try_mongo/video_transcripts/5-building-with-mongoengine/10-demo-register-cage_trans...

00:00 Next thing we need to do as the host
00:03 is to be able to register our cage so that
00:05 people can view it and maybe book it.
00:07 That'd be great, right?
00:08 So, let's go over here and work with that.
00:11 Now, the cage has to be associated with an owner
00:14 through this software key relationship in MongoDB.
00:18 We're going to require an account,
00:19 and that's going to look like just an error message.
00:25 We'll just say if there's no account,
00:27 you must log in first to register a cage.
00:29 Alright, so now we have the account
00:31 and we're going to use that as part of it.
00:33 Let's go ahead and figure out how many square meters
00:36 this is going to be.
00:38 We'll say "meters = " something like this.
00:47 You might want to just directly convert that into a float.
00:50 But I found as I was interacting with this application
00:52 I'd accidentally go to register a cage
00:55 and I meant to list them.
00:56 You want some kind of way to cancel out,
00:57 so let's just suppose if they don't enter anything,
00:59 they just hit enter, it kind of short circuits everything.
01:02 We'll say "if not" something like this,
01:07 so if they don't enter anything, we'll just bail out.
01:09 Otherwise we'll just say, float of meters,
01:13 so convert it from a string to a float.
01:15 We're not doing the error handling on this.
01:17 You guys should probably add that, but we can just do this.
01:20 And we have to ask a bunch of other questions.
01:22 Is it carpeted, does it have toys?
01:24 Thing like that.
01:25 Let me just copy that over .
01:29 This is just user input stuff, right?
01:32 And then, we want to go down
01:34 and we want to actually register the cage.
01:37 Again, we want to do this at our data layer,
01:39 not here in our application code,
01:41 so we'll say "svc.register_cage()" and again,
01:44 that doesn't exist, but it's going to in a second.
01:47 We are going to pass the account.
01:52 We'll pass the active account here,
01:54 we'll pass the name of the cage,
01:57 we'll pass whether or not it allows dangerous,
02:00 just all of these items.
02:02 Whether or not it has toys,
02:04 whether it's carpeted, and the meters.
02:10 Okay, so we're going to go and call this function which,
02:13 obviously, doesn't exist yet,
02:15 but PyCharm will write it for us.
02:17 Thank you, PyCharm.
02:19 Here we can say this is an owner,
02:21 here's the name of the string, and so on.
02:24 There we go.
02:25 Let's say this is going to return a cage
02:28 which we have to import at the top.
02:29 Again, thank you PyCharm.
02:31 This is very, very similar to the create account.
02:33 We're just going to create a cage and save it.
02:39 We've set all the properties and we'll call "cage.save()"
02:42 and that's going to store it in the database.
02:45 Now, we want to, remember if we look over at our owners,
02:49 it has cage IDs to manage the relationships.
02:53 The order in which we do this is super important.
02:57 Now, we need to be a little bit careful
03:00 with this account here.
03:02 We want to make sure that we're getting the latest
03:05 account from the database, so we'll do something like this.
03:08 We'll say "account = find_account_by_email"
03:14 this "active_account.email"
03:17 That makes sure we don't have any stale data.
03:19 Then we're going to go "account.cage_ids"
03:24 This is a list, so we can append to the cage.ID.
03:28 It's super important, the order here.
03:31 We must call save so that this is an actual generated value.
03:36 It's just none beforehand, so we want to make sure
03:38 that's generated in the database
03:40 and then we can return the cage.
03:42 So, that warning up there goes away
03:45 because we are returning the cage.
03:49 The other thing that we need to do is,
03:52 this has changed the account,
03:54 but we haven't pushed those changes back to the database.
04:00 Alright, so our registered cage seems like it's working.
04:03 Let's go over here, and let's do one more thing.
04:06 This active account needs to have that data adjusted as well
04:11 so let's go over here to state, and has a reload account.
04:15 That's not written yet, let's do that.
04:18 This is super easy to do.
04:19 All we have to do is go to the database and pull it back
04:23 so we have this active account global variable
04:25 and we can come over here and say import the service
04:30 and here we're going to say "find_account_by_email"
04:32 "(active_account.email)", alright?
04:35 That's all we've got to do to reload it.
04:37 So, this'll make sure that it can work
04:40 with our "state.active_account"
04:41 It's the fresh one that just got its data changed down here.
04:46 Let's do one more thing before we carry on.
04:48 Let's go ahead and implement register cage here,
04:52 and let's spell suppress correctly.
04:54 Let's add the ability to list our cages
04:57 so that we can test that this actually worked.
