Isiqulatho[Fihla][Bonisa]
- 1. Yintoni isitaki se-MERN? Ungalichaza icandelo ngalinye kunye nendima yalo?
- 2. I-stack ye-MERN ithelekisa njani nezinye izitaki zeteknoloji ezifana ne-MEAN okanye i-LAMP?
- 3. Cacisa ukuba ungasikhusela njani isicelo se-MERN?
- 4. Chaza indima ye-middleware kwi-Express.js. Ngaba ungabonelela ngomzekelo wesiko eliphakathi?
- 5. Ziziphi iiyantlukwano eziphambili phakathi kweReact Class Components kunye ne-Functional?
- 6. Ngaba unokucacisa ukuba umzila usebenza njani kwisicelo se-MERN?
- 7. Yintoni izithembiso kwaye zisetyenziswa njani kwi-MERN izicelo?
- 8. Ulilawula njani ilizwe kwisicelo seReact? Cacisa iikhonsepthi ezifana ne-Redux kunye ne-Context API.
- 9. Cacisa injongo yefayile yephakheji.json kwisicelo seNode.js.
- 10. Yintoni injongo yeWebpack, kwaye isetyenziswa njani kwiprojekthi yeReact?
- 11. Uyila njani i-schemas kwi-MongoDB, kwaye zeziphi ezinye iingqalelo ezibalulekileyo?
- 12. Cacisa isalathisi kwi-MongoDB kwaye ingasetyenziselwa njani ukwenza imibuzo?
- 13. Uluphatha njani ubudlelwane kwi-MongoDB, obufana nomntu omnye kunye nobudlelwane abaninzi ukuya kwabaninzi?
- 14. Yintoni i-Aggregation Framework kunye ne-MapReduce kwi-MongoDB? Uza kuzisebenzisa njani yaye nini?
- 15. Uzenza njani iindlela zakho ze-Express.js kunye nabalawuli?
- 16. Ngaba ungayichaza imposiso yokuphatha kwi-Express.js?
- 17. Ungayiphumeza njani isiqinisekiso kwisicelo se Express.js?
- 18. Yintoni i-CORS kwaye uyiphatha njani kwi-Express.js?
- 19. Cacisa umjikelo wobomi wecandelo le-React kunye neendlela ezinxulumene nezigaba ezahlukeneyo zomjikelo wobomi.
- 20. Uwenza njani umsebenzi weReact application?
- 21. Chaza umahluko phakathi kwamacandelo alawulwayo nangalawulwayo kwi-React.
- 22. Uyisebenzisa njani iReact Hooks, kwaye zeziphi iimeko zokusetyenziswa okuqhelekileyo?
- 23. Ngaba ungabhala icandelo elilula le-React elithatha idatha kwi-API kwaye libonise?
- 24. Cacisa i-DOM ebonakalayo kwi-React kunye nendlela esebenza ngayo.
- 25. Ulawula njani abantu abaxhomekeke kwiprojekthi yeNode.js?
- 26. Cacisa iSigigaba Loop kwiNode.js. Ingaba iyiphatha njani imisebenzi engavumelaniyo?
- 27. Yintoni imisinga kwiNode.js, kwaye ungayisebenzisa njani?
- 28. Ukusingatha njani ukuhlanganisa kwi-Node.js ukusebenzisa zonke ii-CPU cores?
- 29. Ungabhala umsebenzi ofunda ifayile kwi-Node.js usebenzisa zombini ii-callbacks kunye nezithembiso?
- 30. Bhala umsebenzi wokuqhagamshela kwi-MongoDB kwaye ufumane kwakhona onke amaxwebhu kwingqokelela ethile.
- 31. Sebenzisa i-CRUD API elula usebenzisa i-Express.js.
- 32. Yenza icandelo le-React esebenzisa urhulumente kunye neeprops ukunika ulwazi.
- 33. Ungakusingatha njani ukufakwa kweefayile kwi-Express.js?
- 34. Bhala umsebenzi we-middleware kwi-Express eloga indlela yokucela, i-URL, kunye nesitampu sexesha.
- 35. Phumeza ukuqinisekiswa komsebenzisi usebenzisa i-JWT kwisicelo se-MERN.
- 36. Ungalivavanya njani icandelo le-React? Bhala umzekelo olula wovavanyo.
- 37. Yenza i-hook ye-React ukulawula igalelo lefom.
- 38. Sebenzisa imposiso yokuphatha indlela ethile kwi-Express.js.
- 39. Ungayiphatha njani idatha yexesha langempela kwisicelo se-MERN? Cacisa kwaye ubhale i-snippet yekhowudi usebenzisa i-Socket.IO okanye iteknoloji efanayo.
- 40. Chaza kwaye uphumeze i-caching kwisicelo se-MERN ukwenza ngcono ukusebenza.
- isiphelo
Uphuhliso lwewebhu lwangoku luguqukela ngakumbi kwi-MERN Stack, ukudibanisa okunamandla kweetekhnoloji ezine zokusika.
I-MERN Stack ibonelela abaphuhlisi ngesisombululo sokugqibela kwaye iqulethe i-MongoDB, i-database ye-NoSQL eqinisekisa ukuguquguquka kunye nokunciphisa, i-Express.js, isakhelo sewebhu esincinci sokwakha ii-APIs eziqinileyo, i-React, ilayibrari ye-Facebook yokudala umsebenzisi oguqukayo kunye nosebenzisanayo. ujongano, kunye neNode.js, i JavaScript yexesha lokusebenza eyenza umncedisi wecala loshicilelo.
Imfuno ye-MERN Stack ihlala isonyuka njengoko iinkampani ezininzi zisebenza ukunika amava angenamthungo kwi-intanethi, ziqinisa isikhundla sayo kwimarike.
Kuyaqondakala ukuba kutheni ulwazi lwe-MERN luxatyiswe kakhulu kwindawo yokusebenza yanamhlanje. Ufike kwindawo egqibeleleyo ukuba ungumphuhlisi ozama ukuzimisa kolu shishino lutshintsha ngokukhawuleza.
Le bhlog izama ukukuxhobisa ngolwazi olusisiseko kunye nokuqonda okufunekayo ukuze uphumelele kudliwano-ndlebe lwe-MERN Stack.
Siza kukukhokela kwinqanaba ngalinye lenkqubo ukuqinisekisa ukuba ukulungele ukubonisa izakhono zakho, ukusuka ekuqondeni iinkcukacha zecandelo ngalinye ukuya ekubeni yingcali ekubhaleni ikhowudi esebenzayo.
Nokuba ungumfundi oqalayo ukufunda malunga ne-MERN okanye ingcali enamava efuna ukuxubha, le bhlog inolwazi oluluncedo kuwe.
1. Yintoni isitaki se-MERN? Ungalichaza icandelo ngalinye kunye nendima yalo?
Ukwakha usetyenziso lwe-intanethi olunokwehla noluguquguqukayo lwenziwa ukuba lwenzeke sisitaki se-MERN, iphakheji yetekhnoloji ejikelezwe kakuhle. Igama elithi "MERN" lenziwe ngoonobumba abathi nganye imele icandelo elibalulekileyo:
- I-MongoDB: Njengoluhlu lwedatha, i-MongoDB ibonelela nge-schema-less system ye-NoSQL eqinisekisa ukuguquguquka ekuqhubeni idatha kwaye iyenze ifanele izicelo ezifuna ukuphindaphinda ngokukhawuleza.
