Guida Tecnica: Gestione User con Parse in React

accesso e disaccesso utente per react introduzione dopo aver implementato un componente che gestisce la registrazione degli utenti in parse nell'ultima guida, ora imparerai come accedere e disconnettere gli utenti utilizzando la stessa parse user parse user classe il parse user login parse user login metodo memorizza nel tuo spazio di archiviazione locale una sessione utente valida, quindi le chiamate future a metodi come current current recupereranno con successo i dati del tuo utente d'altra parte, logout logout cancellerà questa sessione dal disco e disconnetterà da eventuali servizi collegati nel tuo server parse prerequisiti per completare questo tutorial, avrai bisogno di un'app react creata e collegata a back4app completa la guida precedente in modo da avere una migliore comprensione di la classe parse user se desideri testare/utilizzare il layout della schermata fornito da questa guida, dovresti configurare la ant design ant design libreria obiettivo costruire una funzionalità di accesso e disaccesso utente utilizzando parse per un'app react 1 comprendere i metodi login e logout la gestione degli utenti di parse utilizza il parse user parse user tipo di oggetto, che estende il default parseobject parseobject tipo mentre contiene metodi helper unici, come current current e getusername getusername , che ti aiuteranno a recuperare i dati dell'utente all'interno della tua app puoi leggere di più sul parse user parse user oggetto qui nella documentazione ufficiale https //parseplatform org/parse sdk js/api/master/parse user html in questa guida, imparerai come utilizzare i metodi login login e logout logout che gestiranno il processo di accesso dell'utente, salvando i dati dell'utente localmente 2 creazione di un componente di accesso costruiamo ora il userlogin userlogin componente nella tua app crea un nuovo file nella tua src src directory chiamato userlogin js userlogin js ( userlogin tsx userlogin tsx se stai usando typescript) e aggiungi gli elementi di input utilizzando gli state hooks per gestire i loro dati nota che c'è anche una funzione responsabile dell'aggiornamento di una variabile di stato con l'utente attualmente connesso, che utilizzerai in seguito userlogin js 1 import react, { usestate } from 'react'; 2 import parse from 'parse/dist/parse min js'; 3 import ' /app css'; 4 import { button, divider, input } from 'antd'; 5&#x9; 6 export const userlogin = () => { 7 // state variables 8 const \[username, setusername] = usestate(''); 9 const \[password, setpassword] = usestate(''); 10 const \[currentuser, setcurrentuser] = usestate(null); 11&#x9; 12 // function that will return current user and also update current username 13 const getcurrentuser = async function () { 14 const currentuser = await parse user current(); 15 // update state variable holding current user 16 setcurrentuser(currentuser); 17 return currentuser; 18 }; 19&#x9; 20 return ( 21 \<div> 22 \<div classname="header"> 23 \<img 24 classname="header logo" 25 alt="back4app logo" 26 src={ 27 'https //blog back4app com/wp content/uploads/2019/05/back4app white logo 500px png' 28 } 29 /> 30 \<p classname="header text bold">{'react on back4app'}\</p> 31 \<p classname="header text">{'user login'}\</p> 32 \</div> 33 \<div classname="container"> 34 \<h2 classname="heading">{'user login'}\</h2> 35 \<divider /> 36 \<div classname="form wrapper"> 37 \<input 38 value={username} 39 onchange={(event) => setusername(event target value)} 40 placeholder="username" 41 size="large" 42 classname="form input" 43 /> 44 \<input 45 value={password} 46 onchange={(event) => setpassword(event target value)} 47 placeholder="password" 48 size="large" 49 type="password" 50 classname="form input" 51 /> 52 \</div> 53 \<div classname="form buttons"> 54 \<button 55 onclick={() => douserlogin()} 56 type="primary" 57 classname="form button" 58 color={'#208aec'} 59 size="large" 60 block 61 > 62 log in 63 \</button> 64 \</div> 65 \<divider /> 66 \<div classname="login social"> 67 \<div classname="login social