Get requested fields in Strawberry GraphQL Resolver

Question

How we can get requested fields in Strawberry GraphQL Resolver

query {
   test {
       label
   }
}

How can I get the label field in the resolver?

I have tried:

info.field_nodes[0].selection_set.selections

But it is not returning what I want

score 6 · Answer 1 · answered Jul 22 '22 at 15:42

6

{selection.name for field in info.selected_fields for selection in field.selections}

answered Jul 22 '22 at 15:42

A. Coady

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How about converting fields to snake case? Fields come in camel case within Info object. – Muzaffer Oct 25 '22 at 11:01
Strawberry provides a camelCase converter: `from strawberry.utils.str_converters import to_camel_case`. You could use that build an inverse mapping: `{camelCase: snake_case, ...}`. – A. Coady Oct 26 '22 at 02:23
What you mean by inverse mapping? How it works? – Muzaffer Oct 28 '22 at 10:33
1

`case_map = {to_camel_case(field): field for field in fields}` – A. Coady Nov 06 '22 at 16:16

score 0 · Answer 2 · answered Aug 03 '23 at 16:29

@A.Coady solution doesn't handle nested fields. If your query looks like this:

query StrawberrySchema($id: Int!) {
    StrawberrySchema(id: $id) {
        item {
            name, 
            code,
            num, 
            manufactureName,
        },
        quantity 
    }
}

You will only obtain quantity and item fields. Therefore, I use these functions to retrieve all fields, including the nested ones.

def extract_subfields(selection):
    subfield = {selection.name: []}
    for sub_selection in selection.selections:
        if sub_selection.selections:
            subfield[selection.name].append(extract_subfields(sub_selection))
        else: 
            subfield[selection.name].append(sub_selection.name)
             
    return subfield

def extract_fields(query_fields):
    fields = []
    
    for field in query_fields.selected_fields:
        for selection in field.selections:
            if selection.selections:
                subfield = extract_subfields(selection)
                fields.append(subfield)
            else: 
                fields.append(selection.name)
                
    return fields

And in main class:

@strawberry.type 
class Query:
    @strawberry.field 
    def get_data(self, info, id: int) -> List[StrawberrySchema]: 
        fields = extract_fields(info) # returns [{'item': ['name', 'code', 'num', 'manufactureName']}, 'quantity']
        ...

Get requested fields in Strawberry GraphQL Resolver

2 Answers2