Dot in query parameter name?

[kbonna]

Hi,

I am building REST API and I started using django-filter with DRF for filtering resource list endpoints. I want to follow dot convention for query parameters, e.g.
/articles?age.gt=21&age.lt=40

Is it possible to do this in django-filter? I was searching for the answer, but couldn't find it anywhere. Since filter field names correspond to parameter names and dot cannot be a part of a valid Python variable name I am not sure if this is possible. My current implementation looks like this:

class ArticleFilter(filters.FilterSet):
    age__gt = filters.NumberFilter(field_name="age", lookup_expr="gt")
    
    class Meta:
        model = Article
        fields = ["age__gt"]

[carltongibson]

You'd need to use a custom widget, mapping from the query string argument in value_from_datadict

[kbonna]

Thanks for the solution!

For anyone having the same issue in the future, here's my implementation

class MapQueryParamNameWidget(forms.Widget):
    """Convert query parameter names using mapping dictionary. This can be used if your query
    parameter names contains characters that are not allowed in valid Python variables i.e. dots.

    Args:
        mapping (dict):
            Mapping used in string replace method. For example mapping = {".", "__"} would turn
            query parameter name "age.gt" into "age__gt".
    """

    def __init__(self, mapping):
        super().__init__()
        if not isinstance(mapping, dict):
            raise TypeError("mapping should be a dict")
        self.mapping = mapping

    def value_from_datadict(self, data, files, name):
        mapped_data = dict()
        for param, value in data.items():
            for k, v in self.mapping.items():
                param = param.replace(k, v)
            mapped_data[param] = value

        # turn dict back into QueryDict
        data = QueryDict("", mutable=True)
        data.update(mapped_data)
        return super().value_from_datadict(data, files, name)

with usage:

class ArticleFilter(filters.FilterSet):
    age__gt = filters.NumberFilter(field_name="age", lookup_expr="gt", widget=MapQueryParamNameWidget({".", "__"}))
    
    class Meta:
        model = Article
        fields = ["age__gt"]

[harshithjv]

@kbonna

{".", "__"} in ... widget=MapQueryParamNameWidget({".", "__"})) is a set and not a dict, right?