Retrieving Active Users in a Revit Central Model File (File-Based)
Hello. I asked Gemini for you, and it replies:
You're tackling a common challenge in multi-user Revit workflows. Unfortunately, the Revit API does not provide a direct method to retrieve a list of active users currently working on a file-based central model. This information is managed at the file system level and not exposed through the API. Worksets and session users relate to in-Revit collaboration features (worksharing) and don't reflect file access.
However, we can explore some workarounds, understanding they have limitations:
1. File Locking Detection (Most Reliable but Imperfect):
The most reliable approach is to check for file locks. When a user opens a central model, Revit creates lock files (e.g., .lock, ~$ files on Windows). We can use .NET's System.IO functionality to detect these locks.
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
public static class RevitUtils
{
public static List<string> GetUsersLockingCentralModel(string centralModelPath)
{
List<string> lockingUsers = new List<string>();
if (!File.Exists(centralModelPath))
{
return lockingUsers; // Central model doesn't exist
}
string lockFilePath = Path.Combine(Path.GetDirectoryName(centralModelPath), "~$" + Path.GetFileName(centralModelPath));
if (File.Exists(lockFilePath))
{
try
{
using (var stream = new FileStream(lockFilePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
using (var reader = new StreamReader(stream))
{
string firstLine = reader.ReadLine();
if (!string.IsNullOrEmpty(firstLine))
{
// The first line often contains the username. This is *not* guaranteed by Autodesk though!
lockingUsers.Add(firstLine);
}
}
}
catch (Exception ex)
{
// Handle exceptions (e.g., file access issues)
System.Diagnostics.Debug.WriteLine($"Error reading lock file: {ex.Message}");
}
}
//Check for .lock file (less common with Revit but can happen)
string legacyLockFilePath = centralModelPath + ".lock";
if (File.Exists(legacyLockFilePath))
{
lockingUsers.Add("Lock File Exists"); // Less info available here.
}
return lockingUsers;
}
}
// Example usage:
string centralModelPath = @"C:\Path\To\Your\CentralModel.rvt";
List<string> activeUsers = RevitUtils.GetUsersLockingCentralModel(centralModelPath);
if (activeUsers.Any())
{
foreach(string user in activeUsers)
{
TaskDialog.Show("Active Users", $"User: {user} has the central model open");
}
}
else
{
TaskDialog.Show("Active Users", "No users currently have the central model open.");
}
Key Improvements and Explanations:
- Handling
~$and.lockFiles: The code now checks for both the primary~$lock file and the less common.lockfile (sometimes seen in older Revit versions or specific scenarios). - Reading Lock File Content: The code attempts to read the first line of the
~$lock file. Often, this line contains the username. However, this is not officially documented or guaranteed by Autodesk. It's an observation based on common practice. Therefore, relying on this is not 100% reliable. - Error Handling: A
try-catchblock is added to handle potentialIOExceptions (e.g., if the lock file is already being accessed by another process). - Clearer Return Value: The function returns a
List<string>to handle cases where multiple locks might be present (though rare). - Example Usage with TaskDialog: I have included a simple example of how to use the function and display the results using a
TaskDialogfor better user feedback within Revit.
Limitations:
- Accuracy: Relying on file locks only indicates that a Revit process has the file open. It doesn't guarantee active work. A user might have Revit open with the model loaded but be inactive.
- Username Extraction Unreliable: As mentioned, extracting the username from the lock file is not officially supported and should be treated as an approximation.
- File System Dependency: This approach is inherently tied to the file system and might not be suitable for cloud-based or other non-standard file storage solutions.
2. Revit Server or Cloud Worksharing (If Applicable):
If you're using Revit Server or BIM 360/Autodesk Construction Cloud (ACC), there are more robust ways to track user activity, often through server logs or cloud platform APIs. These are outside the scope of file-based worksharing but are worth considering if you have those infrastructure components.
Conclusion:
While a perfect solution doesn't exist within the Revit API for file-based central models, the file locking method provides a reasonably effective workaround. Remember to clearly communicate the limitations of this approach to your users.
I hope this detailed explanation and enhanced code example are helpful. Please let me know if you have any further questions.
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