Question

Trying to iterate gdb files to area on area overlay


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I have a series of polygon feature classes all in the same geodatabase. I want each feature class to do a 'area on area overlay' with land parcel polygons and create a file for each overlay. I have tried creating a custom transformer with a loop but I couldnt get it to work. Really not sure how to go about doing this.

I dont want to have to pass each feature class to its own 'area on area overlay' transformer.

Any help to find a better way of doing this would be appreciated.


3 replies

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Hi @jacq,

Can you elaborate a bit on what you are trying to do?

If your goal is to clip all feature classes with the same land parcel polygons I would recommend using the 'Clipper' transformer instead (you can send all feature classes to the same 'Clippee' input port + there is an option to transfer the attributes of the 'Clipper' (the landparcel polygons in your case).)

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@jacq I think I'd avoid trying to build a custom transformer with looping. Looping with blocking transformers can be tricky.

I think I'd try cloning your primary polygons (SP_PARCEL) and then grouping each clone with the various View Shed polygons. If you make sure your SP_PARCEL polygons are read first, you'll also be able to use Areas First on the AreaOnAreaOverlayer which will speed things up. You might also be able to make use of parallel processing options on the AreaOnareaOverlayer. I've attached an example workspace:

FME 2018Workspace: areaonareaoverlayer.fmwt

You should be able to use fanout for the output files.

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Thankyou very much for your help, the clipper has given me the result I wanted.

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