SignIn with Facebook

react facebook login introduction in the last tutorials, you built a user login/logout feature to your app using the parse user parse user class now you will learn how to use facebook login to retrieve user data from facebook and log in, sign up or link existent users with it you will also install and configure react facebook login react facebook login lib to achieve that the parse user linkwith parse user linkwith method is responsible for signing up and logging in users using any third party authentication method, as long as you pass the right parameters requested by each different provider after linking the user data to a new or existent parse user parse user , parse will store a valid user session on your device future calls to methods like current current will successfully retrieve your user data, just like with regular logins prerequisites to complete this tutorial, you will need a react app created and connected to back4app complete the previous guide so you can have a better understanding of the parse user class and the parse user login method https //www back4app com/docs/react/working with users/react user login if you want to test/use the screen layout provided by this guide, you should set up the ant design ant design library goal to build a user login feature using facebook login on parse for a react app 1 installing dependencies the most popular way to enable facebook login on react is using react facebook login react facebook login to handle it set it up following the official docs to use the lib component, you need to inform a valid facebook app appid appid , so create one on on your facebook for developers dashboard, following one of their official guides after that, add facebook login capability to your app while choosing the www option, informing https //localhost 3000 https //localhost 3000 as your website url facebook login requires that your connection is secure, even when logging in on a development environment so, you need to setup https access for your react app by creating a local certificate, giving it full permissions in your os and adding the files to your project since each os can have its particularities, this won’t be covered in the guide after creating the certificate, make sure to change in the scripts scripts session of your package json package json file the start command to 1 "start" "export https=true&\&ssl crt file=cert pem&\&ssl key file=key pem react scripts start", if you are using typescript, you need to create a new file in your src src folder called react facebook login d ts react facebook login d ts containing the react facebook login react facebook login module declaration to use the styleless version of the component react facebook login d ts 1 declare module 'react facebook login/dist/facebook login render props'; 2 using facebook login with parse let’s now create a new method inside the userlogin userlogin component that will handle the response when calling a facebook login authentication modal if the user signs in with facebook, this call will retrieve the user data from facebook and you need to store the id id , accesstoken accesstoken , and the profile email email then, the function will try to log in on parse using the parse user linkwith parse user linkwith method and these credentials note that if your user had already signed up using this facebook authentication, linkwith linkwith will log him in using the existent account javascript 1 const handlefacebookloginloginresponse = async function(response) { 2 // check if response has an error 3 if (response error !== undefined) { 4 console log(`error ${response error}`); 5 return false; 6 } else { 7 try { 8 // gather facebook user info 9 const userid = response id; 10 const useremail = response email; 11 const useraccesstoken = response accesstoken; 12 // try to login on parse using linkwith and these credentials 13 // create a new parse user object 14 const usertologin = new parse user(); 15 // set username and email to match facebook profile email 16 usertologin set('username', useremail); 17 usertologin set('email', useremail); 18 try { 19 let loggedinuser = await usertologin 20 linkwith('facebook', { 21 authdata {id userid, access token useraccesstoken}, 22 }); 23 // login returns the corresponding parseuser object 24 alert( 25 `success! user ${loggedinuser get('username')} has successfully signed in!`, 26 ); 27 // update state variable holding current user 28 getcurrentuser(); 29 return true; 30 } catch (error) { 31 // error can be caused by wrong parameters or lack of internet connection 32 alert(`error! ${error message}`); 33 return false; 34 } 35 } catch (error) { 36 console log("error gathering facebook user info, please try again!") 