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GraphQL Resolver

When writing queries and mutations that use a GraphQL service, you'll have access to two resolvers that execute queries and mutations on the connected service.

name​

Type​

string!

Values​

  • graphql:query
  • graphql:mutation

fieldName​

Type​

string!

Description​

A field name or path to anchor the GraphQL query to.

Example​

If you query the original API with the following query:

{
  characters {
    results {
      name
      status
    }
  }
}

The fieldName would be set to characters, which is the field the query will be forwarded to on the origin.

{
  site {
    product(id: "UHJvZHVjdDo3Nw==") {
      id
      name
      prices {
        basePrice {
          value
        }
      }
    }
  }
}

Set fieldName to site.product to use the namespaced product query. The args mapping will set arguments on product.

options​

The options object contains configuration specific to the type of resolver you select.

selectionSet​

Type​

string?

Description​

Defines a GraphQL selectionSet, which is guaranteed to be included in the query to the origin API.

Example​

When making this query:

{
  RickAndMorty_myCharacters {
    results {
      name
    }
  }
}

A resolver with the following options would include status and type on every query to the origin, in addition to whatever fields were requested originally.

{
  "options": {
    "fieldName": "characters",
    "selectionSet": "{ status type }"
  }
}

That data will still be excluded from your response data. This is useful if you need the data for other reasons—to transform it for a custom results field, or to use in a later resolver step.

ttl​

Type​

number?

Description​

The number of seconds to cache query results for. This setting only applies to graphl:query resolvers.

timeout​

Type​

number?

Description​

The number of milliseconds to allowed before timing out. The default is no timeout.

unboxParentSelectionSet​

Type​

boolean?

Description​

Default true. Applicable when used with a selectionSet including _parentFragment. When true, results are transformed so that the results from the parent fragment are at the top level. You can override this behavior by setting unboxParentSelectionSet to false, which could be useful if you want to inspect data that would otherwise be discarded.

Example​

"getFirstCharacterEpisode": {
  "resolver": {
    "name": "graphql:query",
    "service": "rick",
    "fieldName": "character",
    "options": {
      "selectionSet": "{episode {..._parentFragment}}",
      "unboxParentSelectionSet": false
    },
    "results": {
      "ops": [{"path": "$", "mapping": "$finalResolver.episode[0]"}]
    }
  },
  "args": {
    "type": "object",
    "properties": {"id": {"type": "string", "@tag": "id"}},
    "required": ["id"]
  },
  "shape": "Rick_Episode"
}

args​

Type​

ParameterConfig?

Description​

Allows mapping from the QueryContext to the args values (input arguments) for the resolver. Results are not serialized. For more information read about the ParameterConfig.

Example​

{
  "RickAndMorty_characters": {
    "resolver": {
      "name": "graphql:query",
      "service": "rick-and-morty",
      "options": { "fieldName": "characters" },
      "args": {
        "ops": [
          {
            "path": "page",
            "mapping": "$args.page"
          },
          {
            "path": "filter",
            "mapping": "$args.filter"
          }
        ]
      }
    },
    "args": {
      "type": "object",
      "properties": {
        "page": { "type": "integer" },
        "filter": { "@ref": "rick-and-morty:FilterCharacter" }
      }
    },
    "shape": "RickAndMorty_Characters"
  }
}

results​

Type​

ParameterConfig?

Description​

Allows mapping from the QueryContext to the results for the resolver step in a ComposeResolver or whole query. Results are not serialized. For more information read about the ParameterConfig.

Example​

{
  "RickAndMorty_characters": {
    "resolver": {
      "name": "graphql:query",
      "service": "rick-and-morty",
      "options": { "fieldName": "characters" },
      "args": {
        "ops": [
          {
            "path": "page",
            "mapping": "$args.page"
          },
          {
            "path": "filter",
            "mapping": "$args.filter"
          }
        ]
      },
      "results": {
        "ops": [
          {
            "path": "$",
            "mapping": "$finalStep.results"
          }
        ]
      }
    },
    "args": {
      "type": "object",
      "properties": {
        "page": { "type": "integer" },
        "filter": { "@ref": "rick-and-morty:FilterCharacter" }
      }
    },
    "shape": {
      "type": "array",
      "items": {
        "@ref": "RickAndMorty_Character"
      }
    }
  }
}

headers​

Type​

ParameterConfig?

Description​

Allows mapping from the QueryContext to the headers for the resolver request. For more information read about the Headers.

searchParams​

Type​

ParameterConfig?

Description​

Allows mapping from the QueryContext to the searchParams for the resolver request. For more information read about the SearchParams.