Django admin widget to allow proper multiple selection of selected checkbox entries for CheckboxSelectMultiple

widgets.py

class ArrayFieldCheckboxSelectMultiple(CheckboxSelectMultiple):
    """A CheckboxSelectMultiple widget for use with ArrayField which fixes the Multiple items not selected issue"""

    def format_value(self, value):
        """Return selected values as a list."""
        if value is None and self.allow_multiple_selected:
            return []
        elif self.allow_multiple_selected:
            value = [v for v in value.split(",")]

        if not isinstance(value, (tuple, list)):
            value = [value]

        results = [str(v) if v is not None else "" for v in value]
        return results