Parsovanie komplexnejších JSON šturktúr do objetov v jazyku Swift bývala celkom „šmakocinka“. Neskôr Apple vydal protocol Codable, ktorý proce neskutočne urýchlil a samotná štruktúra sa vytvárala pomerne jednoducho.
Predstavme si ale, že máme nasledujúci response zo servera:
{
"count": 82,
"next": "https://swapi.dev/api/people/?page=2",
"previous": null,
"results": [
{
"name": "Luke Skywalker",
"height": "172",
"mass": "77",
"hair_color": "blond",
"skin_color": "fair",
"eye_color": "blue",
"birth_year": "19BBY",
"gender": "male",
"homeworld": "https://swapi.dev/api/planets/1/",
"films": [
"https://swapi.dev/api/films/1/",
"https://swapi.dev/api/films/2/",
"https://swapi.dev/api/films/3/",
"https://swapi.dev/api/films/6/"
],
"species": [],
"vehicles": [
"https://swapi.dev/api/vehicles/14/",
"https://swapi.dev/api/vehicles/30/"
],
"starships": [
"https://swapi.dev/api/starships/12/",
"https://swapi.dev/api/starships/22/"
],
"created": "2014-12-09T13:50:51.644000Z",
"edited": "2014-12-20T21:17:56.891000Z",
"url": "https://swapi.dev/api/people/1/"
},
{
"name": "C-3PO",
"height": "167",
"mass": "75",
"hair_color": "n/a",
"skin_color": "gold",
"eye_color": "yellow",
"birth_year": "112BBY",
"gender": "n/a",
"homeworld": "https://swapi.dev/api/planets/1/",
"films": [
"https://swapi.dev/api/films/1/",
"https://swapi.dev/api/films/2/",
"https://swapi.dev/api/films/3/",
"https://swapi.dev/api/films/4/",
"https://swapi.dev/api/films/5/",
"https://swapi.dev/api/films/6/"
],
"species": [
"https://swapi.dev/api/species/2/"
],
"vehicles": [],
"starships": [],
"created": "2014-12-10T15:10:51.357000Z",
"edited": "2014-12-20T21:17:50.309000Z",
"url": "https://swapi.dev/api/people/2/"
},
{
"name": "R2-D2",
"height": "96",
"mass": "32",
"hair_color": "n/a",
"skin_color": "white, blue",
"eye_color": "red",
"birth_year": "33BBY",
"gender": "n/a",
"homeworld": "https://swapi.dev/api/planets/8/",
"films": [
"https://swapi.dev/api/films/1/",
"https://swapi.dev/api/films/2/",
"https://swapi.dev/api/films/3/",
"https://swapi.dev/api/films/4/",
"https://swapi.dev/api/films/5/",
"https://swapi.dev/api/films/6/"
],
"species": [
"https://swapi.dev/api/species/2/"
],
"vehicles": [],
"starships": [],
"created": "2014-12-10T15:11:50.376000Z",
"edited": "2014-12-20T21:17:50.311000Z",
"url": "https://swapi.dev/api/people/3/"
},
{
"name": "Darth Vader",
"height": "202",
"mass": "136",
"hair_color": "none",
"skin_color": "white",
"eye_color": "yellow",
"birth_year": "41.9BBY",
"gender": "male",
"homeworld": "https://swapi.dev/api/planets/1/",
"films": [
"https://swapi.dev/api/films/1/",
"https://swapi.dev/api/films/2/",
"https://swapi.dev/api/films/3/",
"https://swapi.dev/api/films/6/"
],
"species": [],
"vehicles": [],
"starships": [
"https://swapi.dev/api/starships/13/"
],
"created": "2014-12-10T15:18:20.704000Z",
"edited": "2014-12-20T21:17:50.313000Z",
"url": "https://swapi.dev/api/people/4/"
},
{
"name": "Leia Organa",
"height": "150",
"mass": "49",
"hair_color": "brown",
"skin_color": "light",
"eye_color": "brown",
"birth_year": "19BBY",
"gender": "female",
"homeworld": "https://swapi.dev/api/planets/2/",
"films": [
"https://swapi.dev/api/films/1/",
"https://swapi.dev/api/films/2/",
"https://swapi.dev/api/films/3/",
"https://swapi.dev/api/films/6/"
],
"species": [],
"vehicles": [
"https://swapi.dev/api/vehicles/30/"
],
"starships": [],
"created": "2014-12-10T15:20:09.791000Z",
"edited": "2014-12-20T21:17:50.315000Z",
"url": "https://swapi.dev/api/people/5/"
},
{
"name": "Owen Lars",
"height": "178",
"mass": "120",
"hair_color": "brown, grey",
"skin_color": "light",
"eye_color": "blue",
"birth_year": "52BBY",
"gender": "male",
"homeworld": "https://swapi.dev/api/planets/1/",
"films": [
"https://swapi.dev/api/films/1/",
"https://swapi.dev/api/films/5/",
"https://swapi.dev/api/films/6/"
],
"species": [],
"vehicles": [],
"starships": [],
"created": "2014-12-10T15:52:14.024000Z",
