flex to a variety of different people of different geek creeds.

As I was only half an hour from home I opted for crashing out in my own bed (as opposed to the comfy beanbags that others seemed to have chosen). Unexpected house adventures involving an ethnic cleansing of moths meant I couldn’t make it back for the second day. I really enjoyed the first day though, and I’m looking forward to the next big London geeky event like this.

London .Net User Group on Silverlight

This was on Thursday, and felt a little strange – I felt very much like a spy in their midst. I turned up to hear someone from Microsoft talk about Silverlight – I didn’t go to Mix and this is the first public chance the UK has had so far; also I wanted to hear a pitch directly to the developers as they tend to be more about implementation and actualities, and less about product pitches. I’m going to write up my thoughts on Silverlight separately, but as far as comparisons on the User Group go, this one felt a little flat -I’m now even more grateful to the efforts put in by Niklas, Tink and Aral to try enliven the meetings, find the right venues and grow the respective communities.

Scotch on the Rocks

This was at the beginning of the month, up in Edinburgh. It was definitely good to catch up with people I haven’t seen in a while as well as put faces to the names on all the blogs I skim. There were a few good sessions in there too and I’m actually looking forward to some of the improvements in ColdFusion 8. The Thursday night was suitably alcoholic as well 🙂 I’m surprised at the how small the UK ColdFusion community actually is, and I’m very grateful for the demonstration of Adobe love we had by their sending over of Tim Buntel to talk to us.

Future Geekery

No more geek things for a while now, although looking at my calendar there are quite a few coming up: hopefully I’ll be able to make the next London Flash Platform meeting in July (I’ve had three collisions in a row now, Whitby, Scotch and now Glastonbury); I’m still toying with 360Flex:Seattle in August, although the airfares are not cheap and work won’t pay my costs; September is BarCampBrighton, which currently is currently oversubscribed by at least 3:1; November is FlashOnTheBeach, this time around I’m planning not to have any conflicting deadlines to deal with.

This weeks' model

Since chatting with Peter Bell at 360 Flex, I’ve been doing a lot of thinking about the base model for my Flex-and-ColdFusion Intranet application, “Stream”.

This application was pseudo reverse engineered from a Visual Basic application and has nearly 200 tables of inter-related data – mostly without primary or foreign keys, but that’s another story entirely. For a long while there has been no clear and overall model of the application. The tables and views were mostly responsible for driving the application but there is still a lot of business logic tied up in various peoples’ heads. This is obviously not an ideal situation, as it dramatically raises the bar of entry on this project for any other developers.

As a direct result of the planned migration from Flex 1.5, to new-and-improved Flex 2.0.1 (including the usage of Flex Data Services), I now have to rework the ColdFusion tier. This seems like a good time to rethink how the application works, apply some consistency to the application as well as build up a global model to develop from. Hopefully there will also be a page or two of documentation. 🙂

When working on “Version 1” of Stream I spearheaded the generation of a lot of the code on for the ColdFusion and Flex tiers, which included various parts of code for usage with Cairngorm in Flex as well as unit tests for ColdFusion. However this code was fairly brittle and an increasing number of complicated edge cases meant that eventually the generation was one-time only. The result of this was that this was barely better than no generation at all.

So for the last few weeks, I’ve been playing around with ideas for the new model and how to generate code for the three effective tiers – ActionScript, ColdFusion and database (accessed via an ORM). This is resulting in an bespoke generator application that I’ve named Dynamo. But code generation is only a part of the purpose of Dynamo. The source for my model is the database, so obviously I’ll need to validate my model against this – checking usage of fields and automatically using the database as the basis for any typing information; and as the end result of the application is to display these fields in a Flex UI, I need to validate that I am using all the fields required for each part of the model. This combination of techniques should allow rapid development based on our existing data while dramatically minimise the number of errors caused by missing fields, typos or incorrect data types.

For the generation part of Dynamo, after much thought and reviewing of options I’ve fallen back on an old favourite technique – using XML for the model and XSLT for the generated files. Based on ideas from Peter, I was originally intended to put all of this model meta data into the database itself. However after some initial attempts at putting a hierarchical data model into a database, I realised that I was overly complicating things and that the “simplest thing that could possibly work” was to work with an XML file for the time being – if required later I can always rework my model code to use a database. One drawback with using XSLT is that many people find it complicated and difficult to work with; at some point I’ll replace this with a simpler templating method.

However, one big advantage of using XML and XSLT is that I can incorporate this into my ant build script so that all of the generated code is created when “Stream 2” is compiled and deployed, and the generated files are not checked into source control. This keeps the focus of change entirely on the model and the templates, not on the generated files themselves.

Ideally I’d have a dynamic and active generator – change my model, next request all the changes are reflected. The problem is that I need my VOs for ActionScript to be generated to be compiled into my application, and ColdFusion requires physical files to automatically translate classes to ActionScript. As an aside, I was talking with one of my friends who works in the finance industry and when I told him I was using XML and XSLT he embraced my like a brother exalting the virtues of XLST programming. But when I told him I was generating my code, he became disgusted and seemed to want to pray for my eternal programming soul 🙂

These are still early days, but I’ve switched back from focusing on Dynamo to Stream -which of course was the whole point of this whole exercise. I’ve now started wiring up a number of screens, and apart from the occasional typo or missing field (which is why I need to validate), the development is proceeding rather quickly.

[Addendum: a few weeks later]

The base idea behind this modelling has worked really well – I was able to wire up a lot of screens with data, in rapid succession, with only a small amount of code required – the rest was generated. I’d like to componentise more on the Flex side, but so far the ColdFusion side is working well. However, I’m yet to need to customise the ColdFusion code – and this is where generated code tends to fall over. Dynamo at the moment is sliding away from being a separate application, and may end up being tied into the main code-base of Stream. One unfortunate and unforeseen side effect of this generation system is that I now need to generate my code for the application to work – otherwise there is no base ColdFusion components to handle data accesses. This means that my build times in CFEclipse are in the realm of 20 seconds – hardly ideal.

The confusing land of FDS and CFCs

Things, that so far, seem to be true:

  • FDS invokes CFCs independently of webservers and virtual hosts
  • CFCs therefore require cfmappings
  • As do frameworks used in Application.cfc
  • Without these mappings, there will be confusing errors, stating the CFC is not found
  • ServiceCapture is unable to detect FDS transmissions due to the complexity of proxying such a thing
  • There are still silent failures, but there are a number of logging types that can be enabled (and it is then easy to drown in all the noise)
  • Always remember , without the <cfproperty> tags, no translation of types will occur