Citizen’s MapSite

The National Land Survey of Finland has relaunched its map site. Some thoughts and URL reverse engineering follow.

I’ve been a user of the Citizen’s MapSite (Kansalaisen karttapaikka) ever since it was launched sometime in the late 90’s. While it used to require a registration, the new version works without one. Which is just as well, as there wasn’t any sensible reason why the registration was required. It also appears that it doesn’t require you to access it from a Finnish address anymore either. I’d like to know if it can be accessed from other countries.

That aside, now’s the time for some technical nit-picking. Somewhere on the site I found a long list of supported browsers, which is a good step forward. The code itself still uses a table-based layout and causes almost 300 validation errors on the front page. However, better coding practises and one run through the validator would have let the programmers clean up the site of all validation errors as they are only:

  • unencoded ampersands in URLs, i.e. & is used instead of &
  • missing alt tags, and
  • width and height attributes set for table cells.

Without those errors the site would be valid transitional HTML 4.01. I do have my gripes with the table-based layout, but you can’t have it all. It also goes to show how far we are in Finland from CSS-based designs.

Finally, some reverse-engineering of the URL structure used on the site to enable direct links to points from other sites. The internal coordinate system used is the Finnish KKJ (I can’t remember what it stands for), but WGS-84 coordinates are supported (EUREF-FIN geographical). The following URL shows the minimum that is needed: ?lang=en-GB&y=62.614177&x=29.545735&srsName=LATLON%3Aetrs

I couldn’t figure out how to create an URL with WGS-84 coordinates that would allow different scales than 1:16000, but I guess it has to do with the internal coordinate system. Changing the scale parameter did not help…

Update 23:31: Searching for coordinates that don’t exist in Finland (or more specifically the KKJ national grid coordinates) result in no meaninful error message. Inputting coordinates not found in Finland in the search form on the site informs you of an incorrect entry.

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