1 00:00:00,000 --> 00:00:02,000 Now with that, we're almost there 2 00:00:02,000 --> 00:00:05,000 and we almost got all the logic we need 3 00:00:05,000 --> 00:00:08,000 to create and store new users, 4 00:00:08,000 --> 00:00:10,000 but we're not entirely there yet. 5 00:00:11,000 --> 00:00:15,000 Whilst this will create a new user, it is now possible 6 00:00:15,000 --> 00:00:19,000 that we try to create a user for an email address 7 00:00:19,000 --> 00:00:23,000 that we did already store in the database. 8 00:00:23,000 --> 00:00:26,000 And that is not something we can do 9 00:00:26,000 --> 00:00:29,000 because indeed the user's table is configured 10 00:00:29,000 --> 00:00:31,000 such that the email must be unique. 11 00:00:31,000 --> 00:00:35,000 We can't have multiple users with the same email address. 12 00:00:37,000 --> 00:00:40,000 Hence in auth-actions.js, 13 00:00:40,000 --> 00:00:44,000 we should actually wrap createUser with try catch. 14 00:00:44,000 --> 00:00:47,000 Because this SQLite package, 15 00:00:47,000 --> 00:00:50,000 which we're using for interacting with the database, 16 00:00:50,000 --> 00:00:54,000 will actually throw an error if the database complains, 17 00:00:54,000 --> 00:00:59,000 for example, because we violate that unique constraint. 18 00:01:00,000 --> 00:01:03,000 So we will then get an error here. 19 00:01:04,000 --> 00:01:05,000 And therefore in this catch block, 20 00:01:05,000 --> 00:01:09,000 I wanna check if that error has a code, 21 00:01:09,000 --> 00:01:13,000 which it will have if it's coming from that SQLite package. 22 00:01:13,000 --> 00:01:15,000 That's equal to SQLITE_CONSTRAINT_UNIQUE. 23 00:01:19,000 --> 00:01:20,000 Written like this. 24 00:01:21,000 --> 00:01:25,000 So that's simply a code this package uses 25 00:01:25,000 --> 00:01:28,000 if the SQLite database generates an error 26 00:01:28,000 --> 00:01:31,000 because we violate such a unique constraint, 27 00:01:31,000 --> 00:01:34,000 like the one on the email address. 28 00:01:34,000 --> 00:01:39,000 And in that case, if we get such an error with this code, 29 00:01:39,000 --> 00:01:41,000 I actually don't wanna handle this error 30 00:01:41,000 --> 00:01:45,000 with an error JS file or in any other way. 31 00:01:45,000 --> 00:01:49,000 But instead then, I wanna return an object again. 32 00:01:49,000 --> 00:01:54,000 So return a response to the page that's submitted the form. 33 00:01:54,000 --> 00:01:57,000 And in there, I want to have an errors object, 34 00:01:57,000 --> 00:02:01,000 just as we did before with the email password validation. 35 00:02:01,000 --> 00:02:06,000 And that should be an object that has an email field 36 00:02:07,000 --> 00:02:10,000 where we say, "It seems like an account 37 00:02:10,000 --> 00:02:15,000 for the chosen email already exists." 38 00:02:17,000 --> 00:02:21,000 Now, you could also output a more cryptic error message 39 00:02:21,000 --> 00:02:23,000 so that the user doesn't know 40 00:02:23,000 --> 00:02:26,000 whether the creation now failed 41 00:02:26,000 --> 00:02:29,000 because they used an existing email address 42 00:02:29,000 --> 00:02:31,000 or for some other reason, 43 00:02:31,000 --> 00:02:35,000 so that users can't simply try out different email addresses 44 00:02:35,000 --> 00:02:38,000 to find out which users might have signed up 45 00:02:38,000 --> 00:02:40,000 with your service. 46 00:02:40,000 --> 00:02:42,000 So you could make this more cryptic. 