WEBVTT 00:03.910 --> 00:05.320 Hey, did everyone this year. 00:05.320 --> 00:08.120 And now let's worry about the reviews itself. 00:08.140 --> 00:09.990 Now, reviews are really a simple thing. 00:10.000 --> 00:13.310 It's just like adding a separate page for updating the stock just. 00:13.330 --> 00:14.050 Just like that. 00:14.050 --> 00:16.270 So in this case, we haven't put down any reviews. 00:16.270 --> 00:18.370 Now we're going to do that now reviews. 00:18.370 --> 00:20.650 Just trying to imagine that you'll be having a website. 00:20.650 --> 00:22.390 There will be a lot of cards on that. 00:22.390 --> 00:25.450 So you won't be allowing user to add the reviews just from that page. 00:25.450 --> 00:30.550 You'll be allowing user to add reviews from when somebody clicks on that card and visits the individual 00:30.550 --> 00:34.210 product itself, then we'll allow there or probably somewhere else. 00:34.210 --> 00:37.990 So this is usually the ideal situation where all the details of the product are there. 00:37.990 --> 00:40.270 Just below there the reviews are going to be there. 00:40.450 --> 00:42.670 So if I can go ahead and click on that. 00:42.670 --> 00:47.140 Definitely in that page, I do have an axis of that idea of the product. 00:47.140 --> 00:49.180 Now, how you're going to send the idea of the product. 00:49.180 --> 00:49.900 It's up to you. 00:49.900 --> 00:51.100 You are designing the application. 00:51.100 --> 00:55.210 You can request that in the URL, you can request that in a query. 00:55.210 --> 00:57.760 You can request that in the body however you like to go. 00:57.940 --> 01:02.110 Now, in case you are going to request that in the root itself, then obviously the root is going to 01:02.110 --> 01:03.340 become something like this. 01:03.460 --> 01:07.420 Let me just show you that as a brief example, probably just here. 01:07.570 --> 01:11.740 So if you are requesting that here, so probably something going to look like this, that this is going 01:11.740 --> 01:16.060 to be slash product, then we need to have the product ID itself. 01:16.060 --> 01:24.040 So let's just call this one as simply product product ID and then we are going to have a slash and then 01:24.040 --> 01:25.660 probably more information that you have. 01:25.660 --> 01:31.020 So the point here is that I want to say is you can request the product ID in the URL and the body in 01:31.030 --> 01:32.470 itself and the query as well. 01:32.470 --> 01:33.580 So it depends on you. 01:33.610 --> 01:37.360 Now I will be requesting the this product ID in the body itself. 01:37.360 --> 01:38.170 Again, no big deal. 01:38.170 --> 01:40.600 User can actually go ahead and pass on me this one. 01:40.960 --> 01:42.850 I'll actually copy this one up here. 01:42.850 --> 01:45.040 So let's go ahead and make a copy of this one. 01:45.340 --> 01:49.360 I'll say let's close this one and expand this one and move up here. 01:49.480 --> 01:52.180 So this one is going to be simply add a review. 01:52.180 --> 01:55.780 So let's go ahead and simply say add review. 01:55.780 --> 01:56.350 That's it. 01:56.350 --> 01:57.250 That's pretty much it. 01:57.280 --> 01:59.320 Now let's go ahead and work on with that. 01:59.410 --> 02:02.650 A couple of information that I would like to jog your memory on this one. 02:02.650 --> 02:04.600 So first is the middleware. 02:04.600 --> 02:09.640 So if I go ahead and open this middleware, if you remember that once we are having this request of 02:09.670 --> 02:16.120 user, remember we are finding we are using fine by ID and based on the ID, we are finding a user. 02:16.600 --> 02:19.300 And most important thing is this user is a big object. 02:19.330 --> 02:24.760 Now entirety of the information that is stored in my database about the user, his name, email, his 02:24.760 --> 02:25.810 ID, everything is there. 02:25.810 --> 02:29.650 So just to jog it one more time, if I go ahead and check out the users. 02:29.650 --> 02:34.600 So all this information including is underscore ID has a dot name, dot email, password. 