React에서 Parse를 사용한 사용자 로그인 및 로그아웃 구현
리액트를 위한 사용자 로그인 및 로그아웃
소개
지난 가이드에서 Parse에서 사용자 등록을 처리하는 컴포넌트를 구현한 후, 이제 동일한 Parse.User 클래스를 사용하여 사용자 로그인 및 로그아웃하는 방법을 배우게 됩니다.
Parse.User.logIn 메서드는 유효한 사용자 세션을 로컬 스토리지에 저장하므로, current 와 같은 메서드에 대한 향후 호출이 사용자 데이터를 성공적으로 검색할 수 있습니다. 반면에, logOut 는 이 세션을 디스크에서 지우고 Parse 서버의 모든 연결된 서비스에서 로그아웃합니다.
전제 조건
이 튜토리얼을 완료하려면 다음이 필요합니다:
목표
리액트 앱을 위한 사용자 로그인 및 로그아웃 기능을 구축하는 것입니다.
1 - logIn 및 logOut 메서드 이해하기
Parse 사용자 관리는 Parse.User 객체 유형을 사용하며, 이는 기본 ParseObject 유형을 확장하면서 current 및 getUsername, 같은 고유한 도우미 메서드를 포함하여 앱 전반에 걸쳐 사용자 데이터를 검색하는 데 도움을 줍니다. Parse.User 객체에 대해 더 읽으려면 여기 공식 문서에서.
이 가이드에서는 logIn 및 logOut 메서드를 사용하는 방법을 배우게 되며, 이는 사용자 로그인 프로세스를 처리하고 사용자 데이터를 로컬에 저장합니다.
2 - 로그인 컴포넌트 만들기
이제 앱에서 UserLogIn 컴포넌트를 만들어 보겠습니다. src 디렉토리에 UserLogIn.js 파일을 생성하세요 (UserLogIn.tsx TypeScript를 사용하는 경우) 그리고 상태 훅을 사용하여 입력 요소를 추가하여 데이터를 관리합니다. 현재 로그인한 사용자로 상태 변수를 업데이트하는 함수도 있으며, 나중에 사용할 것입니다:
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
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
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
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,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'} alt=""/>
72 </div>
73 <div className="login-social-item">
74 <img className="login-social-item__image" src={'data:image/png;base64,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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 };이제 상태 변수를 사용하여 Parse.User.logIn 메서드를 호출하는 함수를 구현할 수 있습니다:
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 };이 함수를 UserLogIn 컴포넌트 안에 삽입하고, return 호출 바로 전에 호출하고 테스트하세요. 폼의 로그인 버튼 onClick 액션을 () => doUserLogIn(). 이 화면 레이아웃을 완전히 렌더링하려면, 다음 클래스를 App.css 파일에 추가하세요:
1 @import '~antd/dist/antd.css';
2
3 .App {
4 text-align: center;
5 }
6
7 html {
8 box-sizing: border-box;
9 outline: none;
10 overflow: auto;
11 }
12
13 *,
14 *:before,
15 *:after {
16 margin: 0;
17 padding: 0;
18 box-sizing: inherit;
19 }
20
21 h1,
22 h2,
23 h3,
24 h4,
25 h5,
26 h6 {
27 margin: 0;
28 font-weight: bold;
29 }
30
31 p {
32 margin: 0;
33 }
34
35 body {
36 margin: 0;
37 background-color: #fff;
38 }
39
40 .container {
41 width: 100%;
42 max-width: 900px;
43 margin: auto;
44 padding: 20px 0;
45 text-align: left;
46 }
47
48 .header {
49 align-items: center;
50 padding: 25px 0;
51 background-color: #208AEC;
52 }
53
54 .header_logo {
55 height: 55px;
56 margin-bottom: 20px;
57 object-fit: contain;
58 }
59
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
67 .header_text {
68 color: rgba(255, 255, 255, 0.9);
69 font-size: 15px;
70 }
71
72 .heading {
73 font-size: 22px;
74 }
75
76 .flex {
77 display: flex;
78 }
79
80 .flex_between {
81 display: flex;
82 justify-content: space-between;
83 }
84
85 .flex_child {
86 flex: 0 0 45%;
87 }
88
89 .heading_button {
90 margin-left: 12px;
91 }
92
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
100 .list_item_title {
101 color: rgba(0, 0, 0, 0.87);
102 font-size: 17px;
103 }
104
105 .list_item_description {
106 color: rgba(0, 0, 0, 0.5);
107 font-size: 15px;
108 }
109
110 .form_input {
111 margin-bottom: 20px;
112 }
113
114 .login-social {
115 display: flex;
116 justify-content: center;
117 margin-bottom: 30px;
118 }
119
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
130 .login-social-item--facebook {
131 padding: 4px;
132 background-color: #3C5B9B;
133 }
134
135 .login-social-item__image {
136 width: 100%;
137 }
138
139 .form__hint {
140 color: rgba(0, 0, 0, 0.5);
141 font-size: 16px;
142 text-align: center;
143 }애플리케이션을 실행하고 이 로그인 컴포넌트를 메인 애플리케이션 파일에 가져오세요. 이렇게 생긴 화면과 올바른 자격 증명으로 로그인한 후 성공 메시지를 볼 수 있어야 합니다:

3 - 로그인한 사용자 확인
사용자가 애플리케이션에 성공적으로 로그인한 후, 그 사실을 알 수 있어야 하며 애플리케이션에서 로그아웃할 수 있어야 합니다. 먼저 로그인 양식을 숨기고 사용자 이름이 포함된 환영 메시지를 렌더링합시다. 현재 사용자 이름을 보유하고 있는 상태 변수와 함께 조건부 연산자의 사용에 주목하세요.
