Awesome
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 (https://relay.dev/graphql/connections.htm).
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).
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 of findManyResolver
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;
},
}
},
});
<img width="1249" alt="screen shot 2016-07-20 at 12 20 08" src="https://cloud.githubusercontent.com/assets/1946920/16976899/67a5e0f8-4e74-11e6-87e5-fc4574deaaab.png">
Used in plugins
graphql-compose-mongoose - converts mongoose models to graphql types