GraphQL From The Ground Up - Swift Heroes, Online, October 2020

Video: https://www.youtube.com/watch?v=ufKvmac_4pk

Abstract: You've heard a lot of people talking about GraphQL lately, but what IS it? What are the problems it's supposed to be solving - and what are the problems it's _not_ supposed to be solving? How can you use it to improve your iOS development process? Ellen Shapiro, who maintains the Apollo GraphQL iOS SDK, will help untangle all this and more.

Transcript

1. GRAPHQL FROM THE GROUND UP SWIFT HEROES | THE INTERNETS | OCTOBER 2020 ELLEN SHAPIRO | @DESIGNATEDNERD | APOLLOGRAPHQL.COM
5. WTF IS GRAPHQL?
7. WHAT IS A GRAPH?
9. WHAT IS A GRAPH? (WHEN WE TALK ABOUT GRAPHQL)
10. ! GRAPH THEORY
11. In computer science, graphs are used to represent networks of communication, data organization, computational devices, the flow of computation, etc. https://en.wikipedia.org/wiki/Graph_theory#Computer_science
13. Source: https://neo4j.com/blog/graph-theory-predictive-modeling/
14. DIRECTED GRAPH Source: https://neo4j.com/blog/graph-theory-predictive-modeling/
16. UNDIRECTED GRAPH
17. NODES INDIVIDUAL PIECES OF DATA
18. EDGES RELATIONSHIPS BETWEEN PIECES OF DATA
20. SO IS A RELATIONAL DATABASE A GRAPH? !
21. NOT QUITE.
26. RELATIONAL DATABASES ARE FOCUSED ON SINGLE RELATIONSHIPS
27. GRAPHS HELP YOU TO TRACK MANY RELATIONSHIPS
28. user.father.bestFriend.children[0].middleName
29. ✨ GRAPHQL!
30. GRAPH QUERY LANGUAGE
31. HOW DO I GRAPHQL?
32. SAMPLE SERVER HTTPS://APOLLO-FULLSTACK-TUTORIAL.HEROKUAPP.COM/
33. THE SCHEMA
34. THE SCHEMA WHAT IS IT POSSIBLE TO ASK FOR?
35. SCHEMA DEFINITION LANGUAGE
36. SCHEMA DEFINITION LANGUAGE (BASICALLY, TYPESCRIPT)
41. SCALAR TYPES
42. SCALAR TYPES THE BUILDING BLOCKS OF THE TYPE SYSTEM
43. OPTIONALS?!
44. ✍ POP QUIZ!
45. Q. IS THIS TYPE OPTIONAL?
46. Q. IS THIS TYPE OPTIONAL? String
47. Q. IS THIS TYPE OPTIONAL? String A: IT DEPENDS
50. IS OPTIONAL SWIFT TYPE GRAPHQL TYPE
51. IS OPTIONAL SWIFT TYPE GRAPHQL TYPE No
52. IS OPTIONAL SWIFT TYPE GRAPHQL TYPE No String
53. IS OPTIONAL SWIFT TYPE GRAPHQL TYPE No String String!
54. !
55. GRAPHQL TYPES ARE NULLABLE BY DEFAULT
56. IS OPTIONAL SWIFT TYPE GRAPHQL TYPE No String String!
57. IS OPTIONAL SWIFT TYPE GRAPHQL TYPE No String String! Yes
58. IS OPTIONAL SWIFT TYPE GRAPHQL TYPE No String String! Yes String?
59. IS OPTIONAL SWIFT TYPE GRAPHQL TYPE No String String! Yes String? String
61. OPERATIONS
62. OPERATIONS WHAT ARE THE ENTRY POINTS TO THE GRAPH?
63. QUERY: PLEASE GIVE ME THIS DATA
65. MUTATION: PLEASE CHANGE THIS DATA
66. SUBSCRIPTION: PLEASE UPDATE ME IF DATA CHANGES
68. ✅ HOW THINGS ARE RELATED
69. ✅ HOW THINGS ARE RELATED ✅ WHAT YOU CAN ASK FOR
70. ✅ HOW THINGS ARE RELATED ✅ WHAT YOU CAN ASK FOR ➡ HOW YOU ASK FOR IT
71. GRAPHIQL
89. HOW WOULD REST DO THIS?
97. VALIDATION
99. !