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 };앱을 다시 실행해 보세요. 이제 앱이 사용자 화면과 환영 메시지를 다음과 같이 표시할 것입니다:

4 - 로그아웃 기능 만들기
로그아웃 logOut 메서드는 로그인보다 간단합니다. 왜냐하면 Parse.User.logOut 메서드는 인수를 받지 않고 currentUser 로컬에 저장된 데이터를 자동으로 지우기 때문입니다. 이 함수를 UserLogin 컴포넌트에 생성하고 로그아웃 버튼의 onClick 속성에서 호출하세요:
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 };성공적으로 로그아웃하면 다음과 같은 메시지가 표시됩니다:

여기 이전에 보여준 모든 기능이 포함된 전체 구성 요소 코드가 있습니다:
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
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
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
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
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
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: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=""/>
116 </div>
117 <div className="login-social-item">
118 <img className="login-social-item__image" src={'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAOEAAADhCAMAAAAJbSJIAAAAV1BMVEWZmZn///+SkpKVlZWRkZH19fWgoKDg4OCampqjo6P8/Py+vr7l5eX29vb5+fnIyMirq6vQ0NDp6enW1ta3t7fU1NS7u7uwsLDKysrv7+/b29vi4uKtra2OjCyUAAAJGUlEQVR4nO2d6ZrqIAyGKdSldrSrVh3v/zpPq6PjjCULxhLnOd9/aV8LAUISTKJSq8OxaEtzFGjKCLQhrboojXXOGLcVaE0dYZ33dOYitxdoUBnhNrvhDYSFQJOaCFd7c4f39whXhfvJ99cIG/ObryesBBpWQjjL7APfn7Kl1RifMfavzIebchzQ2FqgdQWE9cgI/CKcCTQfn/CYevh6SbQfnXAPAJYSD4hNWACALpd4QmTC3GNjLsNQwpRGJiwgQJNKGJq4hBXQRXvNRR4Sk/ATBpQZhjEJD2AX7Yfhh8hjIhLOYUDjZB4TjzD3rWRkO2k8wgU8CHtLKrEoTeIRrhA+YzKhJ8UibJE+amwj9KRIhB9YH5VZdQ+KRIjZURkHxllxCLfIVNhrJfWsOITYIJQbhZEIK5RQZkl6VhRCtIuKOGiuD5Nriix0FLpW8GkxCFFDKmdmkiiEH9gnTD8lHxeBcDfRkvtLEQixLiq1IL0+TrY5gj6RTurWss+bnhDZF0pOFGdNT7gEAVMRD+K9JiecwQ5EsQX3TZMTHiHCFwBOT1gAw/AVgNMTdoCRER+DgyYnzPyE0lb0oskJfZ3UZZvXPHBqwpXHQZPKLtXuNDXhbJTQGdHF9g9pIHSv+4CJBkKXtiLnhD5NTbj5Rejs7vDaJ05uS9Mfny+rXmRBvzU54Rebc9acqhd/vssDJ3jGD+3mvcq2aGpJZwyg2NEmr9d/QprWh89j0xwXn/XsactxWGyLtpzP+53yMju1eXU8PNXm04SHbV4uba/BeFibumWZN6EWpK5Kc27p29wOrbp5uw02Sk8Rbo6tsw+xy/1bWddV3J3CoTpZ612Xu9S0x6Bv+QThsXPeNxqm8mVOX2weijnQ1rVF1wYsX0MJZ4VBzwD7V9pRXmm2n6foadT1byu4zsYwwtkO/cevr2QKZAQdS2Jb1xZ3PMYQwg2V7/JKabb1DqBDjneFR8acMyADCCvWf355p24x0tCqKYm986E9hsuKTVjP2X/6oN7u/ApTC/l8381lZFPNJczxMBGP+nlt11x3gr3tDPt8N6XUfBoe4Tp76rWGDUV2qooOnxpwWaLrikX48fx7mYFTopVBpJ7KIURCeqdXSolJYRCGD8GXiTIY6YRduOV7nSyOSCbsxEaPqHBEKqFSQAIikXCnsYtehJkbGiGc+RFZ6diKkEnY6LOi93Kgz5xCeNANiETgEAhXcPSEAlmoMgGBUK0ZvclBySc4YaPZypwFTxgoIRz/okBuDrtJUMIyNgEiu0MAMEIwwEeB8O0FQrhSbmUcvkVECKEIJg0i+PphQt1mxs0pfgyYEM2/iioSIEw4HvyiRXPaITJIqPsTEp37EKHqUWipB4oQoWZDSo/UhAgVf0JGTgZA2Cj+hIycDIBQ8Yo0ZZzq+wkV7+xZtfj8hIrtDCv/0k+I59DFUsoqmOElxOpyRFTHAfQT7tV2UvJcjxCqtaTcFFof4UZtJ+XMFBChXu/FiQfoJcSqx0QTO3XIR6h3rmAC+gjXWjspPw3aQ4gl60YTP4nWQ6h3NuQC+gi1+i8c5uEmE2o1NI6fhOkh1LpzCqjZOk6odtm9ZAN6CBdaCXnbCoAQLwIURyElzMcJte7vAwyNh1DrZBFSNGOcUOvmMA2oezJOqHU6tAEZfeOEWiNoAiaLcUK8MGUkhZRxGyVcKzU0coRqj9X+E/4nvOkvLbzfjDAk0+69CMVmfL2EAfnO72VpxFbeagnFdk9q1zRiO2C161ITUJx23P7GBvEqYMp/r/1hSOnPcUKgbFxcWTgDiE4IlP6LqwBTM06o9nw0oATvOKHeoyf+DUnjhHqD9vh3JowToiW344ndTccJFQd4sxffnh2X2l7KP8j3EKqdEPl7RN8pd2wOv7gXPb9dpILh3pzgIVR7RGrY6xoPodo98CDLqmrm817FpoDEi7/0EZ5iY0BihUH7CLWec1/E8Qz7CDWbGl5olI9wrXfdNohxSYTXT67WkXERXAuDRIjddxNbZJ+Ul/ConNBR4729hKrn/EHUWfEds4K+hFZTwAj1eqOuoiH6CXXPiGdZSkf1E2ovGDHIlfhOCjg3Vr00/ZKbo/MiQLh9g49IyKEBCBU73O6FXf8BRTcodkfdCykyBBGqdtbcCywUBRGqDcl4kFv6RyMYg/Mm3XSQLX1hGiDh23TTQWk5Xv/9jevTPGjcGw5HimmNaB+V50QDJtR7jjgiTwo0TPgOa9ObPCeLSDyjdl/GnZynNh1CWL+PrfHVv8RiUtXv9K/ynpxihFqz2B7kLbWAEb6NrfFmJqKR0/rdNWdZ74U2KKHiYkr38juI8eh3tTFu97L+MqY4oeLooTv535+QwfAGeygoPoNAqLdUzU0WeH1KFor6WR+MzqAQbrV/RDA2mpRJFJsAERzqRiJU/hFTML6Glg2mNfP5LCRakUaoura+g0OkiBl9is0pFuZGJFR8mIh8QvJdQWq9bmi4KZVQ7xYDe3NyZq3ScifApoJLuNFJiCcn0LOjK43GhhCHycj/VriLcoS6UQxChb5TSjoiJ4dfnQOclJjAIVR3tRUpVJhVh2Ghq5+mpFu6eZUmVE2KxOBEHqGqfuoE7ih5lCJ7Sk165tZDUZOlQE4rYVd80TLvL6n5XWxCJTUz0pfdPJ4knxqGIuEe4HDCZB9/Ce5K+uuGVF6Kf6kl5rl4ljC6taEPwlDCTdyJP2VVHQgijJtuYnn56mGESR0PkbLrFSBMPmLNGY5bNiKUMNbdAo54J6AAYaTNIu1WRxnCpJ6ej3YvpxhhMltyp35nbWrKrmtP2TJNLfvnAYBPESZJyXhHZ+fdfnEXfbb+qDrDobTcS3QECJOcNhiddV0zmqFU7zMqJJYc49GThMnRoe/n7DKHfEazKksJkCE1Ewc9S5isS3DacNbscM/7oVgiX9KWAeXYz3qaMEka4305Z1tqCbnPFmB0vhBnggQIk1U++nLOlg1nel415Tikc0VA7dmrJAj7rpq7X33VpVnFvzFltu3sL8reSOWhHfQsGcJex1P/Lu7yl1vTBeB9qd6fjO05B1k7z1nXOY5IjLDvZfU2b09lVzQB1X5/alYvmmpfHT+C/6dv/QMH/ovCU90cLAAAAABJRU5ErkJggg=='} 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 };결론
이 가이드를 마치면서, React에서 Parse 사용자를 로그인하고 로그아웃하는 방법을 배웠습니다. 다음 가이드에서는 유용한 사용자 쿼리를 수행하는 방법을 보여드리겠습니다.