graphql-parse-resolve-info

What is graphql-parse-resolve-info?

The graphql-parse-resolve-info package is a utility for parsing GraphQL resolve info objects. It helps in extracting detailed information about the fields requested in a GraphQL query, which can be useful for optimizing database queries, logging, and other purposes.

What are graphql-parse-resolve-info's main functionalities?

Parsing Resolve Info

This feature allows you to parse the resolve info object provided by GraphQL resolvers. The parsed information includes details about the fields requested in the query, which can be used to optimize data fetching.

const { parseResolveInfo } = require('graphql-parse-resolve-info');

const resolveInfo = /* GraphQL resolve info object */;
const parsedInfo = parseResolveInfo(resolveInfo);
console.log(parsedInfo);

Getting Fields from Resolve Info

This feature helps in extracting the fields requested in the GraphQL query from the resolve info object. This can be useful for determining which fields need to be fetched from the database.

const { getFields } = require('graphql-parse-resolve-info');

const resolveInfo = /* GraphQL resolve info object */;
const fields = getFields(resolveInfo);
console.log(fields);

Handling Nested Fields

This feature allows you to handle nested fields in the GraphQL query. By parsing the resolve info object, you can access nested fields and optimize your data fetching accordingly.

const { parseResolveInfo } = require('graphql-parse-resolve-info');

const resolveInfo = /* GraphQL resolve info object */;
const parsedInfo = parseResolveInfo(resolveInfo);
const nestedFields = parsedInfo.fieldsByTypeName.TypeName.nestedFieldName;
console.log(nestedFields);

Other packages similar to graphql-parse-resolve-info

graphql-fields

The graphql-fields package provides a simple way to get the fields requested in a GraphQL query. It is similar to graphql-parse-resolve-info but offers a more straightforward API for extracting fields. However, it may not provide as detailed information as graphql-parse-resolve-info.

README

graphql-parse-resolve-info

Parses a GraphQLResolveInfo object into a tree of the fields that are being requested to enable optimisations to your GraphQL schema (e.g. to determine which fields are required from the SQL database).

Useful for optimising your GraphQL resolvers by allowing them to look ahead in the request, reducing the number of SQL queries or HTTP requests required to complete the GraphQL request.

Also provides a quick way to get the alias of the current field being resolved.

Usage: requested subfields

To get the tree of subfields of the current field that are being requested:

const parseResolveInfo = require('graphql-parse-resolve-info');
// or import parseResolveInfo from 'graphql-parse-resolve-info';

new GraphQLObjectType({
  name: ...
  fields: {
    ...
    foo: {
      type: new GraphQLNonNull(ComplexType),
      resolve(data, args, context, resolveInfo) {
        const parsedResolveInfoFragment = parseResolveInfo(resolveInfo);
        const { fields } =
          parseResolveInfo.simplifyParsedResolveInfoFragmentWithType(parsedResolveInfoFragment, ComplexType);
        console.dir(fields);
        ...
      }
    }
  }
});

(Note that because GraphQL supports interfaces and hence a resolver may return items of different types we key the fields by the GraphQL type name of the various fragments that were requested. Once you know what type the result was, you can then use this type (and its interfaces) to determine which sub-fields were requested. It's quite commont to know that your result will be of a single type, so we provide a helper that will simplify this for you by passing it the expected type.)

Usage: alias

To get the alias of the current field being resolved (defaults to the field name if no alias was specified):

const parseResolveInfo = require('graphql-parse-resolve-info');

new GraphQLObjectType({
  name: ...
  fields: {
    ...
    foo: {
      type: new GraphQLNonNull(GraphQLString),
      resolve(data, args, context, resolveInfo) {
        const alias = parseResolveInfo(resolveInfo, { aliasOnly: true });
        return alias;
      }
    }
  }
});

Thanks

This project was originally based on https://github.com/tjmehta/graphql-parse-fields, but has evolved a lot since then.

Changelog

0.0.1-alpha1.0 (2017-07-05)

Features

• Add parsing of resolveInfo (6ae734f)
• Introduce buildFieldWithHooks (76cb2af)
• Introduce buildObjectWithHooks (94b9d6f)
• Introduce SchemaBuilder (2b6d5f3)
• recursive field generators (37d73c1)
• resolveInfo: can now process arguments (c94eeb2)
• start enabling field data (62ac647)
• Unique object for each build (94a10d5)