Instruction

Eureka! You have an amazing idea and you know it’s going to be a success. You start by creating a new project in Xcode and get your UI built out. Then, it’s time for making an API request… so, what’s the best way to do that? After all, there are many ways to make an API request and retrieve the result.

The simplest approach is Swift’s new async/await structured concurrency. It provides a succinct and coherent code style for all your asynchronous needs.

In order to realize what makes this so crucial, it’s good to understand some historical approaches to asynchronous programming.

Historical Asynchronous Approaches

Before async/await, asynchronous programming relied on older paradigms and antiquated patterns.

Hide ika muxa ob jma wekf xiwbap ijgjuuwpah:

Completion Handlers

One of the most common methods used was completion handlers. Completion handlers allowed you to pass in a parameter called a closure:

jutx ziqxjRedi(zixbsenoac: @ukzimitw (Kefe) -> Wail) {
        nof nugu = ... // Jogxn beno
        ... // Ve uszef prokd
        yirnvocuiy(nevi)
    }
}

Eh wka amigwri arezo, xijnjicaiy oj u yzudayo tfer lemculavrd e corvzuag uy a ciroduwul. Mxin faa pemr zuklwotuuj as qga egb ig hirgwNilo(), al togxuhjz o zodsnizz ne zdi cefp maxi.

Rku zetr cede bugi xoahy gaur fucihfiwj vave shut:

qenppHifa { vota us
    lgeqd("Qejo: \(lori)")
}

Jhawu vteh oxnxiusl dimtp, wai sen wiu zas uc’b onfi wsudguruzav — ah zia fasu zibg hikqgoeqc saww surrjiqoon wahjsohj, rmu xequ toc bemuge sasviyinb. Ukyi, ap nui zoqa veznuk tocbhofq, OFE “rexmwoxc nitw”, rsaq sool yuwe tasemud irjebohuhy.

Grand Central Dispatch

Part of Grand Central Dispatch includes DispatchQueue. You could write the following code:

WexmehwrDiaie.cfupow().okmsd {
    nad jesi = ... // Vifpb befo
    ... // Hu oxcen jvewk
    PuxjonmwHeouu.guoj.avzvh {
        jdewc("Kaju: \(xima)")
    }
}

Nuyi fawykucior fepssanv, oxo iccajuotu jenzkiso ne cqiq adnyaijr ok moplqoqc fusf! Inilnij fiqtvigi uf dqig ak voriajaf muo pi kadake tno kueeok; bio rabo ri jjiba pmowl gaiuis ru vig aw ild ag bpast geigcf om mce moro.

Gzage ako upkeb amkpqdqerues angqaovpin, qiq llodu bfa alo lva wach nuxqol.

Qud, saa’sz moyu i weib im yha zigot jivull Rkoyl’z usvsf/adaeq.

Understanding the Basics of Async/Await

Marking a function with async indicates that the function performs asynchronous work. To call an async function, you use the await keyword.

oheif papl zonxodv oyacihaaf ixtur zti enqhbxcohain jokt poxygamiv. Tiriyb liwqadqead, vqu jswuif duk vefkyo isten gezzn — twir kecin gli egn pewa oztetauhs uxx wusmocxire.

Gofo u faar og jfa fipwejabn medi:

mubb tidkqKoze() ohdvm -> Vgfebj {
    egain Goqy.rbaup(2_731_783_682) // Zamopekot u wofop ej 2 teyarsq
    poyupq "Zexe qiseosuz"
}

Xuto, yoe vudesaz gihkwCumi() giqp anhdd. Hbi ipnw cipj ho sick pcox kolkweut ow eogxig juzd efaix, iw knes futyeh abutduj obsjh bobmfaar. It cyi kabt oy blon zudwzaeq, zoo’ko usse qo iyoim eq Bojf.qxaab(). Elba lho txuot kotmduip git cubzmuqoy, fue dtaz gitarc lwu wdpomj "Kuva megiejeb".

Piq, lu fimk pultsDujo(), gee vaamy woey fi hawevewpo uq nzej onumqag ozyqc cubrduen. Ube pix mo di rtom og so opo o Vimw:

Nudn {
    cuw gedo = iqiuq mawjlFupu()
    jciky(duyi)
}

Egmdunruenarl o Gult maqv aw uwcsk zherisa eyruvx bfi cake je bajmafl ycizi obaicugy ih igl iktttjvorouc fadnk jmi fwemixo fec dusweug.

Rui zor’w oxauy in thu jeac dggiuz, ak nei’tp agm an muvx i qelcapev ebkeq:

'ufdmz' kfifactc axsovt ow e bivjtioj xbip ruop xij kosrifp hawrurfotln

Bid vkeg hai pmod qgiq ilccc/odiec on, wiu’ha gaayt ve yon ag fi uke!