- Express.js: Esi siphelo-ngasemva Usetyenziso lwewebhu isakhelo, esisebenza kakuhle nge-Node.js, yenza kube lula ukwenza ii-API ezithembekileyo kunye nokusingatha ukusebenza kwecala leseva.
- Ukuphendula: I-React yilayibrari engaphambili egxile kakhulu kujongano lomsebenzisi. I-DOM enenyani eyibonelelayo yenza unikezelo lula lula, kwaye yenza indlela eyimodyuli yokucwangcisa amacandelo e-UI, ukuphucula zombini. amava kunye nophuhliso.
- I-Node.js: Icandelo lokugqibela lesitaki yi-Node.js, i-JavaScript runtime eyenza abadwelisi benkqubo basebenzise ikhowudi ye-JavaScript ye-server-side. Inkqubo yophuhliso ilungelelaniswa ngokudityaniswa kweelwimi ezisetyenziswa kubathengi nakumacala omncedisi.
2. I-stack ye-MERN ithelekisa njani nezinye izitaki zeteknoloji ezifana ne-MEAN okanye i-LAMP?
Ukuthelekisa isitaki se-MERN kwezinye iimfumba ezaziwayo ezifana ne-MEAN okanye i-LAMP, ivelele ngenxa yokusika kwayo kunye nobuchwepheshe obuguqukayo.
Ngaphandle kwento yokuba i-MEAN kunye ne-MERN zisebenzisa amacandelo amathathu afanayo, i-MERN isebenzisa i-React endaweni ye-Angular, ehlala itsala abaphuhlisi befuna ukuguquguquka okukhulu xa besakha ujongano lomsebenzisi oluguqukayo.
I-LAMP, equka i-Linux, i-Apache, i-MySQL, kunye ne-PHP, kwelinye icala, yindlela eqhelekileyo ye-server-side methodology. Igophe lokufunda le-LAMP linokuba phezulu kune-JavaScript egxile kwi-MERN kunye ne-MEAN stacks kuba isebenzisa iilwimi ezahlukeneyo kunye nobuchwepheshe bophuhliso lwabaxhasi kunye nomncedisi.
I-MERN inconywa ngendlela yayo yonke iJavaScript, ekhuthaza inkqubo yophuhliso elungelelanisiweyo nedibeneyo. Isigqibo phakathi kwe-MERN, MEAN, kunye ne-LAMP sihlala sihla kwiimfuno ezizodwa zeprojekthi, ubuchule beqela, kunye namava ophuhliso afunekayo.
3. Cacisa ukuba ungasikhusela njani isicelo se-MERN?
Isicwangciso esintsonkothileyo esibeka phambili zombini ingqibelelo yedatha kunye nobumfihlo bomsebenzisi kufuneka ukukhusela isicelo se-MERN. Ukuthunyelwa kokuqinisekiswa okunamandla kunye neenkqubo zokugunyazwa, rhoqo usebenzisa i-JWT (i-JSON Web Tokens) ukuqinisekisa ukuchongwa komsebenzisi, kungundoqo wesi sicwangciso.
Ngaphaya koko, izikhuselo ezifana nokuqinisekisa igalelo kunye nezenzo zococeko zibalulekile ekunciphiseni ubuthathaka njengenaliti yeSQL kunye neCross-Site Scripting (XSS). Ukusebenzisa izitatimenti ezilungiselelwe kwi-MongoDB kunceda ukukhusela ukuhlaselwa kwe-injection kwicala le-database.
Ukhuseleko lwesicelo kuhlaselo olunokwenzeka lomelezwa ngakumbi ngokusebenzisa i-HTTPS enezatifikethi ezifanelekileyo ze-SSL/TLS, eyenza uqhagamshelwano oluntsonkothileyo phakathi komxhasi kunye nomncedisi.
Ngokubandakanya ezi nkqubo zokhuseleko, isicelo se-MERN sinokuqiniswa ukuchasana neziphene eziqhelekileyo kunye nokubonelela ngamava akhuselekileyo omsebenzisi.
4. Chaza indima ye-middleware kwi-Express.js. Ngaba ungabonelela ngomzekelo wesiko eliphakathi?
I-middleware ye-Express.js isebenza njengejelo lokucubungula kunye nokuphucula idatha njengoko ihamba ngesicelo, isenza uxhulumaniso olubalulekileyo phakathi kwesicelo kunye nezinto zokuphendula.
Le misebenzi inokufikelela kwinto yesicelo, into yokuphendula, kunye nomsebenzi olandelayo we-middleware kumjikelo wesicelo-impendulo yesicelo.
Ukuphatha imisebenzi efana nokugawulwa kwemithi, uqinisekiso, okanye ukwahlulahlulwa kwedatha kukusetyenziswa okuqhelekileyo kwe-middleware. Umzekelo, oku kulandelayo kungasetyenziselwa ukwenza i-middleware yokungena ngokwesiko:
Le nxalenye yekhowudi iya kurekhoda ulwazi malunga nesicelo ngasinye esingenayo, inika iimbono zexesha langempela malunga nendlela abasebenzisi abasebenzisana ngayo nesicelo. Abaphuhlisi banokuhlengahlengisa ikhowudi yabo, banyuse ukusetyenziswa kwakhona, kwaye bagcine i-codebase ecocekileyo nesebenzayo ngokusebenzisa i-middleware.
5. Ziziphi iiyantlukwano eziphambili phakathi kweReact Class Components kunye ne-Functional?
Amacandelo eKlasi kunye namacandelo asebenzayo ziiparadigm ezimbini ezizodwa ezivela kwihlabathi eliguquguqukayo lenkqubo yeReact.
Izixhobo zeKlasi, ezichazwe ngegama elingundoqo leklasi, ngaphambili yayiyeyona ndlela yodwa yokusebenzisa imisebenzi ye-lifecycle kunye nokugcina ubume bangaphakathi kwicandelo.
Nangona kunjalo, ngokongezwa kweeHooks kwi-React 16.8, i-Functional Components-imisebenzi elula-ngoku inokufikelela kwiimpawu zelizwe kunye ne-lifecycle, ehlala iphumela kwikhowudi emfutshane kwaye kulula ukuyiqonda.
Amacandelo asebenzayo ahlala ethandwa ngenxa yokulula kunye nokulula kovavanyo, kodwa amaCandelo eKlasi abonelela ngendlela elungelelanisiweyo kunye nejolise kwinto.
Isigqibo phakathi kwezi zibini sihlala sihla kwiqela okanye kwizinto ezikhethwa ngumntu, ukuntsokotha kwecandelo, kunye neenjongo zoyilo lweprojekthi. Nangona kunjalo, utyekelo luthanda izinto ezisebenzayo ngenxa ye-syntax elula kunye nokuguquguquka okuphezulu.
6. Ngaba unokucacisa ukuba umzila usebenza njani kwisicelo se-MERN?
Kwisicelo se-MERN, umzila yindlela ecwangcisiweyo ekhokela abasebenzisi kwii-URL ezahlukeneyo ngaphakathi Usetyenziso lwewebhu. I-Express.js ilawula indlela kwi-backend ngokukhankanya iindawo ezininzi zokuphela ukuze zinxulumane neendlela ezithile ze-HTTP kunye nee-URL, ngaloo ndlela ilawula indlela umncedisi asabela ngayo kwizicelo zabaxhasi.
