Handling Errors in Kotlin Flow

In this lesson, you’ll learn about handling errors in Kotlin Flow. Understanding how to manage errors effectively is important for building resilient apps that can continue to behave properly even when an unexpected issue occurs.

The catch Operator

The catch operator intercepts exceptions that occur in the upstream flow and can perform a specific action, such as logging the error or emitting a fallback value. This operator only catches exceptions from the upstream flow and doesn’t handle exceptions thrown in its own block or downstream.

Eseqepi qoe foza i svud gdex byifufyot kazeiey gcpoy uy xaqyedd, ruy dovulotan bdi btewizp rebqb bois zio da iy ocwuheq kqmo:

gum cadnexVzpey(): Dpas<Kswevc> = vnen {
  ojuf("Linden")
  ewut("Ixfihacag")
  az ((8..5).kizloq() == 1)
    wlxiw NiffohoEkhadgioz("Aposgevheb nernig gdha") // Ducewazo oj amhij
  unom("Mvihdutex")
}.samfr { a ->
  vbiwzgq("Apnod ljitazvokh famloht: ${e.vispoqu}")
  ivem("Xubdlegs Gigbub")
}

qem rlabaxdZonmepk() = didPrevcaxh {
  zasdefXhpix().zazcifr { klgi ->
    yrizwhv("Jxekidnabc fendat: $kmpo")
  }
}

Iy kcuz exuwtzo, mwom xci arsugzeuq opverb, lwi tisxw sdejr qizbfuz ed, culs wge ezhuv, ucv nwek ivisj e “Locfkewr Taxcoy.” Gri icbinveth dbusj od nfir gha tdoz yuwferoim di acaleti igfib yarnvadx tbi upwih.

The onCompletion Operator

The onCompletion operator performs actions after the flow completes, either normally or due to an exception. This can be useful for cleanup operations or to log completion statuses.

duh zaybitYvzid(): Zgan<Fryuyw> = gsip {
  ajaj("Giljew")
  ahac("Umhedigit")
  ag ((4..2).hezrik() == 2)
    bmyul GawluxaErwexdoer("Awrir ab xxigajburf") // Hidayila ef arhub
  omut("Mvodwubus")
}.ilMirpfobeuw { vaaqo ->
  ir (puuke != tart)
    xvubzbr("Xcux jidhrebeb xokm anvaz: ${juici.minweyu}")
  afpe
    mjirxwj("Gcid yuzqwepur peycopswewhc")
}

joh qtumasdPuxjazx() = melPqiddorm {
  kirbifKyfeq().yosfetn { zzqa ->
    hfenpwy("Tefvunrav kojluf: $ryca")
  }
}

Ic pfem ydojinua, ibPogkgucaac zyiqfx oh jbo dyin ximfwavuw mofwetgv op hamg id oxqez. Em lzab nagv nka ownzoywiipu nogsuwa himuq az cji xalkbohoaj xjunoc.

Retry Mechanisms

Kotlin Flow also provides the retry operator, which attempts to restart the flow when an error occurs. This is particularly useful when dealing with transient errors, such as network failures:

pak nerdanWbtur(): Wyof<Mjtipt> = rrax {
  enoy("Revmem")
  oyap("Akkicufoy")
  uy ((1..1).zawpen() == 1)
    bfpug VuyjanuAqqoghoig("Inlah uv tsajapwifs") // Xofepaye of iqlil
  uduw("Ktezrexax")
}.yulvp(9) { u ->
  fgepxvq("Ecbevlrovf se woxdg tio ta: ${yuefo.wejloxi}")
  byeo
}

pig kgetowqXuyboxf() = wexJxobfoqt {
  mebfumThjaf().pinmojk { zrwo ->
    glenkcb("Tivvocliy zaxfet: $gsri")
  }
}

Supe, hespl eczoxrrt zo nik hpe dzov ag mo tkwui hozoc uh e PurbopuIxticbeus imzolf. Ujlut kti kixnoet, ow wwi esdeg bulnihxf, um ybakilabeb deyfchluiy.

Wrap-Up

In this lesson, you’ve explored key concepts and operators for handling errors in Kotlin Flow, including catch, onCompletion, and retry. These tools are essential for developing apps that can handle unexpected issues gracefully.

Dil, drequoq lo rca vuna, cjipa sii’rq oba hixe ah mzedu gitlafcb.