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To let users make posts, we have to have a model to store the posts in. We'll also want to add some methods to our `User` model to make fetching posts easier.
New terms
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ForeignKeyField- A field that points to another database record.
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Our post model is going to be really
simple.
0:00
And actually very similar to our entry
model from the databases course.
0:02
But then we'll set up some handy methods
on our user model to make it
0:06
easier to get messages that a given user
has posted.
0:09
'Kay.
So we need to create our post model.
0:12
This is gonna be the thing that users can
submit.
0:16
So these are like your Status Updates on
Facebook or your Tweets on Twitter.
0:20
So, let's go down here and make a new
class.
0:25
And we're gonna call this Post.
0:30
And it's going to be a model.
0:32
Now, we don't need to use the user mix in
on this because this isn't a user, so
0:36
we're just gonna do straight model.
0:40
So, we're gonna have a timestamp for when
the post was created,
0:43
DateTimeField default equals
datetime.datetime.now.
0:49
So just like when our user was created.
0:54
The user, which is a foreign key.
0:56
I have a hard time typing foreign key at
times.
1:00
And we have to add a couple of attributes
here.
1:04
Let's talk about these attributes.
1:06
So we add one here that's called
rel_model.
1:07
And that's the model that this foreign key
points to, so it points to the user model.
1:11
Notice we have the capital U down there on
user.
1:16
And then we have related_name, and we're
gonna call this posts.
1:20
So related_name is what the related_model
would call this model.
1:24
So, if you're a user, what do you call the
post model instances that you've created?
1:31
You call those your posts, right?
1:36
So, related_name is posts.
1:38
And then we need to create a text area to
hold all the stuff.
1:41
And that's going to be a text field.
1:46
All right, class meta database equals
DATABASE,
1:49
all caps, order_by is going to be negative
1:53
timestamp because we want to have the
newest items first.
1:58
Now I wanna point out, we did this up here
on users.
2:03
And I did it again down here on post.
2:08
Those have to be tuples and to be tuples
they have to have a comma in them.
2:12
Now order_by could be a list if you wanna
do it as a list instead of a tuple.
2:16
But if you're gonna make it a tuple, which
I really think you should.
2:19
Because they're not going to be changed,
they're not going to be modified.
2:22
Then you want to be sure and put in that
comma.
2:24
The reason that we're doing the tuple with
the comma instead of just a string for
2:27
an individual field is you can have it
order by multiple fields, and
2:30
if there's a conflict, two of them came in
at the exact same timestamp,
2:34
you could then have it sorted by something
else.
2:37
Okay.
2:39
Let's change our user just a little bit.
2:40
We're gonna add a new method here called
get_posts.
2:45
And we're gonna return
Post.select().where(Post.user == self).
2:51
Now we could use the reverse foreign key
3:01
that we have where we can do like
user.posts.
3:05
And that's probably a better idea, really.
3:08
But writing this get_post let's us see how
we're doing this join thing.
3:10
Well not join but this, this query.
3:14
And then let's add another one here called
get_stream.
3:16
Eventually this is going to be our posts
plus the posts of people that we follow.
3:21
But for now it's just going to basically
be exactly the same as get_posts.
3:25
But we're gonna structure it just a little
bit different.
3:29
And you'll see what here.
3:33
We're going to do it here.
3:34
So post.user == self.
3:35
And notice that inside those parentheses
so.
3:37
These are almost identical to each other.
3:41
But this is going to get changed later.
3:43
So, these two let us select the posts that
we want.
3:46
So, these are all the posts that belong to
a certain user.
3:50
Once we get our social graph set up, we'll
be able to change that
3:54
get_stream method to gets posts from
users you followed too.
3:56
I can't wait.
3:59
Before we get there though, let's set up
the form and
4:01
the view that we'll use to create a new
post.
4:03
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