The problem with OGC support ..

is that the focus is too largely geared towards server certification. While i understand the importance of server compliance using tools such as CITE, if the subsequent clients consuming these services are poorly implemented, the end user surely has to question the point of it all.

I would really like to see a set of “best practices” written up for OGC clients to at least, try to follow.

Here’s my list (which is by no means complete)

WMS

  • Use layer Title’s and not Name’s
  • Support layer grouping’s
  • Be able to pull out individual layers from a service
  • Be able to split layers into separate requests if desired. Layers will be returned based on their draw time and not have to wait for the slowest layer
  • Select desired output format
  • Select desired coordinate system
  • Interpret the ScaleHint element so user’s are aware of any view scale restrictions
  • A console to debug requests sent without referring to server logs
  • Support for GetFeatureInfo and GetLegendGraphic requests
  • Support for BASIC HTTP authentication
  • Tiled requests. If i already have the image for that area, just download the difference when i pan.

WFS

  • Use layer Title’s and not Name’s
  • Support of the maxfeatures parameter
  • Support of the BBOX/Intersects Filter at the very least
  • Caching of features. If i zoom out or pan from the current view, why should i have to wait for another WFS request when i already have the features?
  • Status indicator
  • Ability to send manual POST requests to the server.
  • Support for the GZIP / Deflate HTTP compression schemes if the server supports it. Everyone knows GML compresses smaller than shapefiles in most cases … lets speed things up a bit
  • Whether the WFS GML is converted or read natively, ultimately that WFS layer should be treated no differently than a local dataset in your client.

Let me know if you disagree or think something should be added … i’d certainly like to hear other people’s thoughts on the issue or if you’ve run into similar issues.

4 thoughts on “The problem with OGC support ..”

  1. Chris,

    This is a great set of best practices for w*s clients.

    Three more for wms:

    – Ability to use your own styled layer descriptor (bonus points for implementing an sld editor using the existing styling/classification mechanism)

    – Adding vendor specific parameters to the request

    – Access to the layer abstracts … the title and name of the layer are often not enough to really assess the content.

    Thanks for a great article. It’ll get lots of developers thinking.

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