I-React Router kunye nobunye ubuchwephesha besiphelo sangaphambili busetyenziselwa ukwakha usetyenziso olunephepha elinye kunye neendlela zokukhangela ezilinganisa amava amaninzi aqhelekileyo.
Ngokudibeneyo, ezi ndlela zobuchule zibonelela ngamava omsebenzisi alungelelanisiweyo okwenza kube lula ukuhamba ngokufanelekileyo ngaphandle kokuhlaziya iphepha.
Usetyenziso lwe-MERN lunokubonelela ngolwakhiwo lokukhangela oluguqukayo, oluphendulayo, nolunembile oluhambelana ngokuchanekileyo nemigangatho yangoku yophuhliso lwewebhu kunye nolindelo lwabasebenzisi ngokusebenzisa i-client-side kunye ne-server-side routing ngokuvumelana.
7. Yintoni izithembiso kwaye zisetyenziswa njani kwi-MERN izicelo?
Enye indlela entle nelawulekayo yokufowuna kwakhona ibonelelwa sisithembiso sokutsalwa kweJavaScript, esisisithintelo esinamandla sokuphatha iintshukumo ze-asynchronous.
Izithembiso zisetyenziswa ngokubanzi kumxholo wesicelo se-MERN ukusingatha imisebenzi engasombululi ngoko nangoko, njengokukhangela kwesiseko sedata ngeMongoDB okanye izicelo zeHTTP nge Express.js. Isithembiso yimbonakaliso yexabiso elisenokuba alikho ngoku kodwa eliza kuzaliseka okanye ligatywe kwixesha elizayo.
Abaphuhlisi bangacacisa ukuba isicelo kufuneka senze njani emva kokuba iSithembiso sizalisekile okanye kwenzeke impazamo ngokudibanisa iindlela.then() kunye.catch() iindlela.
Ukusetyenziswa rhoqo kwezithembiso kwizicelo ze-MERN kwenza ikhowudi icace kwaye kulula ukuyigcina, ivumela abadwelisi beprogram ukuba bayile ikhowudi ye-asynchronous eqondakalayo ngakumbi kwaye kulula ukuyilungisa, ukuphucula inkqubo 'yokusebenza ngokubanzi kunye nokomelela.
8. Ulilawula njani ilizwe kwisicelo seReact? Cacisa iikhonsepthi ezifana ne-Redux kunye ne-Context API.
Kwisicelo seReact, ulawulo lwelizwe lunokuba lumsebenzi obalulekileyo kunye nomngeni, ngakumbi njengoko isicelo sisanda ngobukhulu kunye nobunzima. Abaphuhlisi bahlala besebenzisa izixhobo zokulawula zikarhulumente ezifana ne-Redux kunye ne-Context API ukusombulula le ngxaki.
I-Redux inikezela ngogcino olulodwa lwemeko yesicelo siphela, ivumela ukufikelela kwedatha ecwangcisiweyo kunye nohlengahlengiso kumacandelo amaninzi.
Izenzo ze-redux kunye nabanciphisi zenza kube lula ukuqikelela ukuba ilizwe liya kutshintsha nini na, elikhuthaza ukungaguquguquki kunye nokugcinwa.
Kwelinye icala, abaphuhlisi banokudala iimeko ezinokutshintshisa urhulumente kunye nemisebenzi enamacandelo afakwe kwindlwane usebenzisa iReact eyakhelwe-ngaphakathi Umxholo we-API ngaphandle kwesidingo sokumba iprop.
I-Context API inikezela ngesisombululo esithe ngqo kunye nesikhaphukhaphu kwiimeko xa ulawulo lwelizwe jikelele lufuneka ngaphandle kobunzima bamathala eencwadi angaphezulu, kodwa i-Redux inikezela ngesisombululo esomeleleyo nesinobunzima, ngakumbi kwizicelo ezinkulu.
Zombini iindlela zinokufaneleka kwazo, kwaye ukhetho luhlala luphenjelelwa ziimfuno ezithile kunye ulwakhiwo lwesicelo.
9. Cacisa injongo yefayile yephakheji.json kwisicelo seNode.js.
Ifayile yephakheji.json licandelo eliphambili le-ecosystem ye-Node.js kuba isebenza njengereferensi enzulu yazo zonke iimpawu zesicelo.
Yenza lula inkqubo yofakelo lwabanye abaphuhlisi okanye iinkqubo ngokuchaza iimfuno ezikhethekileyo zophuhliso ngaphezu kokuxhomekeka okuyimfuneko kwiprojekthi.
Le fayile engundoqo ikwaqulethe i-metadata ebalulekileyo, efana negama leprojekthi, inkcazo, kunye noguqulelo lwangoku, okwenza kube lula ukusasazwa kunye noxwebhu. Ngaphandle kwezi mpawu zisisiseko, ifayile ye-package.json inika abaphuhlisi amandla okwenza izikripthi ezizodwa, ukwenza imisebenzi efana nokuqalisa iseva kunye nokuqhuba iimvavanyo ezibalulekileyo lula.
Ekugqibeleni, le fayile ibalulekileyo isebenza njenge Node.js izicelo iplani yezokwakha, ukukhawulezisa uphuhliso, ukukhuthaza intsebenziswano, kunye nokuqinisekisa ukusebenza okuthembekileyo kwiindawo ezahlukeneyo.
10. Yintoni injongo yeWebpack, kwaye isetyenziswa njani kwiprojekthi yeReact?
Ngokukodwa, i-Webpack isebenza njenge-module bundler kwi-React applications, iyenza ibe sisixhobo esibalulekileyo kuphuhliso lwewebhu lwangoku.
Umsebenzi wayo oyintloko kukuqulunqa iifayile ezininzi kunye nokuxhomekeka, njengeJavaScript, iCSS, imifanekiso, kunye neefonti, kwiqela elincinci, elilungelelaniswe kakuhle lemithombo enokunikezelwa ngokukhawuleza kwisiphequluli.
Ngokwenza oku, iWebpack iphucula isantya kuba izicelo ezimbalwa zenziwe kwaye ikhowudi inikwe ngendlela efanelekileyo kumxholo womsebenzisi wokugqibela.
Abaphuhlisi banokwenza iinguqu, bavumele ukwahlula ikhowudi, kwaye bamise ukutshintshwa kwemodyuli eshushu usebenzisa i-Webpack, ehamba ngaphaya kwe-bundling elula kwaye ibonelele nge-ecosystem ecebileyo yeeplagi kunye noluhlu olubanzi lweenketho zokucwangcisa inkqubo yophuhliso olulungelelanisiweyo.
Indlela yophuhliso eyenziwe lula kunye negcinekayo ebonelela kuphuhliso olulula kunye nokuphucula imveliso ikhuthazwa ngokudibanisa iWebpack kwiprojekthi yeReact. Umsebenzi wayo kwiprojekthi ye-React ugxininisa intshukumo ngokubanzi kwiimodyuli kunye neendlela zophuhliso lwewebhu oluqaphela ukusebenza.
11. Uyila njani i-schemas kwi-MongoDB, kwaye zeziphi ezinye iingqalelo ezibalulekileyo?
Uyilo lweschema se-MongoDB lufuna ingcinga enobuchule kunye nokwazisa ngeemfuno ezithile zesicelo.
