Swift meets GraphQL in this lightweight, easy to use framework. SociableWeaver uses a declarative style of programming and makes GraphQL queries look natural in Swift code. Through the use of Swift 5.1 function builders and CodingKeys, SociableWeaver removes all of the need for unsafe strings and Dictionaries when creating objects and fields.
Xcode 11.x or a Swift 5.1x toolchain with Swift Package Manager.
For projects using a .xcodeproj the best method is to navigate to File > Swift Packages > Add Package Dependency.... From there just simply enter https://github.com/NicholasBellucci/SociableWeaver as the package repository url and use the master branch or the most recent version. Master will always be inline with the newest release. The other method is to simply add .package(url: "https://github.com/NicholasBellucci/SociableWeaver.git", from: "0.1.0") to your Package.swift file's dependencies.
Add the following entry to your Cartfile and run $ carthage update SociableWeaver
github "NicholasBellucci/SociableWeaver"SociableWeaver supports all that GraphQL has to offer. In order to get everything out of this framework, just make sure that any Codable models used contain CodingKeys. For example:
public struct Post: Codable {
public enum CodingKeys: String, CodingKey, CaseIterable {
case id, title, content
}
public let id: String
public let title: String
public let content: String
public init(id: String, title: String, content: String) {
self.id = id
self.title = title
self.content = content
}
}If CodingKeys aren't possible, SociableWeaver does support strings. It is highly recommended this be used as a last resort as it will make queries more difficult to manage.
GraphQL is all about querying specific fields on objects and returning only what is needed. With SociableWeaver constructing objects with fields is a breeze.
Weave(.query) {
Object(Post.self) {
Field(Post.CodingKeys.id)
Field(Post.CodingKeys.title)
Field(Post.CodingKeys.content)
}
}query {
post {
id
title
content
}
}Arguments are a key part of GraphQL and allow for much more refined queries. SociableWeaver supports arguments on both objects and fields.
The only requirement is that the value for the argument conforms to ArgumentValueRepresentable. Core types such as String, Int, Bool etc. will already conform. Enumerations will need to conform to the EnumValueRepresentable protocol.
Weave(.query) {
Object(Post.self) {
Field(Post.CodingKeys.title)
Object(Post.CodingKeys.author) {
Field(Author.CodingKeys.id)
Field(Author.CodingKeys.name)
.argument(key: "lastName", value: "Doe")
}
Object(Post.CodingKeys.comments) {
Field(Comment.CodingKeys.id)
Field(Comment.CodingKeys.content)
}
.argument(key: "filter", value: CommentFilter.recent)
}
}query {
post {
title
author {
id
name(lastName: "Doe")
}
comments(filter: RECENT) {
id
content
}
}
}Optionals are supported and can be included in the query. In the instance where an optional should be included and the value is nil, the resulting GraphQL value will be null.
In order to include an optional make sure to get the argument value of the property without including a ?. This will result in a query param of age: null.
public struct Author: Codable {
public enum CodingKeys: String, CodingKey, CaseIterable {
case id, name, age, birthplace
}
...
public let age: Int?
...
}
extension Author: ArgumentValueRepresentable {
public var argumentValue: String {
var params: [String: String?] = [:]
...
params["age"] = age.argumentValue
...
let paramStrings: [String] = params.compactMap { argument in
guard let value = argument.value else {
return nil
}
return "\(argument.key): \(value)"
}
return "{ \(paramStrings.joined(separator: ",")) }"
}
}'Aliases are key when querying a single object multiple times in the same request.
Weave(.query) {
Object(Post.self) {
Object(Post.CodingKeys.comments) {
Field(Comment.CodingKeys.id)
Field(Comment.CodingKeys.content)
}
.argument(key: "filter", value: CommentFilter.recent)
.alias("newComments")
Object(Post.CodingKeys.comments) {
Field(Comment.CodingKeys.id)
Field(Comment.CodingKeys.content)
}
.argument(key: "filter", value: CommentFilter.old)
.alias("oldComments")
}
}query {
post {
newComments: comments(filter: RECENT) {
id
content
}
oldComments: comments(filter: OLD) {
id
content
}
}
}GraphQL fragments can help when building complicated queries. SociableWeaver makes them extremely simple and allows the proper references to be placed exactly where they would be in the query. With the help of a FragmentBuilder the FragmentReference can be added to the objects that require the fields and the Fragment can be added to the operation itself.