item login social item facebook"> 68 \<img classname="login social item image" src={'https //findicons com/files/icons/2830/clean social icons/250/facebook png'} alt=""/> 69 \</div> 70 \<div classname="login social item"> 71 \<img classname="login social item image" src={'data\ 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alt=""/> 72 \</div> 73 \<div classname="login social item"> 74 \<img classname="login social item image" src={'data\ 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alt=""/> 75 \</div> 76 \</div> 77 \<p classname="form hint">don't have an account? \<a classname="form link" href="#">sign up\</a>\</p> 78 \</div> 79 \</div> 80 ); 81 }; userlogin tsx 1 import react, { usestate, fc, reactelement } from 'react'; 2 import ' /app css'; 3 import { button, divider, input } from 'antd'; 4 const parse = require('parse/dist/parse min js'); 5&#x9; 6 export const userlogin fc<{}> = () reactelement => { 7 // state variables 8 const \[username, setusername] = usestate(''); 9 const \[password, setpassword] = usestate(''); 10 const \[currentuser, setcurrentuser] = usestate\<parse object | null>(null); 11&#x9; 12 // function that will return current user and also update current username 13 const getcurrentuser = async function () promise\<parse user | null> { 14 const currentuser (parse user | null) = await parse user current(); 15 // update state variable holding current user 16 setcurrentuser(currentuser); 17 return currentuser; 18 } 19&#x9; 20 return ( 21 \<div> 22 \<div classname="header"> 23 \<img 24 classname="header logo" 25 alt="back4app logo" 26 src={ 27 'https //blog back4app com/wp content/uploads/2019/05/back4app white logo 500px png' 28 } 29 /> 30 \<p classname="header text bold">{'react on back4app'}\</p> 31 \<p classname="header text">{'user login'}\</p> 32 \</div> 33 \<div classname="container"> 34 \<h2 classname="heading">{'user login'}\</h2> 35 \<divider /> 36 \<div classname="form wrapper"> 37 \<input 38 value={username} 39 onchange={(event) => setusername(event target value)} 40 placeholder="username" 41 size="large" 42 classname="form input" 43 /> 44 \<input 45 value={password} 46 onchange={(event) => setpassword(event target value)} 47 placeholder="password" 48 size="large" 49 type="password" 50 classname="form input" 51 /> 52 \</div> 53 \<div classname="form buttons"> 54 \<button 55 onclick={() => douserlogin()} 56 type="primary" 57 classname="form button" 58 color={'#208aec'} 59 size="large" 60 block 61 > 62 log in 63 \</button> 64 \</div> 65 \<divider /> 66 \<div classname="login social"> 67 \<div classname="login social item login social item facebook"> 68 \<img classname="login social item image" src={'https //findicons com/files/icons/2830/clean social icons/250/facebook png'} alt=""/> 69 \</div> 70 \<div classname="login social item"> 71 \<img classname="login social item image" src={'data\ image/png;base64,ivborw0kggoaaaansuheugaaan8aaadicamaaad5w+jtaaabwvbmvex////qqzu0qfnchft7vauufppk7f08gvr0o/zzofb7uqd7uadpncp/vqdqpzaspk7plhrpoysyoklpoyzpnst97ovwgnskpensxfh8wgavouhplrj+9/b0pad4xsoix5fd7+h74udvenlru0f61tt1r6vuc2vtzvvxiop5zsvpnjb93p4nefofrpeqxpnk5dbus2zt9u++0vtuvyfelfwq1rt2u7j86ejyl5hrsz7/9+x80nt94637xdx8yu//+/d93jb+785sjvwdu/j+9nzc1fvv9p7a5v1frmdl8+nd4spru34zqklohwd0qktwhnpwdjf1ly/5ssl82ibuzjjyidl3pyfswdjwezb1mi7vazn8zwh+68l7wjdq04okszlurkrfuig7tjkgsersq1dsusqateq4o31kk9pjnrq/qmrijuvjmcrho5uyzqvkmmtioqjbqhlesjcm1x3qaaaltuleqvr4no2c2x/a2bwafrnibattyiiwmnusm46begyczdy7ctc47iztdkbjdj1u09ad9v9/qcqeskdlbrpx4pfvys9y+nzovefcbxpcb0hrlh+en9cnzg/lrn+fhieto+nuo9pmlqzkbezpyqhrrzz1zporwm4ddwuilauakhpfb5uiuzyicblsbfsodlm/kysgwv6izihta3l4kkip1670khljvqwjyvooqm2biak1j7f3lb81nbkkap6rnalzpo5vrpbp2okqq3nbowpyiz6kvqa23fkx1dmlwak2jgozovtrkpmt1k5rjguyqk5ugsi3z1h7wrxoza1xqglgflqk8zq975ip3rpn6dkda+r5esfr54vsymd4mjcjtrmmhs6tlc1pshfmpstqnta3vbmo2zloiuw5thch0lmzkqsu6+fhw46kigqhynlasxpmslubr8kd0ba77fboztvyi/oqhtoocx4ossqhlldldnympxyuei2rylhwrmnwi9orlkhpm9uipahqyzvzxojgjirhzx8wz80lspn8z30kxca3l4haj7dexym1k5vsmvg9ceoysm0vsao2yjkzrbfizjedjbxojkt1crgzojeq1cs3d1ypyt/tjddybb0dh3seo8d14qdhmnqn+bugktgb7hzzp45du0y0er2ytdseo3e+28njxcrovwdbvq8rt8pavq8st7mfrf6l9nwi5hrnewtbvh4mcbrs9r/ceuuh5aafmnpkktbjt+7ojnqtvr3e6h2d3xu7ykkgur8vgr65wacicjn/3pi8nijxzyyfsntohpxoiaw+uzhfbtjvwhkr0iyf3b8grhdiyvapcqecujn+fhd8f4awhtfbxvkjgjkboiaotxtf/vwitrlhidtfuybwrhbu8l5rqjp6zcy+tjq7iefl9bbh2slp6hftrowus6h2jvx25gkv6ehxpazsfaqybwotgit9iothtdwkrmdt/exzz6xk9e4wrh+h4/9yfplc5pxk6bsuoxjn/z0lf40e10vuziq2wbsbzfoooai99m6f6hevzx71r6dh5rfrgygsvx3wi0dvhle2rheehgw/rasf8ryjil5kvvwira/l+subezl58hw8odxh/d6afjzjpz58fqgrv2h93qb8y/gz/byqhimjhsct9fjqozqyscdxr2w/mbxv2qzfgpxpumt+brzcscn6pcf5fedwe/jrieetgwxd4mum5rt8fkbpjtfx2ejx6rmcb78jc6gqmmpg8oogtufyjuy6rn8zhk839qzb7wmfkzt4ubdb4qvlutke364e5fxgw8/goz/bzgwnv3og56iqpoy0wmsfwa8vvay1jm2d/ulp4beofb+wfmm43gxoetxcmpvvcpejkhwedbdyyp3cchzhvr1cubefmulvh0tm58hxs200m0kln2tp5cf47tphhysnpv/q4gk5kbqvwl8wjohdz5wjja7bqpixwpymhluezeb/9aksd4b+i4y7l5wtjrtao8vwu48stwo38vwb+qp+n7dwjopew/ilut/gpe0hjdzpdk/utg7e4/k9p0nt4ott6okvofwyehrc4/09gqrpv08e6f4cfjomv/2nywd+bqwx+tgzfnuxkz+o6exgdul89q/tbwj2z8v4yepr80svj5j3unplj4nxe2y/elt7xiqps/przm8r+4fq5sgdwf0o+j2yhxi4t7qj9vrcz285gfpt7xr74epr89tl2w+e0uulkun3co3ghz19uoyf3wldll/muwt5lqogvpucxx4o+r1b8ps8qx6lag+1esfurin67z/uun+igxkn5ffqg98hvw9+bp12fx7zdb+dre/lbe7o9mench5j6q9tp7rbs9t7z51d39rrb7jt+qpss1va6z/w01vllzh7s6v1o9z+ihydq8/p3n+bov5lzv7u3on9wmc7g1skzn9+b99+4i6er6z2d3f1fozx0g9glznnm+sd3b+gbbnypr3cxuigc2bs7hes2hfa90oon99c3u/j/i4hfsvzd7gvfpb3pkzfeh8zkmh1iyhsun/g1t6w39xjr8ha2k3kawdxwpn9i8/zuhxld4c0hn/v+moge4yrmyyqk703eh6r6xmcaiewzf7z0up1mso/k4gbuj4+ae+xw7m5ymri7xjcb3x6bggwhm/+aawho8og8hbm+d13fjj0ak5y00iampe7rzxewgdg9ocfesdsavgczvg9c300oh7o3gqxwgui8k02x2ycwuxs9q/8juqmvh9mejq7f5oapyps6sctpqp6fjcz53rxt8c/qmt/4mxhoabcfpfn4effotkti4fgklif1lrj5hrj096xqm122gdptlfv7qlmel5uftxzk8nrsmxdeyp5bbm+d/wz8ehq39xkkkfvoszpz/nps/x/ndwti1eg0iycmlv9vbxrzgmabuamnah05tbnuohbra4w7mowrzbfu5bamwzj55me7nswobljeqg+hdyt8vwl60xszjvti0rnjqhv2n3s09gj+bqsnoi05phryoh5pie3ngg82umadb1f7wc3dzq+wbwb9f/5alowb8hid9oewmwn85t/bswmgyi3bdsibegwrxvojetnxmzcwhyggs9g+k6t1fdytnkbmzs2uy5byklzz392mrljkh68htlaal7pd3yxuvgr/iw6ge2hh05oj5wtiypaahljiqjvu4kpnk/vsmryrppj+sl5zvsrgp5vcbcp6qic6pxsjj68rdkityf81igyhy/pjff0p2kkvzdwcdwyxzbxr6rcep0yzejthyw+iym6nxfcmqnw9jek5aqih8f1ewveap3ht9laqnx5vymfeotxixb5jeqghmv3my+al3d7d3jb4nq3bgokszduaxox7i9u+897+789ybx1n/n5m8bk0iuh2jgct9v18ug//rno8csg83qxx8tq01bxqzviosn0uuvb0u2/yhluz1vcgyfuak23u6dv8dydvxl1+696+2+ioz3+677tp5eqnbxv0ewm9gn98byoe6fm7x+bcwvibviboyc6fhv1ohr3fsshtxf1ikk+ctbnjcbcatq52bdssx11vr2mqupzrn+v1wr9fn82vq/op2rruav7s97+dnspbrxih9fhxkj4suqgpufpyfwulrysbglmollt5j7mecsbfn7mqgancx6riez4odghnztx8perdcsuj2/cdbza3yyjhmbmjr19xasc8tkgb0n/j1+oigy+bdinkffuf/bjuztbt6aal0hvzga4rfzghllwiotnoqbb9pkxj5wguerdcchi3ljiekmqwzvnjhvvmwzefpkxjzegusgcoer8fscocdqbgetk4cjmkbpuzravmsekxmus4w9/so7ksenfbhy1fltgm7n/ivzxt4hxhestvs+x6jneq5phze1rknrgejdozxyur+kzgf0g6krxz+mmpgveca6ltebxgisshtw9zhecbqee0wunkxr7hfwjvde3ypujuusxopnoo/o0/dgdlyg7aazi56vnyzyh1hla99mhi4/duoiror5o6qi/pdxx69mart3otfkkhjqd76qpq0vkssovq7s/jwdxq2uysusufuftg0udq6k4qrgymzfigoe4ngixfuepm7zxi6qhulplbmcxhpafijlk37p2wlorsiqvjv2dm/ikfsbb96uq0yvtmbmpm4jzhhsomhec7musrfyzjxt0mep6ctcox5qsqo1+gobobi6vzmkzltsma+prfot2lwvmqbwnvycbepfi2b9xb7x5g0vy9lsubbndwaa6zvmpgygwrm3g1dfgkqnforrc+jm3rtzvepkriayhnzc1i5sdsmlk/whcjdwqyatpyaaaaabjru5erkjggg=='} alt=""/> 72 \</div> 73 \<div classname="login social item"> 74 \<img classname="login social item image" src={'data\ 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alt=""/> 75 \</div> 76 \</div> 77 \<p classname="form hint">don't have an account? \<a classname="form link" href="#">sign up\</a>\</p> 78 \</div> 79 \</div> 80 ); 81 }; ora puoi implementare la funzione che chiamerà il parse user login parse user login metodo, utilizzando variabili di stato javascript 1 const douserlogin = async function () { 2 // note that these values come from state variables that we've declared before 3 const usernamevalue = username; 4 const passwordvalue = password; 5 try { 6 const loggedinuser = await parse user login(usernamevalue, passwordvalue); 7 // login returns the corresponding parseuser object 8 alert( 9 `success! user ${loggedinuser get( 10 'username' 11 )} has successfully signed in!