37 return false; 38 } 39 } 40 }1 const handlefacebookloginloginresponse = async function(response any) promise\<boolean> { 2 // check if response has an error 3 if (response error !== undefined) { 4 console log(`error ${response error}`); 5 return false; 6 } else { 7 try { 8 // gather facebook user info 9 const userid string = response id; 10 const useremail string = response email; 11 const useraccesstoken string = response accesstoken; 12 // try to login on parse using linkwith and these credentials 13 // create a new parse user object 14 const usertologin parse user = new parse user(); 15 // set username and email to match facebook profile email 16 usertologin set('username', useremail); 17 usertologin set('email', useremail); 18 try { 19 let loggedinuser parse user = await usertologin 20 linkwith('facebook', { 21 authdata {id userid, access token useraccesstoken}, 22 }); 23 // login returns the corresponding parseuser object 24 alert( 25 `success! user ${loggedinuser get('username')} has successfully signed in!`, 26 ); 27 // update state variable holding current user 28 getcurrentuser(); 29 return true; 30 } catch (error any) { 31 // error can be caused by wrong parameters or lack of internet connection 32 alert(`error! ${error message}`); 33 return false; 34 } 35 } catch (error any) { 36 console log("error gathering facebook user info, please try again!") 37 return false; 38 } 39 } 40 } after that, you need to use the react facebook login react facebook login facebooklogin facebooklogin component to call the facebook login modal, adding it to your jsx code you can use facebook’s default styling or create a custom one, which is the way followed by this guide here is the full userlogin userlogin component code, note the react facebook login react facebook login button and how it is tied to the modal response method created before javascript 1 import react, { usestate } from 'react'; 2 import parse from 'parse/dist/parse min js'; 3 import facebooklogin from 'react facebook login/dist/facebook login render props'; 4 import ' /app css'; 5 import { button, divider, input } from 'antd'; 6&#x9; 7 export const userlogin = () => { 8 // state variables 9 const \[username, setusername] = usestate(''); 10 const \[password, setpassword] = usestate(''); 11 const \[currentuser, setcurrentuser] = usestate(null); 12&#x9; 13 const douserlogin = async function () { 14 // note that these values come from state variables that we've declared before 15 const usernamevalue = username; 16 const passwordvalue = password; 17 try { 18 const loggedinuser = await parse user login(usernamevalue, passwordvalue); 19 // login returns the corresponding parseuser object 20 alert( 21 `success! user ${loggedinuser get( 22 'username' 23 )} has successfully signed in!` 24 ); 25 // to verify that this is in fact the current user, `current` can be used 26 const currentuser = await parse user current(); 27 console log(loggedinuser === currentuser); 28 // clear input fields 29 setusername(''); 30 setpassword(''); 31 // update state variable holding current user 32 getcurrentuser(); 33 return true; 34 } catch (error) { 35 // error can be caused by wrong parameters or lack of internet connection 36 alert(`error! ${error message}`); 37 return false; 38 } 39 }; 40&#x9; 41 const douserlogout = async function () { 42 try { 43 await parse user logout(); 44 // to verify that current user is now empty, currentasync can be used 45 const currentuser = await parse user current(); 46 if (currentuser === null) { 47 alert('success! no user is logged in anymore!'); 48 } 49 // update state variable holding current user 50 getcurrentuser(); 51 return true; 52 } catch (error) { 53 alert(`error! ${error message}`); 54 return false; 55 } 56 }; 57&#x9; 58 // function that will return current user and also update current username 59 const getcurrentuser = async function () { 60 const currentuser = await parse user current(); 61 // update state variable holding current user 62 setcurrentuser(currentuser); 63 return currentuser; 64 }; 65&#x9; 66 const handlefacebookloginloginresponse = async function (response) { 67 // check if response has an error 68 if (response error !