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To create our `Relationship` instances, we need a couple of views and HTML links.
Alert!
In this video and the others in this course, you'll see me using {{ current_user.is_authenticated() }}. At the time of filming, this was the correct way to use the is_authenticated() method on the UserMixin from flask-login. BUT, as is often the case in open source, things have changed. You'll now want to always use it as a property instead. So, use {{ current_user.is_authenticated }} instead. No parentheses!
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Creating our relationships is
straight-forward.
0:00
Since the relationship is a model we'll
just need to make a new instance.
0:03
Let's go back to Workspaces and set up a
couple of views and
0:06
the appropriate HTML links to handle this.
0:09
Okay, so, let's see about building a
couple of views.
0:12
One for following a user and one for
unfollowing a user.
0:15
So, I'm gonna do these, let's scroll this
up here, I'm gonna do these to where we,
0:20
we do a follow, and then, the user name.
0:24
We could this with like, follow, and then,
a, an ID, if we wanted.
0:28
I think the user name, though, makes a
nicer looking URL, and
0:33
if you were doing this with say, a public
app instead of this one,
0:36
where it's kind of inside of a company
kind of an intranet app.
0:39
Then exposing the IDs could potentially
open you up to some security problems,
0:44
but you'd weigh that with the rest of your
team and with your own needs.
0:49
So we're gonna have this at
/follow/<username>.
0:53
And then we're gonna wrap this with
login_required, and
0:56
we're gonna say follow(username).
1:00
And then so we need to do a try here.
1:03
And the to_user is gonna be
models.User.get
1:06
models.User.username is like username the,
1:11
the double stars here is a case
insensitive search.
1:16
So where the username is this username,
but it could be uppercase,
1:20
lowercase, whatever.
1:24
Except models.DoesNotExist.
1:26
We need to do something, but for now,
let's just pass, and, and
1:32
we'll just have it go on.
1:35
Else, so the pass didn't happen.
1:37
Then we're gonna try
models.Relationship.create.
1:41
And the from_user is going to be our
g.user.
1:47
And we have to get that current_object.
1:51
Oops, forgot my comma.
1:54
And the to_user is gonna be the user that
we looked up, up on line 120.
1:57
So, the exception here would be
2:03
a models.IntegrityError since we have the
uniqueness constraint on there.
2:08
Then if we try to create another record
for the same,
2:15
like, I tried to follow you twice, then it
would trigger this integrity error.
2:20
If that happens, we're just gonna pass,
because, really, things are okay.
2:24
And if that pass doesn't happen, then
we're gonna flash up a message,
2:29
we're gonna say You're now following, and
then we'll put in a name.
2:32
And let's use to_user.username.
2:38
We could use the username that comes in to
the URL, but they might have typed it
2:42
slightly different, so let's use the
actual username.
2:46
And we're gonna send that back with a
success category.
2:49
Let me get back over here.
2:52
And we want to do return redirect url_for
stream and
2:55
the username is going to be the username,
again,
3:01
we should probably do to_user.username
just to be safe.
3:05
Alright, so, pull this down a little bit
so we can see the whole function.
3:11
So, we're doing this /follow/<username>
login_required, and
3:17
then, we're gonna try and find the user.
3:21
If that user doesn't exist we'll, we'll do
something with this later.
3:24
If the user does exist,
3:27
then we're gonna create this relationship
and, then we're gonna flash up a message.
3:29
So, let's actually take this whole thing
and copy it and then paste it.
3:34
And let's change this one to unfollow,
unfollow.
3:41
Okay.
3:47
We still want to get the user, but instead
of calling create we want to do get.
3:47
And then we want to call the
delete_instance.
3:56
And so what we're, what we're doing here
is, we're calling this get.
3:59
We're getting the same relationship that
we had before.
4:02
But now we're gonna delete it, when it
comes up.
4:05
And let's say You've unfollowed.
4:08
And then we'll put in the username and we
still leave it a success,
4:12
because they successfully did the thing
that they wanted to do.
4:16
Alright, so those are our two views.
4:21
So let's go add a couple of things in to
our templates.
4:24
And first of all let's go to the
user_stream template and
4:29
here we have these followers and
following.
4:34
Instead of the zeroes lets put in a couple
of counts.
4:36
So we can say user.followers().count,
4:39
and here, we can say
user.following().count.
4:44
And I forgot my closing brackets right
there, or my closing braces, rather.
4:50
And then, here, we need to put in a
follow/unfollow button.
4:56
And so, let's do, if
current_user.is_authenticated,
5:01
cuz we only want them to be able to do
this if they're logged in, all right.
5:08
And then inside there, if user does not =
current_user.
5:12
End that if.
5:20
Then let's say, if not user in
5:21
current_user.following, and end that if.
5:26
All right, so let's look at what we've got
so far.
5:32
So make sure they're logged in.
5:35
We make sure that we're not looking at the
user that's logged in.
5:38
And then we make sure that the user is not
already being followed by this user.
5:41
Okay, so if all that's true [LAUGH] then
we need to print out an href
5:48
url_for follow.
5:53
And the username would be user.username.
5:56
And we'll do a class on this of small, and
we'll say, follow.
6:00
And really now we need an else.
6:05
And we want almost this exact same thing.
6:10
So I'm just gonna copy it again.
6:12
And instead of follow, we want unfollow.
6:14
And we want unfollow there as well.
6:17
Okay.
And then,
6:22
we're still gonna call our super, and
we're still gonna do our end block.
6:22
So, that's all normal.
6:25
And, let's go try this out.
6:28
So, I'm gonna actually log out.
6:31
And then, I'm gonna sign up.
6:33
I'm gonna do a new one.
6:35
I'm gonna say test user, test@example.com.
6:36
And a password.
6:42
I'm gonna register.
6:45
Sweet, okay.
6:46
So now I'm gonna go look at Kenneth Love.
6:47
Oh.
Oh, that's right.
6:52
I forgot to log in.
6:53
So let's log in.
6:55
And test@example.com.
6:55
Password.
7:00
Okay.
So now I'm logged in.
7:03
So that says Hello testuser!
7:04
So, here's Kenneth Love.
7:06
He has no followers and nobody is
following, he's not following anybody.
7:08
So let's go ahead and hit Follow.
7:12
Look, our follower count went up.
7:13
And the unfollow, the following is still
empty.
7:16
So now I'm gonna log out and I'm gonna log
back in as me.
7:20
And put in my password.
7:26
Sweet, alright, and if I go look at my
account then I see I have a follower.
7:30
And let's go over here to test user, and
7:35
I'm gonna go ahead, he's following one, or
she, they.
7:40
I'm gonna go and follow them, there's
that.
7:44
And now, let's go back to my account and
check that out.
7:48
So, I have one follower and I am following
one person.
7:53
Those buttons will make our app a lot
easier to use.
7:58
And thanks to our followers and following
methods it was straight
8:01
forward to add some information to our
user pages too.
8:04
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