Models

Flask makes it really easy to build routes, control HTTP methods and 0:00 headers and pars and send out JSON. 0:04 But why write all of that ourselves, we don't have to, right? 0:06 There's an excellent package named Flask-RESTful that we're going 0:10 to use to save ourselves some work. 0:13 With Flask-RESTful, you create classes, kind of like models, that represent your 0:15 resources and the HTTP methods that you want to allow on those resources. 0:19 We're gonna spend a lot of time working with these resources, so 0:24 let's get started right away. 0:26 Okay well, the first thing I need to do is, install the necessary packages. 0:29 So let's do pip install flask-restful and 0:33 then, I need an ORM, so I'm gonna install peewee as well. 0:37 I don't have to install Flask, 0:42 because it's automatically installed on workspaces, so that's great for me. 0:43 If you're working along at home, you'll need to install Flask as well. 0:49 If Flask-restful doesn't already install it for you, I have a feeling it does. 0:52 All right, so now, I want to make my basic app and my first models. 0:56 I wanna be really creative, so I'm gonna call my app app.py. 1:02 All right, easy enough and then, let's go ahead and we'll make our normal app. 1:06 Flask import flask and 1:13 then let's debug equal to true, host equal to 0.0.0.0. 1:16 Since we're on workspaces we need to be looking at all the ports and not just or 1:22 not, sorry not the ports, all the interfaces. 1:26 And not just the looped back local host interface and then, port. 1:28 Why do I have available here? 1:34 We'll do 8000, all right, so port is at 8000. 1:35 And then we'll make Flask(_ _name_ _), paying attention to the current file. 1:41 And then let's add a route to this, just to be certain that things are working. 1:46 And we'll just do addl loop at that forward slash,def hello_world and 1:57 we'll just return 'Hello World'. 2:00 All right, now let's get down here and if the name is equal to main, so 2:01 if we're running the file directly. 2:06 Then we're gonna do app.run debug=DEBUT, 2:09 host=HOST and port=PORT. 2:14 While I'm thinking of those, I'm gonna change my spaces to 4 and all right. 2:18 So I'm gonna save that, I think we're good there. 2:24 I'm not gonna even run and test this right now. 2:28 Actually, I will. 2:32 Let's go ahead and do that, so we'll do python app.py and 2:33 then we'll hit here and go 8000. 2:38 And cool, we got Hello World, great. 2:41 All right, so now I wanna make my models. 2:45 I'm gonna make another new file models.py and then let's setup these models. 2:47 So we're going to import datetime and then from pewee import, 2:54 I don't like doing that but that's the pewee standard. 3:00 Database = SqLiteDatabase and I'm wanna call this courses.SqLite, 3:05 you can call this whatever you want of course. 3:12 All right and then make a course model and 3:19 we'll give this a title, that's a CharField. 3:23 And we give it a URL, that's a CharField and I'm gonna make this one (unique=True). 3:27 So, that people don't submit the same URL twice, hopefully. 3:32 I mean, you could maybe use a forward slash at the end of one of them and 3:35 you don't at the end of the other one. 3:40 But close enough, And then we will do a created_at,. 3:41 Which is a DateTimeField and we will set a default in here of datetime.datetime.now. 3:45 And we don't put the parenthesis, because we want to call the function. 3:51 Whenever it creates the field and not whenever it instantiates the model. 3:56 And we'll do class meta and database=database. 4:02 All right, so pretty straightforward model. 4:07 This is some of the other models that we've made in the past and 4:11 let's make one more here. 4:16 Class Review which is also a model and 4:18 course = foreignKeyField. 4:23 And this is related to course up here, and related name, 4:27 I'm gonna call this review set. 4:32 And rating is an integer field, 4:37 comment is a text field with a default of an empty string. 4:42 Basically makes a thread, they don't have to put in a comment. 4:47 We'll just record an empty string if they don't provide one. 4:49 And then again, created_at is date time field, default is datetime.datetime.now. 4:53 And that's mainly just for housekeeping, so 5:00 that we can see when things were created. 5:04 Database = DATABASE. 5:07 And then let's set up an initialize function and 5:10 we'll do DATABASE.connect, DATABASE.create_tables. 5:15 And I wanna create course and review. 5:23 We'll have this be safe, so those two tables already exist, it just passes over, 5:27 it doesn't try to throw an error or anything. 5:30 And then database.close, all right. 5:32 Cool. 5:37 So two models, title and u.r.l created for that course and 5:37 course rating and comment and created_at for review. 5:42 Nothing new or out of the ordinary there. 5:46 Now I need to make sure that the app 5:49 makes sure that the models are created whenever the app starts. 5:52 So let's quit the app real quick, 5:56 control C and then, let's come over here. 6:02 And up here at the top, we'll add in import models 6:06 and then down here in the name main, 6:12 let's have it do models.initialize. 6:15 Okay cool. 6:21 So it will run this function whenever the app starts or 6:23 it should but let's make sure of that. 6:27 So, I will run that and if I refresh my column over here. 6:31 Yeah there we go, courses.sqllite. 6:37