WEBVTT 00:00.020 --> 00:02.450 Our next step is to set up the payment service. 00:02.450 --> 00:04.430 So inside Solution Explorer. 00:04.460 --> 00:06.950 Now back to our API functionality. 00:06.950 --> 00:09.860 I'm just going to right click the API and say new folder. 00:09.860 --> 00:12.320 And I'm going to call it services. 00:12.320 --> 00:20.360 And inside the services folder let's just clean things up inside here I'm going to create a new file. 00:20.360 --> 00:25.040 And I'm going to create a class called Payments Service. 00:26.060 --> 00:31.970 And we're typically do this or put something inside a services folder where we're using a third party 00:32.000 --> 00:37.100 service that doesn't rely on our database or Entity Framework or anything like that. 00:37.100 --> 00:38.810 And let's configure this. 00:38.810 --> 00:43.400 So we're going to need to inject inside here our configuration. 00:43.400 --> 00:47.600 So I'm going to use the I configuration interface and call it config. 00:47.630 --> 00:53.990 So that we've got access to the configuration keys that we've just created inside our payment service 00:53.990 --> 00:58.460 class I'm going to create a method a public async task. 00:58.670 --> 01:05.350 And this is going to return a payment intent that we get from the stripe package that we installed. 01:05.800 --> 01:10.330 And for some reason I've got using system and using stripe there. 01:10.450 --> 01:11.770 We'll need the using stripe. 01:11.770 --> 01:15.820 I'm not sure why it's dimmed out, but it is necessary for what we're doing here. 01:15.820 --> 01:22.570 And I'll use the method name of create or update payment intent. 01:22.630 --> 01:30.430 And we'll pass in to this method as an argument, the basket and call it basket, as we're going to 01:30.430 --> 01:35.770 need to see what's inside there in order to work out how much their order is going to be so that we 01:35.770 --> 01:37.300 can notify stripe. 01:37.360 --> 01:41.050 This is how much the customer is intending to pay. 01:41.110 --> 01:48.310 Now we've got the create or update payment intent, because we're not going to stick our user to the 01:48.310 --> 01:50.950 current basket until they've actually paid for it. 01:50.950 --> 01:56.380 So they will have the opportunity to go back into our store, add or remove items. 01:56.380 --> 02:03.540 And when they come back into the checkout, they'll once again hit the endpoint that uses this service 02:03.570 --> 02:05.370 to update the payment intent. 02:05.370 --> 02:06.870 That's the idea here. 02:06.900 --> 02:11.640 Inside this, we're going to use another setting from the stripe package. 02:11.640 --> 02:16.500 And this is going to be for our stripe configuration and the API key. 02:16.650 --> 02:18.840 And we're going to set this to config. 02:18.840 --> 02:26.220 And in square brackets we need to access the stripe settings colon secrets key. 02:26.730 --> 02:28.650 And it's one of those pesky strings. 02:28.650 --> 02:32.130 And once again your typo warning is here. 02:32.130 --> 02:37.590 Please double check that this matches what you've used inside your app settings, whether you've used 02:37.620 --> 02:40.440 Appsettings.json or app settings development. 02:40.590 --> 02:43.380 Jason, please double check that string. 02:43.410 --> 02:47.700 The easiest way for this not to work is to have a typo in there. 02:47.730 --> 02:49.650 Then we're going to create a service. 02:49.650 --> 02:54.660 So I'm going to say var service equals new payment intent service. 02:54.660 --> 02:57.030 Something else that we get from stripe. 02:57.750 --> 03:00.240 And then we'll create an intent. 03:00.240 --> 03:05.220 So we'll use var intent equals new payments intent. 03:05.250 --> 03:07.860 Again something we get from stripe. 03:08.040 --> 03:15.390 And then we can work out our subtotal based on what is contained inside the basket. 03:15.390 --> 03:24.840 So I'll specify var subtotal equals basket dot items dot sum. 03:25.140 --> 03:29.070 And then we can work out how much our basket is worth. 