let authorFragment = FragmentBuilder(name: "authorFields", type: Author.self)
let query = Weave(.query) {
Object(Post.self) {
Object(Post.CodingKeys.author) {
FragmentReference(for: authorFragment)
}
Object(Post.CodingKeys.comments) {
Field(Comment.CodingKeys.content)
Object(Comment.CodingKeys.author) {
FragmentReference(for: authorFragment)
}
}
}
Fragment(authorFragment) {
Field(Author.CodingKeys.id)
Field(Author.CodingKeys.name)
}
}query {
post {
author {
...authorFields
}
comments {
content
author {
...authorFields
}
}
}
}
fragment authorFields on Author {
id
name
}Operation names aren't required but can make the queries more unique.
Weave(.query) {
Object(Post.self) {
Field(Post.CodingKeys.id)
Field(Post.CodingKeys.title)
Field(Post.CodingKeys.content)
}
}
.name("GetPostAndContent")query GetPost {
post {
id
title
content
}
}Since direct JSON is not needed when making queries in SociableWeaver, variables can and should be define in a method and passed into the query as arguments.
queryPost(id: 1)
func queryPost(id: Int) {
Weave(.query) {
Object(Post.self) {
Field(Post.CodingKeys.title)
Field(Post.CodingKeys.content)
Object(Post.CodingKeys.author) {
Field(Author.CodingKeys.id)
Field(Author.CodingKeys.name)
}
}
.argument(key: "id", value: id)
}
}query {
post(id: 1) {
title
content
author {
id
name
}
}
}Directives in GraphQL allows the server to affect execution of the query. The two directives are @include and @skip both of which can be added to fields or included fragments. The example defines true or false but in an actual query these values would be boolean variables.
Just to note, Skip will always take precedent over include. Also any objects/fragments that end up not having fields will be removed from the query.
let query = Weave(.query) {
Object(Post.self) {
Field(Post.CodingKeys.title)
Field(Post.CodingKeys.content)
.include(if: true)
Object(Post.CodingKeys.author) {
Field(Author.CodingKeys.name)
}
.include(if: false)
Object(Post.CodingKeys.comments) {
Field(Comment.CodingKeys.content)
.include(if: true)
.skip(if: true)
Object(Comment.CodingKeys.author) {
Field(Author.CodingKeys.name)
.skip(if: true)
}
}
}
}query {
post {
title
content
}
}Mutations work the same as simple queries and should be used when data is supposed to be written. An Object.schemaName will replace the name of the Object or Key included in the initializer.
Weave(.mutation) {
Object(Post.self) {
Field(Post.CodingKeys.id)
Field(Post.CodingKeys.title)
Field(Post.CodingKeys.content)
}
.schemaName("createPost")
.argument(key: "title", value: "TestPost")
.argument(key: "content", value: "This is a test post.")
.argument(key: "author", value: "John Doe")
}mutation {
createPost(title: "TestPost", content: "This is a test post.", author: "John Doe") {
id
title
content
}
}Inline fragments are useful when querying on an interface or union type as they allow the return of underlying types.
Weave(.query) {
Object(Post.self) {
Field(Post.CodingKeys.title)
Field(Post.CodingKeys.content)
Object(Post.CodingKeys.comments) {
Field(Comment.CodingKeys.content)
Object(Comment.CodingKeys.author) {
InlineFragment("AnonymousUser") {
Field(Author.CodingKeys.id)
}
InlineFragment("RegisteredUser") {
Field(Author.CodingKeys.id)
Field(Author.CodingKeys.name)
}
}
}
}
}query {
post {
title
content
comments {
content
author {
... on AnonymousUser {
id
}
... on RegisteredUser {
id
name
}
}
}
}
}GraphQL meta fields can be customized and are recognized to have two proceeding underscores. The __typename meta field is a GraphQL default and can be used to return the object type in the results of a query.
Custom meta fields can be defined by using MetaFieldType.custom. This enum takes an associated String which does not need to include the double underscores before the name. For example: .custom("schema") results in __schema.