02:35.050 --> 02:40.690 Everything is available to me in the request dot user and that's all the information I need so I can 02:40.690 --> 02:41.980 go ahead and add that view. 02:42.640 --> 02:48.730 Just one last thing before we add that we need to also verify and check that whether this user has already 02:48.730 --> 02:53.230 done a review in the past or not, if he has already added a review in the past, we just want to update 02:53.230 --> 02:54.730 that review and that's pretty much it. 02:54.730 --> 02:56.530 That's all that's all what we're going to do. 02:56.710 --> 02:57.220 Okay. 02:57.880 --> 03:00.970 So first, let's extract all the information from the body. 03:00.970 --> 03:04.060 So all the information will be coming up in request or body. 03:04.060 --> 03:05.500 Let's go ahead and extract that. 03:05.500 --> 03:09.730 So we're going to go ahead and say, hey, I need some information that will be coming up from there. 03:09.940 --> 03:14.050 And precisely the one thing that I'm looking for is the rating that's going to be coming in. 03:14.050 --> 03:16.300 The rating is going to be between one and five. 03:16.300 --> 03:21.280 My front end guy is responsible for restricting that between one and five. 03:21.310 --> 03:23.680 We will be requesting a comment as well. 03:23.680 --> 03:27.670 So we're going to go ahead and say, hey, bring me the common and we'll also get a product ID. 03:27.670 --> 03:30.190 So we're going to go ahead and say, hey, give me a product ID. 03:30.220 --> 03:33.430 So all these information will be coming up from the body itself. 03:33.430 --> 03:39.880 Now coming on to the model itself of the product, not here, the product model. 03:39.880 --> 03:40.600 There we go. 03:40.630 --> 03:45.960 Now inside this product model, we are adding the review so user we can extract then from our request 03:46.080 --> 03:46.870 the user. 03:46.870 --> 03:48.070 So this is an ID. 03:48.070 --> 03:53.260 So all I have to say is remember in order to access this ID, I'll have to say request dot user dot 03:53.260 --> 03:54.280 underscore ID. 03:54.310 --> 03:56.290 Similarly, I can access the name as well. 03:56.290 --> 04:00.820 No big issue and then rating and the comment is coming up already in the body. 04:00.820 --> 04:01.930 So no big deal there. 04:02.590 --> 04:04.630 Now let's go ahead and construct that. 04:04.630 --> 04:10.390 So we're going to go ahead and create a simple review that is going to be pushed inside the ETA reviews. 04:10.390 --> 04:12.460 So let's go ahead and call this one as a review. 04:12.700 --> 04:15.130 Now, this review is going to be an object that will be pushed. 04:15.130 --> 04:21.790 So again, we have a property of user and this user is going to look like from request dot, user, 04:21.790 --> 04:26.470 dot and again, make sure it is underscore ID because that's how the values are stored in the database. 04:26.470 --> 04:32.650 We just saw that inside our guy for the mongoose, not mongoose, the MongoDB. 04:33.460 --> 04:36.310 So we got the user similarly we'll getting the name as well. 04:36.310 --> 04:42.580 So request dot user dot name in case you want to add email up to you how you are designing your application. 04:42.790 --> 04:45.820 We will be saying that, hey, I will be having a rating as well. 04:45.820 --> 04:49.960 The rating we're going to wrap it around between the number because that's what we are expecting. 04:49.960 --> 04:56.530 And I expect that whoever is sending me it says job to send me between one and a five number. 04:56.710 --> 04:59.230 And then further down the road we'll have the comments. 04:59.230 --> 05:01.840 So let's go ahead and say comment is going to be simply comment. 05:02.000 --> 05:06.440 And since we are using JavaScript modern version, we can just go ahead and remove this and this will 05:06.440 --> 05:08.030 still take care of the things. 05:08.300 --> 05:12.460 Now the next thing is just let's go ahead and push this into the database. 05:12.470 --> 05:17.900 Now we can actually go ahead and push it into database pretty easily, but we have to first check that 05:17.900 --> 05:18.800 in what product? 