100. VALIDATION IS WHAT I'M TRYING TO ASK FOR EVEN POSSIBLE?
104. VALIDATION + TYPES = CODE GENERATION
105. APOLLO IOS
107. ⬆ (IT ME)
110. A VERY SHORTENED VERSION OF APOLLO'S GENERATED CODE
111. public final class LaunchInfoQuery: GraphQLQuery { public init(id: GraphQLID) { self.id = id } public struct Data: GraphQLSelectionSet { public var launch: Launch? { public struct Launch: GraphQLSelectionSet { public var site: String? public var mission: Mission? public var rocket: Rocket? public struct Mission: GraphQLSelectionSet { public var name: String? } public struct Rocket: GraphQLSelectionSet { public var name: String? } } } }
112. public final class LaunchInfoQuery: GraphQLQuery { public init(id: GraphQLID) { self.id = id } public struct Data: GraphQLSelectionSet { public var launch: Launch? { public struct Launch: GraphQLSelectionSet { public var site: String? public var mission: Mission? public var rocket: Rocket? public struct Mission: GraphQLSelectionSet { public var name: String? } public struct Rocket: GraphQLSelectionSet { public var name: String? } } } }
113. public final class LaunchInfoQuery: GraphQLQuery { public init(id: GraphQLID) { self.id = id } public struct Data: GraphQLSelectionSet { public var launch: Launch? { public struct Launch: GraphQLSelectionSet { public var site: String? public var mission: Mission? public var rocket: Rocket? public struct Mission: GraphQLSelectionSet { public var name: String? } public struct Rocket: GraphQLSelectionSet { public var name: String? } } } }
114. public final class LaunchInfoQuery: GraphQLQuery { public init(id: GraphQLID) { self.id = id } public struct Data: GraphQLSelectionSet { public var launch: Launch? { public struct Launch: GraphQLSelectionSet { public var site: String? public var mission: Mission? public var rocket: Rocket? public struct Mission: GraphQLSelectionSet { public var name: String? } public struct Rocket: GraphQLSelectionSet { public var name: String? } } } }
116. public final class LaunchInfoQuery: GraphQLQuery { public init(id: GraphQLID) { self.id = id } public struct Data: GraphQLSelectionSet { public var launch: Launch? { public struct Launch: GraphQLSelectionSet { public var site: String? public var mission: Mission? public var rocket: Rocket? public struct Mission: GraphQLSelectionSet { public var name: String? } public struct Rocket: GraphQLSelectionSet { public var name: String? } } } }
117. public final class LaunchInfoQuery: GraphQLQuery { public init(id: GraphQLID) { self.id = id } public struct Data: GraphQLSelectionSet { public var launch: Launch? { public struct Launch: GraphQLSelectionSet { public var site: String? public var mission: Mission? public var rocket: Rocket? public struct Mission: GraphQLSelectionSet { public var name: String? } public struct Rocket: GraphQLSelectionSet { public var name: String? } } } }
118. YOU DON'T HAVE TO WRITE THIS CODE
119. YOU DON'T HAVE TO WRITE THIS CODE (TIMES THE NUMBER OF OPERATIONS)
120. YOU DON'T HAVE TO WRITE A URLSESSION WRAPPER
122. YOU DO HAVE TO WRITE SOME CODE
123. apolloClient.fetch(query: LaunchInfoQuery(id: "80")) { result in switch result { case .failure(let error): print("Error: \(error)") case .success(let graphQLResult): if let errors = graphQLResult.errors { print("Errors: \(errors)") } if let missionName = graphQLData?.data?.launch?.mission?.name { print("Mission name: \(String(describing: missionName)") } } }
124. apolloClient.fetch(query: LaunchInfoQuery(id: "80")) { result in switch result { case .failure(let error): print("Error: \(error)") case .success(let graphQLResult): if let errors = graphQLResult.errors { print("Errors: \(errors)") } if let missionName = graphQLData?.data?.launch?.mission?.name { print("Mission name: \(String(describing: missionName)") } } }
125. apolloClient.fetch(query: LaunchInfoQuery(id: "80")) { result in switch result { case .failure(let error): print("Error: \(error)") case .success(let graphQLResult): if let errors = graphQLResult.errors { print("Errors: \(errors)") } if let missionName = graphQLData?.data?.launch?.mission?.name { print("Mission name: \(String(describing: missionName)") } } }
126. apolloClient.fetch(query: LaunchInfoQuery(id: "80")) { result in switch result { case .failure(let error): print("Error: \(error)") case .success(let graphQLResult): if let errors = graphQLResult.errors { print("Errors: \(errors)") } if let missionName = graphQLData?.data?.launch?.mission?.name { print("Mission name: \(missionName) } } }
128. PARTIAL RESULTS
129. apolloClient.fetch(query: LaunchInfoQuery(id: "80")) { result in switch result { case .failure(let error): print("Error: \(error)") case .success(let graphQLResult): if let errors = graphQLResult.errors { print("Errors: \(errors)") } if let missionName = graphQLData?.data?.launch?.mission?.name { print("Mission name: \(missionName) } } }
130. apolloClient.fetch(query: LaunchInfoQuery(id: "80")) { result in switch result { case .failure(let error): print("Error: \(error)") case .success(let graphQLResult): if let errors = graphQLResult.errors { print("Errors: \(errors)") } if let missionName = graphQLData?.data?.launch?.mission?.name { print("Mission name: \(missionName) } } }
131. USE SWIFT EXTENSIONS TO HANDLE NULLABILITY GRACEFULLY
132. extension LaunchInfoQuery.Data.Launch { var missionName: String { self.mission?.name ?? "(Unknown)" } }
