Starting a new Transaction is not permitted - Error

Rhino.Inside Revit
1

Hi guys,

I have been trying to get into Revit API. When I try to create a custom Python component in Grasshopper, I get the following error.

  1. Solution exception:Starting a new transaction is not permitted. It could be because another transaction already started and has not been completed yet, or the document is in a state in which it cannot start a new transaction (e.g. during failure handling or a read-only mode, which could be either permanent or temporary).

I have tried it in a Python component that is shared here. And got the above error.

Code here:

import clr
clr.AddReference('System.Core')
clr.AddReference('RhinoInside.Revit')
clr.AddReference('RevitAPI') 
clr.AddReference('RevitAPIUI')

import rhinoscriptsyntax as rs
import Rhino
import RhinoInside
import Grasshopper
import Autodesk

doc = RhinoInside.Revit.Revit.ActiveDBDocument
sheets = []

if RUN:
    #This is required to start a transaction in the Revit Document
    t = Autodesk.Revit.DB.Transaction(doc, 'Add Sheets')
    t.Start()
    for i in range(len(sheetNumbers)):
        newSheet = Autodesk.Revit.DB.ViewSheet.Create(doc, titleblock.Id)
        newSheet.SheetNumber = sheetNumbers[i]
        newSheet.Name = sheetNames[i]
        sheets.append(newSheet)
    t.Commit()

a = sheets

Any idea why I am getting this error?

2

Hi @mucahitbgoker,

Your code is fine, but if occur any exception during the transaction, the transaction is never Commited or RolledBack.

To solve this I use a with statement, that ensures the Transaction t is disposed in case of exception.

import clr
clr.AddReference('System.Core')
clr.AddReference('RhinoInside.Revit')
clr.AddReference('RevitAPI') 
clr.AddReference('RevitAPIUI')

import rhinoscriptsyntax as rs
import Rhino
import RhinoInside
import Grasshopper
import Autodesk

doc = RhinoInside.Revit.Revit.ActiveDBDocument
sheets = []

if RUN:
    #This is required to start a transaction in the Revit Document
    with Autodesk.Revit.DB.Transaction(doc, 'Add Sheets') as t :
        t.Start()
        for i in range(len(sheetNumbers)):
            newSheet = Autodesk.Revit.DB.ViewSheet.Create(doc, titleblock.Id)
            newSheet.SheetNumber = sheetNumbers[i]
            newSheet.Name = sheetNames[i]
            sheets.append(newSheet)
        t.Commit()

a = sheets
1 Like
3

Hi @kike,

I have tried with statement as well. I still get the same error though.

When I clear my solution and retry it, this time i get the below error.

  1. Solution exception:Sheet number is already in use.
    Parameter name: sheetNumber

image

4

This is because the Sheet is created on the previous iteration.

You need to make the component a bit smarter and using a FilteredElementCollector check a sheet with that number do not exist before creating a new one.
If it already exist you may want to add it to the resulting list of sheets.

5

:man_facepalming:. Using with statement actually solves the problem. I just needed to check parameter type :slight_smile:
When I changed it from Item access to List access, it worked just fine.

thanks @kike

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