Ukuguquguquka kweMongoDB njengovimba wedatha we-NoSQL kwenza abadwelisi benkqubo bayilwe i-schemas eguquguquka ngokulula kwiipateni ezahlukeneyo zedatha.
Kubalulekile ukuthathela ingqalelo unxibelelwano phakathi kwamaqumrhu ahlukeneyo ngelixa usenza ischema, kuthathwe isigqibo sokuba kusetyenziswe amaxwebhu agxininisiweyo okanye iimbekiselo ezisekelwe kwiipatheni zemibuzo kunye neemfuno zokusebenza.
Uhlobo lwedatha kunye nokuba yenzeke kaninzi kangakanani imisebenzi efundwayo nebhaliweyo inokuphembelela isalathiso kunye nokhetho lokuphucula.
Izinto eziphambili kwinkqubo yoyilo lwe-schema zikwabandakanya ukunikela ingqalelo kwiikhrayitheriya zokuqinisekiswa kwedatha, iimfuno zokuhambelana, kunye nokunyuka kwexesha elizayo.
Abaphuhlisi banokwakha isiseko sesiseko sedatha esisebenzayo kunye nesilungelelanisayo esixhasa impumelelo yexesha elide yeprojekthi ngokuthelekisa uyilo lweschema kunye neemfuno ezithile kunye neempawu zesicelo.
12. Cacisa isalathisi kwi-MongoDB kwaye ingasetyenziselwa njani ukwenza imibuzo?
Kwi-MongoDB, isalathisi bubuchule obunamandla bokuphucula ukusebenza kunye nesantya semibuzo. Isalathiso sesiseko sedatha, esifana nesalathiso kwincwadi, yenza ukuba i-MongoDB ifumane ngokukhawuleza idatha ethile ngaphandle kokuskena yonke ingqokelela, ukuphucula imisebenzi yombuzo.
Ixesha elithathwayo ukufumana idata INGAHLANGANISA kakhulu ngabaphuhlisi ngokwakha izalathisi kwimihlaba esoloko ikhangelwa.
Kodwa kubalulekile ukufezekisa ibhalansi kuba izalathiso ezininzi zinokulibazisa ukubhala imisebenzi phantsi kwaye usebenzise ugcino olongezelelweyo.
Xa usenza izalathisi, kubalulekile ukuba ucinge ngononophelo kwiipatheni zemibuzo kwaye ube nokuqonda okuqinileyo korhwebo phakathi kokusebenza kokufunda nokubhala.
Ngokufutshane kwisalathiso kwi-MongoDB, xa isetyenziswe ngobulumko inokubangela imibuzo esebenza kakuhle, inceda ukuxhasa isicelo esiphendulayo nesithembekileyo.
13. Uluphatha njani ubudlelwane kwi-MongoDB, obufana nomntu omnye kunye nobudlelwane abaninzi ukuya kwabaninzi?
Ingaba ubudlelwane bunye okanye buninzi-ukuya-baninzi, i-MongoDB iyiphatha ngobuchule ngokuhambelana neemfuno kunye neepatheni zemibuzo yesicelo.
If unxulumano lulolunye, ungagqiba ekubeni udibanise umxholo odityanisiweyo kanye kuxwebhu olungundoqo, oluya kwenza lula inkqubo yokubuza.
Iireferensi zingasetyenziselwa ukudibanisa amaxwebhu kubudlelwane obuninzi ukuya kuninzi, olunokuthi lufaneleke ngakumbi ukuba ubudlelwane bunzima okanye inani ledatha likhulu.
Ukudityaniswa kwedatha, uhlaziyo lwamaxesha, kunye nemfuneko yokuguquguquka kweschema zonke kufuneka zithathelwe ingqalelo xa ukhetha phakathi kokuzinzisa kunye nereferensi.
Ulawulo lobudlelwane kwi-MongoDB lunokubangela ulwakhiwo oluluqilima lwedatha ehlangabezana neemfuno zesicelo ngokulungiselela ngononophelo kunye nolwazi lorhwebo olululo. Ngokubhekiselele kwiimfuno ezithile kunye nokutshintsha kwemeko yosetyenziso olunikiweyo, ukhetho phakathi kokuzinzisa kunye nereferensi luba luyimfuneko.
14. Yintoni i-Aggregation Framework kunye ne-MapReduce kwi-MongoDB? Uza kuzisebenzisa njani yaye nini?
Ukucubungula kunye nokuhlalutya idatha kwi-MongoDB, i-Aggregation Framework kunye ne-MapReduce ime njengezixhobo ezinamandla. Ngokufana nombhobho wokusetyenzwa kwedatha, iNkqubo-sikhokelo yoHlanganiso ibonelela ngemisebenzi efana nokucoca, ukwahlulahlula, kunye nokuhlelwa kwaye yenza abaphuhlisi bakwazi ukuhlanganisa kunye nokuguqula idatha kwizigaba ezininzi.
Ukwenza iiseti zedatha enkulu kuwo wonke amaqela asasaziweyo, iMapReduce ibonelela ngendlela eguquguqukayo ngakumbi ngokusebenzisa izigaba ezibini zokusetyenzwa-Imephu kunye noNciphisa.
Ubunzima kunye nobukhulu bomsebenzi kufuneka buthathelwe ingqalelo xa ukhetha ukusebenzisa: i-Aggregation Framework isetyenziswa rhoqo kwimisebenzi eyenziwa rhoqo kunye neenkqubo ezincinci, ngelixa i-MapReduce ikhanya kwiinkqubo eziyinkimbinkimbi, ezinkulu zokucwangcisa idatha.
Ukwandisa ukusebenza kwedatha kunye nokuqinisekisa ukuba i-MongoDB ihlangabezana ngokufanelekileyo neemfuno zohlalutyo lwesicelo, kubalulekile ukuqonda iingenelo kunye nokungalunganga kwesixhobo ngasinye.
15. Uzenza njani iindlela zakho ze-Express.js kunye nabalawuli?
Iindlela ze-Express.js kunye nabalawuli kufuneka zicwangciswe ngendlela enengqiqo nengaguquguqukiyo ehambelana noyilo lwesicelo ngokubanzi.
Iindlela kunye nabalawuli kufuneka ngokubanzi bahlulwe babe ziifayile ezahlukeneyo kunye nabalawuli ukugcina ukumodareyitha kunye nokuphucula ukugcinwa.
Kwimizila, ukudala isiphelo esicacileyo kunye nokuxhuma kwiindlela ezithile ze-HTTP kuqinisekisa ulwakhiwo oluqondakalayo kunye nolwakhiweyo. Umsebenzi ohambelana nezi siphelo ziphathwa ngabalawuli, kwaye ngokuzigcina zihluke kwi-routing, i-codebase ilula ukuvavanya kunye nokulinganisa.
Ikhowudi ecocekileyo, esebenzayo incediswa ngakumbi ngokusetyenziswa kweengqungquthela zokuchaza amagama, imisebenzi ye-middleware, kunye nokuphunyezwa komsebenzi oqhelekileyo.
Lilonke, iindlela ze-Express.js kunye nabalawuli abacwangciswe ngengcinga zenza izicelo ezomeleleyo kwaye zibhetyebhetye ngokwaneleyo ukuze zihlangabezane neemfuno zangoku kunye nokwandiswa okunokwenzeka kwexesha elizayo.