04:59 Let's also do a success message,
05:02 "Registered new cage with id"
05:09 Make that an F string, actually.
05:12 "cage.ID" so we've got to store that up here.
05:19 Excellent, so now we've got our cage
05:20 and we'll see that come out, but let's go ahead
05:22 and we're going to require an account again,
05:24 which is the same info up here.
05:31 And all we've got to do is get the cages.
05:33 So, let's write like this.
05:36 Let's say, "cages = svc.find_cages_for_user"
05:44 Right, got to write that function.
05:46 There we go, creates an account.
05:49 Let's not call it active account, let's just say account
05:52 and that is an owner, and it returns a cage.
05:58 Actually, it's not a cage, what does it return?
05:59 It returns a list of cages, so we've got to go
06:01 to the typing module here, typing, and new cage.
06:06 Okay, perfect.
06:07 What we're going to do is, we already have the owner,
06:10 and because of our refresh account stuff, it should be fresh
06:14 so we'll have cage IDs, and we should have this
06:17 "account.cage_ids" right there that we can use.
06:21 Now, how do we query for this particular thing?
06:25 We're going to do something you haven't seen yet.
06:27 We're going to come to the cage, and again,
06:29 we're going to go to this objects and I'm going to do the query,
06:31 but instead of saying, remember before we had "email = "
06:34 and that did the query against MongoDB for testing quality?
06:38 We have something different we need to do.
06:40 We want to go to the ID of the cage,
06:42 and we don't want to just say, well, it's equal to,
06:45 it's not going to be equal to the list.
06:47 We can't say not cage IDs, because one is an object ID
06:51 and one is a list of object IDs,
06:54 so we have to use a special operator,
06:56 and MongoDB has all these simple dollar operators.
07:00 $set, $in, $not, $or,
07:04 these types of things.
07:07 And the way that we work with those in MongoEngine
07:10 is we use a double underscore to say
07:12 we're applying this to the ID but then there's this other
07:15 thing that we're doing and we're going to say "in"
07:18 This query right here, do a little cleanup,
07:21 this query says go to the cage and find all the cages
07:24 whose ID is in this list of IDs.
07:26 Now, we'll have "cages = " this is a query
07:32 but we want to execute the query and sort of snapshot it
07:35 for our app so it'll return cages.
07:41 And that should make our app totally happy.
07:44 That little warning, up and away.
07:46 Okay, great, so we've written this function
07:48 and we've used the "in" operator,
07:50 the double underscore, to access it.
07:52 Here's our cages, we just need to print them out.
07:54 Or see in cages...
07:58 Let's make these F strings, and we'll put them here
08:00 and we'll say "c." whatever we want here.
08:02 We want name...
08:06 Let's also print out something like this.
08:10 You have however many lengths of cages you have
08:13 and then we'll print those off, okay?
08:15 Let's try to test these two things that we've written.
08:19 For host, we first want to register a cage.
08:22 Actually, let's try to list our cages.
08:30 Login "michael@talkpython.fm." Let's list our cages
08:32 You have zero cages, great, so let's register a cage.
08:37 Now we're logged in it'll let us.
08:39 It's 2.2 square meters.
08:41 Yes, it's carpeted.
08:42 Yes, it has toys.
08:43 No, it has no venomous.
08:45 This'll be Bully's Cage.
08:49 It looks like we haven't set the price, hmm.
08:52 We've forgotten something, haven't we?
08:53 Okay, good thing we tested that here.
08:59 The price, and this will be, how much are you charging?
09:03 Alright, let's go ahead.
09:04 Price here, price, okay.
09:09 That was kind of annoying that that crashed,
09:12 but it's also cool.
09:13 Why is that cool?
09:14 Because if we said the cage must have a price and it didn't,
09:17 if that was regular MongoDB, that would've just let
09:19 that happen, but because it was MongoEngine, it did not.
09:22 Alright, let's do this again.
09:31 List my cages.
09:33 Whoops, list my cages.
09:34 We have no cages, let's register a cage and do this again.
09:42 How much are we charging?
09:44 We're charging $29 a night.
09:46 This is one fancy cage, folks.
09:48 Boom, we've registered a new cage.
09:50 Now, let's list your cages.
09:52 Ooh, we have "1 cages."
09:54 Maybe a plurality thing there, but Bully's cage is out.
09:57 Let's register one more cage.
10:00 This is a huge cage.
10:02 It's carpeted, has all the toys,
10:03 and this one's even for venomous snakes.
10:05 This would be the "Large boa cage," who knows.
10:11 And this is $39.
10:12 Now if we look at our cages, we have two cages.
10:16 Beautiful, so it looks like our registering
10:18 and our listing cages is working great.