05:18.800 --> 05:21.500 I have to push this because this is right now just hanging. 05:21.500 --> 05:25.010 So I need to find a product in which I can add this information. 05:25.010 --> 05:27.410 Let's go ahead and find that particular product. 05:27.410 --> 05:29.810 So we're going to go ahead and say, hey, product. 05:30.890 --> 05:35.540 And since this is a database operation await and we're going to go ahead and say, hey, I want to find 05:35.540 --> 05:42.980 a product and I'm going to use a find by ID and I'll just provide this exact same product ID that you 05:42.980 --> 05:44.450 are sending me in the body. 05:44.570 --> 05:45.410 So there we go. 05:45.410 --> 05:47.300 I found I found that product. 05:47.300 --> 05:54.560 Hopefully now we need to check whether this user has already made a review or not. 05:54.560 --> 06:01.070 And since each of these array is injecting this user ID, only one user is allowed to send one review 06:01.070 --> 06:01.490 only. 06:01.490 --> 06:02.570 Let's go ahead and check that. 06:02.570 --> 06:03.230 It's pretty easy. 06:03.230 --> 06:05.900 We can go ahead and use a method on the error itself. 06:06.140 --> 06:08.060 So we're going to go ahead and see 06:10.280 --> 06:13.070 already reviewed. 06:13.070 --> 06:15.440 So this is going to be a boolean, true and false value. 06:15.470 --> 06:17.120 How we're going to go ahead and get that. 06:17.240 --> 06:19.460 We're going to go ahead and load this product. 06:19.460 --> 06:25.700 And inside this product we are going to look for the reviews, error reviews, make sure you look for 06:25.700 --> 06:26.600 the model here. 06:26.720 --> 06:29.330 And this is an error reviews. 06:30.310 --> 06:34.690 Now inside these reviews, we can use all the methods that we got, so we're going to go ahead and simply 06:34.690 --> 06:36.070 look for a find here. 06:36.100 --> 06:40.900 Now, this fine method gets gives us a true and false value based on whether the condition is being 06:40.900 --> 06:41.800 matched or not. 06:41.830 --> 06:44.800 So I'm going to go ahead and access one property into this review. 06:44.800 --> 06:47.860 So I'm going to go ahead and loop through each of these values. 06:47.860 --> 06:50.980 So I'm going to go ahead and say, Hey, individual review. 06:51.400 --> 06:54.460 Now this is how we are going to go ahead and work on with that. 06:54.580 --> 06:59.000 So this is going to be a simple method that we're going to call and we're going to go ahead and say, 06:59.000 --> 07:08.170 hey, on these each item of the review, we are having a property of DOT user and this property is going 07:08.170 --> 07:12.970 to be equal to whatever the request is coming to me. 07:13.210 --> 07:16.210 I'll say that, hey, there is a user coming up there as well. 07:16.210 --> 07:21.160 So request dot user dot underscore ID. 07:21.460 --> 07:24.760 So if this matches, that means this guy has already reviewed. 07:24.760 --> 07:29.620 But the problem is this ID, this underscore ID is a based on object. 07:29.620 --> 07:32.200 So this is based on kind of a value. 07:32.200 --> 07:34.330 So I need to convert that into a string. 07:34.330 --> 07:38.350 And this is a really important thing to a string and make sure you fire this up. 07:38.590 --> 07:41.260 This is kind of a one on one thing inside this one. 07:41.260 --> 07:46.000 So we'll be saying to a string, okay, this again, repeating this stuff because this can be a little 07:46.000 --> 07:46.900 bit confusing. 07:46.900 --> 07:49.210 I'm marking this Boolean field. 07:49.210 --> 07:54.570 I'm saying, hey, go into the reviews array and use the property dot fine, which is a classic error 07:54.580 --> 08:00.190 method which allows you to just run some condition on each and every object we're calling each object 08:00.190 --> 08:01.980 as review or rev. 08:01.990 --> 08:05.200 Now inside this ref, go ahead and check the user property. 08:05.200 --> 08:10.930 If this user property matches with whatever the user underscore ID, I'm giving it to you. 08:10.930 --> 08:11.860 That means it's a true. 08:11.860 --> 08:15.700 That means this user has already b has done the review. 