https://github.com/tonyfromundefined/graphql-connection-resolver
Helps to easily implement the relay connection specification (inspired by Nexus.js Connection Plugin)
https://github.com/tonyfromundefined/graphql-connection-resolver
connection graphql relay
Last synced: 3 months ago
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Helps to easily implement the relay connection specification (inspired by Nexus.js Connection Plugin)
- Host: GitHub
- URL: https://github.com/tonyfromundefined/graphql-connection-resolver
- Owner: tonyfromundefined
- Created: 2020-08-30T10:25:50.000Z (almost 5 years ago)
- Default Branch: master
- Last Pushed: 2020-11-02T04:44:57.000Z (over 4 years ago)
- Last Synced: 2024-10-19T01:18:54.213Z (8 months ago)
- Topics: connection, graphql, relay
- Language: TypeScript
- Homepage:
- Size: 13.7 KB
- Stars: 2
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# 🔗 GraphQL Connection Resolver
[](https://www.npmjs.com/package/graphql-connection-resolver)
[](https://bundlephobia.com/result?p=graphql-connection-resolver)
Helps to easily implement the relay connection specification (inspired by [Nexus.js Connection Plugin](https://nexus.js.org/docs/plugin-connection))
## What is the `Connection`?
- [GraphQL Cursor Connection Specification](https://relay.dev/graphql/connections.htm)
## Install
```bash
$ yarn add graphql-connection-resolver
```
## Example
### Schema
```graphql
scalar DateTime
type Query {
chatRoom(id: String!): ChatRoom
}
type ChatRoom {
id: ID!
# if messages empty, returns null
messages(
first: Int
last: Int
before: Int
after: Int
): ChatMessageConnection!
}
type ChatMessage {
id: ID!
createdAt: DateTime!
}
type ChatMessageConnection {
edges: [ChatMessageEdge!]!
pageInfo: PageInfo!
}
type ChatMessageEdge {
node: ChatMessage!
cursor: String!
}
type PageInfo {
hasPreviousPage: Boolean!
hasNextPage: Boolean!
startCursor: String
endCursor: String
}
```
### Resolver
```typescript
import { connection } from 'graphql-connection-resolver'
export const ChatRoom = {
messages: connection({
/**
* returns a list of the model with `parent`, `args`, `ctx`
* You must request one more than given by first and last.
* Inside the library, if nodes return the same number as the given `first` or `last`, the next page is considered to not exist.
* and if nodes return more than the given number, the next page is considered to exist.
*/
async nodes(parent, args, ctx) {
return [
/* ... */
]
},
/**
* Extract a string to be used as a cursor from node.
* It automatically performs base64 encoding and decoding inside,
* so just return plain text.
*/
cursorFromNode(node) {
return node.createdAt.toISOString()
},
}),
}
```
## Note
- You must request one more than given by first and last. Inside the library, if nodes return the same number as the given `first` or `last`, the next page is considered to not exist, and if nodes return more than the given number, the next page is considered to exist.
```typescript
connection({
async nodes(args) {
const items = await fetchItems({
/* ... */,
limit: args.first + 1,
})
/* ... */
}
})
```
## References
- [Nexus.js Connection Plugin](https://nexus.js.org/docs/plugin-connection)
- [GraphQL Cursor Connections Specification](https://relay.dev/graphql/connections.htm)
> If you have a feature request or a bug, please create a new issue. And also, pull requests are always welcome 🙏