1
00:00:00,000 --> 00:00:05,000
[??] [CODE/RACER - Database Access]

2
00:00:05,000 --> 00:00:11,000
In our last set of videos, we learned how to sign in and authenticate with Facebook.

3
00:00:11,000 --> 00:00:15,000
In this video, we're going to save that information from Facebook

4
00:00:15,000 --> 00:00:18,000
to our own local database.

5
00:00:18,000 --> 00:00:23,000
In order to do this, we're going to use a project called Sequelize.

6
00:00:23,000 --> 00:00:28,000
Sequelize is an object-relational-mapper for node.js.

7
00:00:28,000 --> 00:00:33,000
In order to install it, we have to add it to our packages,

8
00:00:33,000 --> 00:00:41,000
so let's open up our package.json and add it in.

9
00:00:45,000 --> 00:00:50,000
Save the file and then run npm install to install it.

10
00:01:02,000 --> 00:01:05,000
Great. Now we have Sequelize installed.

11
00:01:05,000 --> 00:01:08,000
Let's tell our application how to use it.

12
00:01:08,000 --> 00:01:13,000
First, we'll open up our app.coffee and import it.

13
00:01:23,000 --> 00:01:27,000
Now let's take a look at the documentation and see what we do next.

14
00:01:27,000 --> 00:01:30,000
It looks like we have to configure it.

15
00:01:30,000 --> 00:01:35,000
Let's go ahead and open up our configuration file that we made earlier.

16
00:01:36,000 --> 00:01:42,000
Now we'll add our database credentials into this configuration file.

17
00:01:45,000 --> 00:01:49,000
Since we're going to be working in development,

18
00:01:49,000 --> 00:01:52,000
I'm going to create a key for development right here.

19
00:01:53,000 --> 00:01:59,000
This way, when we go to deploy it, we can specify a production environment as well.

20
00:02:21,000 --> 00:02:26,000
We're going to use the MySQL database locally to work with it,

21
00:02:26,000 --> 00:02:29,000
and we'll specify that we're logging.

22
00:02:30,000 --> 00:02:33,000
This helps a lot when trying to debug errors.

23
00:02:36,000 --> 00:02:39,000
Now let's go back and see how we initialize Sequelize.

24
00:02:46,000 --> 00:02:52,000
When initializing it, we'll give it the keys that we just specified over in our configuration file.

25
00:03:30,000 --> 00:03:36,000
In this part down here, the define key says timestamps are true.

26
00:03:36,000 --> 00:03:42,000
What that will do is add a created_at and updated_at field to each of our models.

27
00:03:42,000 --> 00:03:47,000
Every time a model is created or saved, those fields will be updated automatically.

28
00:03:47,000 --> 00:03:51,000
Now that we've got Sequelize installed, let's create a User model 

29
00:03:51,000 --> 00:03:53,000
to save our Facebook data.

30
00:03:53,000 --> 00:03:57,000
I'm going to do that back on the console and make a models directory.

31
00:04:00,000 --> 00:04:04,000
Inside of the models directory is where I'll put the user file.

32
00:04:09,000 --> 00:04:12,000
Now let's open up the User model.

33
00:04:13,000 --> 00:04:19,000
Let's refer back to the Sequelize documentation to see how we create a model.

34
00:04:19,000 --> 00:04:22,000
It looks like we use the define keyword.

35
00:04:23,000 --> 00:04:26,000
We're not going to use any validations right now.

36
00:04:28,000 --> 00:04:31,000
Since we're storing our model in a separate file,

37
00:04:31,000 --> 00:04:34,000
it looks like we're going to have to use the import method.

38
00:04:34,000 --> 00:04:38,000
Before we create our model, we need to create our database

39
00:04:38,000 --> 00:04:42,000
and also add a table to it.

40
00:04:42,000 --> 00:04:45,000
I'm going to use Sequel Pro in order to do that.