47 00:02:42,000 --> 00:02:44,000 Here also for us during development 48 00:02:44,000 --> 00:02:46,000 so that we can see that this works, 49 00:02:46,000 --> 00:02:48,000 I'll use this pretty specific message. 50 00:02:50,000 --> 00:02:52,000 Now, if we have any other error, 51 00:02:52,000 --> 00:02:54,000 we'll not make it into this if check. 52 00:02:54,000 --> 00:02:57,000 And in that case, I just wanna throw that error 53 00:02:57,000 --> 00:03:01,000 so that the default next JS error handling mechanism 54 00:03:01,000 --> 00:03:03,000 can kick in, 55 00:03:03,000 --> 00:03:06,000 which means that the closest error JS file 56 00:03:06,000 --> 00:03:08,000 will take over if we have one. 57 00:03:09,000 --> 00:03:10,000 Well, and with that, 58 00:03:10,000 --> 00:03:12,000 we therefore now will create a user 59 00:03:12,000 --> 00:03:15,000 if that email address isn't taken already, 60 00:03:15,000 --> 00:03:17,000 otherwise will generate this error. 61 00:03:17,000 --> 00:03:20,000 And if we make it past this try catch block, 62 00:03:20,000 --> 00:03:24,000 we therefore will have successfully created a user. 63 00:03:24,000 --> 00:03:28,000 And in that case, I want to call redirect, 64 00:03:29,000 --> 00:03:33,000 a function that's imported from next navigation. 65 00:03:35,000 --> 00:03:38,000 And I wanna redirect the user to the training page 66 00:03:38,000 --> 00:03:42,000 because we don't need to stay on the authentication page 67 00:03:42,000 --> 00:03:44,000 if we just created a new user. 68 00:03:44,000 --> 00:03:48,000 Instead then, I wanna forward that user 69 00:03:48,000 --> 00:03:49,000 who's using the website 70 00:03:49,000 --> 00:03:52,000 to the main pages that make up my website. 71 00:03:52,000 --> 00:03:54,000 In this case, to the training page. 72 00:03:56,000 --> 00:03:59,000 And therefore, let's now give this a try. 73 00:03:59,000 --> 00:04:01,000 If we save everything and we go back here, 74 00:04:01,000 --> 00:04:04,000 if I enter an invalid password that's too short, 75 00:04:04,000 --> 00:04:05,000 I get that error. 76 00:04:06,000 --> 00:04:10,000 If I enter a valid password though, you see, I'm redirected. 77 00:04:10,000 --> 00:04:12,000 So that seems to work. 78 00:04:13,000 --> 00:04:15,000 However, if I now go back 79 00:04:15,000 --> 00:04:18,000 and I try to use that same email address again, 80 00:04:18,000 --> 00:04:22,000 even if I have a valid password, I get an error, 81 00:04:22,000 --> 00:04:26,000 because we have that unique constraint in the database. 82 00:04:27,000 --> 00:04:29,000 Of course, if I use a different email address, 83 00:04:29,000 --> 00:04:31,000 it works again. 84 00:04:31,000 --> 00:04:33,000 And that's therefore the user creation 85 00:04:33,000 --> 00:04:35,000 and the signup process, 86 00:04:35,000 --> 00:04:38,000 which is an important first step. 87 00:04:38,000 --> 00:04:39,000 But at this point, 88 00:04:39,000 --> 00:04:43,000 we actually haven't added any authentication yet, 89 00:04:43,000 --> 00:04:46,000 we just can create users. 90 00:04:46,000 --> 00:04:49,000 But we don't have any log in mechanism, 91 00:04:49,000 --> 00:04:51,000 we can't check whether a request 92 00:04:51,000 --> 00:04:54,000 is coming from a logged in user, 93 00:04:54,000 --> 00:04:56,000 we got nothing like that. 94 00:04:56,000 --> 00:04:59,000 And that's therefore what we'll work on next.