` 12 ); 13 // to verify that this is in fact the current user, `current` can be used 14 const currentuser = await parse user current(); 15 console log(loggedinuser === currentuser); 16 // clear input fields 17 setusername(''); 18 setpassword(''); 19 // update state variable holding current user 20 getcurrentuser(); 21 return true; 22 } catch (error) { 23 // error can be caused by wrong parameters or lack of internet connection 24 alert(`error! ${error message}`); 25 return false; 26 } 27 };1 const douserlogin = async function () promise\<boolean> { 2 // note that these values come from state variables that we've declared before 3 const usernamevalue string = username; 4 const passwordvalue string = password; 5 try { 6 const loggedinuser parse user = await parse user login(usernamevalue, passwordvalue); 7 // login returns the corresponding parseuser object 8 alert( 9 `success! user ${loggedinuser get('username')} has successfully signed in!`, 10 ); 11 // to verify that this is in fact the current user, `current` can be used 12 const currentuser parse user = await parse user current(); 13 console log(loggedinuser === currentuser); 14 // clear input fields 15 setusername(''); 16 setpassword(''); 17 // update state variable holding current user 18 getcurrentuser(); 19 return true; 20 } catch (error any) { 21 // error can be caused by wrong parameters or lack of internet connection 22 alert(`error! ${error message}`); 23 return false; 24 } 25 }; inserisci questa funzione all'interno del userlogin userlogin componente, appena prima della return return chiamata, per essere chiamata e testata ricorda di aggiornare l'azione del pulsante di accesso del modulo onclick onclick a () => douserlogin() () => douserlogin() se vuoi rendere completamente questo layout della schermata, aggiungi queste classi al tuo app css app css file app css 1 @import ' antd/dist/antd css'; 2&#x9; 3 app { 4 text align center; 5 } 6&#x9; 7 html { 8 box sizing border box; 9 outline none; 10 overflow auto; 11 } 12&#x9; 13 , 14 before, 15 after { 16 margin 0; 17 padding 0; 18 box sizing inherit; 19 } 20&#x9; 21 h1, 22 h2, 23 h3, 24 h4, 25 h5, 26 h6 { 27 margin 0; 28 font weight bold; 29 } 30&#x9; 31 p { 32 margin 0; 33 } 34&#x9; 35 body { 36 margin 0; 37 background color #fff; 38 } 39&#x9; 40 container { 41 width 100%; 42 max width 900px; 43 margin auto; 44 padding 20px 0; 45 text align left; 46 } 47&#x9; 48 header { 49 align items center; 50 padding 25px 0; 51 background color #208aec; 52 } 53&#x9; 54 header logo { 55 height 55px; 56 margin bottom 20px; 57 object fit contain; 58 } 59&#x9; 60 header text bold { 61 margin bottom 3px; 62 color rgba(255, 255, 255, 0 9); 63 font size 16px; 64 font weight bold; 65 } 66&#x9; 67 header text { 68 color rgba(255, 255, 255, 0 9); 69 font size 15px; 70 } 71&#x9; 72 heading { 73 font size 22px; 74 } 75&#x9; 76 flex { 77 display flex; 78 } 79&#x9; 80 flex between { 81 display flex; 82 justify content space between; 83 } 84&#x9; 85 flex child { 86 flex 0 0 45%; 87 } 88&#x9; 89 heading button { 90 margin left 12px; 91 } 92&#x9; 93 list item { 94 padding bottom 15px; 95 margin bottom 15px; 96 border bottom 1px solid rgba(0, 0, 0, 0 06); 97 text align left; 98 } 99&#x9; 100 list item title { 101 color rgba(0, 0, 0, 0 87); 102 font size 17px; 103 } 104&#x9; 105 list item description { 106 color rgba(0, 0, 0, 0 5); 107 font size 15px; 108 } 109&#x9; 110 form input { 111 margin bottom 20px; 112 } 113&#x9; 114 login social { 115 display flex; 116 justify content center; 117 margin bottom 30px; 118 } 119&#x9; 120 login social item { 121 width 54px; 122 height 54px; 123 border radius 54px; 124 padding 12px; 125 margin 0 12px; 126 border 1px solid #e6e6e6; 127 box shadow 0 2px 4px #d6d6d6; 128 } 129&#x9; 130 login social item facebook { 131 padding 4px; 132 background color #3c5b9b; 133 } 134&#x9; 135 login social item image { 136 width 100%; 137 } 138&#x9; 139 form hint { 140 color rgba(0, 0, 0, 0 5); 141 font size 16px; 142 text align center; 