Invoke Button - How to?

Jan_R_Christel · February 24, 2025, 10:02am

Hi there

I’m trying to find some documentation on how the .invoke button yaml file is meant to work. I did find the debug button sample in the repository but drew a bit of a blank…

I have:

a .dll named: PushIt.dll with the namespace path to the IExternal command class being: duHast.PushIt.Main

> namespace duHast.PushIt
> {
>     [Transaction(TransactionMode.Manual)]
>     [Regeneration(RegenerationOption.Manual)]
>     public class Main : IExternalCommand
>     {
>         Models.RevitDataModel _revitDataModel;
>         duHast.Utils.WPF.Stores.NavigationStore _navigationStore;
>         duHast.Utils.WPF.Stores.MessageStore _messageStore;
>         RevitExternalEventHandlerManager _eventManager;
> 
>         public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements)

I placed that dll and all its dependencies into a lib folder within my extension:
duHast.extension>>duHast.tab>>lib>>PushIt.dll
my yaml file:

title: PushIt
tooltip: A rapid layouting extension for Revit
author: “Jan Christel”
highlight: new
context: zero-doc
assembly: ‘PushIt’
command_class: ‘duHast.PushIt.Main’

When pressing the button in the Revit UI I get an exception:
Can not find type “duHast.Main” in assembly “C:\…pushit.dll”

I’m not sure why the message is not showing the complete namespace address or why the .dll name is in all lower case in the message? Or whether that matters

I’m using pyRevit version 5.0.1

Thank you guys for the great work that is pyRevit…wouldnt know what to do without it!

Jan_R_Christel · February 25, 2025, 10:33am

Worked out a few bugs:

Command class can just be ‘Main’ and it starts the command just fine:

yaml

title: PushIt

tooltip: A rapid layouting extension for Revit

author: "Jan Christel"

highlight: new

context: zero-doc

assembly: 'PushIt'

command_class: 'Main'

Next problem is that this command uses some external references and, when started fails to find them.

Some more googling points towards, I think, 2 solutions:

An assembly resolver or a startup.cs.

I tried the assembly resolver following this link ( last entry)
However I only seem to get this to work when I hard code the path to my /bin directory since the line:

folderPath = Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location);

Throws an “The path is not of a legal form!” exception

I then tried the startup.cs method:
I placed a starup.cs file in the same directory as my extension:

| - Extensions
| - startup.cs
| - duHast.Extension

this is the content based on this post

foreach (string wbAssembly in new string {
“CsvHelper.dll”,
“LoadingSpinner.dll”,
“Microsoft.Bcl.AsyncInterfaces.dll”,
“Microsoft.Bcl.HashCode.dll”,
“Newtonsoft.Json.dll”,
“RevitUtils.23.0.0.1.dll”,
“System.Buffers.dll”,
“System.Collections.Immutable.dll”,
“System.Memory.dll”,
“System.Numerics.Vectors.dll”,
“System.Reflection.Metadata.dll”,
“System.Runtime.CompilerServices.Unsafe.dll”,
“System.Threading.Channels.dll”,
“System.Threading.Tasks.Extensions.dll”,
“System.ValueTuple.dll”,
“Utils.23.0.0.1.dll”
})

Assembly.Load(File.ReadAllBytes(Path.Combine(BinPath, wbAssembly)));

I feel though like I am missing something: I dont know where and how BinPath gets defined?

Jan_R_Christel · February 25, 2025, 10:43am

hm progress of sorts:

I re-checked the pyRevit repo and noticed the error of my ways and moved the startup.cs into the duHast.extension folder. I believe it now gets executed because I can see at Revit startup a pyRevit exception output flicker past…but I’m not fast enough to save it…bummer!

my current startup.cs: (I think its missing a lot though)

foreach (string wbAssembly in new string {
“CsvHelper.dll”,
“LoadingSpinner.dll”,
“Microsoft.Bcl.AsyncInterfaces.dll”,
“Microsoft.Bcl.HashCode.dll”,
“Newtonsoft.Json.dll”,
“RevitUtils.23.0.0.1.dll”,
“System.Buffers.dll”,
“System.Collections.Immutable.dll”,
“System.Memory.dll”,
“System.Numerics.Vectors.dll”,
“System.Reflection.Metadata.dll”,
“System.Runtime.CompilerServices.Unsafe.dll”,
“System.Threading.Channels.dll”,
“System.Threading.Tasks.Extensions.dll”,
“System.ValueTuple.dll”,
“Utils.23.0.0.1.dll”
})

BinPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
Assembly.Load(File.ReadAllBytes(Path.Combine(BinPath, wbAssembly)));

Jan_R_Christel · March 2, 2025, 3:53am

Got a working solution:

I added a startup.py ( I dumped the startup.cs) in the root directory of the extension.

import System
from System.IO import File
from System.IO import MemoryStream
from System.Reflection import Assembly
import traceback


# do not load these, since they are the external command and dont need to be laoded
ignore_dlls = [
    "PushIt.dll",
]

# Load the DLLs required for the extension
# build the bin path
bin_directory_within_extension=r"duHast.tab\PushIt.panel\bin"
# file path of this file
startup_file_path = __file__
# get the directory of the startup file
startup_directory = System.IO.Path.GetDirectoryName(startup_file_path)

# build the full path to the bin directory\
bin_directory = System.IO.Path.Combine(startup_directory, bin_directory_within_extension)

# get all dlls in the bin directory
dlls_to_load  = System.IO.Directory.GetFiles(bin_directory, "*.dll")


for dll in dlls_to_load:

    try:
        #full_path = System.IO.Path.Combine(bin_directory, dll)
        # get the file name from the path
        dll_name_only = System.IO.Path.GetFileName(dll)
        
        # check if the dll should be ignored
        if dll_name_only in ignore_dlls:
            print("Ignoring: {dll}".format(dll=dll_name_only))
            continue

        print("Attempting to load: {dll}".format(dll=dll_name_only))
        
        # Check if the file exists
        if not File.Exists(dll):
            print("File not found: {dll}".format(dll=dll))
            continue

        dll_bytes = File.ReadAllBytes(dll)
        # Should print <class 'bytes'>
        #print("bytes array is of type: {}".format(type(dll_bytes)))
    
        # Load assembly into the default AppDomain
        stream = MemoryStream(dll_bytes)
        assembly = Assembly.Load(stream.ToArray())

        # Ensure it's registered for other add-ins
        System.AppDomain.CurrentDomain.Load(assembly.GetName())
        print("loaded successfully: {dll}".format(dll=dll_name_only))
    except Exception as e:
        print("Failed to load {dll} with exception: {e}".format(dll=dll, e=e))
        print(traceback.format_exc())
        continue

That will load all the .dll located in the /bin directory and make them available to the invoked command.