Revit API help with 2 sequential transactions

[Anonymous]

Currently, I made a tool to rename view numbers (“Detail Number”) on a sheet based on their location on the sheet. Where this is breaking is the transactions. Im trying to do two transactions sequentially in Revit Python Shell. I also did this originally in dynamo, and that had a similar fail , so I know its something to do with transactions. Transaction #1: Add a suffix (“-x”) to each detail number to ensure the new numbers won’t conflict (1 will be 1-x, 4 will be 4-x, etc) Transaction #2: Change detail numbers with calculated new number based on viewport location (1-x will be 3, 4-x will be 2, etc) Better visual explanation here: https://www.docdroid.net/EP1K9Di/161115-viewport-diagram-.pdf.html Attached is the python file, but essentially what im trying to do is: # <---- Make unique numbers t = Transaction(doc, 'Rename Detail Numbers') t.Start() for i, viewport in enumerate(viewports): setParam(viewport, "Detail Number",getParam(viewport,"Detail Number")+"x") t.Commit() # <---- Do the thang t2 = Transaction(doc, 'Rename Detail Numbers') t2.Start() for i, viewport in enumerate(viewports): setParam(viewport, "Detail Number",detailViewNumberData[i]) t2.Commit() Attached is py file

[jeremytammik]

dear chris,

please research this topic in depth and give it a nice deep ponder:

http://thebuildingcoder.typepad.com/blog/about-the-author.html#5.33

the behaviour you describe indicates (well, hints at, very subtly) a need for regeneration.

cheers,

jeremy

[matthew_taylor]

Hi Chris,
To follow up on Jeremy's very insightful suggestion, check out transactionGroups and assimilate.

Cheers,

-Matt

[jeremytammik]

Thank you Matt, fully concur.

I added more background info in my answer to the same question on StackOverflow:

http://stackoverflow.com/questions/40728351/2-sequential-transactions-setting-detail-number-revit-ap...

Cheers, 

Jeremy

[jeremytammik]

More was said on this issue in the StackOverflow thread, plus a completely different underlying problem was unearthed.

I summarised the entire discussion on The Building Coder:

http://thebuildingcoder.typepad.com/blog/2016/12/need-for-regen-and-parameter-display-name-confusion...

Cheers,

Jeremy