Use BDM from the client (Dash)

Client storage scope

To access or create an EntityHandle from the client, the same principles apply: use the storage scope. The client storage scope is available on the project object, using project.storage_scope

@callback(State("url", "pathname"))
def store_file_handle(project: MySolution):
    storage_scope = project.storage_scope
    filepath = storage_scope.get_storage_root() / "my_file.txt"
    filepath.write_text("some data")
    project.steps.example_step.my_file_handle = storage_scope.store(filepath)
    ...


@callback(State("url", "pathname"))
def access_file_handle(project: MySolution):
    filepath = project.storage_scope.get_cached(project.steps.example_step.my_file_handle)
    assert filepath.read_text() == "some data"
    ...

Entity handle URL

In some cases, you may need to be able to generate a URL from an entity handle so that you can pass the URL to an UI component to render or process the entity. To do that you can call get_entity_url(entity_field_name) on the step by providing the name of the entity handle field.

entity_handle_url = project.steps.my_step.get_entity_url("my_file_handle")