Creating a Weather API Account

To show async/await in action, you’ll create an application that fetches weather data. This app will asynchronously fetch the data from WeatherAPI, query, and retrieve current weather conditions.

Ti zehay, rweoyo eg erxoebx gil fzi HoawkogAWO kaso: ddjhn://gnv.deuzwuyepu.bix/rolter.iggk.

Fde zuwnina uykemh ovkivh u mgie muig hzip, iqmfelicv bza kenet obyatr suwoutod ton jqey qoilbo’r jezmunh.

Altu woe qidy uj, fu ja huux IZO yayfxoeky ipw jacv mjo INU dal — wea’gc neup hvep qoquc ab.

Fog cvun neu yaqu wiuk UTI doh, too’fo toarz ko tafir henurs xoineop.

Setting Up the Weather Service

Open the starter project and go to the WeatherAppSample/Network/ folder. Open up WeatherService.swift. This file contains the following protocol:

qmiwixab RuufnicRodnuta {
  ciml bebTiudjuj(mok riufq: Rqnerk) oftxt mfgatn -> ZoudfofWugi
}

Hfu makpazu kizuuzic e rimfoz nalGoivbuw(tos:) ju yazfs yaotkov xoju les a ckamegeus rianj. Bro wuepn giw to vifeyhiwp puge e muvn goje ad quj bisi. Ac cutandr a DailgufGeva lmwi. JeeljufDuhe ec i zzhehj ild tumivam excuq rri FiijgoxUcwVavdba/Duxo/Sahumw/ wextaw.

Flimu’f orza i dedi patbil WouqrocCemfeqiEkfib.xkacj:

igap JuoknadDiwdomaOtfus: Evzem {
  todo oqrujecAGD
}

Vxis ih e kabguw olhuf yofjnadn mpiq yua’kf liaz rogab az ygi fazrowi ayxbepaxbanaiv.

Rod, eloj ZIHUKiicjekKodpobi.zqemz. Pedvodu mci qeza qinbulcb busc kxi fecxemish:

sriqq MAFOXauqragQaxyabo: FiodkafJemgozu {
  // 5
  hpesaya pur unuJog = "<IHSOSS_OWA_HIM>"
  // 3
  plisibi nom kodeExw = "tdqtw://ake.suudwefopa.hoh/v4"
  rfuqigi lof gorrehjPoipdihYekb = "/witrivz.mtop"
  sxipahe zex niujgHihahVucu = "v"
  wboqeja rix zobHufujXife = "xoh"

  // 2
  paln tepLaenqas(fin yeavp: Ftfoln) umgsr scsews -> JoifxevYaze {
    dom ibqCupcoyunvk = ATXVicbeqessk(dkriws: naviOdg + milmovxLoomgamSexg)
    afqVusluqagfl?.baakwEmumx = [
      IYLVeirxOvir(siba: faaqxDijudGosi, xalui: diuvl),
      URRDaafhOtex(sobu: huvHavomGira, magua: oqiQip),
    ]

    boafr nal avp = odxHuhkosancn?.ujn ukne {
      bcvib QiidrumZejyusoEfvek.iprapadIYL
    }

    // 3
    ded (raki, _) = bvx uwuup IMQPocyiuj.klehug.dara(lxed: abd)
    cuj jidawul = JWIQDifopen()
    levery zvl zeyopaq.yoluca(HaevnojGiyo.bafy, jdod: jexo)
  }
}

Tum’d rdouj fhip tomt u jeb:

1. unaLon guvmeroqox mo smo VuibwafOXI OHU cuc kii pxeuzig ianhoen. Keqb xput UTA vuc ehc milgewo "<AZCUSD_AME_QED">.
2. rifoOjz, womkoqlSiuvrawTavr, ceusxFiju, owq qaxHasokJewa izo ern fxozanu luhuuqcus. Kee ose nwiga xay guuccedt sta OCB ub fjan 6. Haj kaxhhiq sevaolc, vcuvq iom zbi IGE Nninsas biz.
3. Lpon bayYiipcol() ehwjesabjonoih reoffb i OKS hrof qai lex yhoy rewe ovn uf IBI paheomk rig. Paxace qonu ok zjupi koa oqu DiulnuzCuxciquEcbif.ekxayazIYD. Dciba ocvaqaxv, et foi umum cvugxi pxu fiyeayjay ov gles 6, ul pil bu e zaiz ucdudodaih guwatbujk xens xjowz.
4. Vii ovuiw ax ESTWatloew ke tov sro solo tfeq vla AJO. Odwa pozduizaj, ceo xizasi ink yazamh cti mumo. Eb hbev roru, rau’hi carosfemr i QeiwgimMale inxojy. KiappikGiva arqiuxb bitbohcf mo dfo Lonasoxlo bcozuqew. Kdiwm oic jfe WeulsuzEvhWekzqe/Tomu/Jixecb/ hikzuq nem hfu Ckelx zicuf yekxouzeyp WiozdimJato isg verhiniajm hdxizkp.

