AutoGraph

A GraphQL Client in Swift

remind101
120
12
Swift

AutoGraph

CocoaPods Compatible
CircleCI

The Swiftest way to GraphQL

Features

AutoGraph is a Swift client framework for making requests using GraphQL and mapping the responses to strongly typed models. Models may be represented by any Decodable type. AutoGraph relies heavily on Swift’s type safety to drive it, leading to safer, compile time checked code.

Requirements

Swift 5.9

  • Swift 5.3.2 iOS 11 - use version 0.15.1
  • Swift 5.2 iOS 10 - use version 0.14.7
  • Swift 5.1.3 iOS 10 - use version 0.11.1
  • Swift 5.0 iOS 8 - use version 0.10.0
  • Swift 5.0 pre Decodable - use version 0.8.0
  • Swift 4.2+ - use version 0.7.0.
  • Swift 4.1.2 - use version 0.5.1.

Platforms

  • [x] iOS 13.0+
  • [ ] tvOS
  • [ ] watchOS
  • [x] macOS 10.15+
  • [ ] Linux

Installation

CocoaPods

platform :ios, '13.0'
use_frameworks!

pod 'AutoGraph'

Swift Package Manager (SPM)

dependencies: [
.package(url: "https://github.com/remind101/AutoGraph.git", .upToNextMinor(from: "0.16.0"))
]

Code Generation

See https://github.com/remind101/AutoGraphCodeGen for Code Generation.

Storage and Caching

AutoGraph’s current philosophy is to bring your own storage/caching layer. There’s simply too much variety in the ways users may wish to store or cache their data and therefore we don’t include any specific approach. Simply use AutoGraph to handle codegen and networking and then use whatever storage desired.

This doesn’t preclude us from exploring storage/caching in the future, but if so it will come as a separate library with AutoGraph as a dependency.

Query Builder

AutoGraph includes a GraphQL query builder to construct queries in a type safe manner. However, using the query builder is not required; any object which inherits GraphQLQuery can act as a query. String inherits this by default.

Query Example

Raw GraphQL         AutoGraph
-----------         ---------
query MyCoolQuery {         AutoGraphQL.Operation(type: .query, name: "MyCoolQuery", fields: [
  user {                        Object(name: "user", fields: [
    favorite_authors {              Object(name: "favorite_authors", fields: [,
      uuid                              "uuid",
      name                              "name"
    }                               ]),
    uuid                            "uuid",
    signature                       "signature"
  }                             ])
}

Mutation Example

Raw GraphQL
-----------
mutation MyCoolMutation {
  updateFavoriteAuthor(uuid: "long_id", input: { name: "My Cool Name" })
  {
    favorite_author {
      uuid
      name
    }
  }
}

AutoGraph
---------
AutoGraphQL.Operation(type: .mutation, name: "MyCoolMutation", fields: [
                            Object(
                            name: "updateFavoriteAuthor",
                            arguments: [ // Continues "updateFavoriteAuthor".
                                "uuid" : "long_id",
                                "input" : [
                                   "name" : "My Cool Class"
                                ]
                            ],
                            fields: [
                                Object(
                                name: "favorite_author",
                                fields: [
                                    "uuid",
                                    "name"
                                    ])
                                ]
                        ])

Supports

Subscriptions

AutoGraph now supports subscriptions using the graphql-ws protocol. This is this same protocol that Apollo GraphQL server uses, meaning subscriptions will work with Apollo server.

let url = URL(string: "wss.mygraphql.com/subscriptions")!
let webSocketClient = try WebSocketClient(url: url)
webSocketClient.delegate = self   // Allows the user to inspect errors and events as they arrive.

let client = try AlamofireClient(url: AutoGraph.localHost,
                                 session: Session(configuration: MockURLProtocol.sessionConfiguration(),
                                                  interceptor: AuthHandler()))
let autoGraph = AutoGraph(client: client, webSocketClient: webSocketClient)

let request = FilmSubscriptionRequest()
let subscriber = self.subject.subscribe(request) { (result) in
    switch result {
    case .success(let object): // Handle new object.
    case .failure(let error):  // Handle error
    }
}

// Sometime later...
try autoGraph.unsubscribe(subscriber: subscriber!)

Decodable for type safe Models

AutoGraph relies entirely on Decodable for mapping GraphQL JSON responses to data models. It’s as easy as conforming the model to Decodable!

JSONValue for type safe JSON

Behind the scenes AutoGraph uses JSONValue for type safe JSON. Feel free to import it for your own needs.

Threading

AutoGraph performs all network requests and mapping off of the main thread. Since a Request will eventually return whole models back to the caller on the main thread, it’s important to consider thread safety with the model types being used. For this reason, using immutable struct types as models is recommended.

Network Library

AutoGraph currently relies on Alamofire for networking. However this isn’t a hard requirement. Pull requests for this are encouraged!

Usage:

Request Protocol

  1. Create a class that conforms to the Request protocol. You can also extend an existing class to conform to this protocol. Request is a base protocol used for GraphQL requests sent through AutoGraph. It provides the following parameters.
    1. queryDocument - The query being sent. You may use the Query Builder or a String.
    2. variables - The variables to be sent with the query. A Dictionary is accepted.
    3. rootKeyPath - Defines where to start mapping data from. Empty string ("") will map from the root of the JSON.
    4. An associatedtype SerializedObject: Decodable must be provided to tell AutoGraph what data model to decode to.
    5. A number of methods to inform the Request of its point in the life cycle.
class FilmRequest: Request {
    /*
     query film {
        film(id: "ZmlsbXM6MQ==") {
            id
            title
            episodeID
            director
            openingCrawl
        }
     }
     */

    let query = Operation(type: .query,
                          name: "film",
                          fields: [
                            Object(name: "film",
                                   alias: nil,
                                   arguments: ["id" : "ZmlsbXM6MQ=="],
                                   fields: [
                                    "id",  // May use string literal or Scalar.
                                    Scalar(name: "title", alias: nil),
                                    Scalar(name: "episodeID", alias: nil),
                                    Scalar(name: "director", alias: nil),
                                    Scalar(name: "openingCrawl", alias: nil)])
                            ])

    let variables: [AnyHashable : Any]? = nil

    let rootKeyPath: String = "data.film"

    public func willSend() throws { }
    public func didFinishRequest(response: HTTPURLResponse?, json: JSONValue) throws { }
    public func didFinish(result: Result<Film, Error>) throws { }
}

Sending

Swift

  1. Call send on AutoGraph
    1. autoGraph.send(request, completion: { [weak self] result in ... }
  2. Handle the response
    1. result is a generic Result<SerializedObject, Error> enum with success and failure cases.

Objective-C

Sending via Objective-C isn’t directly possible because of AutoGraph’s use of associatedtype and generics. It is possible to build a bridge(s) from Swift into Objective-C to send requests.

Contributing

  • Open an issue if you run into any problems.

Pull Requests are welcome!

  • Open an issue describing the feature add or problem being solved. An admin will respond ASAP to discuss the addition.
  • You may begin working immediately if you so please, by adding an issue it helps inform others of what is already being worked on and facilitates discussion.
  • Fork the project and submit a pull request. Please include tests for new code and an explanation of the problem being solved. An admin will review your code and approve it before merging.
  • Keep LinuxTests up-to-date swift test --generate-linuxmain
  • If you see an error like this while building from the command line could not build Objective-C module try prepending commands with xcrun -sdk macosx

License

The MIT License (MIT)

Copyright © 2017-Present Remind101

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the “Software”), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.