Dynamic, rule-based borders between polygons

[RobertMartin2]

Hi all,

I've been working with a polygon feature class that looks something like this:

[ATTACH=CONFIG]29055[/ATTACH]

Wherever two polygons of different types (shown above with different colors) meet there needs to be a thick dashed line between them. The solution so far has been to keep a separate feature class for the lines, which of course needs to be updated every time the polys change. This has gotten to be pretty tedious and is creating a lot of redundancy in our data. Is there any type of map layer that can be generated on-the-fly based on spatial relationships and attribute data of a feature class? I'm guessing a geometric network would be involved, but that's all I've got. Does anyone have any insights?


Thanks,
Robert

[TrishRice]

This help topic shows how to use symbol levels for this.
http://resources.arcgis.com/en/help/main/10.1/index.html#//00s500000025000000

To keep the thin lines between polygons of the same value, put a duplicate copy of the layer in the TOC and style it transparent with the thin border.

[RobertMartin2]

Trish, that's a really interesting solution. I'm afraid I made a mistake with the screenshot though -- it should look something like this.

[ATTACH=CONFIG]29094[/ATTACH]

In other words, I'd only like to preserve interior borders between polygons. Can that be achieved with symbol levels too?

Thanks,
Robert

[TrishRice]

Yup that'll work just fine.  That means you can ignore my second paragraph about using two copies of the layer.  Just use the one copy in the TOC and follow the instructions in the link to set up symbol levels.  This is identical to the kind of task they use in the example, where they style polygons to only show the border where it changes. 🙂

[RobertMartin2]

Thanks Trish, I gave that a try but I am still getting exterior borders around the dissolved polys. Is there any way to keep only interior lines where the polys change? Or am I not doing this right?

[TrishRice]

Oh ok.  You did it right but I misunderstood your problem.  Sorry.  😕  I don't know how to exclude the exterior borders in this case.  Maybe some fancy footwork with topology rules?

I'm a little surprised nobody else has chimed in yet.