Topic: Underlay loaded?

[Joe Burke]

I'm looking for a way to determine whether an underlay reference (PDF, DWF or DGN) is loaded or not.

I hope it can be done. My efforts so far, using 2008, have failed.

TIA for any assistance.

[VVA]

removed

[T.Willey]

Could you provide an example Joe?  I haven't had any need, so I don't know off hand, but with an example we call can play.

[Joe Burke]

Could you provide an example Joe?  I haven't had any need, so I don't know off hand, but with an example we call can play.

Hi Tim,

Here's an example DWF file from the 2008 Help folder.

This returns a selection set of DWF references (ssget "x" '((0 . "DWFUNDERLAY"))). Likewise "PDFUNDERLAY" for PDF files and "DGNUNDERLAY" for Microstation DGN references.

Within Developer Help > DXF Reference > Entities Section check the UNDERLAY object type.

[T.Willey]

Looks like for DGN files and DWF files, there is an XData item if the item is not to be loaded.  Don't know about the PDF, as I couldn't figure out how to load one.

Get the ' namedobjdict '.

Then for DGN files, look for ' ACAD_DGNDEFINITIONS '
for DWG files, look for ' ACAD_DWFDEFINITIONS '
within the NOD.

Then each item, code 350, will be the definition.

If there is an XData entry of
(-3 ((ACAD (1000 . "NOLOAD"))))
then it will not load, otherwise it is loaded.

[Joe Burke]

Looks like for DGN files and DWF files, there is an XData item if the item is not to be loaded.  Don't know about the PDF, as I couldn't figure out how to load one.

Get the ' namedobjdict '.

Then for DGN files, look for ' ACAD_DGNDEFINITIONS '
for DWG files, look for ' ACAD_DWFDEFINITIONS '
within the NOD.

Then each item, code 350, will be the definition.

If there is an XData entry of
(-3 ((ACAD (1000 . "NOLOAD"))))
then it will not load, otherwise it is loaded.

Many thanks, Tim. That sounds like a reliable method. I won't have time to test it until this evening.

After my post I also noticed this. Given a DWF underlay, the ActiveX Height and Width properties return a numeric value when the file is loaded. They toss an exception when the underlay is unloaded. At least true in 2008. I haven't tested in 2010 yet.

[T.Willey]

You're welcome Joe.  I rather not go the exception route if a reliable way could be had.

I used the code posted in this thread to step through items.  It helped find this item.  Maybe it could help you also.
[ http://www.theswamp.org/index.php?topic=37979.msg429968#msg429968 ]

[Joe Burke]

Tim,

This (-3 ("ACAD" (1000 . "NOLOAD"))) works very nice.

Thanks again.