GIS Info

GIS Standards

I read through Inside Idaho's "Standards" page (concerning the data they offer) and decided it was time for an update. In the process, I tracked down, updated and read through a lot of the supporting references. My GIS Standards page is not the last word, but it's some newer ones (or was, in 2006).

Google Maps API experiments

The Google Maps team has continued rapid prototyping and improvement of their user interface, and now makes it easy to make annotation overlays to the map data they provide, with the "My Maps" tab at Google Maps. Meanwhile, the roll-your-own javascript API continues to add more features. A number of my initial experiments were broken by version changes, and weren't worth patching.

Three relevant artifacts applying the Google Maps application programming interface (API):

Beyond Google's own documentation, the Blackpool Community Church Javscript team tutorial from Mike Williams seems to be the best resource going.

Other links on this topic

The Map Room is a good weblog about maps.

The Natural Resources Conservation Service (NRCS) has an updated set of maps for the state, with various themes.

What is AJAX?

As mentioned in my blog, it's an acronym for "Asynchronous Javascript and XML."

The key component of implementing Ajax is the javascript XMLHttpRequest object, first implemented IE5 for Windows as an ActiveX object. You, as programmer, write an "event handler" function (onreadystatechange) that is called when the object's readyState property changes. Typically, you're interested in proceeding only when readyState = 4, i.e., loading is complete and the requested data are fully in-hand.

The data of interest don't have to be in XML format, nor do they need to be manipulated with XSLT (eXtensible Stylesheet Language Transformations), but the full-blown Ajax concept encompasses that.

Tom von Alten      tva_∂t_fortboise_⋅_org

Saturday, 21-Sep-2013 16:36:52 MDT
http://www.fortboise.org/maps/index.html