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Showing posts from November, 2011

Observations on web service design for mobile devices

This post was prompted by my use of back end third party services for the FINDaPAD app and my recent set of posts about push pins and Bing Maps control. I want to explore the affect the design of the back end services can have on a mobile app UX & UI design. For FINDaPAD we make use of two sets of third party services, Nestoria & UK Crime API . Nestoria is a property search service for the UK and other countries whilst UK Crime API provides crime information for England & Wales, we use the second to generate crime stats for a local area when viewing a property in FINDaPAD. Even though Nestoria claim on their website ' The API is very much a work in progress.' I believe this be a well thought out API from a consumers perspective, it has a compact data schema (JSON or XML) and it enforces a pagination convention on the consumer which has a bigger benefit for mobile app development than for full blown desktop for the simple reason of CPU performance and power co

How many pins can Bing Maps handle in a WP7 app - part 3

I've finally got round to finishing this 3 part series about manipulating push pins on the Bing Maps control in WP7 - the final part took longer than expected! In the first part I showed what happens to memory usage and UI performance when you have to many pins to show and how virtualizing the pins can reduce and improve both of these. In the second part I showed how you could optimise the HTTP calls to the back end services and how scrolling around the map control can be used to start and stop the requesting of more data. In this part what I want to show is how you can group & cluster pins and effectively remove the idea of using a pins completely but still convey the geo-location data to the user. I'll be using techniques described in the polygons posts I wrote previously to help with the grouping & clustering of pins. For this post like the previous posts I'm going to be using the UK Police API for street level crime, see here . This API gives a lot of

Setting up RavenDB in IIS 7.5

I started exploring RavenDB today and the first part was to get an instance running under IIS, specifically running under IIS 7.5 (Windows 7). This is a quick post to help explain a very simple issue I had because of my lack of familiarity with IIS 7.5. I downloaded the latest binaries  and followed the instructions for setting up RavenDB can be found here . This was very quick and simple, I thought I had everything working, but then I started seeing the following: I know RavenDB is being loaded into the IIS Worker Process - because I can see 'Raven' in the error message. Apart from that ' Your request didn't match anything that Raven knows to do, sorry... ' didn't really help point me in any useful direction. I can't even tell if the problem is related to RavenDB or IIS 7.5. It turns out the problem was related to the ACL for the website configured in IIS 7.5. Specifically I hadn't associated the Application Pool Identity with the website.

Please welcome FINDaPAD to the WP7 app store

I'm proud to announce the release of FINDaPAD into the WP7 app store , it's been a long journey working on this app and I'd like to thank my co-workers Rich  &  Nick  for all their hard work. We've spent the last 6 months working on this at the weekends and as with all software released to market the last few weeks seem to have been the hardest. So what is a FINDaPAD?  FINDaPAD is a property search app for buy or rental properties in the UK housing market. We aren't the first app to go to market offer property search services but we do believe we offer something different from a UI perspective - we've tried to follow the Metro-style guidelines for WP7 as much as possible. The app is very much designed with the idea of being used when you're  out & about looking for properties and you need a quick and easy way to search the local area. You also have the ability to search locations using post code, place name or geo-location. The res

Tessellating shapes on top of Bing Maps in a WP7 app - part 2

In my previous post  I showed how to tessellate polygons over Bing Maps control. This was a demonstration of how to achieving tessellation over the map control for a WP7 app. The problem is this is a sub-optimal solution from a UI perspective. This post shows how I've changed to code to use an asynchronous pattern for creating the polygons. The code is available for download. The primary problem with the solution is not the actual calculation but ' where ' the calculation was being performed. All the work was done on the main UI (Dispatcher) thread. Simply this means the app would freeze whilst calculating the required the polygons for the currently visible map area. The secondary problem was overloading the UI thread with rendering requests. Obviously all the visible polygons need rendering to the screen, but if you chuck a lot of work at the UI thread nothing else in your app is going to be able to do any UI work until all those requests have been processed. This mea