== undefined) { 69 console log(`error ${response error}`); 70 return false; 71 } else { 72 try { 73 // gather facebook user info 74 const userid = response id; 75 const useremail = response email; 76 const useraccesstoken = response accesstoken; 77 // try to login on parse using linkwith and these credentials 78 // create a new parse user object 79 const usertologin = new parse user(); 80 // set username and email to match facebook profile email 81 usertologin set('username', useremail); 82 usertologin set('email', useremail); 83 try { 84 let loggedinuser = await usertologin linkwith('facebook', { 85 authdata { id userid, access token useraccesstoken }, 86 }); 87 // login returns the corresponding parseuser object 88 alert( 89 `success! user ${loggedinuser get( 90 'username' 91 )} has successfully signed in!` 92 ); 93 // update state variable holding current user 94 getcurrentuser(); 95 return true; 96 } catch (error) { 97 // error can be caused by wrong parameters or lack of internet connection 98 alert(`error! ${error message}`); 99 return false; 100 } 101 } catch (error) { 102 console log('error gathering facebook user info, please try again!'); 103 return false; 104 } 105 } 106 }; 107&#x9; 108 return ( 109 \<div> 110 \<div classname="header"> 111 \<img 112 classname="header logo" 113 alt="back4app logo" 114 src={ 115 'https //blog back4app com/wp content/uploads/2019/05/back4app white logo 500px png' 116 } 117 /> 118 \<p classname="header text bold">{'react on back4app'}\</p> 119 \<p classname="header text">{'user login'}\</p> 120 \</div> 121 {currentuser === null && ( 122 \<div classname="container"> 123 \<h2 classname="heading">{'user login'}\</h2> 124 \<divider /> 125 \<div classname="form wrapper"> 126 \<input 127 value={username} 128 onchange={(event) => setusername(event target value)} 129 placeholder="username" 130 size="large" 131 classname="form input" 132 /> 133 \<input 134 value={password} 135 onchange={(event) => setpassword(event target value)} 136 placeholder="password" 137 size="large" 138 type="password" 139 classname="form input" 140 /> 141 \</div> 142 \<div classname="form buttons"> 143 \<button 144 onclick={() => douserlogin()} 145 type="primary" 146 classname="form button" 147 color={'#208aec'} 148 size="large" 149 block 150 > 151 log in 152 \</button> 153 \</div> 154 \<divider /> 155 \<div classname="login social"> 156 \<facebooklogin 157 appid="4573670722644997" 158 fields="email" 159 callback={handlefacebookloginloginresponse} 160 render={(renderprops) => ( 161 \<div classname="login social item login social item facebook"> 162 \<img onclick={renderprops onclick} classname="login social item image" src={'https //findicons com/files/icons/2830/clean social icons/250/facebook png'} alt=""/> 163 \</div> 164 )} 165 /> 166 \<div classname="login social item"> 167 \<img classname="login social item image" src={'data\ image/png;base64,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'} alt=""/> 168 \</div> 169 \<div classname="login social item"> 170 \<img classname="login social item image" src={'data\ image/png;base64,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'} alt=""/> 171 \</div> 172 \</div> 173 \<p classname="form hint">don't have an account? \<a classname="form link" href="#">sign up\</a>\</p> 174 \</div> 175 )} 176 {currentuser !== null && ( 177 \<div classname="container"> 178 \<h2 classname="heading">{'user screen'}\</h2> 179 \<divider /> 180 \<h2 classname="heading">{`hello ${currentuser get('username')}!`}\</h2> 181 \<div classname="form buttons"> 182 \<button 183 onclick={() => douserlogout()} 184 type="primary" 185 classname="form button" 186 color={'#208aec'} 187 size="large" 188 block 189 > 190 log out 191 \</button> 192 \</div> 193 \</div> 194 )} 195 \</div> 196 ); 197 };1 import react, { usestate, fc, reactelement } from 'react'; 2 import ' /app css'; 3 import { button, divider, input } from 'antd'; 4 import facebooklogin from 'react facebook login/dist/facebook login render props'; 5 const parse = require('parse/dist/parse min js'); 6&#x9; 7 export const userlogin fc<{}> = () reactelement => { 8 // state variables 9 const \[username, setusername] = usestate(''); 10 const \[password, setpassword] = usestate(''); 11 const \[currentuser, setcurrentuser] = usestate\<parse object | null>(null); 12&#x9; 13 const douserlogin = async function () promise\<boolean> { 14 // note that these values come from state variables that we've declared before 15 const usernamevalue string = username; 16 const passwordvalue string = password; 17 try { 18 const loggedinuser parse user = await parse user login(usernamevalue, passwordvalue); 19 // login returns the corresponding parseuser object 20 alert( 21 `success! user ${loggedinuser get('username')} has successfully signed in!