Hi!

hostName is the name of the server, where the project is hosted. For projects saved locally, it is just "localhost".
To get the host name of the current project, use the GetCurrentProjectNameAndHost method:

project_name, host = AllplanBaseElements.ProjectService.GetCurrentProjectNameAndHost()

To get project names and hosts of all available projects, you can try the GetAttributesFromAllProjects method. This will give you a list of all project attributes of all existing projects. The project name would be saved in the attribute 405, and the host in 403.

The result of the method GetAttributesFromAllProjects is a bit tricky in the handling, because it is a plain list of attribute IDs and values of all projects. Here is a small code snippet, that would create a list of tuples like (project_name, project_host):

        all_projects_attributes = AllplanBaseElements.ProjectAttributeService.GetAttributesFromAllProjects()
        project_names = []
        project_hosts = []

        for project_attribute in all_projects_attributes:
            if project_attribute[0] == 403:
                project_hosts.append(project_attribute[1])
            elif project_attribute[0] == 405:
                project_names.append(project_attribute[1])

        project_names_and_hosts = []

        for idx, project_name in enumerate(project_names):
            project_names_and_hosts.append((project_name, project_hosts[idx]))

Regarding doc: it is the document adapter. You get this object from the framework in various function calls. I don't know, where do you want to implement the OpenProject method. E.g. in the modify_control_properties function, you get the document adapter here as the fifth argument. Have a look on the templates in:

etc\PythonPartsFramework\PythonPartsScriptTemplates\StandardPythonPart

to see, which function gives you the document adapter argument.

Lastly, regarding OpenProject: I see, there is a bit mess with the arguments. The right order is:
1. Document adapter
2. Host name
3. Project name

like this:

        AllplanBaseElements.ProjectService.OpenProject(document,
                                                       "localhost",
                                                       "Hello Allplan! 2024")

Best,
Bart