NSLS-II/DAMA

Hi, How can I get databroker to use my custom Handler?

I have tried the following steps so far based on the Event Model documentation:

1. Define a class called FitsHandler
2. Add an entry to the handler registry
3. Create a filler that uses the updated handler registry

When I try accessing an event from the catalog, it uses the default filler. Can I change it at runtime to use the new filler?

I've seen the documentation about registering entry points during setup, but I'm not yet at the point of creating a package.

Here's the code...

from databroker import catalog, catalog_search_path
import databroker.core
import event_model
from astropy.io import fits

class FitsHandler:
    def __init__(self, file_path, **resource_kwargs):
        if os.path.exists(file_path) and os.path.isfile(file_path):
            self._fits_file_path = file_path
            return self
        raise OSError  # FileNotFoundError

    def __call__(self, **datum_kwargs):
        hdulist = fits.open(self._fits_file_path)

        # Image data is generally the last entry in the FITS file
        ccd_image_data = hdulist[-1]

        return ccd_image_data

handler_registry = databroker.core.discover_handlers()
handler_registry["FITS"] = FitsHandler
filler = event_model.Filler(handler_registry)

runs = catalog["My_Catalog"]
print(list(runs))
run = runs[-1]  # How to use custom handler / filler here?

>>> databroker.__version__
'1.2.0'

Thanks for reading this!