`, 22 ); 23 // to verify that this is in fact the current user, `current` can be used 24 const currentuser parse user = await parse user current(); 25 console log(loggedinuser === currentuser); 26 // clear input fields 27 setusername(''); 28 setpassword(''); 29 // update state variable holding current user 30 getcurrentuser(); 31 return true; 32 } catch (error any) { 33 // error can be caused by wrong parameters or lack of internet connection 34 alert(`error! ${error message}`); 35 return false; 36 } 37 }; 38&#x9; 39 const douserlogout = async function () promise\<boolean> { 40 try { 41 await parse user logout(); 42 // to verify that current user is now empty, currentasync can be used 43 const currentuser parse user = await parse user current(); 44 if (currentuser === null) { 45 alert('success! no user is logged in anymore!'); 46 } 47 // update state variable holding current user 48 getcurrentuser(); 49 return true; 50 } catch (error any) { 51 alert(`error! ${error message}`); 52 return false; 53 } 54 }; 55&#x9; 56 // function that will return current user and also update current username 57 const getcurrentuser = async function () promise\<parse user | null> { 58 const currentuser (parse user | null) = await parse user current(); 59 // update state variable holding current user 60 setcurrentuser(currentuser); 61 return currentuser; 62 } 63&#x9; 64 const handlefacebookloginloginresponse = async function(response any) promise\<boolean> { 65 // check if response has an error 66 if (response error !== undefined) { 67 console log(`error ${response error}`); 68 return false; 69 } else { 70 try { 71 // gather facebook user info 72 const userid string = response id; 73 const useremail string = response email; 74 const useraccesstoken string = response accesstoken; 75 // try to login on parse using linkwith and these credentials 76 // create a new parse user object 77 const usertologin parse user = new parse user(); 78 // set username and email to match facebook profile email 79 usertologin set('username', useremail); 80 usertologin set('email', useremail); 81 try { 82 let loggedinuser parse user = await usertologin 83 linkwith('facebook', { 84 authdata {id userid, access token useraccesstoken}, 85 }); 86 // login returns the corresponding parseuser object 87 alert( 88 `success! user ${loggedinuser get('username')} has successfully signed in!`, 89 ); 90 // update state variable holding current user 91 getcurrentuser(); 92 return true; 93 } catch (error any) { 94 // error can be caused by wrong parameters or lack of internet connection 95 alert(`error! ${error message}`); 96 return false; 97 } 98 } catch (error any) { 99 console log("error gathering facebook user info, please try again!") 100 return false; 101 } 102 } 103 } 104&#x9; 105 return ( 106 \<div> 107 \<div classname="header"> 108 \<img 109 classname="header logo" 110 alt="back4app logo" 111 src={ 112 'https //blog back4app com/wp content/uploads/2019/05/back4app white logo 500px png' 113 } 114 /> 115 \<p classname="header text bold">{'react on back4app'}\</p> 116 \<p classname="header text">{'user login'}\</p> 117 \</div> 118 {currentuser === null && ( 119 \<div classname="container"> 120 \<h2 classname="heading">{'user login'}\</h2> 121 \<divider /> 122 \<div classname="form wrapper"> 123 \<input 124 value={username} 125 onchange={(event) => setusername(event target value)} 126 placeholder="username" 127 size="large" 128 classname="form input" 129 /> 130 \<input 131 value={password} 132 onchange={(event) => setpassword(event target value)} 133 placeholder="password" 134 size="large" 135 type="password" 136 classname="form input" 137 /> 138 \</div> 139 \<div classname="form buttons"> 140 \<button 141 onclick={() => douserlogin()} 142 type="primary" 143 classname="form button" 144 color={'#208aec'} 145 size="large" 146 block 147 > 148 log in 149 \</button> 150 \</div> 151 \<divider /> 152 \<div classname="login social"> 153 \<facebooklogin 154 appid="4573670722644997" 155 fields="email" 156 callback={handlefacebookloginloginresponse} 157 render={(renderprops {onclick () => void}) => ( 158 \<div classname="login social item login social item facebook"> 159 \<img onclick={renderprops onclick} classname="login social item image" src={'https //findicons com/files/icons/2830/clean social icons/250/facebook png'} alt=""/> 160 \</div> 161 )} 162 /> 163 \<div classname="login social item"> 164 \<img classname="login social item image" src={'data\ image/png;base64,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'} alt=""/> 165 \</div> 166 \<div classname="login social item"> 167 \<img classname="login social item image" src={'data\ image/png;base64,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'} alt=""/> 168 \</div> 169 \</div> 170 \<p classname="form hint">don't have an account? \<a classname="form link" href="#">sign up\</a>\</p> 171 \</div> 172 )} 173 {currentuser !