143 } procedi e avvia la tua applicazione, importando questo componente di accesso nel tuo file principale dell'applicazione dovresti vedere uno schermo proprio come questo e anche un messaggio di successo dopo aver effettuato l'accesso con le credenziali corrette 3 controllo dell'utente connesso dopo che il tuo utente ha effettuato con successo l'accesso all'applicazione, dovrebbe essere in grado di saperlo e anche di disconnettersi dall'applicazione prima, nascondiamo il modulo di accesso e visualizziamo un messaggio di benvenuto contenente il nome utente nota l'uso dell'operatore condizionale in combinazione con la variabile di stato che contiene il nome utente attuale userlogin js 1 // your imports 2 export const userlogin = () => { 3 // state variables and functions 4&#x9; 5 return ( 6 \<div> 7 \<div classname="header"> 8 \<img 9 classname="header logo" 10 alt="back4app logo" 11 src={ 12 'https //blog back4app com/wp content/uploads/2019/05/back4app white logo 500px png' 13 } 14 /> 15 \<p classname="header text bold">{'react on back4app'}\</p> 16 \<p classname="header text">{'user login'}\</p> 17 \</div> 18 {currentuser === null && ( 19 \<div classname="container"> 20 \<h2 classname="heading">{'user login'}\</h2> 21 \<divider /> 22 \<div classname="form wrapper"> 23 \<input 24 value={username} 25 onchange={(event) => setusername(event target value)} 26 placeholder="username" 27 size="large" 28 classname="form input" 29 /> 30 \<input 31 value={password} 32 onchange={(event) => setpassword(event target value)} 33 placeholder="password" 34 size="large" 35 type="password" 36 classname="form input" 37 /> 38 \</div> 39 \<div classname="form buttons"> 40 \<button 41 onclick={() => douserlogin()} 42 type="primary" 43 classname="form button" 44 color={'#208aec'} 45 size="large" 46 block 47 > 48 log in 49 \</button> 50 \</div> 51 \<divider /> 52 \<div classname="login social"> 53 \<div classname="login social item login social item facebook"> 54 \<img classname="login social item image" src={'https //findicons com/files/icons/2830/clean social icons/250/facebook png'} alt=""/> 55 \</div> 56 \<div classname="login social item"> 57 \<img classname="login social item image" src={'data\ image/png;base64,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'} alt=""/> 58 \</div> 59 \<div classname="login social item"> 60 \<img classname="login social item image" src={'data\ 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alt=""/> 61 \</div> 62 \</div> 63 \<p classname="form hint">don't have an account? \<a classname="form link" href="#">sign up\</a>\</p> 64 \</div> 65 )} 66 {currentuser !== null && 67 (\<div classname="container"> 68 \<h2 classname="heading">{'user screen'}\</h2> 69 \<divider /> 70 \<h2 classname="heading">{`hello ${currentuser get('username')}!`}\</h2> 71 \<div classname="form buttons"> 72 \<button 73 onclick={() => {}} 74 type="primary" 75 classname="form button" 76 color={'#208aec'} 77 size="large" 78 > 79 log out 80 \</button> 81 \</div> 82 \</div>) 83 } 84 \</div> 85 ); 86 }; userlogin tsx 1 // your imports 2 export const userlogin fc<{}> = () reactelement => { 3 // state variables and functions 4 5 return ( 6 \<div> 7 \<div classname="header"> 8 \<img 9 classname="header logo" 10 alt="back4app logo" 11 src={ 12 'https //blog back4app com/wp content/uploads/2019/05/back4app white logo 500px png' 13 } 14 /> 15 \<p classname="header text bold">{'react on back4app'}\</p> 16 \<p classname="header text">{'user login'}\</p> 17 \</div> 18 {currentuser === null && ( 19 \<div classname="container"> 20 \<h2 classname="heading">{'user login'}\</h2> 21 \<divider /> 22 \<div classname="form wrapper"> 23 \<input 24 value={username} 25 onchange={(event) => setusername(event target value)} 26 placeholder="username" 27 size="large" 28 classname="form input" 29 /> 30 \<input 31 value={password} 32 onchange={(event) => setpassword(event target value)} 33 placeholder="password" 34 size="large" 35 type="password" 36 classname="form input" 37 /> 38 \</div> 39 \<div classname="form buttons"> 40 \<button 41 