Building MapServer & MapScript on Windows

Jul 242011

imageThere are already Windows packages available for MapServer ready for deployment. However if you need to make a modification to the source files, apply a patch, or just want to see how MapServer is made then you can build MapServer from its C source files. Thanks to the ready made build kits this process should only take 10-15 minutes from start to finish.

Prerequisites: Microsoft Visual Studio with C++

1. Download the MapServer SDK (Software Development Kit) from http://www.gisinternals.com/sdk/. I’m using Visual Studio 2010, and building on a 32-bit Windows machine (still using XP..), so I’m using release-1600-dev

These build kits, provided by one of MapServer’s developers Tamas Szekeres,  contain everything you need to compile both MapServer and GDAL. Checking out all the files from the MapServer SVN repository is not enough, as this does not contain the GDAL or RegEx dependencies (DLLs that MapServer depends on), or SWIG – a tool used to create MapScript files for each of the different scripting languages available in MapServer such as Python, Ruby, PHP, Perl etc.

Using ArcObjects and .NET in Python

Apr 172011

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This question was posed on the GIS Stack Exchange, and the replies include a number of interesting approaches. Below is another one.

Why not just use .NET?

I have several years worth of DLLs built using VB.NET and ArcObjects. Recently I’ve been using more and more open-source libraries, the majority of which can be manipulated using Python.

A major advantage of using a interpreted language (rather than one that needs to compile) like Python is that you can easily change paths and variables in a script.

You can deliver a folder of .NET ArcObjects DLLs, a sample Python script and an end user can automate their workflow themselves. This negates the requirement to build a UI on top of your code as a (Python familiar) user can script it themselves.

DLLs still have their place as ArcObjects includes many functions not available in the ESRI Python libraries. It is also easier to write and test ArcObjects code in Visual Studio with all the advantages of error checking and auto-completion. Continue reading »

Creating Previews of PDF Maps

Jan 182011

imageThe MapFish print module used by both MapFish and GeoExt generates PDF maps that can be saved to clients machines. Over time you can acquire hundreds of different PDFs, but unfortunately Windows XP does not generate thumbnail previews to help find them again later.

The script below solves this problem by generating a PNG image of all the PDFs in a folder. The image to the left shows the results of the script when run on a series of UN Mission Maps.

This relies on two programs to be installed. ImageMagick – a free image conversion software package, and GhostScript another free program that can be used to access, read, and create PDF files. You may have to reboot your machine after installing these programs for the script to run successfully.

The script uses a convert utility program which comes with ImageMagick. Continue reading »

Installing Python Modules on Windows

Oct 202010

image Installing Python modules on 32 bit Windows is a fairly simple process once you get to know the vocabulary of packages (Python scripts and libraries), eggs (similar to a bundled zip file), and the Cheeseshop (the Python “app store” equivalent – now renamed the Python Package Index or PyPi).

Many popular packages in PyPi have custom Windows installers that take care of both Python files and any associated DLLs. For example Shapely and NumPy.

For other packages the easiest way to add them to your Python installation is to use Setup Tools. Download the Windows setup package corresponding to your version of Python from http://pypi.python.org/pypi/setuptools and double click to install.

This adds an easy_install.exe to your C:\Python\Scripts folder that can be used to quickly add packages.  You run easy_install from the Windows command line followed by the name of the package. It searches the online PyPi for the best match for your Python version, and then downloads and installs it.

Continue reading »

64-bit Mapscript for Python on Windows

Aug 032010

Tamas Szekeres maintains a site with many different compiled versions of MapServer at http://vbkto.dyndns.org/sdk/ (the site can occasionally be overloaded or down). These are compiled daily direct from the source. It is a veritable Aladdin’s cave of treasures – especially if you are installing on a Windows Server, and even more so if you are installing for 64bit.

It gets even better though! Included in the installation are the latest SQL Server 2008 driver, 64 bit GDAL, and MapScript Python bindings. MapScript allows MapServer functions and classes to be scripted in a variety of languages.

As Python is becoming ubiquitous in the GIS world (opensource and proprietary), if you aren’t familiar with PHP then You can download the zip file and extract to a folder on your machine, in the example below I used C:\ms4w64 (old habits die hard!).

Continue reading »

Using TileCache on IIS

Jul 042010

imageI’ve previously written about using PyISAPie to run Python under IIS – this allows Python scripts to run faster than using CGI. Rather than starting up the Python interpreter each time a request is made to the web server, PyISAPIe starts the interpreter once and only needs to run the script at each request.

TileCache provides a Python-based WMS-C/TMS server – this is allows you create a local disk-based cache of any WMS server (in my case MapServer), and then connect to it through a WMS-C client such as OpenLayers. Using a cache means that rather than have MapServer create an image for every single request for a tile, the first time a tile is requested the image is saved in a folder on the server. On all subsequent requests for the same data TileCache can retrieve this file without needing MapServer. Performance increase is incredible – however watch out for filling up disk space, and remember to empty the cache if you change symbology or update your data.

As mod_python is now officially dead (and has been moved in Apache’s attic), it is yet another reason if you are using Windows servers to run everything through IIS rather than the rather clumsy Apache on Windows. Why pay for Windows, and then install a web server port, thereby losing all the tools, security, and utilities within Windows to manage and administer the web server?

The aim of this post is to describe the set up of TileCache, running through IIS. Continue reading »

Visualising GeoJSON in 15 Minutes

May 242010

The objective of this post is to save a GeoJSON feature collected from the web to an image file, and was inspired by the Shapely manual. This will be done using Windows, Python 2.5 (although 2.6 should be almost exactly the same steps), and some additional Python packages. This example uses GeoJSON data from a CloudMade geocoding service.

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The greatest difficulty when trying to do things in Python is getting the right packages to match your Python version, and making sure all the package dependencies are in place.

Continue reading »

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