41
00:04:45,000 --> 00:04:48,000
However, that's not completely necessary.

42
00:04:53,000 --> 00:04:57,000
Now we're going to create our users table.

43
00:05:06,000 --> 00:05:10,000
We're only going to save a few attributes that we get back from Facebook.

44
00:05:10,000 --> 00:05:17,000
For right now I'll just save the Facebook ID, the first name, last name, and email.

45
00:05:32,000 --> 00:05:38,000
In a real application, you would probably want to use an unsigned integer for the Facebook ID.

46
00:05:38,000 --> 00:05:44,000
However, since this is just an example, using a varchar is going to be a lot easier.

47
00:05:44,000 --> 00:05:49,000
Now that we've got our database set up, let's go ahead and create our model.

48
00:05:49,000 --> 00:05:56,000
Since our User model is in a separate file, we're going to have to export that information.

49
00:06:04,000 --> 00:06:07,000
Now let's refer back to the documentation.

50
00:06:07,000 --> 00:06:11,000
It looks like we have to give it a model and then say the different data types.

51
00:06:24,000 --> 00:06:29,000
Here we'll enter all of the information we put in the database.

52
00:06:46,000 --> 00:06:51,000
We're going to want to save certain information that we get back from Facebook.

53
00:06:51,000 --> 00:06:55,000
We'll do this using a custom method inside of our User model.

54
00:06:55,000 --> 00:06:58,000
If we look back at the documentation in Sequelize,

55
00:06:58,000 --> 00:07:03,000
we can see that we can define class methods and instance methods.

56
00:07:03,000 --> 00:07:09,000
We'll go ahead and define a class method called findOrCreateFromMetadata.

57
00:07:09,000 --> 00:07:13,000
What this will do is save the metadata from Facebook.

58
00:07:13,000 --> 00:07:17,000
Or if a user with the Facebook ID already exists,

59
00:07:17,000 --> 00:07:20,000
it will return that user.

60
00:07:20,000 --> 00:07:25,000
This way we won't duplicate information inside of the database.

61
00:07:35,000 --> 00:07:38,000
First, we'll look up to see if the Facebook ID exists.

62
00:07:53,000 --> 00:07:59,000
If the query is successful, we'll store that information inside of a user object.

63
00:07:59,000 --> 00:08:05,000
However, this might not actually exist inside of the database.

64
00:08:05,000 --> 00:08:11,000
The success callback defines whether or not the query was successful.

65
00:08:11,000 --> 00:08:16,000
So if the user doesn't exist, we'll build and save it.

66
00:08:17,000 --> 00:08:23,000
At this point we're going to need access to the User model.

67
00:08:23,000 --> 00:08:28,000
We can't call this.build in order to create our user

68
00:08:28,000 --> 00:08:32,000
because this now refers to the success callback.

69
00:08:32,000 --> 00:08:37,000
So what we'll do is define a variable called model up here

70
00:08:37,000 --> 00:08:41,000
that will have the binding of the User model,

71
00:08:45,000 --> 00:08:48,000
and then we change the reference over in our build function.

72
00:08:48,000 --> 00:08:53,000
Now we'll go ahead and assign the metadata to our different database attributes.

73
00:09:17,000 --> 00:09:20,000
Once we've built the model, we'll save it.

74
00:09:22,000 --> 00:09:32,000
And if it's successful, we'll assign that again to a user object and run the callback.

75
00:09:38,000 --> 00:09:45,000
If it fails, we'll go ahead and log the error 

76
00:09:45,000 --> 00:09:49,000
and we'll run the callback with an error and no object.

77
00:09:55,000 --> 00:09:59,000
Now, that's what happens if we don't have a user in the database.

78
00:09:59,000 --> 00:10:02,000
If we do, the user should be returned,

79
00:10:02,000 --> 00:10:09,000
so we'll just run the callback and send in that user object.