onclick={() => douserlogin()} 42 type="primary" 43 classname="form button" 44 color={'#208aec'} 45 size="large" 46 block 47 > 48 log in 49 \</button> 50 \</div> 51 \<divider /> 52 \<div classname="login social"> 53 \<div classname="login social item login social item facebook"> 54 \<img classname="login social item image" src={'https //findicons com/files/icons/2830/clean social icons/250/facebook png'} alt=""/> 55 \</div> 56 \<div classname="login social item"> 57 \<img classname="login social item image" src={'data\ image/png;base64,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'} alt=""/> 58 \</div> 59 \<div classname="login social item"> 60 \<img classname="login social item image" src={'data\ image/png;base64,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'} alt=""/> 61 \</div> 62 \</div> 63 \<p classname="form hint">don't have an account? \<a classname="form link" href="#">sign up\</a>\</p> 64 \</div> 65 )} 66 {currentuser !== null && 67 (\<div classname="container"> 68 \<h2 classname="heading">{'user screen'}\</h2> 69 \<divider /> 70 \<h2 classname="heading">{`hello ${currentuser get('username')}!`}\</h2> 71 \<div classname="form buttons"> 72 \<button 73 onclick={() => {}} 74 type="primary" 75 classname="form button" 76 color={'#208aec'} 77 size="large" 78 > 79 log out 80 \</button> 81 \</div> 82 \</div>) 83 } 84 \</div> 85 ); 86 }; procedi e riavvia la tua app nota che la tua app mostrerà ora la schermata utente e il messaggio di benvenuto proprio come questo 4 creare una funzione di disconnessione il logout logout metodo è più semplice del login poiché il parse user logout parse user logout metodo non richiede argomenti e cancella automaticamente i dati di currentuser currentuser memorizzati localmente crea questa funzione nel userlogin userlogin componente e chiamala nell' onclick onclick attributo del pulsante di logout userlogout js 1 const douserlogout = async function () { 2 try { 3 await parse user logout(); 4 // to verify that current user is now empty, currentasync can be used 5 const currentuser = await parse user current(); 6 if (currentuser === null) { 7 alert('success! no user is logged in anymore!'); 8 } 9 // update state variable holding current user 10 getcurrentuser(); 11 return true; 12 } catch (error) { 13 alert(`error! ${error message}`); 14 return false; 15 } 16 }; userlogout tsx 1 const douserlogout = async function () promise\<boolean> { 2 try { 3 await parse user logout(); 4 // to verify that current user is now empty, currentasync can be used 5 const currentuser parse user = await parse user current(); 6 if (currentuser === null) { 7 alert('success! no user is logged in anymore!'); 8 } 9 // update state variable holding current user 10 getcurrentuser(); 11 return true; 12 } catch (error any) { 13 alert(`error! ${error message}`); 14 return false; 15 } 16 }; se esegui un logout con successo, vedrai un messaggio come questo ecco il codice completo del componente contenente tutte le funzioni mostrate prima userlogin js 1 import react, { usestate } from 'react'; 2 import parse from 'parse/dist/parse min js'; 3 import ' /app css'; 4 import { button, divider, input } from 'antd'; 5&#x9; 6 export const userlogin = () => { 7 // state variables 8 const \[username, setusername] = usestate(''); 9 const \[password, setpassword] = usestate(''); 10 const \[currentuser, setcurrentuser] = usestate(null); 11&#x9; 12 const douserlogin = async function () { 13 // note that these values come from state variables that we've declared before 14 const usernamevalue = username; 15 const passwordvalue = password; 16 try { 17 const loggedinuser = await parse user login(usernamevalue, passwordvalue); 18 // login returns the corresponding parseuser object 19 alert( 20 `success! user ${loggedinuser get( 21 'username' 22 )} has successfully signed in!