Weave(.query) {
Object(Post.self){
Field(Post.CodingKeys.title)
Field(Post.CodingKeys.content)
Object(Post.CodingKeys.author) {
MetaField(.typename)
Field(Author.CodingKeys.name)
}
}
}query {
post {
title
content
author {
__typename
name
}
}
}SociableWeaver support pagination out of the box and can be easily customized. Features supported include slicing, edges, and page info inclusion.
Slicing in GraphQL is great for fetching a specified amount of objects in a response. With SociableWeaver this can be specified with the Object.slice method.
Weave(.query) {
Object(Post.CodingKeys.comments) {
Field(Comment.CodingKeys.id)
Field(Comment.CodingKeys.author)
Field(Comment.CodingKeys.content)
}
.slice(amount: 2)
}{
comments(first: 2) {
id
author
content
}
}Cursor-based pagination is described as being the most powerful pagination type GraphQL provides. Setup this pagination by declaring the pagination type for an object.
Weave(.query) {
Object(Post.CodingKeys.comments) {
Field(Comment.CodingKeys.id)
Field(Comment.CodingKeys.author)
Field(Comment.CodingKeys.content)
}
.slice(amount: 2)
.paginationType(.cursor)
}{
comments(first: 2) {
edges {
cursor
node {
id
author
content
}
}
}
}Including page info such as whether or not there is a next page or the end cursor is very flexible and supports a custom model.
Weave(.query) {
Object(Post.CodingKeys.comments) {
Field(Comment.CodingKeys.id)
Field(Comment.CodingKeys.author)
Field(Comment.CodingKeys.content)
}
.slice(amount: 2)
.paginationType(.cursor)
.pageInfo(type: PageInfo.self,
keys: PageInfo.CodingKeys.startCursor,
PageInfo.CodingKeys.endCursor,
PageInfo.CodingKeys.hasNextPage)
}{
comments(first: 2) {
edges {
cursor
node {
id
author
content
}
}
pageInfo {
startCursor
endCursor
hasNextPage
}
}
}SociableWeaver provides a couple of custom types that help to build more natural looking queries. These types may or may not have been included in examples but will also be defined in this section to provide more clarity.
The ForEachWeavable struct was added for times where you may want to add objects or fields in a loop. More discussion around this use case can be found here.
let authors = [
Author(id: "1", name: "John", age: 17, birthplace: [:]),
Author(id: "2", name: "Jane", age: 29, birthplace: [:]),
Author(id: "3", name: "Adam", age: 41, birthplace: [:])
]
let query = Weave(.query) {
ForEachWeavable(authors) { author in
Object("postsForAuthor") {
Field(Author.CodingKeys.id)
Field(Author.CodingKeys.name)
Field(Author.CodingKeys.age)
Field(Author.CodingKeys.birthplace)
}
.argument(key: "id", value: author.id)
}
}{
postsForAuthor(id: "1") {
id
name
age
birthplace
}
postsForAuthor(id: "2") {
id
name
age
birthplace
}
postsForAuthor(id: "3") {
id
name
age
birthplace
}
}Due to current limitations with function builders, individual elements are not currently accepted. For that reason each function builder initializer has a corresponding initializer for a single element. BuilderType.individual has been set up to specify when an object or fragment will consist of only one element. The default value for the builderType parameter on all initializations is .individual. This means that passing it is not required and will result in the same outcome.
Object(Post.CodingKeys.author) {
Field(Author.CodingKeys.name)
}
Fragment(authorFragment, .individual) {
Field(Author.CodingKeys.name)
}This enumeration has been provided to allow for customization when it comes to object and fields that are initialized with a model or coding key. Defaulted to camel case.
Field(Comment.CodingKeys.createdAt)
.caseStyle(.lowercase)
public enum CaseStyleOption {
case lowercase
case uppercase
case capitalized
case camelCase
case pascalCase
case snakeCase
case kebabCase
}GraphQL enumeration values are represented as uppercase representations of the case names. For this reason, custom enumerations in swift that should be passed as argument values can conform to EnumValueRepresentable. This protocol conforms to ArgumentValueRepresentable and is extended to provide the argumentValue as an uppercase version of the case value.
enum PostCategories: EnumValueRepresentable {
case art
case music
case technology
}
Object(Post.self) {
...
}
.argument(key: "category", value: PostCategories.technology)
/// Result: post(category: TECHNOLOGY) { ... }SociableWeaver is, and always will be, MIT licensed. See LICENSE for details.