QGIS Planet

OpenLayers: failure of map redraw on panning

Just a quick heads up for those of you using OpenLayers. There seem to have been a lot of problems lately with OpenLayers refusing to redraw its layers when panning, where everything was working before. One possible solution turned up in this thread on OpenLayers Users. The credit for solving the problem is therefore not [...]

Norwegian Trekking with QGIS Server

I have blogged about the awesomeness that is QGIS Server before. Maybe you have seen some of the nice maps that Andreas Neumann has made in Uster, Switzerland. Over the past 3 months we were contracted to help prototyping a new mapping service for the Norwegian Trekking Association. We really got a chance to put QGIS Server (and the new QGIS Web Client project) through its paces. Why not take a little look for yourself. We had quite a lot of fun optimising the client's data set for good performance and generally making sure everything works smoothly.

Note:

- the site is still a test site, but the fine folks from Norway gave me the OK to let people take it for a whirl.
- we have not yet implemented search support.
- We made a bunch of different print layouts for you to try out!

It's now incredibly easy to get your QGIS cartography online. In the near future I plan to test out techniques for tilecaching with QGIS Server and once that works it will be the end of the line for my 11+ year love affair with UMN Mapserver for the most part I think.

Get your map on! QGIS Server in action (click for full image)

Get your map on! QGIS Server in action (click for full image)

 

 

 

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Live vehicle tracking with OpenLayers

The last three or four weeks we have been preparing the Tracks4Africa site for the next season of 'Voetspore' (translated from Afrikaans: 'foot steps') - a South African TV program which follows the adventures of a group of 4x4 drivers as they traverse africa. For this season, one of the vehicles has been fitted with two tracking devices - a satellite transponder and a GSM unit. By wiring up a couple of Django views to deliver GeoJSON, and consuming that from OpenLayers we are able to deliver real time data on the vehicle positions during their excursion. The data is degraded to show one vertex per hour, although the complete dataset is much more detailed.

 

The trip just started this weekend from  Cape Agulhas, the Southern Tip of Africa (and coincidentally not far from where I live) to Alexandria in Egypt (which is coincidentally extremely far from where I live). You can track their progress by visiting the dedicated Tracks4Africa Voetspore page created for this purpose.

Voetspore map on Tracks4Africa (click for large view)

Voetspore map on Tracks4Africa (click for large view)

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FossGIS Web Mappers Toolbox

I thought I would take a moment to run through the tools in my digital toolbox that I use to develop GIS enabled web sites. I try to pick the best of breed in each area rather than learn multiple tools that do the same thing – life is short and there isn’t enough time for me to do that.  I would be interested to read in the comments if anyone has suggestions of better alternatives:

Operating system: Debian or Ubuntu Server Edition. Really don’t run your web site on Windows, its just a silly waste of time and money.

Web server – Apache 2. It’s a no brainer really, its fast, robust and infinitely configurable while easy to get running in a default configuration.

Programmers editor: Vim (or emacs if you prefer). Being able to use the same editor on both local development machines and remote servers is indispesible. Also if you hand write your html it tends to have less gumpf clogging up the works compared to the Frontpage etc. generated sites I have seen out there. If you must use a GUI editor there are a few good choices under Linux, but VIM does it for me.

Web Application framework: (Geo)Django. With its support for spatial extensions,  intuitive MVC architecture and wealth of 3rd party add-ons, Django is a great choice for building your web applications with Python.

Backend Database: PostgreSQL/PostGIS. It does everything you need including store geospatial data.  Some people suggest SpatialLite as an alternative, but thus far I have haven’t used it in a production system so I don’t know what limitations, if any, it has.

Javascript Framework: Jquery. I know there are some good competitors but JQuery and JQuery-UI are so great I haven’t felt a need to go and discover their competitors. There are a huge number of add ons for JQuery and plenty of helpful people out there if you get stuck.

CSS Framework: Blueprint CSS. I think CSS frameworks are still a relatively new concept. They take a lot of the pain out of layout and make your site look good with minimal effort. Blueprint implements the 960 grid and the results are pretty much always pleasing on the eye.

CSS Compressor: http://www.csscompressor.com/. This web site will take your CSS and squish it by removing comments, white space etc. It typically makes my  CSS files around 25% smaller.