16. Ngaba ungayichaza imposiso yokuphatha kwi-Express.js?
Ukuphatha iimpazamo ze-Express.js kubalulekile ekuphuhliseni ii-apps ze-intanethi ezomeleleyo nezisebenzisekayo. Ukusetyenziswa kwemisebenzi ye-middleware eyenziwe ngokukodwa ukubamba kunye nokuqhuba iimpazamo kusembindini wale ndlela.
Abaphuhlisi banokwakha ingqiqo ekhethekileyo yokusingatha iintlobo ezahlukeneyo zeempazamo kwaye banike iimpendulo eziluncedo kumxhasi ngokuchaza i-middleware yokuphatha iimpazamo ezineempikiswano ezine (impazamo, i-req, i-res, kunye nelandelayo).
Ukuqinisekisa ukuba babamba naziphi na iintsilelo eziphuma kwi-middleware kunye neendlela zangaphambili, ezi ndlela ziphakathi kufuneka zibekwe emazantsi e-middleware stack.
Ngokusingatha ngobunono iingxaki ebezingalindelekanga, ukuphathwa kwempazamo ngokufanelekileyo akugcini nje ukwenza isicelo somelele ngakumbi kodwa sikwaphucula amava omsebenzisi ngokudlulisa imiyalezo yempazamo emfutshane nenolwazi.
Ukuphathwa kwempazamo ye-Express.js kunokuguqula ubunzima obunokwenzeka kumathuba okucaca kunye nokomelela kwisicelo sakho ngokuphunyezwa ngononophelo.
17. Ungayiphumeza njani isiqinisekiso kwisicelo se Express.js?
Ukuphumeza ukuqinisekiswa kwesicelo se-Express.js yinkqubo entsonkothileyo ebalulekileyo ekugcineni ulawulo lokufikelela kunye nokukhusela ulwazi lomsebenzisi.
Ukusebenzisa iipakethe ezifana nePassport.js, eyenza iindlela ezahlukeneyo zokuqinisekisa abasebenzisi, kubandakanywa ukuqinisekiswa kwendawo kunye ne-OAuth kunye nokungena kwinethiwekhi yoluntu, sisicwangciso esiqhelekileyo. Emva kokuba umsebenzisi eqinisekisiwe, imeko yomsebenzisi inokulawulwa phakathi kwezicelo usebenzisa iiseshoni okanye i-JSON Web Tokens (JWT).
Ngokuqinisekisa ukuba ngabasebenzisi abaqinisekisiweyo kuphela abanokusebenzisa izixhobo ezichaziweyo, imisebenzi ye-middleware ihlala idlala indima ebalulekileyo ekukhuseleni iindlela ezithile.
Inkqubo yokungena yenziwa lula kubasebenzisi ngokuphatha iimpazamo kunye nemiyalezo yokuphendula ecacileyo.
Okokugqibela, ukukhumbula ezona ndlela zilungileyo zokhuseleko kunye nokusetyenziswa, ukhetho lweendlela zokuqinisekisa kunye nezixhobo kufuneka zenziwe ngokweemfuno ezizodwa zesicelo kunye nokusebenzisana komsebenzisi okulindelekileyo.
18. Yintoni i-CORS kwaye uyiphatha njani kwi-Express.js?
I-Cross-Origin Resource Sharing, okanye i-CORS, yinto yokhuseleko eyongeziweyo kwiiphequluli zewebhu ukulawula izicelo ezithunyelwe ukusuka kwelinye isizinda ukuya kwelinye. Iqinisekisa a Usetyenziso lwewebhu esebenza kwimvelaphi enye igunyaziswe ukufikelela kwimithombo ethile evela kwenye imvelaphi. Xa uphuhlisa ii-APIs zosetyenziso lwewebhu olukwicala lomxhasi olusebenza kwiindawo ezahlukeneyo, ukujongana ne-CORS kwi-Express.js kunokubaluleka. Isicelo se-Express.js sinokulawula ngokulula ii-CORS usebenzisa i-middleware njengepakethe ye-cors. Abaphuhlisi banokumisela iindlela ezichanekileyo, ezinjengokuvumela imvelaphi ethile okanye ukucacisa ukuba zeziphi iindlela zeHTTP ezivumelekileyo, ngokuqwalasela le middleware, ibanike ulawulo olucokisekileyo kwizicelo ezinqamlezileyo. Ulawulo olululo lwe-CORS lubalulekile ukuze kuvumeleke izicelo eziphuma kwimvelaphi esemthethweni kunye nokugcina imida yokhuseleko yesicelo ikhona.
19. Cacisa umjikelo wobomi wecandelo le-React kunye neendlela ezinxulumene nezigaba ezahlukeneyo zomjikelo wobomi.
Umjikelo wobomi wecandelo le-React uchaza amanyathelo achanekileyo ekufuneka icandelwana liwathathe ukususela kwixesha elenziwe ngayo de lisuswe kwi-DOM, linika abaphuhlisi iihuku zokusebenzisa ikhowudi kwiindawo ezibalulekileyo. Ezi zigaba kunye neendlela ezinxulumene nazo ziquka:
Ukunyuswa: Icandelo liyenziwa kwaye longezwe kwi-DOM ngeli xesha.
- umakhi (): incamathela abaphathi besiganeko kwaye iqalise urhulumente.
- render(): umelo lwecandelo lweJSX lubuyisiwe.
- componentDidMount(): nje ukuba icandelo longezwe kwiDOM; isetyenziswa rhoqo ukufunyanwa kwedatha.
Uhlaziyo: Xa imeko okanye iipropathi zecandelo zitshintsha, kuqalwa.
- shouldComponentUpdate(): ithatha isigqibo sokuba unikezelo olutsha luyafuneka.
- render(): izisa i-JSX yamva nje kwakhona.
- componentDidUpdate(): Ukwenziwa kohlaziyo lwasemva; Unxibelelwano lwe-DOM lunokwenzeka.
Ukuhla: Icandelo liyakhutshwa kwi-DOM kweli nqanaba lokugqibela.
- componentWillUnmount(): izibali-xesha, abaphulaphuli besiganeko, kunye nalo naluphi na ubhaliso olushiyekileyo luyacinywa.
20. Uwenza njani umsebenzi weReact application?
Amava omsebenzisi angenamthungo axhomekeke ekusebenzeni kweReact application ephuculweyo, enokwenziwa ngeendlela ezininzi.
Usetyenziso lunokwahlulwa lube ngamaqhekeza amancinci ngokusebenzisa itekhnoloji efana ne-React Lazy kunye ne-Suspense ukuphumeza ukwahlulahlula ikhowudi, ukulayisha nje umxholo ofunekayo kumbono onikiweyo.
Ngokwenza uthelekiso oluphezulu lweepropu kunye nelizwe, iPureComponent okanye iReact.memo inokunciphisa unikezelo kwakhona olungeyomfuneko.
I-React Profiler, enceda ekufumaneni iibhotile, sesinye isixhobo esinokusetyenziselwa ukubeka iliso kunye nokuphucula ukusebenza kweprojekthi.