03:29.070 --> 03:39.480 So I'll use x goes two x dot quantity multiplied by x dot product dot price. 03:39.480 --> 03:41.550 And that will give us our subtotal. 03:41.550 --> 03:44.640 And then we can work out our delivery fee based on the subtotal. 03:44.670 --> 03:51.660 Because we know if their order is over $100, then it's going to be free. 03:51.690 --> 03:53.940 Otherwise it's going to be $5. 03:53.940 --> 03:58.170 So the delivery fee will be equal to the subtotal. 03:58.170 --> 04:03.140 And we'll check to see if it's greater than 10,000, which means $100. 04:03.320 --> 04:06.050 And if that is the case, we'll set it to be zero. 04:06.080 --> 04:08.000 Otherwise, it's going to be 500. 04:08.000 --> 04:12.290 And then we can check to see if we already have a payment ID set. 04:12.320 --> 04:16.730 Now what we'll need to do next actually is we'll need to go back to our basket entity. 04:16.730 --> 04:23.120 And we're going to add a couple of things inside here related to payments. 04:23.120 --> 04:32.150 So inside the properties for the basket let's add on a prop that's going to be a string and make it 04:32.150 --> 04:32.780 optional. 04:32.780 --> 04:37.220 And this is going to be a client secret that we'll store inside this basket. 04:37.220 --> 04:43.310 And this is what the client will use to communicate directly with stripe without involvement of our 04:43.340 --> 04:43.880 API. 04:43.910 --> 04:47.720 But we need to get the client secret when we create the payment intent. 04:47.720 --> 04:52.190 And once we have the payment intent, stripe will send us back the payment intent. 04:52.190 --> 04:54.200 And that includes the client secret. 04:54.200 --> 04:56.030 So that we can get this back to the client. 04:56.030 --> 04:57.950 We'll include it with our basket. 04:57.980 --> 05:03.370 Even though it says client secret, it doesn't matter that we're sending it back to the client. 05:03.370 --> 05:07.210 It is supposed to be given to the client to communicate with stripe. 05:07.360 --> 05:11.200 And also we'll have a prop that's a string again optional. 05:11.200 --> 05:15.220 And this can be for the payment intent ID. 05:16.030 --> 05:22.420 And the idea of this one being inside our basket as well is if they do update their payment intent, 05:22.420 --> 05:27.520 or they do update their shopping cart or basket and then they come back to the checkout, then we're 05:27.520 --> 05:30.160 going to need to update the payment intent. 05:30.190 --> 05:36.490 Let stripe know of the new amount based on the changes they've made to the basket, and that will update 05:36.490 --> 05:41.260 the payment intent in stripe so that when the customer does go to pay, everything matches. 05:41.260 --> 05:46.180 Because if there is a mismatch between the amount that we said they were intending to pay and then something's 05:46.180 --> 05:48.700 changed, then the payment won't work. 05:49.090 --> 05:54.460 So we have made a change to an entity, which does mean we're going to need to create a new migration, 05:54.460 --> 05:55.990 but we'll come on to that soon. 05:56.080 --> 06:01.420 So now we have that available, we can continue with our payment service. 06:01.420 --> 06:09.780 And we're going to check to see if the string is null or empty for the basket dot payment intent ID 06:10.200 --> 06:13.230 if it is empty, that means it's a new payment intent. 06:13.230 --> 06:15.900 So we'll create the configuration for that. 06:15.900 --> 06:17.820 And we need to create some options. 06:17.820 --> 06:24.330 So I'll say var options equals new payment intent creates options. 06:24.570 --> 06:26.430 And we'll open curly brackets. 06:26.430 --> 06:28.380 And then we'll specify an amount. 06:28.380 --> 06:32.730 And that's going to be equal to the subtotal plus the delivery fee. 06:33.600 --> 06:41.220 We'll also need to specify the currency which we'll set to USD in this case and the payment method types 06:41.400 --> 06:44.670 we will specify in square brackets. 