` 23 ); 24 // to verify that this is in fact the current user, `current` can be used 25 const currentuser = await parse user current(); 26 console log(loggedinuser === currentuser); 27 // clear input fields 28 setusername(''); 29 setpassword(''); 30 // update state variable holding current user 31 getcurrentuser(); 32 return true; 33 } catch (error) { 34 // error can be caused by wrong parameters or lack of internet connection 35 alert(`error! ${error message}`); 36 return false; 37 } 38 }; 39&#x9; 40 const douserlogout = async function () { 41 try { 42 await parse user logout(); 43 // to verify that current user is now empty, currentasync can be used 44 const currentuser = await parse user current(); 45 if (currentuser === null) { 46 alert('success! no user is logged in anymore!'); 47 } 48 // update state variable holding current user 49 getcurrentuser(); 50 return true; 51 } catch (error) { 52 alert(`error! ${error message}`); 53 return false; 54 } 55 }; 56&#x9; 57 // function that will return current user and also update current username 58 const getcurrentuser = async function () { 59 const currentuser = await parse user current(); 60 // update state variable holding current user 61 setcurrentuser(currentuser); 62 return currentuser; 63 }; 64&#x9; 65 return ( 66 \<div> 67 \<div classname="header"> 68 \<img 69 classname="header logo" 70 alt="back4app logo" 71 src={ 72 'https //blog back4app com/wp content/uploads/2019/05/back4app white logo 500px png' 73 } 74 /> 75 \<p classname="header text bold">{'react on back4app'}\</p> 76 \<p classname="header text">{'user login'}\</p> 77 \</div> 78 {currentuser === null && ( 79 \<div classname="container"> 80 \<h2 classname="heading">{'user login'}\</h2> 81 \<divider /> 82 \<div classname="form wrapper"> 83 \<input 84 value={username} 85 onchange={(event) => setusername(event target value)} 86 placeholder="username" 87 size="large" 88 classname="form input" 89 /> 90 \<input 91 value={password} 92 onchange={(event) => setpassword(event target value)} 93 placeholder="password" 94 size="large" 95 type="password" 96 classname="form input" 97 /> 98 \</div> 99 \<div classname="form buttons"> 100 \<button 101 onclick={() => douserlogin()} 102 type="primary" 103 classname="form button" 104 color={'#208aec'} 105 size="large" 106 block 107 > 108 log in 109 \</button> 110 \</div> 111 \<divider /> 112 \<div classname="login social"> 113 \<div classname="login social item login social item facebook"> 114 \<img classname="login social item image" src={'https //findicons com/files/icons/2830/clean social icons/250/facebook png'} alt=""/> 115 \</div> 116 \<div classname="login social item"> 117 \<img classname="login social item image" src={'data\ image/png;base64,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'} alt=""/> 118 \</div> 119 \<div classname="login social item"> 120 \<img classname="login social item image" src={'data\ 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alt=""/> 121 \</div> 122 \</div> 123 \<p classname="form hint">don't have an account? \<a classname="form link" href="#">sign up\</a>\</p> 124 \</div> 125 )} 126 {currentuser !== null && ( 127 \<div classname="container"> 128 \<h2 classname="heading">{'user screen'}\</h2> 129 \<divider /> 130 \<h2 classname="heading">{`hello ${currentuser get('username')}!`}\</h2> 131 \<div classname="form buttons"> 132 \<button 133 onclick={() => douserlogout()} 134 type="primary" 135 classname="form button" 136 color={'#208aec'} 137 size="large" 138 > 139 log out 140 \</button> 141 \</div> 142 \</div> 143 )} 144 \</div> 145 ); 146 }; userlogin tsx 1 import react, { usestate, fc, reactelement } from 'react'; 2 import ' /app css'; 3 import { button, divider, input } from 'antd'; 4 const parse = require('parse/dist/parse min js'); 5&#x9; 6 export const userlogin fc<{}> = () reactelement => { 7 // state variables 8 const \[username, setusername] = usestate(''); 9 const \[password, setpassword] = usestate(''); 10 const \[currentuser, setcurrentuser] = usestate\<parse object | null>(null); 11&#x9; 12 const douserlogin = async function () promise\<boolean> { 13 // note that these values come from state variables that we've declared before 14 const usernamevalue string = username; 15 const passwordvalue string = password; 16 try { 17 const loggedinuser parse user = await parse user login(usernamevalue, passwordvalue); 18 // login returns the corresponding parseuser object 19 alert( 20 `success! user ${loggedinuser get('username')} has successfully signed in!