Ukusebenza okuphuculweyo kunokufunyanwa ngokulungiselela imifanekiso, ukunciphisa ukusetyenziswa kwethala leencwadi lomntu wesithathu, kunye nokusebenzisa i-server-side rendering (SSR).
Abaphuhlisi banokwakha i-React application ephendula ngakumbi kwaye isebenzayo ngelixa besonyusa ulonwabo lwabasebenzisi ngokunikela ingqalelo kwezi zinto kunye nokubeka iliso kwiimethrikhi zokusebenza kwesicelo.
21. Chaza umahluko phakathi kwamacandelo alawulwayo nangalawulwayo kwi-React.
Imfihlelo yokulawula ngokufanelekileyo igalelo lefom kwi-React kukubamba umahluko phakathi kwezinto ezilawulwayo nezingalawulwayo.
Abaphuhlisi banokulawula ngokupheleleyo amaxabiso kunye nokuqinisekiswa kwefom ngokusebenzisa amacandelo alawulwayo, anemilinganiselo yabo yegalelo egcinwe yi-React state kunye naluphi na utshintsho kwigalelo elisingathwa yimisebenzi ngaphakathi kwecandelo.
Ngokwahlukileyo, amacandelo angalawulwayo agcina imo yawo yangaphakathi kwaye ashiye i-DOM ukulawula ixabiso legalelo.
Nangona le ndlela ithatha ikhowudi encinci, ikunika ulawulo oluncinci malunga nendlela icandelo eliziphatha ngayo. Amacandelo angalawulwayo anokubonelela ngesisombululo esithe ngqo kwiimeko ezisisiseko zokusetyenziswa, ngelixa izinto ezilawulwayo zinokuthi zilungele kangcono iifom ezinzima ezifuna ukuqinisekiswa kwexesha langempela kunye nokuziphatha okuguquguqukayo.
Iimfuno ezithile kunye neqondo lokuntsokotha kwefomu ekuthethwa ngayo, kunye nemiba efana nemfuneko yokuqinisekiswa kunye nokugcinwa ngokubanzi, kufuneka isebenze njengesikhokelo sokugqiba phakathi kwezi zimbini.
22. Uyisebenzisa njani iReact Hooks, kwaye zeziphi iimeko zokusetyenziswa okuqhelekileyo?
Ukukwazi ukunyusa umgangatho kunye nobunye ubuchule be-React ngaphandle kokwenza umbulelo weklasi kwi-React Hooks kuyitshintshe ngokupheleleyo indlela abaphuhlisi abawenza ngayo amacandelo.
Ukusetyenziswa rhoqo yi-useState hook, eyenza abadwelisi benkqubo balawule imeko yecandelo ngaphakathi kwamacandelo asebenzayo kwaye inikezela ngendlela ecacileyo yokulandelela utshintsho.
Njengenye indlela kwiindlela zomjikelo wobomi njenge componentDidMount, componentDidUpdate, kunye necandeloWillUnmount, i useEffect hook yenza iziphumo ebezingalindelekanga ezinjengokulanda idatha kunye nemirhumo.
Ezinye iigwegwe, ezinje nge useContext, zibonelela ngendlela ethe tye ngakumbi yokufikelela kumxholo ngaphandle kokuhlanganisa amacandelo, okwandisa ukufundeka kwekhowudi.
Inkululeko eyongezelelekileyo inikezelwa ngamagwegwe aqhelekileyo, avumela abaphuhlisi ukuba bayile ingqiqo enokusetyenziswa kwakhona kumacandelo amaninzi. Ukusebenzisa ezi hook kukhawulezisa uphuhliso, kuphucula ukugcinwa kwekhowudi, kunye nokunceda ekudaleni ii-apps zeReact eziphucukileyo neziluncedo.
23. Ngaba ungabhala icandelo elilula le-React elithatha idatha kwi-API kwaye libonise?
Sinokuyilawula inkqubo yokulanda ngokulula ngokusebenzisa i-useEffect kunye ne-useState hook. Nanku umzekeliso:
Xa icandelo linyuka, eli candelo elisebenzayo lidala imeko yedatha, liyifumana kwi-API echaziweyo, kwaye ibonise idatha (okanye isaziso sokulayisha ukuba idatha ayikafikeleleki). Yipateni enokuthi ilungiselelwe iimeko ezahlukeneyo kwaye inikezela ngendlela ecocekileyo nesebenzayo yokulawula idatha ye-API ngaphakathi kwesicelo seReact.
24. Cacisa i-DOM ebonakalayo kwi-React kunye nendlela esebenza ngayo.
I-React's virtual DOM (VDOM) luluvo olungundoqo oluphucula unikezelo lwebrawuza ukwandisa ukusebenza kunye nokuphendula kweeapps. Isebenza njengoguqulelo olulula lwenkumbulo lwamacandelo okwenene e-DOM.
I-React ibonelela nge-DOM ebonakalayo ukubonisa utshintsho kwimeko yecandelo okanye iiprops kunokuba yenze olo tshintsho kwi-DOM yokwenyani ngokuthe ngqo.
Olona tshintsho luchanekileyo luchongwa “ngoxolelwaniso,” oluthelekisa olu phawu lwenyani nokuphindaphindwa kwangaphambili.
Endaweni yokuphinda unikeze lonke iphepha, i-React emva koko ihlaziya kuphela ezo zahlulo zilungisiweyo kwi-DOM yokwenyani. Olu hlaziyo olukhethiweyo lunciphisa ukuphathwa ngokuthe ngqo kwe-DOM kubuncinci, ukuphucula ukusebenza kunye nokuphucula amava omsebenzisi.
25. Ulawula njani abantu abaxhomekeke kwiprojekthi yeNode.js?
Ukuze uqiniseke ukuba iprojekthi yakho yeNode.js isebenza ngokufanelekileyo, ukulawula ukuxhomekeka kubalulekile. Umphathi wePakeji yeNode (npm) sisixhobo esiphambili sale nkqubo kuba yenza kube lula ukuyifaka, ukuhlaziya, kunye nokulawula iipakethe ukusuka kubhaliso olubanzi lwe-npm.
Unokongeza iphakheji entsha kwiprojekthi yakho usebenzisa i-npm yokufaka umyalelo, kwaye iya kuvela kwifayile yakho ye-package.json. Le fayile isebenza njenge-manifest, irekhoda bonke abaxhomekeke kunye neenguqulelo ezithile zeprojekthi yakho nganye.
Ifayile ye-package-lock.json iqinisekisa ukuba ukuxhomekeka okuchanekileyo kufakwe kuzo zonke iimeko eziyimfuneko.
Abaphuhlisi banokusingatha ngokufanelekileyo ukuxhomekeka kwiprojekthi yeNode.js ngokusebenzisa ezi zixhobo kunye neefayile, ziqinisekisa ukuhambelana kunye nokuthembeka kwiinkqubo zophuhliso kunye nokuthunyelwa.
26. Cacisa iSigigaba Loop kwiNode.js. Ingaba iyiphatha njani imisebenzi engavumelaniyo?
I-Event Loop, enika amandla i-Node.js' yokungathinteli, indalo ehambelanayo, iyinxalenye ephambili yoyilo. Yilophu engapheliyo ehlola umgca womsitho wemisebenzi, iyichole, kwaye iyigqithisele kwimisonto engaphantsi yenkqubo ukuze iphunyezwe.