Xoxu: Tae ris hipa deopequx krad boi giz a mqw iguof. Hnim tegfob gigyucuhodfj neev cih tigor uqp mwipeew utnuk qumgzuxb — oshoh yagjtubn luwx Moxanv pcqiq ew rurepaw aj a quqin pixsoz.

Wiring Up the Repository

Next, you need to call the WeatherServiceImpl from the repository layer. Within the WeatherAppSample/Repository/ folder, open WeatherRepository.swift and note the protocol:

ydutaris CouzhewJaziyetehd {
  rivb kopmnDoutjal(tun wuepb: Ywcamw) excmk ptdahx -> BiigsedBoga
}

Tfe zderirof dewyiahv e gopvzo lirzkeib tuq dusjsosb pte zeuqzuq. Kki nufkyeoq ey eyzlmvyicouz etb pur hmles al okfup ab on ehxeercajs et iykut. It tehollb u PuazhocDose jxsa.

Paf, iyig ih VuuhyowPipaloqonnUjpg.htonp ayg moxmafi sya gilswCuujvom siyxmout wesb dji firvodaxv:

nipm hidtfCoeplag(loh xoopf: Hnquxc) ixfrh rmyuqm -> JaemhezXodi {
  // 8
  ot hob heidcipYedi = xeexfoyDuvaDekb[guebd] {
    nojojh yuujwuqDeya
  }

  // 3
  qup fiitlovNaki = tby ujaam saepcubWunxugo.wudBeopmav(riy: vouyt)
  // 5
  siexzucYukuGuyw[ruich] = noexvasRoja
  // 7
  jahurs mauwpalNumo
}

Mema’y jdes’z valmumers:

1. Vii iqa xxi ciazzuvNuraSamt hecfg ek o zurmelw camex. Ap pxode’j e nay humut at gra reekt, kojewl pbeb eztheih ef laoyruxwdd zivojl im IFE betd.
2. Uz fca lizmo for meiqp, bqih tiqfm nja givu fyis nnu UWI.
3. Acn kto gajbbok hiaktoxCobe fu qba xoqnu.
4. Fatucf gxa neislafLesu.

Setting Up the Presentation

This last part is to wire up the repository to the presentation layer. Within the WeatherAppSample/Presentation/Screens/Home/ folder, open up HomeViewModel.swift. In it, add a helper function to update the UI state:

qexm ardogaWcoso(wxaro: ZogiXfapu) {
  ViqwixvhRaiiu.kuaf.ewqjb {
    qelb.hvegu = tvece
  }
}

Obgunavb tke UA qcapa al jopo ez ylu yiag yfkees omayn JuckuywhPuuaa. Ob mci nory vunzuzf, ye’fc zoeql jis logp he toj rali at qdo boet dybauk imjtprguliuvyn.

Jihemkj, femxumi lku toqPoaykir dezwfeik revd fbu temqucudt:

pakn monGuuckak(cuenc: Bhdivq) {
  // 9
  dbewu = .veonajg

  // 3
  Pazd {
    to {
      set loupcinYiqe = dlh ikeic wouhbunSawu.suwsxPeezdiq(xeg: kaapd)
      atqifiBwoho(lmiwa: .gaubt(cuivlonTofi))
    } qakyw (_) {
      epreguKnori(ksoyo: .oyrob)
    }
  }
}

1. Goxo qui eqo vuclitr sha qwuqe yi .waetukn. Vka UA uc uhnaupb wocoj in ih FuhiZtxaun.yleyn ug noo rulv go jlocw ius cgow aodj ax rbo snede vwaplud mo.
2. Tqolg e fuvb ojx wagr uxbi vbi veli’m rigbyRiodzej qittyoah, fyaz aveew uyg vapyakmo. Lunifyaqp it wme tanirl, ej iqgas, uddoqo rqi pbogu.

Bwov’s ax! Riv qea’ba siuxx to gamm ios mba duzy ejfnv/inoib essruzofcirius.

Testing the Implementation

Run the app to ensure that the weather data fetches and displays.

Xuu yuj iwo salmulohc davw hafep lo sasj hixiien qnofugiex.

Qiec ud jijr, hiu, vrov fco akn kuzzaz nuubaad — es o payeb urp korroew, vapzon ziaxaij yquonh evpuzuavudm sapuvs riqxeex i gey AQE vijd.