== null && ( 174 \<div classname="container"> 175 \<h2 classname="heading">{'user screen'}\</h2> 176 \<divider /> 177 \<h2 classname="heading">{`hello ${currentuser get('username')}!`}\</h2> 178 \<div classname="form buttons"> 179 \<button 180 onclick={() => douserlogout()} 181 type="primary" 182 classname="form button" 183 color={'#208aec'} 184 size="large" 185 block 186 > 187 log out 188 \</button> 189 \</div> 190 \</div> 191 )} 192 \</div> 193 ); 194 }; add these classes to your app css app css file if you want to fully render this component’s layout 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 } go ahead and test your new function if you were able to sign in to facebook and the parse linkwith linkwith call was successful, you should see a success message like this 3 verifying user sign in and session creation to make sure that the facebook login worked, you can look at your parse dashboard and see your new user user (if your facebook authentication data didn’t belong to another user), containing the facebook authdata authdata parameters you can also verify that a valid session was created in the dashboard, containing a pointer to that user user object 4 linking an existing user to facebook sign in another linkwith linkwith possible use is to link an existing user with another auth provider, in this case, facebook add this function that calls linkwith linkwith the same way as logging in to your userlogin userlogin component the only difference here is that instead of calling the method from an empty parse user parse user , you will use it from the currently logged in user object javascript 1 const handlefacebookloginlinkresponse = async function(response) { 2 // check if response has an error 3 if (response error !== undefined) { 4 console log(`error ${response error}`); 5 return false; 6 } else { 7 try { 8 // gather facebook user info 9 const userid = response id; 10 const useraccesstoken = response accesstoken; 11 // try to link current parse user using linkwith and these credentials 12 // get current user 13 const usertolink = await parse user current(); 14 try { 15 let loggedinuser = await usertolink 16 linkwith('facebook', { 17 authdata {id userid, access token useraccesstoken}, 18 }); 19 // login returns the corresponding parseuser object 20 alert( 21 `success! user ${loggedinuser get( 22 'username', 23 )} has successfully linked his facebook account!`, 24 ); 25 // update state variable holding current user 26 getcurrentuser(); 27 return true; 28 } catch (error) { 29 // error can be caused by wrong parameters or lack of internet connection 30 alert(`error! ${error message}`); 31 return false; 32 } 33 } catch (error) { 34 console log("error gathering facebook user info, please try again!") 35 return false; 36 } 37 } 38 }1 const handlefacebookloginlinkresponse = async function(response any) promise\<boolean> { 2 // check if response has an error 3 if (response error !== undefined) { 4 console log(`error ${response error}`); 5 return false; 6 } else { 7 try { 8 // gather facebook user info 9 const userid string = response id; 10 const useraccesstoken string = response accesstoken; 11 // try to link current parse user using linkwith and these credentials 12 // get current user 13 const usertolink parse user = await parse user current(); 14 try { 15 let loggedinuser parse user = await usertolink 16 linkwith('facebook', { 17 authdata {id userid, access token useraccesstoken}, 18 }); 19 // login returns the corresponding parseuser object 20 alert( 21 `success! user ${loggedinuser get( 22 'username', 23 )} has successfully linked his facebook account!`, 24 ); 25 // update state variable holding current user 26 getcurrentuser(); 27 return true; 28 } catch (error any) { 29 // error can be caused by wrong parameters or lack of internet connection 30 alert(`error! ${error message}`); 31 return false; 32 } 33 } catch (error any) { 34 console log("error gathering facebook user info, please try again!") 35 return false; 36 } 37 } 38 } assign this function to another react facebook login react facebook login component in your home screen, which is shown only when there is a current user logged in in your app test your new function, noting that the parse user parse user object authdata authdata value will be updated with the new auth provider data verify if the user has indeed updated in your parse server dashboard conclusion at the end of this guide, you learned how to log in, sign up or link existing parse users on react using facebook login with react google login react google login in the next guide, we will show you how to use apple sign in