06:44.670 --> 06:47.670 And then quotes is going to be card. 06:47.700 --> 06:52.320 That's the payment type that we are going to accept for our application. 06:52.320 --> 07:03.290 And then we can use intents equals and then use await service and create async to create that payment 07:03.290 --> 07:06.290 intent and we need to pass it the options. 07:06.860 --> 07:12.530 And what this returns to us is a payment intent from stripe. 07:12.590 --> 07:14.570 We'll also add the else condition. 07:14.570 --> 07:21.020 So below that curly brackets we'll add else open curly brackets again and create some options for if 07:21.050 --> 07:22.940 we're updating a payment intent. 07:22.970 --> 07:25.310 So I'll use options here again. 07:25.310 --> 07:31.850 And this will be new payment intent update options. 07:31.880 --> 07:38.450 And all we need to do here is double check the amount and set the amount based on what they've updated 07:38.450 --> 07:38.870 it to. 07:38.900 --> 07:44.660 So we'll use amount equals subtotal plus delivery fee inside here. 07:44.660 --> 07:48.740 And we don't need to set anything else because the currency and payment method types well they're not 07:48.740 --> 07:49.640 going to change. 07:49.670 --> 07:56.210 And then we can use await service and update async. 07:56.210 --> 08:02.570 And we'll pass in the basket and the payment intent ID and the options for this method. 08:02.570 --> 08:07.160 and below the else statement we can return the intent. 08:07.160 --> 08:09.770 And that's the code for the service complete. 08:09.770 --> 08:14.870 And because it is a service, then we're going to add this to our program class so that we can use it 08:14.870 --> 08:19.010 inside our controller and inject it inside our controller. 08:19.010 --> 08:21.680 So we'll open up the program class next. 08:21.680 --> 08:25.700 And inside here inside where we're defining our services. 08:25.700 --> 08:28.490 And because it's a service we can put it wherever we want. 08:28.520 --> 08:34.070 I'll just add it below the middleware because I feel that's the cleanest tidiest place to add it, not 08:34.070 --> 08:35.390 because I have to put it here. 08:35.390 --> 08:37.760 And then I'll specify builder services. 08:37.760 --> 08:40.340 And this one we're going to use add scoped. 08:40.340 --> 08:44.690 And remember the scoped is scoped to the HTTP request. 08:44.690 --> 08:51.950 So when the HTTP request is received and it's going to the payments controller that we don't have yet, 08:52.130 --> 08:56.900 the payments controller will have this payment service injected into it. 08:57.230 --> 09:03.940 And when the payment controller is created by the framework, then it also creates a new instance of 09:03.940 --> 09:08.470 our payment service that we're adding inside here. 09:08.470 --> 09:14.860 And because we've updated our basket entity, that means we also need a new migration. 09:14.860 --> 09:16.510 So I'm just going to open up the terminal. 09:16.540 --> 09:19.120 Go back to the tab where I'm running the API. 09:19.150 --> 09:31.330 I'm just going to stop it and clear this window and say dotnet new or dotnet f migrations ads and just 09:31.330 --> 09:36.010 say basket entity updated and press return. 09:36.010 --> 09:39.160 And this should work without issue and it has done so. 09:39.160 --> 09:40.660 Let's go and check the new migration. 09:40.660 --> 09:43.720 Just make sure we see what we expect to see. 09:43.750 --> 09:45.430 Please always do this. 09:45.430 --> 09:50.620 Please don't assume that just because it looks like it worked, it has worked. 09:50.620 --> 09:55.570 And what we'd expect to see in here is the two columns being added, the client secret and the payment 09:55.570 --> 09:56.500 intent ID. 09:56.830 --> 09:57.850 So that looks good. 09:57.850 --> 10:04.300 And the next thing we'll take a look at is adding a payments controller that makes use of this service.