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We've used the `UserMixin` from Flask-Login. Now, let's use the `LoginManager` to set up our application so we can load users. This will get us ready to create our user CRUD.
Use from flask_login instead of from flask.ext.login
New Terms
-
LoginManager- An appliance to handle user authentication. -
user_loader- A decorator to mark the function responsible for loading a user from whatever data source we use.
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Flask-login needs to be able to find the
current user or
0:00
any user we're looking for.
0:03
To help create a process,
0:05
we need to create a function that will
return an instance of our user model.
0:06
It'll actually take longer to explain than
it will to build so
0:08
let's do both at the same time over on
workspaces.
0:12
All right.
So,
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if we're gonna use this log in manager, we
actually need to go ahead and import it.
0:16
So, let's go up here to our imports.
0:20
And we're gonna say from flask.ext.login
import LoginManager.
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And we have to add a few more things
before we can use this.
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So, one of those things we have to add,
because we're gonna be using sessions, is,
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we have to add our secret key.
0:35
And so again, you [UNKNOWN], you just
generate some random stuff.
0:39
[SOUND] And there you go, there's your
secret key.
0:43
And then we need to create our log in
manager.
0:48
So actually we're gonna say login_manager
equals LoginManager.
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[SOUND] Create an instance of that.
0:53
And login_manager.init_app of pass of the
app.
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So this sets up the log in manager for our
application.
1:01
So paying attention to like our views and
controlling our user, and
1:05
getting our global object and all that
kind of stuff.
1:09
And then we have to say
login_manager.login_view
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is gonna be named login.
1:16
Now we don't have that view yet.
1:18
We will later.
1:20
So this is just saying, hey, if they're
not logged in, and
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you gotta redirect them somewhere to log
in, we're gonna call the view log in.
1:24
So redirect them to there.
1:29
Okay, and then we're going to provide
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a function that the log in manager will
use when it needs to look up a user.
1:34
So, we decorate this with
login_manager.user_loader,
1:39
creatively named.
1:45
And we'll say load_user.
1:47
And we're gonna get a user ID passed into
this.
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All right, so, let's do this.
1:54
We'll say try, [SOUND] return
models.User.get,
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models.User.id, is equal to userid.
2:01
And, unless we get models.DoesNotExist,
and then return None.
2:07
So where does this models.DoesNotExist
comes from?
2:14
That's actually from peewee.
2:17
But since we imported everything from
peewee inside models,
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we have access to all of peewee's stuff.
2:21
Kinda cool.
2:24
Though this is an exception that's raised
whenever
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you say give me a record that looks like
this.
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And the database says, I don't have a
record that looks like that.
2:31
So that's why it comes back there.
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We get does not exist.
2:36
We wanna catch that.
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And we'll just return none cause that user
doesn't exist.
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We don't have that user.
2:40
So let's actually add something over here
in our user, or in our models file.
2:42
Down here at the bottom, let's add an
initialize method.
2:48
[SOUND] So def initialize.
2:54
And we'll call DATABASE.connect cuz we
wanna connect to the database.
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We'll call DATABASE.create_tables and
right now,
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we're just gonna create User cuz that's
the only table that we have.
3:06
And of course, we want that to be safe,
so,
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safe equals True and when that's done, we
wanna call close on the database.
3:14
So then, down here at the bottom of
apps.py, or app.py, sorry.
3:19
Let's make sure that the models are
initialized,
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[SOUND] and let's automatically create,
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just in case it doesn't exist, let's
create a user for ourselves.
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So models.user.create_user, cuz we're not
gonna use create,
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we're gonna use create_user, so that it
encrypts the password for us.
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Name, I'll just say kennethlove, email is
kenneth@teamtreehouse.com.
3:44
Password is, let's go with something super
secure, let's use password.
3:53
[SOUND] Cause that's the best.
3:57
And I'm gonna make myself an admin.
3:59
[SOUND] All right, so save.
4:02
So if we were to do pythonapp.py down on
our shelf, then,
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it would initialize our models and it
would create a super user for
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us just in case that user doesn't exist
already.
4:14
So if we wanted to be able to log in
without having to create like,
4:18
some fake users, it's not that big of a
deal, but, you know, it's nice to have.
4:20
That's a really small function, but it's
super important how our app behaves.
4:25
And one of my favorite things about the
Python ecosystem,
4:29
we didn't have to write any of the down
and dirty code.
4:32
Okay, next up is building forms in Python.
4:35
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