`, 21 ); 22 // to verify that this is in fact the current user, `current` can be used 23 const currentuser parse user = await parse user current(); 24 console log(loggedinuser === currentuser); 25 // clear input fields 26 setusername(''); 27 setpassword(''); 28 // update state variable holding current user 29 getcurrentuser(); 30 return true; 31 } catch (error any) { 32 // error can be caused by wrong parameters or lack of internet connection 33 alert(`error! ${error message}`); 34 return false; 35 } 36 }; 37&#x9; 38 const douserlogout = async function () promise\<boolean> { 39 try { 40 await parse user logout(); 41 // to verify that current user is now empty, currentasync can be used 42 const currentuser parse user = await parse user current(); 43 if (currentuser === null) { 44 alert('success! no user is logged in anymore!'); 45 } 46 // update state variable holding current user 47 getcurrentuser(); 48 return true; 49 } catch (error any) { 50 alert(`error! ${error message}`); 51 return false; 52 } 53 }; 54&#x9; 55 // function that will return current user and also update current username 56 const getcurrentuser = async function () promise\<parse user | null> { 57 const currentuser (parse user | null) = await parse user current(); 58 // update state variable holding current user 59 setcurrentuser(currentuser); 60 return currentuser; 61 } 62&#x9; 63 return ( 64 \<div> 65 \<div classname="header"> 66 \<img 67 classname="header logo" 68 alt="back4app logo" 69 src={ 70 'https //blog back4app com/wp content/uploads/2019/05/back4app white logo 500px png' 71 } 72 /> 73 \<p classname="header text bold">{'react on back4app'}\</p> 74 \<p classname="header text">{'user login'}\</p> 75 \</div> 76 {currentuser === null && ( 77 \<div classname="container"> 78 \<h2 classname="heading">{'user login'}\</h2> 79 \<divider /> 80 \<div classname="form wrapper"> 81 \<input 82 value={username} 83 onchange={(event) => setusername(event target value)} 84 placeholder="username" 85 size="large" 86 classname="form input" 87 /> 88 \<input 89 value={password} 90 onchange={(event) => setpassword(event target value)} 91 placeholder="password" 92 size="large" 93 type="password" 94 classname="form input" 95 /> 96 \</div> 97 \<div classname="form buttons"> 98 \<button 99 onclick={() => douserlogin()} 100 type="primary" 101 classname="form button" 102 color={'#208aec'} 103 size="large" 104 block 105 > 106 log in 107 \</button> 108 \</div> 109 \<divider /> 110 \<div classname="login social"> 111 \<div classname="login social item login social item facebook"> 112 \<img classname="login social item image" src={'https //findicons com/files/icons/2830/clean social icons/250/facebook png'} alt=""/> 113 \</div> 114 \<div classname="login social item"> 115 \<img classname="login social item image" src={'data\ 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alt=""/> 116 \</div> 117 \<div classname="login social item"> 118 \<img classname="login social item image" src={'data\ 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alt=""/> 119 \</div> 120 \</div> 121 \<p classname="form hint">don't have an account? \<a classname="form link" href="#">sign up\</a>\</p> 122 \</div> 123 )} 124 {currentuser !== null && 125 (\<div classname="container"> 126 \<h2 classname="heading">{'user screen'}\</h2> 127 \<divider /> 128 \<h2 classname="heading">{`hello ${currentuser get('username')}!`}\</h2> 129 \<div classname="form buttons"> 130 \<button 131 onclick={() => douserlogout()} 132 type="primary" 133 classname="form button" 134 color={'#208aec'} 135 size="large" 136 > 137 log out 138 \</button> 139 \</div> 140 \</div>) 141 } 142 \</div> 143 ); 144 }; conclusione alla fine di questa guida, hai imparato come accedere e disconnettere gli utenti di parse su react nella prossima guida, ti mostreremo come eseguire query utili sugli utenti