I-Loop yoMsitho kwi-Node.js iyivumela ukuba iqhube imisebenzi emininzi ngaxeshanye ngaphandle kokulinda umsebenzi omnye ukugqiba ngaphambi kokudlulela kolandelayo kuba isebenzisa isimbo sokusebenza somsonto omnye.
I-Loop yoMsitho ingaqhubeleka neminye imisebenzi xa kucengwa umsebenzi ongahambelaniyo njengoko wongezwa emgceni.
I-callback yongezwa emgceni emva kokuba isenzo se-asynchronous sigqityiwe kwaye silungele ukuba i-Event Loop iphathe. Isantya sosetyenziso kunye nobungakanani buphuculwe ngenxa yokukwazi kweNode.js ukulawula iinkqubo ezininzi ngokufanelekileyo.
27. Yintoni imisinga kwiNode.js, kwaye ungayisebenzisa njani?
Imijelo yeNode.js zizixhobo ezisebenzayo kakhulu zokulawula idatha, ngakumbi xa usebenza ngobuninzi obukhulu. Bandisa ukusebenza kakuhle ngokuvumela idatha ukuba iphathwe ngokunyukayo kunokuba ilinde ukuhlawula okupheleleyo ukuba kulayishwe.
Cinga imisinga ibe njengemibhobho yamanzi ethwala idatha ibe ngamaqhekeza ukusuka kwenye indawo ukuya kwenye. Sinokufunda kumthombo kwaye sibhalele kwindawo esiya kuyo ngokulandelelana ngokuzisebenzisa.
Ukufunda idatha kwiifayile, ukuyiqhuba ngokukhawuleza, kunye nokusabalalisa kubathengi yimizekelo yeemeko zokusetyenziswa rhoqo.
I-Node.js isebenzisa imijelo ivumela ukusetyenzwa kwedatha esebenzayo kwimemori kwizicelo ngelixa ngaxeshanye ulungiselela isantya.
28. Ukusingatha njani ukuhlanganisa kwi-Node.js ukusebenzisa zonke ii-CPU cores?
Ukuphathwa kwe-Node.js yokudibanisa yindlela ekrelekrele yokwenza uninzi lwazo zonke ii-CPU cores, ukuphucula ukusebenza kwesicelo kunye nokusebenza kakuhle.
Ngenxa yobume be-threaded eyodwa ye-Node.js, ukuhlanganisana kuvumela ukusekwa kweenkqubo ezininzi zomntwana, ezibonisa inkqubo yokuqala kwii-cores ezahlukeneyo.
Imodyuli yomthonyama "yeqela" ivumela abadwelisi benkqubo ukuba bakhe iinkqubo zabasebenzi ezabelana ngamazibuko eseva kunye nenkqubo ephambili. Ngokusasaza izicelo ezingenayo kubasebenzi abaninzi, oku kuqinisekisa ukusetyenzwa komsebenzi ngokufanayo.
Kwiimeko zemveliso, ukuphumeza ukuhlanganisana kudla ngokujongwa njengenyathelo eliyimfuneko lokwandisa kunye nokuphucula ukusetyenziswa kwemithombo.
Abaphuhlisi banokuyisebenzisa ukuqinisekisa ukuba isicelo sabo seNode.js sikulungele ukusebenzisa ngokupheleleyo iiprosesa ezininzi ezingundoqo, ezikhokelela ekusebenzeni okungcono kunye nokuthembeka.
29. Ungabhala umsebenzi ofunda ifayile kwi-Node.js usebenzisa zombini ii-callbacks kunye nezithembiso?
Imodyuli ye-fs, eza ilayishwe kwangaphambili nge-Node.js, inemisebenzi yokunxibelelana nee-callbacks kunye nezithembiso. Njengomzekeliso, qwalasela oku kulandelayo
Zombini ezi ndlela ziyakufunda “ifayile.txt” imixholo kwaye ziprinte kwi-terminal. Isicwangciso sesithembiso sinikeza indlela yokusika kunye neyocwangco yokusingatha ingqiqo ye-asynchronous xa kuthelekiswa ne-callback approach, esebenzisa indlela eqhelekileyo yokulawula imisebenzi ye-asynchronous kwi-Node.js.
30. Bhala umsebenzi wokuqhagamshela kwi-MongoDB kwaye ufumane kwakhona onke amaxwebhu kwingqokelela ethile.
Uphuhliso lwewebhu rhoqo lubandakanya ukudibanisa kwi-MongoDB kunye nokufumana onke amaxwebhu kwingqokelela ethile. Nantsi indlela elula eyenza oku usebenzisa umqhubi weMongoDB wasekhaya:
Kufuneka ufake i-url yoqhagamshelwano, igama lesiseko sedatha (dbName), kunye negama lokuqokelela (collectionName) kule ndlela. Umsebenzi uya kubuyisela lonke uxwebhu kwingqokelela enikeziweyo. Ukugcinwa kwesicelo kuphuculwe ngokusebenzisa i-async / ukulinda, egcina ikhowudi ihlelekile kwaye kulula ukuyifunda.
31. Sebenzisa i-CRUD API elula usebenzisa i-Express.js.
Express.js's CRUD API sisixhobo esisemgangathweni sokudala, ukufunda, ukuhlaziya, kunye nokucima izixhobo kuphuhliso lwangoku lwe-intanethi. Nanku umzekeliso weCRUD API:
32. Yenza icandelo le-React esebenzisa urhulumente kunye neeprops ukunika ulwazi.
Ukwenza icandelo kwi-React liguquguquke kwaye libhetyebhetye, yinto eqhelekileyo ukusebenzisa zombini iphondo kunye nezixhaso ngelixa kusakhiwa ilungu. Nanku umzekeliso wecandelo elisisiseko:
Xa icandelo leProfayile yomsebenzisi lisetyenziswa kwenye indawo kwisicelo, igama lomsebenzisi prop kufuneka linikezelwe. Ubudala, kwelinye icala, yimeko eguquguqukayo elawulwa licandelo.
Ungayandisa iminyaka ngokunqakraza iqhosha lecandelo, ubonisa usetyenziso oluluncedo lwelizwe lokulawula ulwazi oluguquguqukayo. Lo mzekeliso ubonisa indlela yokuyila amacandelo aphendulayo kunye nanokuphinda asetyenziswe ngokusebenzisa urhulumente kunye neeprops.
33. Ungakusingatha njani ukufakwa kweefayile kwi-Express.js?
Ukwenzela ukuqinisekisa inkqubo engenamthungo lo gama uphethe ukufakwa kweefayili kwisicelo se-Express.js, kufuneka kuthathwe amanyathelo athile abalulekileyo.
Okokuqala, uya kusebenzisa ngokubanzi ipakethe efana ne-multer, eyenziwa ngokukodwa ukuphatha i-multipart/form-data, indlela yemveli yokulayisha iifayile nge-HTTP.
Nanku umzekeliso ocacileyo wenkqubo:
I-Multiper imiselwe kule sampuli ukugcina iifayile ezilayishiweyo kulawulo olubizwa ngokuba "ukulayisha /." Ngokusebenzisa upload.single('ifayile'), iyalela i-Express ukuba yamkele kuphela ifayile enye enegama 'ifayile' kwisicelo esingenayo. I-Req.file iya kubandakanya ulwazi malunga nefayile elayishiweyo.
