try_mongo/video_transcripts/5-building-with-mongoengine/14-demo-view-bookings-as-guest_transcript_final.txt

00:00 Alright we're down to the very last thing we're
00:02 going to do as a guest which is to view our bookings.
00:05 We're able to book a gauge but as a guest we couldn't see
00:09 what are your upcoming stays for your snakes
00:12 and things like that. So, again, just for the sake of time
00:15 let me go over here and put some pre-written code
00:17 and we'll go write the data access later.
00:21 So, require an account and we're going to call
00:24 "get_bookings_for_user" and this is going to return a set of
00:27 bookings and just to remind you what that looks like
00:30 the bookings are going to have the days, possible reviews and
00:33 the snake ID is going to be really important.
00:37 So what we want to do is we want to say give us the snake
00:41 given a snake ID and a super simple way for us to do that
00:44 is to actually generate a dictionary using a
00:47 dictionary comprehension. So this little expression on here
00:51 is going to create a dictionary where they key is the ID
00:54 and the value is the snake for all the snakes
00:58 belonging to us, whoever the logged in user is.
01:00 Then we're going to get the bookings and this part we're
01:03 going to write and then we're going to loop over here
01:06 and we're going to print out the snake
01:10 and we'll use the dictionary to look up
01:11 to get the name here. We're going to print the cage name
01:15 and you're going to import date/time there.
01:19 We're going to create a date/time and do a little bit
01:22 of math here on the check out. So we're going to turn this
01:25 back into day. If you're checking in on this day
01:27 for five days or something like that.
01:29 Okay so that's what our view bookings UI
01:33 pretty much stretch. Right, with our app
01:36 this is kind of the UI code, if you will.
01:39 But we've got to write this bookings for user
01:43 this is going to be a "bson.ObjectID"
01:48 We'll bring it back as a list of booking, I believe.
01:52 Now, notice one other thing before we write this code
01:56 Over here we're saying "b.cage.name"
02:00 Now cages have bookings, but bookings don't have cages.
02:04 There's not a super nice way to create that
02:07 reverse association in MongoEngine,
02:11 so what we're going to do is part of what we're going to do
02:14 in this function is we're going to set up that relationship
02:17 and let's call this "user_id" or account ID
02:20 or something like that. Okay, so
02:22 the first thing we need to do is find the owner
02:25 so close account equals let's pass in an email instead
02:31 something like that and before I forget
02:33 pass in the email there. Okay great.
02:35 We'll have our account and we've already verified
02:38 that they're logged in. So we can just assume that
02:40 that happens. So we can say booked cages and so we can
02:43 find all the cages that have been booked
02:46 by this person. So we can say "Cage.objects"
02:51 and now we'll do a few other interesting things
02:52 we haven't seen yet. Let's say filter
02:54 and here we'll say "bookings__"
02:58 and then we're looking for
03:00 the guest owner ID. Let's go to our booking
03:06 that matches the owner. That equals to "account.id"
03:14 We don't actually care about all the details about the cage
03:16 and you can skip this little part right here,
03:18 but just as a means of efficiency we go over here
03:22 and say only. We haven't talked about this yet.
03:24 What we can do is say we only want to get back
03:27 two pieces of information not potentially tons of
03:30 information in this document. We want the bookings,
03:34 and we want the name. So when we say "cage.nameabove"
03:37 that means something, right?
03:40 So let's create the bookings and we'll do this with
03:42 a list comprehension. So we'll say bookings is this
03:46 and I'm going to write it one way and then I'm going to have
03:48 to make a change to do this reverse association with
03:50 the cage. So I can say booking
03:55 or booking in the book cages
03:59 but remember there are other bookings that are unrelated
04:02 to us. Here right could be two different snakes staying
04:04 in the same cage, different days. We need a little test
04:12 alright so this is going to be the bookings that are
04:17 assigned to us within the cages for which we have booked
04:21 right, so show me all the cages where we've booked
04:23 at least one of the bookings and we're going to strip out
04:26 the unrelated ones. So you might think that we're kind of done
04:29 and that we're very, very close to done, but we're not done.
04:33 So we've run this, you should see this is going to crash.
04:37 It's that line right there. I almost messed up.
04:40 So if this is actually for cage in the booked cages
04:44 and each cage contains a booking. So we've got to do a
04:47 double loop here. Booking in "cage.bookings"
04:52 What we're going to do is going to take the tyrannical list of
04:54 cages which nested inside them contain a bunch of bookings
04:59 and we're going to flatten that list with a double loop
05:02 go through each cage, go through each booking and just
05:04 turn that into a list and across all those bookings
05:08 across all the cages only show the ones which we some point
05:11 have booked. Okay so this is close but if we try to run it
05:16 this reverse lookup of the cage here it's not going to work.
05:21 So, let's see we're going to try and run that real quick
05:24 save, go to guest login as Sarah
05:30 now if we try to view your bookings
05:32 we see no cage. So let's view one more little trick.
05:36 We can do a transformation at this level, right
05:39 this is like the select part of the list comprehension
05:42 now this has to be an expression
05:44 I don't think we can do this with a lambda expression
05:49 cause it doesn't allow us to make modifications
05:51 so we got to define this little local function
05:53 so we'll say "map_cage_to_booking"
05:59 given a cage and a booking this is going to
06:03 be the silliest thing you've seen. "booking.cage = cage"
06:08 well, and then we're going to return cage--sorry--booking
06:13 but why do we need that? We need that so we come down here
06:16 and we add this function. It's going to take a booking and it's
06:20 going to put that same booking right back into the list
06:24 but the booking will be changed in that it's
06:25 going to have a cage associated with it.
06:27 Okay, I know that's not super obvious but that's what
06:30 we need to make that one line work.
06:33 I made a quick error here, I had booking cage here
06:38 and cage booking there so cage booking, cage booking
06:42 okay looks like its ready. We'll try again.
06:55 Alright, so fewer bookings. Woo hoo it works!
06:57 We have one booking. Our snake Slither is booked in the
07:01 large boa on the stay for five days.
07:04 Let's add one more booking just to make sure this is working.
07:07 We'll book a cage, alright so let's try to book that other
07:12 available booking. This time we're going to put Bully in there
07:16 and I guess we're going to book that one. Great
07:18 we view our bookings again. We now have our snakes booked
07:20 into the different sections at the different times.
07:24 Let's just try one more time now that those bookings
07:26 should have been used up, to see what happens.
07:30 So let's try to book one more cage. Say we'll start
07:32 on that date and we'll check out on that date
07:35 and we'll use this one. "Sorry, no cages, both
07:38 available spots have already been booked." Just so happens
07:41 to be to our snakes. Awesome.
07:43 It looks like the guest side of things is 100% working