08:16.960 --> 08:19.040 Now again, please don't get confused here. 08:19.060 --> 08:22.930 This rev is actually repeating over each of the object. 08:22.930 --> 08:27.220 This request is coming to me from the front end itself. 08:27.220 --> 08:29.080 So again, really simple one. 08:29.210 --> 08:29.520 Okay. 08:29.530 --> 08:32.590 Moving further down the road now I have the access of this. 08:32.590 --> 08:35.160 I can actually run that simple if an LS condition. 08:35.170 --> 08:38.290 So let's go ahead and simply work on this. 08:38.290 --> 08:43.450 If an LS if already reviewed now if he has already reviewed, then we are going to work on that. 08:43.450 --> 08:46.450 If not, then simply we can go ahead and run the LS. 08:46.450 --> 08:50.190 If he hasn't already reviewed, then it is the simplest thing of all to do. 08:50.200 --> 08:52.210 We're going to go ahead and run this product. 08:52.210 --> 08:56.080 We're going to say, Hey, we want to have an access of this reviews array. 08:56.080 --> 09:00.790 So we're going to go ahead and say, Hey, I have this sort of views and this can have a simple push 09:00.790 --> 09:05.170 property and go ahead and push up our already designed object, which is review. 09:05.320 --> 09:06.940 So we are going to push that. 09:06.940 --> 09:09.610 Now one more thing we have to worry about in this case. 09:09.610 --> 09:10.690 So this is our reviews. 09:10.690 --> 09:13.360 But remember, we have this number of reviews as well. 09:13.480 --> 09:16.120 So this number of reviews needs to be updated as well. 09:16.120 --> 09:17.830 So let's go ahead and work with that. 09:17.830 --> 09:23.500 So once this is being done, so we're going to go ahead and say product dot. 09:24.310 --> 09:28.360 Let me go ahead and copy this actually number of reviews. 09:28.360 --> 09:29.200 Copy that. 09:30.950 --> 09:38.600 Product number of reviews is going to be it is going to be calculated from product, dot reviews, dot 09:38.600 --> 09:39.380 length. 09:39.620 --> 09:44.720 Now obviously I know and I'm fully aware that there is one more property we need to check on, which 09:44.720 --> 09:45.590 is the ratings. 09:45.590 --> 09:51.260 So rating is basically an average of all the users review that they have given divided by total number 09:51.260 --> 09:52.440 of reviews that I have. 09:52.460 --> 09:54.650 I will take care of that in a minute. 09:54.650 --> 10:00.560 But first, let's check out the condition that if a user hasn't already reviewed, we have pushed the 10:00.560 --> 10:01.580 values inside this. 10:01.580 --> 10:05.680 But if a user has already reviewed, then we might want to update the value. 10:05.690 --> 10:07.190 So let's go ahead and update that. 10:07.190 --> 10:08.990 So I'm going to go ahead and access again. 10:08.990 --> 10:12.770 Same thing we're going to say product dot reviews. 10:15.110 --> 10:15.590 A review. 10:15.590 --> 10:16.990 So I want to look through this array. 10:17.000 --> 10:21.020 So I'm going to go ahead and use the classic for each command. 10:21.050 --> 10:25.050 No, it doesn't suggest me anything in the classic for each. 10:25.070 --> 10:27.830 I'll access to each of the review and I'll. 10:27.830 --> 10:30.310 I would like to run a simple method on that. 10:30.320 --> 10:37.670 What I'll say I want to match that particular element inside the arrays, which is having this review. 10:37.670 --> 10:41.090 So I'm going to go ahead and use a simple event ls condition up here. 10:41.090 --> 10:44.630 And again, actually I can go ahead and use the same condition here. 10:45.020 --> 10:51.200 I'm going to go ahead and copy this and I will paste the condition here instead of rev. 10:51.200 --> 10:52.640 This time we are calling it as review. 10:52.640 --> 10:54.860 So let's go ahead and copy this and update that. 10:55.130 --> 11:00.410 So now we are finding the users, whatever the review is, I hope this is pretty clear. 11:00.470 --> 11:02.240 In that case, we need to just update. 