Online mapping with ArcIMS

ArcIMS is a mapserver. http://www.esri.com/software/arcgis/arcims/index.html
Check out the demo movies. The mapserver runs various map services, which are collections of geo-data & settings for how layers are to be displayed. In response to a request, the mapserver uses one or more map services & creates a map & writes an image of the map to a file. The mapserver then sends the name of the image file back to the requesting web page, so the map can be displayed.

Shape files

Shape files for interactive maps should be thoughtfully considered before map development: They may be difficult or impossible to change later.
  • Field names best if ALL CAPS, 10 or fewer characters, with no spaces or odd characters.
  • Unique identifier. Have one.
  • All shape files must have coordinate system defined. Use ArcCatalog. RClick on the shape | Properties | Fields. Click on the Shape field to get dialog.
  • All shape files should have a spatial index. Also index fields to be searched. Use ArcCatalog.
  • If you're using a wizard to develop your application, you may not be able to format column contents for display. So create fields and fill with formatted info. Use ArcView; open attribute table, add field, calculate values.
  • But drop unnecessary fields.
  • Once a shape file is used in a map service, the shape file should not be structurally altered or moved or copied or deleted. It will turn to garbage, but you may not know.
  • A shape file in a map service can have columns updated. Stop the map service first, update, restart.

AXL Config files

A map service is defined in an .axl file. It is text, and a flavor of XML. It points to shape files and specifies how they are displayed.
  • Renderers. See the chapter "Using ArcXML Renderers" in the pdf documentation below, or "Using Renderer Elements" in the web version.
  • AXL files are best created in an ArcIMS application called Author. You add files to a map, and tweak settings. When you save, Author writes out an AXL file describing your map.
  • The Author application is limited. For example, you cannot set the break points for a graduated thematic layer. The important thing is to get all needed layers (shape files) in the right top-to-bottom order.
  • AXL documentation is at http://161.188.204.80/maps/ArcXML_Programmers_Ref_Gd.pdf
  • AXL files can be modified with a text editor. Make a backup, change one thing, then test. There are no error messages if your AXL file fails in creating a map service. So the only clue you have is the last thing you changed.
  • Sample AXL
  • The workspace tag, the pointer to shape file location, will likely have to be updated if you migrate a map to another mapserver, like Philly.

Creating and updating a map service

To create a map service, you need these items of info:
  • Name for your map service.
  • Name & location of AXL file.
  • ImageServer1 is the virtual server.
  • Other items are defaults.
You can make changes to the AXL file at any time. The changes will take effect when the map service is restarted. NOTE: To see map service changes reflected in a map application, you must exit your browser and start a new browser session.

The HTML Viewer

Can be created in a Designer wizard with no scripting. Or modeled after template.
  • Advantages: Rubber band zoom. Runs in a Web browser with no software install required. Appropriate for intranet. Slightly customizable.
  • Disadvantages: Interface is busy, with many "tools". Appropriate for public? Legend not visible. Won't work over a WAN? Extensive customizing may yield negative returns.
  • Foreclosure map example. Changes made: Pixel tolerance to 6. Select fields to display & hide ID & Shape fields. Initial active layer set to Foreclosures. URL enabled. Page frames tinkered to give data frame full width & increased depth.
    http://maps.kricar.com/website/fc_05/viewer.htm
  • Tulsa crime map. http://www.tulsapolice.org/mapcentral.html

ASP maps

Ted Mellnik, The Charlotte Observer tmellnik@charlotteobserver.com
704-358-5028