Free Versus Proprietary Geo Stack – Where is Flex?
A detailed post in GIS in XML , titled ” Neo vs Paleo Geography ” does a nice comparision between free and proprietary GIS technologies including the cost implications.
One thing I found missing in the “Browser Client Viewer” section of the post is Adobe Flex. There is mention of OpenLayers, Silverlight DeepEarth and Silverlight Map Control. But I think Flex has a far better potential in the Geospatial applications arena as compared to Silverlight.
The Flex OpenScales Actionscript/MXML library is very capable. It has been been ported from the rich and trusty OpenLayers JS to ActionScript and is under active development.
Contrary to popular perception, the Flex SDK is free but you have to purchase the Flex Builder IDE like you have to buy the Visual Studio with Microsoft Expressions Studio for Silverlight development.
If you choose, you can develop Flex application using the free and opensource FlashDevelop IDE complete with intellisense and compiler support. It is as capable as the Flex Builder IDE except that the “Design View” is not available here.
By the way, you can develop Flex applications in Visual Studio 2008 using the free ” Tofino ” plug-in. Flex can connect to .NET via the free WebORB for .NET. WebORB enables seamless integration between .NET server applications and Flex/Flash applications. It allows you to use AMF or RTMP from your .NET server back end to your Flex front-end including more sophisticated communication like data push, remote shared objects and message broadcasting.
Hi Farid,
Good point. I guess I’m not familiar with the Flex side of things. Coming from the declarative XML background of SVG, I’ve never looked into Actionscript/MXML. I wonder how it compares to C# and Xaml as far as ease of development?
Hi Randy,
It all depends on how comfortable you are in a particular technology. I find ActionScript and MXML easier as I have a Java/Javascript background. Overall, Flex development is faster and easier as it has a larger component library.
MXML and XAML are similar is the sense that :
tags are (usually) classes
attributes are properties (fields with automatic getter and setter method call)
the root tag of the XML is the base class you’re inheriting
all other tags are instances that are added up to the parent container
both use xml namespaces in a similar way (although the URL schemes are different), to specify that the name of a class belongs to another AS3 package or C# namespace(s)
In MXML, you include ActionScript code within a Script tag. In XAML, you write it in code behind.
The biggest advantage I find is that you can have a single IDE (Flex Builder) to create a Flex application unlike Silverlight where you need Expression Studio and Visual Studio.
Please feel free to correct me if I am wrong as I have not worked much in WPF/Silverlight.