"edited": "2014-12-20T21:17:50.317000Z",
"url": "https://swapi.dev/api/people/6/"
},
{
"name": "Beru Whitesun lars",
"height": "165",
"mass": "75",
"hair_color": "brown",
"skin_color": "light",
"eye_color": "blue",
"birth_year": "47BBY",
"gender": "female",
"homeworld": "https://swapi.dev/api/planets/1/",
"films": [
"https://swapi.dev/api/films/1/",
"https://swapi.dev/api/films/5/",
"https://swapi.dev/api/films/6/"
],
"species": [],
"vehicles": [],
"starships": [],
"created": "2014-12-10T15:53:41.121000Z",
"edited": "2014-12-20T21:17:50.319000Z",
"url": "https://swapi.dev/api/people/7/"
},
{
"name": "R5-D4",
"height": "97",
"mass": "32",
"hair_color": "n/a",
"skin_color": "white, red",
"eye_color": "red",
"birth_year": "unknown",
"gender": "n/a",
"homeworld": "https://swapi.dev/api/planets/1/",
"films": [
"https://swapi.dev/api/films/1/"
],
"species": [
"https://swapi.dev/api/species/2/"
],
"vehicles": [],
"starships": [],
"created": "2014-12-10T15:57:50.959000Z",
"edited": "2014-12-20T21:17:50.321000Z",
"url": "https://swapi.dev/api/people/8/"
},
{
"name": "Biggs Darklighter",
"height": "183",
"mass": "84",
"hair_color": "black",
"skin_color": "light",
"eye_color": "brown",
"birth_year": "24BBY",
"gender": "male",
"homeworld": "https://swapi.dev/api/planets/1/",
"films": [
"https://swapi.dev/api/films/1/"
],
"species": [],
"vehicles": [],
"starships": [
"https://swapi.dev/api/starships/12/"
],
"created": "2014-12-10T15:59:50.509000Z",
"edited": "2014-12-20T21:17:50.323000Z",
"url": "https://swapi.dev/api/people/9/"
},
{
"name": "Obi-Wan Kenobi",
"height": "182",
"mass": "77",
"hair_color": "auburn, white",
"skin_color": "fair",
"eye_color": "blue-gray",
"birth_year": "57BBY",
"gender": "male",
"homeworld": "https://swapi.dev/api/planets/20/",
"films": [
"https://swapi.dev/api/films/1/",
"https://swapi.dev/api/films/2/",
"https://swapi.dev/api/films/3/",
"https://swapi.dev/api/films/4/",
"https://swapi.dev/api/films/5/",
"https://swapi.dev/api/films/6/"
],
"species": [],
"vehicles": [
"https://swapi.dev/api/vehicles/38/"
],
"starships": [
"https://swapi.dev/api/starships/48/",
"https://swapi.dev/api/starships/59/",
"https://swapi.dev/api/starships/64/",
"https://swapi.dev/api/starships/65/",
"https://swapi.dev/api/starships/74/"
],
"created": "2014-12-10T16:16:29.192000Z",
"edited": "2014-12-20T21:17:50.325000Z",
"url": "https://swapi.dev/api/people/10/"
}
]
}
A máme za úlohu vytvoriť model. Štandartný postup zahrnul určite nejaký „zkrášlovač“ kódu, kde by sme response vedeli vizuálne lepšie prečítať a postupne písali štruktúru s potrebnými atribútami.
Malé response pohodička, ale pri väčších sa môže hlava zakrútiť.
Ako si mravčiu prácu automatizovať? Odpoveď je app.quicktype.io.
Táto online utilita ušetrí množstvo času a nervov. Jedine čo stačí je skopírovať a prilepiť JSON response do ľavého textového editora.
import Foundation
// MARK: - Welcome
struct Welcome: Codable {
let count: Int
let next: String
let previous: JSONNull?
let results: [Result]
}
// MARK: - Result
struct Result: Codable {
let name, height, mass, hairColor: String
let skinColor, eyeColor, birthYear: String
let gender: Gender
let homeworld: String
let films, species, vehicles, starships: [String]
let created, edited: String
let url: String
enum CodingKeys: String, CodingKey {
case name, height, mass
case hairColor = "hair_color"
case skinColor = "skin_color"
case eyeColor = "eye_color"
case birthYear = "birth_year"
case gender, homeworld, films, species, vehicles, starships, created, edited, url
}
}
enum Gender: String, Codable {
case female = "female"
case male = "male"
case nA = "n/a"
}
Výsledok horného responsu okamžite transformuje na štuktúry, ktoré len stačí jemne modifikovať. Výhodou je, že tool dokáže automaticky rozpoznať snake case atribúty a pomocou CodinKey automaticky pretransformovať na CamelCase zápis.
Modelovanie štruktúr nebude viac nočnou morou 🙂