Javascript Compressor: Google Closure. This web service / web app will squash your javascript down nice and small using a variety of techniques.  With simple optimisations, I typically get around 40% reduction in code size. It also optimises your code for good measure.  They provide lots of detailed documentation to get you on your way.

Web Mapping Control: OpenLayers. It’s a bit of a no-brainer. I haven’t really looked that hard but is there anything that really competes with it (other than the Google Maps API)?

Web Mapping Server: UMN Mapserver. One day soon I am going to replace this entry with QGIS’ own mapserver implementation by Marco Hugentobler, but for now Mapserver is the best thing since sliced bread – it’s  a doddle to install, incredible flexible and you can generate basic mapfiles using QGIS so it’s easy to get started with. Also worth a mention is Mapnik which can produce gorgeous maps.

Web Mapping Cache: TileCache. I keep meaning to try out MapProxy since it supports region delimitation using shapefiles rather than bounding boxes – which can drastically reduce the size of your seeded cache. But for now, TileCache is really easy to set up and you should have it running in just a few minutes.

Did I leave anything out? If you take the above tools, software and web services, you will have everything you need to produce some great web mapping software.

pixelstats trackingpixel

FossGIS Web Mappers Toolbox

I thought I would take a moment to run through the tools in my digital toolbox that I use to develop GIS enabled web sites. I try to pick the best of breed in each area rather than learn multiple tools that do the same thing - life is short and there isn't enough time for me to do that.  I would be interested to read in the comments if anyone has suggestions of better alternatives:

Operating system: `Debian`_ or`Ubuntu Server Edition`_. Really don't run your web site on Windows, its just a silly waste of time and money.

Web server - `Apache 2`_. It's a no brainer really, its fast, robust and infinitely configurable while easy to get running in a default configuration.

Programmers editor: `Vim`_ (or emacs if you prefer). Being able to use the same editor on both local development machines and remote servers is indispesible. Also if you hand write your html it tends to have less gumpf clogging up the works compared to the Frontpage etc. generated sites I have seen out there. If you must use a GUI editor there are a few good choices under Linux, but VIM does it for me.

Web Application framework: `(Geo)Django`_. With its support for spatial extensions,  intuitive MVC architecture and wealth of 3rd party add-ons, Django is a great choice for building your web applications with Python.

Backend Database:`PostgreSQL/PostGIS`_. It does everything you need including store geospatial data.  Some people suggest SpatialLite as an alternative, but thus far I have haven't used it in a production system so I don't know what limitations, if any, it has.

Javascript Framework: `Jquery`_.I know there are some good competitors but JQuery and JQuery-UI are so great I haven't felt a need to go and discover their competitors. There are a huge number of add ons for JQuery and plenty of helpful people out there if you get stuck.

CSS Framework: `Blueprint CSS`_. I think CSS frameworks are still a relatively new concept. They take a lot of the pain out of layout and make your site look good with minimal effort. Blueprint implements the 960 grid and the results are pretty much always pleasing on the eye.

CSS Compressor: http://www.csscompressor.com/. This web site will take your CSS and squish it by removing comments, white space etc. It typically makes my  CSS files around 25% smaller.

Javascript Compressor: `Google Closure`_. This web service / web app will squash your javascript down nice and small using a variety of techniques.  With simple optimisations, I typically get around 40% reduction in code size. It also optimises your code for good measure. They provide lots of detailed documentation to get you on your way.

Web Mapping Control: `OpenLayers`_.It's a bit of a no-brainer. I haven't really looked that hard but is there anything that really competes with it (other than the Google Maps API)?

Web Mapping Server: `UMN Mapserver`_. One day soon I am going to replace this entry with QGIS' own mapserver implementation by Marco Hugentobler, but for now Mapserver is the best thing since sliced bread - it's  a doddle to install, incredible flexible and you can generate basic mapfiles using QGIS so it's easy to get started with. Also worth a mention is Mapnik which can produce gorgeous maps.

Web Mapping Cache: `TileCache`_. I keep meaning to try out MapProxy since it supports region delimitation using shapefiles rather than bounding boxes - which can drastically reduce the size of your seeded cache. But for now, TileCache is really easy to set up and you should have it running in just a few minutes.

Did I leave anything out? If you take the above tools, software and web services, you will have everything you need to produce some great web mapping software.

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