134. WHAT IS GRAPHQL GOOD FOR?
135. GET WHAT YOU WANT
136. GET WHAT YOU WANT NOT WHAT FRONTEND, ANDROID, 3RD PARTY APIS, AND YOUR GRANDMA WANT
137. YOU CAN ADD STUFF TO A GRAPH WAY FASTER THAN A REST API*
138. A REST PLAY Me: Can we add this field that's on endpoint A to endpoint B? Backend: Sure, we'll put it in the backlog.
140. ANYTHING IN THE SCHEMA CAN BE ACCESSED VIA RELATIONSHIPS IN THE GRAPH
141. user.father.bestFriend.children[0].middleName
142. user.father?.bestFriend.children?[0].middleName
143. WHAT IS GRAPHQL NOT GOOD FOR?
144. UPLOADING FILES
146. BETTER GRAPHQL UPLOADS
147. BETTER GRAPHQL UPLOADS 1. Upload to something that returns a URL
148. BETTER GRAPHQL UPLOADS 1. Upload to something that returns a URL 2. Send the URL to your graph using GraphQL
149. BETTER GRAPHQL UPLOADS 1. Upload to something that returns a URL 2. Send the URL to your graph using GraphQL 3. Tear out way less hair than trying to upload with GQL
150. HIGHLY OPTIMIZED QUERIES
151. GQL TOOLING HELPS FIND BOTTLENECKS
152. GQL TOOLING HELPS FIND BOTTLENECKS (BUT IT CAN'T ELIMINATE THEM)
153. BEING ABLE TO ! COMPLETELY REMOVE THINGS QUICKLY
154. GOOD NEWS: NO VERSIONING
155. BAD NEWS: NO VERSIONING
156. @deprecated
158. ! → " →
159. SIMPLE SECURITY
160. YOU CAN ASK FOR ANYTHING YOU WANT!
161. DEVELOPERS
162. SECURITY TEAM
165. YOU'RE GONNA HAVE TO THINK MORE GRANULARLY ABOUT SECURITY
166. MAYBE DON'T LEAVE SCHEMA INTROSPECTION UNPROTECTED
167. OBLIGATORY SUMMARY SLIDE
168. OBLIGATORY SUMMARY SLIDE ▸ A Graph is a way of conceptualizing data based on pieces of data (nodes) and the ways those pieces are connected (edges).
169. OBLIGATORY SUMMARY SLIDE ▸ A Graph is a way of conceptualizing data based on pieces of data (nodes) and the ways those pieces are connected (edges). ▸ GraphQL is a way of querying your data and how it's connected
170. OBLIGATORY SUMMARY SLIDE ▸ A Graph is a way of conceptualizing data based on pieces of data (nodes) and the ways those pieces are connected (edges). ▸ GraphQL is a way of querying your data and how it's connected ▸ The Schema defines what you can ask for (with types!)
171. OBLIGATORY SUMMARY SLIDE ▸ A Graph is a way of conceptualizing data based on pieces of data (nodes) and the ways those pieces are connected (edges). ▸ GraphQL is a way of querying your data and how it's connected ▸ The Schema defines what you can ask for (with types!) ▸ Operations let you ask for and receive only the data you want
172. OBLIGATORY SUMMARY SLIDE ▸ A Graph is a way of conceptualizing data based on pieces of data (nodes) and the ways those pieces are connected (edges). ▸ GraphQL is a way of querying your data and how it's connected ▸ The Schema defines what you can ask for (with types!) ▸ Operations let you ask for and receive only the data you want ▸ GraphQL is a real cool hammer - not every problem is a nail
173. WANT TO TRY APOLLO-IOS? https://www.apollographql.com/docs/ios/tutorial/ THANK YOU!