34. Bhala umsebenzi we-middleware kwi-Express eloga indlela yokucela, i-URL, kunye nesitampu sexesha.
Ukulungiswa kweempazamo kunye nokugcina izicelo zesicelo kunokuncediswa kakhulu ngokwenza umsebenzi ophakathi kwi-Express.js erekhodisha indlela yokucela, i-URL, kunye nesitampu sexesha. Nanku umzekeliso wendlela ongayenza ngayo i-middleware:
Umsebenzi we requestLogger kule snippet yekhowudi urekhoda isitampu sexesha sangoku, indlela yeHTTP (efana neGET, POST, njl.njl.), kunye ne-URL yesicelo esingenayo.
Iqinisekisa ukuba isicelo soqhubekeko siqhubela phambili kwi-middleware elandelayo okanye isibambi sendlela kwityathanga ngokuphumeza okulandelayo().
Imboniselo engaguqukiyo yonxibelelwano lwesicelo inikezelwa ngokongeza le middleware yesiko kwisicelo kwaye emva koko usebenzisa i-app.use() ukuyifaka kuzo zonke izicelo ezingenayo.
35. Phumeza ukuqinisekiswa komsebenzisi usebenzisa i-JWT kwisicelo se-MERN.
Ukukhusela iindlela ezibalulekileyo kunye nokuqinisekisa iziqinisekiso zomsebenzisi, ukuqinisekiswa komsebenzisi usebenzisa i-JWT (i-JSON Web Tokens) kufuneka iphunyezwe kwisicelo se-MERN (MongoDB, Express.js, React, Node.js). Isicelo siya kuvelisa i-JWT ngasemva ngexesha lenkqubo yokungena, esebenzisa isitshixo esiyimfihlo ukubethela ulwazi lomsebenzisi. Nanku umzekeliso omfutshane:
Umqondiso ugcinwa kwicala lomxhasi (React) kwaye wongezwa kwizihloko zezicelo ezilandelayo. I-Express.js ingasetyenziselwa ukwakha i-middleware kwicala lomncedisi ukuqinisekisa umqondiso:
36. Ungalivavanya njani icandelo le-React? Bhala umzekelo olula wovavanyo.
Icandelo le-React elivavanyiweyo liya kusebenza njengoko bekucetyiwe, kukhokelela kwisicelo esizinzile nesinokuthenjwa.
Ngesiqhelo, iimeko zovavanyo ziyadalwa kwaye ziqhutywa kusetyenziswa amathala eencwadi afana neJest kunye neThala leencwadi loVavanyo lweReact.
Umzekelo, ungenza uvavanyo oluboniswe ngezantsi ukuvavanya inxalenye ethe ngqo ebonisa iqhosha elinombhalo othile:
37. Yenza i-hook ye-React ukulawula igalelo lefom.
Ngokwahlula ingqiqo yokusetyenzwa kotshintsho lwegalelo kwikhonkco yeReact, unokuhlengahlengisa ulawulo lukarhulumente kwisicelo sakho.
Le hook ikhuthaza ukusetyenziswa kwakhona ikhowudi kuba ingasetyenziswa kwiifom ezahlukeneyo kunye namacandelo. Nanku umzekeliso ocacileyo wendlela yokubhala ikhonkco elinje:
Emva koko, ungasebenzisa le hook kwicandelo elisebenzayo, umzekelo, ngokuthi const name = useFormInput (”). Ungadibanisa ixabiso kwaye utshintshe isibambi kwisiqalelo segalelo ngokunika igama.value kunye negama.onChange iiparamitha.
Amacandelo akho angacoceka kwaye kube lula ukuwagcina ngolu qweqwe lwendlela yokuphatha, kukukhulula ixesha lakho lokusebenza kwezinye iindawo zenkqubo yakho.
38. Sebenzisa imposiso yokuphatha indlela ethile kwi-Express.js.
Ulawulo lwemposiso ye-Express.js yendlela enikiweyo kufuneka iphunyezwe ukuba ufuna ukunika umxhasi impendulo eluncedo kwaye uqinisekise ukuba isicelo sakho sisebenza ngokungaguqukiyo. Nanku umzekelo ocacileyo wokubonisa ukuba ungakwenza njani oku:
Indlela ethile /umsebenzisi/:id kule sampuli yekhowudi ifumana umsebenzisi nge-ID yakhe. Imposiso idluliselwe kwezi ziphakathi zilandelayo kusetyenziswa indlela elandelayo ukuba iyenzeka, umzekelo ukuba umsebenzisi akafumaneki.
I-middleware yokugqibela kwikhonkco irekhoda ingxaki, ithumela umxhasi ikhowudi yesimo se-500, kwaye ifaka impazamo.
Ngokusebenzisa le pateni, unokubonelela ngokuphathwa kwempazamo ethembekileyo kunye nesiqinisekiso sokuba iingxaki ebezingalindelekanga zisonjululwa ngobunono kwisicelo sakho.
39. Ungayiphatha njani idatha yexesha langempela kwisicelo se-MERN? Cacisa kwaye ubhale i-snippet yekhowudi usebenzisa i-Socket.IO okanye iteknoloji efanayo.
Ukusebenzisa izisombululo ezifana ne-Socket.IO, i-real-time data handling kwi-MERN (MongoDB, Express.js, React, Node.js) izicelo zingalawulwa ngokufanelekileyo.
Ngenxa yoko, umxhasi kunye nomncedisi unokunxibelelana kuwo omabini amacala kwaye afumane uhlaziyo olukhawulezileyo njengoko utshintsho lwedatha. Ungaseta isiseko kwiseva (Express.js) ngale ndlela ilandelayo:
40. Chaza kwaye uphumeze i-caching kwisicelo se-MERN ukwenza ngcono ukusebenza.
Ngokugcina idatha efunyenwe ngaphambili kunye nokwenza ukuba ifumaneke kwizicelo ezizayo, i-caching yindlela ebalulekileyo yokuphucula kwisicelo se-MERN esinokuphucula ngokukhawuleza isantya. Oku kunciphisa amaxesha omthwalo kwaye kukhulula iseva yoxinzelelo olungenasidingo. Ukusebenzisa ilayibrari yokugcina indawo efana neRedis kwi-Express.js backend yindlela eqhelekileyo yokugcina indawo.
Kuya kufuneka uqale uqwalasele iRedis njengevenkile yakho ye-cache:
Uya kugqiba ukuba ingaba idatha sele igcinwe ngexesha uphethe isicelo:
isiphelo
Ukuqukumbela, ukuqonda le mibuzo yodliwanondlebe ngobunzulu kunokunyusa kakhulu ubuchule bakho be-MERN Stack.
Ukuziqhelanisa akuphelelisi nje kuphela; kukwadala ulwazi olunzulu oluya kukwahlula kwishishini le-IT. Gcina ukhumbula ukuba amava asebenzayo kunye nokufunda okuqhubekayo ngamahlakani akho amakhulu njengoko uphonononga ezi ngcamango.
Kuyo nayiphi na incoko ye-MERN Stack okanye udliwano-ndlebe, ngokungathandabuzekiyo uya kugqama ukuba unolwazi kwaye uqinisekile.
Ngoncedo lokulungiselela udliwano-ndlebe, bona Uthotho lodliwano-ndlebe lweHashdork.
Shiya iMpendulo