80
00:10:09,000 --> 00:10:11,000
And finally, we need to tell Node what to do 

81
00:10:11,000 --> 00:10:15,000
in case there's an error when querying the database.

82
00:10:22,000 --> 00:10:24,000
That looks good for now.

83
00:10:24,000 --> 00:10:29,000
Let's go ahead back to our application.coffee.

84
00:10:29,000 --> 00:10:34,000
What we have to do is import the User model we just created.

85
00:10:47,000 --> 00:10:51,000
Now let's scroll down to our authentication portion.

86
00:10:51,000 --> 00:10:55,000
Instead of just rendering a template saying that we've authenticated,

87
00:10:55,000 --> 00:10:59,000
what we'll do is call our findOrCreateFromMetadata 

88
00:10:59,000 --> 00:11:04,000
and send in the body of the Facebook response.

89
00:11:11,000 --> 00:11:16,000
We also have to send in our error and object callbacks.

90
00:11:23,000 --> 00:11:26,000
So let's see if the user exists.

91
00:11:34,000 --> 00:11:40,000
In the case that the user does exist, we'll set a user ID session variable

92
00:11:40,000 --> 00:11:46,000
and redirect to an endpoint called /me.

93
00:11:50,000 --> 00:11:53,000
We haven't made that endpoint yet, but we will.

94
00:12:02,000 --> 00:12:08,000
For now, if the user doesn't exist, we'll just redirect them to the homepage.

95
00:12:11,000 --> 00:12:15,000
Finally, we'll create our /me endpoint.

96
00:12:20,000 --> 00:12:26,000
First, we'll check to see if there's a user ID key inside of the session.

97
00:12:30,000 --> 00:12:37,000
If there is a user, we'll go ahead and create a User.findById method.

98
00:12:58,000 --> 00:13:02,000
You'll notice that we're rendering this me.eco template 

99
00:13:02,000 --> 00:13:05,000
in the event that we find the user.

100
00:13:05,000 --> 00:13:07,000
Let's go ahead and create that.

101
00:13:11,000 --> 00:13:16,000
It looks like we have an error on line 13 of our application file.

102
00:13:16,000 --> 00:13:19,000
Let's go ahead and see what's going on.

103
00:13:19,000 --> 00:13:25,000
It seems like I've messed up the indentation here when defining our Sequelize variables.

104
00:13:34,000 --> 00:13:37,000
Let's go ahead and try and run it again.

105
00:13:37,000 --> 00:13:41,000
So we load up our homepage and click Log In.

106
00:13:41,000 --> 00:13:47,000
I'm already logged in to Facebook, so it won't ask me to authorize the application.

107
00:13:48,000 --> 00:13:51,000
It seems our server died. Let's see what happened.

108
00:13:51,000 --> 00:13:55,000
It says we have no method findOrCreateFromMetadata.

109
00:13:55,000 --> 00:14:00,000
That's going to be in the User model. Let's open that up and see what's going on.

110
00:14:01,000 --> 00:14:06,000
It looks like I forgot the classMethods argument.

111
00:14:19,000 --> 00:14:21,000
Let's try it again.

112
00:14:25,000 --> 00:14:30,000
It looks like we have another error saying that we have no method findById.

113
00:14:30,000 --> 00:14:34,000
A quick look in the User model shows that I misspelled it.

114
00:14:34,000 --> 00:14:37,000
Let's correct it and try again.

115
00:14:40,000 --> 00:14:45,000
It would seem once more that we're indented just a bit too much.

116
00:14:45,000 --> 00:14:49,000
These are some of the quirks of CoffeeScript that you have to get used to.

117
00:14:51,000 --> 00:14:54,000
Here I have another typo.

118
00:14:57,000 --> 00:15:00,000
And we finally got that to work.

119
00:15:00,000 --> 00:15:03,000
Let's go ahead and look inside of our database.

120
00:15:05,000 --> 00:15:08,000
All of our content is there.