wiki:FAQ

FAQ


The formal FAQ document is found at:

http://www.mapserver.org/faq.html


However, given the nature of the Wiki I would like this to be a dynamic FAQ for new issues. It is also reasonable to post questions here for which the answer is not yet known.

Where is information about MapServer error messages?

How do I find out what developments are going on in MapServer?

  • Starting with MapServer 3.6, a HISTORY.TXT file is included in the source package and documents the changes between releases and their impact on users.
  • Also check the ReleasePlans
  • MapServer RFCs list all of the major changes and include discussions

What are the most significant changes in the last year or so? I haven't used Mapserver for about 18 months. What might I be most excited about?

Well, the last 18 (this was written on 7/3/02) months have seen the releases of 3.5 and 3.6. Version 3.5 was a major reworking of the MapServer internals and could have been called 4.0. Most importantly 3.5 leveled the playing field across data sources. Anything you could do with shapefiles could now be done with OGR datasources, SDE or even PostGIS. This included query support.

3.5 also marked the start of MapServer support for the !OpenGIS WMS standard. MapServer could act as a WMS server AND could act as a WMS client (cascading MapServer). GML output also made it debut.

3.6 was much more of a maintenance release although there were new features added. See the above question for a reference to the change log. DM Solutions introduced their PHP MapServer management tools based on the 3.6 release.

3.7 is in the works and will be more of a major release with the main features being the addition of 24-bit input/output support (yeah!) and advanced symbolization options (drop shadows, multiple stacked symbols, feature offsets) using the new style object.

Is there an easier way to edit .map/mapfiles files?

Anytime I put numbers in the MAXSCALEDENOM / MINSCALEDENOM, the layers are not displayed at all. I have put numbers of varying ranges in, but no luck. Any ideas?

Try putting a [scale] tag in your template to view the range of scale values that your map produces as you zoom in and out. This will help you in figuring the numbers to use as minscaledenom and maxscaledenom.

Also, if the scale value is not in the range that you expect it may be because the UNITS at the top level of your map are not set properly. The UNITS parameter must correspond to the units used by the EXTENT in your mapfile.

Why isn't the map file in XML format? XML is really cool…

This topic has surfaced a few times on the mailing list, here are some threads. My own recollection is that an XML map file would make MapServer more complex for little benefit, and that other functionality is higher up on the wish list. But if you think you know why the map file should be XML, you can always have another try convincing people.

Comment: Many people who know enough about XML to make a convincing argument also have the skills needed to change the Mapserver code to add the feature. Instead of trying to convince others you can do it yourself, find a programmer who wants to help, or pay a programmer. Or start by breaking up the code into relevant fragments so others can code part of it while you're working in one corner. A programmer could make MapServer recognize an XML map file in addition to the current map file format, so XML can be used by those who want it. An improvement is to allow MapServer to write an XML version of a map file (from either format) in a way which allows use in a script to do conversion.

How do I add a north arrow to my maps

Add the following to your symbols. The GIF should of course be an existing file. Disclaimer: This north arrow always points up. If you use some weird projection, where north isn't straight up (does such a projection exist?), you will have to do something else.

    SYMBOL
      NAME "n_arrow"
      TYPE pixmap
      IMAGE "images/nordpil6.gif"
    END

Add this layer and adjust the feature points to your map size

    LAYER
        NAME "n_arrow"
        STATUS DEFAULT
        TRANSFORM FALSE
        TYPE POINT
        FEATURE
          POINTS 650 80 END
        END
        CLASS
          STYLE
            SYMBOL "n_arrow"
          END
        END
    END

I'm using Windows 2003 and see a Load Symbol error

if you get this error:

loadsymbol().Unable to access file. Parsing error near(your image path) 
  • Check the path of your image
  • Check the image file permission
  • Change the file Permission to anonymous if to be used over the internet

right click on image -> security -> Add -> (type) Anonymous ->(at least give read access)

NOTE: If you are unable to see any other images then follow the same above procedure for you tmp folder and ref images.

How do I Create a clickable Reference map?

make sure u have changed the image tag to input tag

    <img name="ref" src="[ref]"> TO <input type="image" name="ref" src="[ref]" border="0">

this subtle difference makes the image clickable, as if its a form input

How can I improve the documentation?

  • Extend the Wiki by adding content
  • File a new ticket in the Issue Tracker in the "MapServer Documentation" component
Last modified 5 years ago Last modified on May 2, 2012 12:23:20 PM