graphql-compose-connection
This is a plugin for graphql-compose family, which adds to the ObjectTypeComposer
connection
resolver.Live demo: https://graphql-compose.herokuapp.com/
This package completely follows to Relay Cursor Connections Specification ().
Besides standard connection arguments
first
, last
, before
and after
, also added significant arguments:filter
arg - for filtering recordssort
arg - for sorting records. Build in mechanism allows sort by any unique indexes (not only by id). Also supported compound sorting (by several fields).
CHANGELOG
Installation
npm install graphql graphql-compose graphql-compose-connection --save
Modules
graphql
and graphql-compose
are in peerDependencies
, so should be installed explicitly in your app. They should not installed as submodules, cause internally checks the classes instances.Example
Implementation details offindManyResolver
and countResolver
can be found in this file.import { prepareConnectionResolver } from 'graphql-compose-connection';
import { UserTC, findManyResolver, countResolver } from './user';
prepareConnectionResolver(userTC, {
findManyResolver,
countResolver,
sort: {
// Sorting key, visible for users in GraphQL Schema
_ID_ASC: {
// Sorting value for ORM/Driver
value: { _id: 1 },
// Field names in record, which data will be packed in `cursor`
// edges {
// cursor <- base64(cursorData), for this example `cursorData` = { _id: 334ae453 }
// node <- record from DB
// }
// By this fields MUST be created UNIQUE index in database!
cursorFields: ['_id'],
// If for connection query provided `before` argument with above `cursor`.
// We should construct (`rawQuery`) which will be point to dataset before cursor.
// Unpacked data from `cursor` will be available in (`cursorData`) argument.
// PS. All other filter options provided via GraphQL query will be added automatically.
// ----- [record] ----- sorted dataset, according to above option with `value` name
// ^^^^^ `rawQuery` should filter this set
beforeCursorQuery: (rawQuery, cursorData, resolveParams) => {
if (!rawQuery._id) rawQuery._id = {};
rawQuery._id.$lt = cursorData._id;
},
// Constructing `rawQuery` for connection `after` argument.
// ----- [record] ----- sorted dataset
// ^^^^^ `rawQuery` should filter this set
afterCursorQuery: (rawQuery, cursorData, resolveParams) => {
if (!rawQuery._id) rawQuery._id = {};
rawQuery._id.$gt = cursorData._id;
},
},
_ID_DESC: {
value: { _id: -1 },
cursorFields: ['_id'],
beforeCursorQuery: (rawQuery, cursorData, resolveParams) => {
if (!rawQuery._id) rawQuery._id = {};
rawQuery._id.$gt = cursorData._id;
},
afterCursorQuery: (rawQuery, cursorData, resolveParams) => {
if (!rawQuery._id) rawQuery._id = {};
rawQuery._id.$lt = cursorData._id;
},
},
// More complex sorting parameter with 2 fields
AGE_ID_ASC: {
value: { age: 1, _id: -1 },
// By these fields MUST be created COMPOUND UNIQUE index in database!
cursorFields: ['age', '_id'],
beforeCursorQuery: (rawQuery, cursorData, resolveParams) => {
if (!rawQuery.age) rawQuery.age = {};
if (!rawQuery._id) rawQuery._id = {};
rawQuery.age.$lt = cursorData.age;
rawQuery._id.$gt = cursorData._id;
},
afterCursorQuery: (rawQuery, cursorData, resolveParams) => {
if (!rawQuery.age) rawQuery.age = {};
if (!rawQuery._id) rawQuery._id = {};
rawQuery.age.$gt = cursorData.age;
rawQuery._id.$lt = cursorData._id;
},
}
},
});