GraphQL From The Ground Up - SoftGeeks, Online, October 2020

Video: https://www.youtube.com/watch?v=8YplqeZ2BYA

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 SOFTGEEKS | 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. Source: https://neo4j.com/blog/graph-theory-predictive-modeling/
15. Source: https://neo4j.com/blog/graph-theory-predictive-modeling/
16. Source: https://neo4j.com/blog/graph-theory-predictive-modeling/
17. DIRECTED GRAPH Source: https://neo4j.com/blog/graph-theory-predictive-modeling/
19. UNDIRECTED GRAPH
20. NODES INDIVIDUAL PIECES OF DATA
21. EDGES RELATIONSHIPS BETWEEN PIECES OF DATA
23. SO IS A RELATIONAL DATABASE A GRAPH? !
24. NOT QUITE.
29. RELATIONAL DATABASES ARE FOCUSED ON SINGLE RELATIONSHIPS
30. GRAPHS HELP YOU TO TRACK MANY RELATIONSHIPS
31. user.father.bestFriend.children[0].middleName
32. ✨ GRAPHQL!
33. GRAPH QUERY LANGUAGE
34. HOW DO I GRAPHQL?
35. SAMPLE SERVER HTTPS://APOLLO-FULLSTACK-TUTORIAL.HEROKUAPP.COM/
36. THE SCHEMA
37. THE SCHEMA WHAT IS IT POSSIBLE TO ASK FOR?
38. SCHEMA DEFINITION LANGUAGE
39. SCHEMA DEFINITION LANGUAGE (BASICALLY, TYPESCRIPT)
44. SCALAR TYPES
45. SCALAR TYPES THE BUILDING BLOCKS OF THE TYPE SYSTEM
46. OPTIONALS?!
47. ✍ POP QUIZ!
48. Q. IS THIS TYPE OPTIONAL?
49. Q. IS THIS TYPE OPTIONAL? String
50. Q. IS THIS TYPE OPTIONAL? String A: IT DEPENDS
53. IS OPTIONAL SWIFT TYPE GRAPHQL TYPE
54. IS OPTIONAL SWIFT TYPE GRAPHQL TYPE No
55. IS OPTIONAL SWIFT TYPE GRAPHQL TYPE No String
56. IS OPTIONAL SWIFT TYPE GRAPHQL TYPE No String String!
57. !
58. GRAPHQL TYPES ARE NULLABLE BY DEFAULT
59. IS OPTIONAL SWIFT TYPE GRAPHQL TYPE No String String!
60. IS OPTIONAL SWIFT TYPE GRAPHQL TYPE No String String! Yes
61. IS OPTIONAL SWIFT TYPE GRAPHQL TYPE No String String! Yes String?
62. IS OPTIONAL SWIFT TYPE GRAPHQL TYPE No String String! Yes String? String
64. OPERATIONS
65. OPERATIONS WHAT ARE THE ENTRY POINTS TO THE GRAPH?
66. QUERY: PLEASE GIVE ME THIS DATA
68. MUTATION: PLEASE CHANGE THIS DATA
69. SUBSCRIPTION: PLEASE UPDATE ME IF DATA CHANGES
71. ✅ HOW THINGS ARE RELATED
72. ✅ HOW THINGS ARE RELATED ✅ WHAT YOU CAN ASK FOR
73. ✅ HOW THINGS ARE RELATED ✅ WHAT YOU CAN ASK FOR ➡ HOW YOU ASK FOR IT
74. GRAPHIQL
93. HOW WOULD REST DO THIS?
101. VALIDATION
103. !
104. VALIDATION IS WHAT I'M TRYING TO ASK FOR EVEN POSSIBLE?
108. VALIDATION + TYPES = CODE GENERATION
109. APOLLO IOS
111. ⬆ (IT ME)
114. A VERY SHORTENED VERSION OF APOLLO'S GENERATED CODE
115. 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. 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? } } } }
120. 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? } } } }
121. 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? } } } }
122. YOU DON'T HAVE TO WRITE THIS CODE
123. YOU DON'T HAVE TO WRITE THIS CODE (TIMES THE NUMBER OF OPERATIONS)
124. YOU DON'T HAVE TO WRITE A URLSESSION WRAPPER
126. YOU DO HAVE TO WRITE SOME CODE
127. 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)") } } }
128. 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)") } } }
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: \(String(describing: 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) } } }
132. PARTIAL RESULTS
133. 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) } } }
134. 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) } } }
135. USE SWIFT EXTENSIONS TO HANDLE NULLABILITY GRACEFULLY
136. extension LaunchInfoQuery.Data.Launch { var missionName: String { self.mission?.name ?? "(Unknown)" } }
138. WHAT IS GRAPHQL GOOD FOR?
139. GET WHAT YOU WANT
140. GET WHAT YOU WANT NOT WHAT FRONTEND, ANDROID, 3RD PARTY APIS, AND YOUR GRANDMA WANT
141. YOU CAN ADD STUFF TO A GRAPH WAY FASTER THAN YOU CAN WITH A REST API
142. 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.
144. ANYTHING IN THE SCHEMA CAN BE ACCESSED VIA THE RELATIONSHIPS DEFINED IN THE GRAPH
145. user.father.bestFriend.children[0].middleName
146. user.father?.bestFriend.children?[0].middleName
147. WHAT IS GRAPHQL NOT GOOD FOR?
148. UPLOADING FILES
150. BETTER GRAPHQL UPLOADS
151. BETTER GRAPHQL UPLOADS 1. Upload to something that returns a URL
152. BETTER GRAPHQL UPLOADS 1. Upload to something that returns a URL 2. Send the URL to your graph using GraphQL
153. 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
154. HIGHLY OPTIMIZED QUERIES
155. GQL TOOLING HELPS FIND BOTTLENECKS
156. GQL TOOLING HELPS FIND BOTTLENECKS (BUT IT CAN'T ELIMINATE THEM)
157. BEING ABLE TO ! COMPLETELY REMOVE THINGS QUICKLY
158. GOOD NEWS: NO VERSIONING
159. BAD NEWS: NO VERSIONING
160. @deprecated
162. ! → " →
163. SIMPLE SECURITY
164. YOU CAN ASK FOR ANYTHING YOU WANT!
165. DEVELOPERS
166. SECURITY TEAM
169. YOU'RE GONNA HAVE TO THINK MORE GRANULARLY ABOUT SECURITY
170. MAYBE DON'T LEAVE SCHEMA INTROSPECTION UNPROTECTED
171. OBLIGATORY SUMMARY SLIDE
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).
173. 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
174. 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!)
175. 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
176. 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
177. WANT TO TRY APOLLO-IOS? https://www.apollographql.com/docs/ios/tutorial/ THANK YOU!