add FileFromRelativePath

https://forum.dynamobim.com/t/get-current-dynamo-file-path/13521/25

OpenMEPRevit/Application/Windows.cs

@@ -1,4 +1,6 @@
-using Autodesk.DesignScript.Runtime;
+using System.IO;
+using Autodesk.DesignScript.Runtime;
+using Dynamo.Applications;
 
 namespace OpenMEPRevit.Application;
 
@@ -38,4 +40,28 @@ private Windows()
             {"version", version}
         };
     }
+
+    /// <summary>
+    /// Return the full path of relative path same folder with current script.
+    /// e.g. FileFromRelativePath("test.txt") will return the full path of test.txt in the same folder with current script.
+    /// </summary>
+    /// <param name="relativeFileName">The file name.extension</param>
+    /// <returns name="filePath">path</returns>
+    public static string FileFromRelativePath(string relativeFileName)
+    {
+        try
+        {
+            string fileName = DynamoRevit.RevitDynamoModel.CurrentWorkspace.FileName;
+            if (string.IsNullOrEmpty(fileName)) throw new ArgumentNullException(nameof(relativeFileName));
+            var directory = Path.GetDirectoryName(fileName);
+            if (directory == null) throw new ArgumentNullException(nameof(relativeFileName));
+            string filePath = Path.Combine(directory, relativeFileName);
+            if (!File.Exists(filePath)) throw new FileNotFoundException("File not found");
+            return filePath;
+        }
+        catch (Exception e)
+        {
+            return string.Empty;
+        }
+    }
 }