11:02.240 --> 11:04.340 So individual element, which is review. 11:04.340 --> 11:11.590 In this case, your comment comment is going to be updated by whatever the comment we have. 11:11.600 --> 11:13.850 Remember, we are extracting the comment up here. 11:14.540 --> 11:15.920 So this is being updated. 11:15.920 --> 11:17.390 Your rating should also be updated. 11:17.390 --> 11:22.190 So we're going to go ahead and say review DOT rating, are we calling it as rating? 11:23.270 --> 11:24.920 We are calling it as rating. 11:24.920 --> 11:25.370 Yep. 11:26.180 --> 11:28.850 So rating is going to be updated as rating. 11:29.300 --> 11:29.480 Okay. 11:29.630 --> 11:30.670 So this is all good. 11:30.680 --> 11:35.000 Now, we have found that particular element inside the array and we have updated that. 11:35.060 --> 11:39.440 Now there is one more thing still remaining that no matter how you have pushed the value inside the 11:39.440 --> 11:44.480 array, there is one more property we are calculating, which is this average ratings. 11:44.480 --> 11:45.710 So there is an SX there. 11:45.710 --> 11:47.270 This is an average rating. 11:47.390 --> 11:54.260 Let's go up here and say now we need to adjust ratings. 11:55.580 --> 11:58.760 Okay, so how we are going to adjust rating first, we need to access that. 11:58.760 --> 12:06.550 So product DOT ratings now this is going to be updated by an average of how many reviews we have. 12:06.560 --> 12:08.120 So let's go ahead and access that. 12:08.120 --> 12:17.080 So let's go ahead and say, hey, product dot reviews and each of these reviews inside this array, 12:17.090 --> 12:21.350 we can actually run a simple reduce method again, reduces a classic JavaScript method. 12:21.350 --> 12:22.790 Let's go ahead and work on with that. 12:22.790 --> 12:26.150 It gives you an accumulator and the item as well. 12:26.210 --> 12:31.670 So inside this further down the road, we can actually go ahead and say, hey, on each of this item, 12:31.670 --> 12:39.140 there is a property of rating that needs to be accumulated and we are going to start with zero again. 12:39.140 --> 12:42.650 You can read the box a little bit more onto that, but this is how we do it. 12:42.650 --> 12:46.790 And this whole thing is going to be divided by how many total reviews we have. 12:46.790 --> 12:53.990 And we can find that simply by saying product, dot reviews, dot length. 12:54.200 --> 12:54.860 There we go. 12:55.010 --> 12:56.120 So again, really simple. 12:56.120 --> 13:00.620 We have just loop through the array, use the reduced method to find the property and we are just calculating 13:00.620 --> 13:03.920 the average and we are updating this rating up here. 13:04.040 --> 13:06.740 Now only thing that's remaining is now to save this one. 13:06.740 --> 13:08.450 So we're going to go ahead and save it. 13:08.450 --> 13:11.000 So how we can save that again, we have done this many times. 13:11.000 --> 13:12.020 Shouldn't be a big deal. 13:12.350 --> 13:15.710 We're going to go ahead and say, hey, product, go ahead and save this one. 13:15.710 --> 13:22.340 But this time, since we are manipulating a lot of properties, it is really nice to have this validate 13:22.340 --> 13:24.350 before save flag. 13:24.470 --> 13:28.550 So no, it's not going to suggest me validate before save. 13:28.550 --> 13:32.000 Let's go ahead and turn off this flag so that we don't face any issues. 13:32.960 --> 13:35.060 So this is all done and this is all good. 13:35.060 --> 13:37.620 Now, further down the road, we are going to just send a response. 13:37.620 --> 13:42.860 So we're going to say restart status and the status is going to be 200, obviously. 13:43.010 --> 13:47.330 And then we're going to go ahead and say, Hey, Jason, response and we are going to go ahead and say 13:47.330 --> 13:49.040 success is going to be true. 13:49.040 --> 13:50.810 That's all the response we are sending. 13:51.080 --> 13:55.760 So hopefully things are okay and very understandable as well. 13:55.760 --> 13:57.830 Let's go ahead and catch up in the next video.