1 00:00:03,710 --> 00:00:07,605 Now that we have learnt about Mongoose Population, 2 00:00:07,605 --> 00:00:14,040 and how it enables us to populate one document with information from another document. 3 00:00:14,040 --> 00:00:20,605 In this exercise, we will modify the express server that we have been working on so far. 4 00:00:20,605 --> 00:00:25,580 In the dish schema that we have defined earlier, we had comments. 5 00:00:25,580 --> 00:00:28,365 For the comments, we had the author field 6 00:00:28,365 --> 00:00:31,490 that we use to store the details about the author. 7 00:00:31,490 --> 00:00:40,815 In this exercise, we will turn the author field into a reference to a user document, 8 00:00:40,815 --> 00:00:46,265 and we will use Mongoose population to populate the information into 9 00:00:46,265 --> 00:00:50,330 the dishes document as and when required in order 10 00:00:50,330 --> 00:00:54,440 to supply the information to the client. 11 00:00:54,440 --> 00:00:59,960 Now the use of populate and Mongoose population should be done 12 00:00:59,960 --> 00:01:05,550 judiciously so as not to cause too much of overhead on the server side. 13 00:01:05,550 --> 00:01:06,890 Now in this exercise, 14 00:01:06,890 --> 00:01:09,395 we're going to use it simply to populate the information 15 00:01:09,395 --> 00:01:13,280 into the author field of our comments. 16 00:01:13,280 --> 00:01:18,660 So, let's proceed with the exercise to learn how we use Mongoose population. 17 00:01:18,660 --> 00:01:21,455 To get started on this exercise, 18 00:01:21,455 --> 00:01:25,315 go to the project and open the user.js file. 19 00:01:25,315 --> 00:01:27,730 So, in the user.js file, 20 00:01:27,730 --> 00:01:29,600 we store the user schema. 21 00:01:29,600 --> 00:01:35,515 I'm going to modify the user schema by adding in a couple of more fields in there. 22 00:01:35,515 --> 00:01:38,220 One is the first name, 23 00:01:38,220 --> 00:01:40,070 which will be of 24 00:01:40,070 --> 00:01:48,115 the type string and 25 00:01:48,115 --> 00:01:52,025 the default would be an empty string. 26 00:01:52,025 --> 00:01:56,555 So, the first name as the name implies, 27 00:01:56,555 --> 00:02:03,630 stores the first name for the user and then we'll have another field called last name, 28 00:02:03,630 --> 00:02:06,540 which is also of the same kind. 29 00:02:06,540 --> 00:02:13,540 So, I'm just going to copy these two pieces of information and then copy it in 30 00:02:13,540 --> 00:02:20,735 here and so now our user document will contain, 31 00:02:20,735 --> 00:02:22,840 in addition to the username and password, 32 00:02:22,840 --> 00:02:26,760 username and hush and salt that we have seen earlier, 33 00:02:26,760 --> 00:02:34,450 that is automatically added by the passport local Mongoose module. 34 00:02:34,450 --> 00:02:39,840 We will also have the first name and last name for the user being defined here. 35 00:02:39,840 --> 00:02:43,505 Later on we will see how we would initialize 36 00:02:43,505 --> 00:02:50,765 these values by modifying the user's registration process. 37 00:02:50,765 --> 00:02:52,950 Now once we have completed this, 38 00:02:52,950 --> 00:02:56,599 so this way the user's information 39 00:02:56,599 --> 00:03:00,880 can simply be retrieved by looking up the user document here. 40 00:03:00,880 --> 00:03:05,200 So, now that we have the information about the user in the user document, 41 00:03:05,200 --> 00:03:08,560 going into the dish schema, 42 00:03:08,560 --> 00:03:11,015 so going into dishes.js file. 43 00:03:11,015 --> 00:03:13,260 In the dish schema earlier, 44 00:03:13,260 --> 00:03:18,465 we were storing the author of the document in the form of a string here. 45 00:03:18,465 --> 00:03:22,700 Now we're going to be taking advantage of the fact that we 46 00:03:22,700 --> 00:03:27,425 have the support of mongoose population. 47 00:03:27,425 --> 00:03:33,740 So I'm going to turn the comment field from a string into 48 00:03:33,740 --> 00:03:41,975 mongoose schema types object ID. 49 00:03:41,975 --> 00:03:49,120 So, this way, sorry, wrong field. 50 00:03:49,120 --> 00:03:53,135 I meant to turn the author field into 51 00:03:53,135 --> 00:04:02,295 mongoose schema types object ID. 52 00:04:02,295 --> 00:04:05,390 So, the author field now instead of storing a string, 53 00:04:05,390 --> 00:04:10,835 will have a reference to the user document. 54 00:04:10,835 --> 00:04:14,105 So, when I turn the author field into this type, 55 00:04:14,105 --> 00:04:20,180 then the second property that I defined here will be a reference, 56 00:04:20,180 --> 00:04:25,229 which would be a reference to the user model. 57 00:04:25,229 --> 00:04:27,980 So, this way, we are now going to be 58 00:04:27,980 --> 00:04:31,370 connecting this author field and this author field will 59 00:04:31,370 --> 00:04:37,585 simply store a reference to the ID of the user document, 60 00:04:37,585 --> 00:04:43,790 instead of storing the details about the author in the form of a name. 61 00:04:43,790 --> 00:04:45,100 Now when we do that, 62 00:04:45,100 --> 00:04:48,350 we can use mongoose populate to populate 63 00:04:48,350 --> 00:04:53,115 this information into our dishes document whenever required. 64 00:04:53,115 --> 00:04:58,595 So, with this modification to the dishes schema, in dishes.js file, 65 00:04:58,595 --> 00:05:05,910 we'll now update the dish router to use the mongoose population. 66 00:05:05,910 --> 00:05:09,030 So, going to dishRouter.js. 67 00:05:09,030 --> 00:05:16,120 In dish router, recall that when we were getting a dish here, 68 00:05:16,120 --> 00:05:19,470 now when you get the dish here, 69 00:05:19,470 --> 00:05:23,820 we say dishes find then. 70 00:05:23,820 --> 00:05:26,610 So, right at that point, 71 00:05:26,610 --> 00:05:36,005 we'll say dishes find and we will say after this, populate. 72 00:05:36,005 --> 00:05:41,924 So, we are using the population support in mongoose 73 00:05:41,924 --> 00:05:48,165 and we'll say populate comments author. 74 00:05:48,165 --> 00:05:49,740 So, by stating this, 75 00:05:49,740 --> 00:05:51,060 we are saying when 76 00:05:51,060 --> 00:05:58,750 the dishes document has been constructed to send back the reply to the user, 77 00:05:58,750 --> 00:06:05,810 we're going to populate the author field inside there from the user document in there. 78 00:06:05,810 --> 00:06:09,095 So, this call to the populate will ensure that 79 00:06:09,095 --> 00:06:14,665 the other field will be populated with the information as required. 80 00:06:14,665 --> 00:06:18,565 Similarly, going to the dish ID here, 81 00:06:18,565 --> 00:06:21,660 even in the dish ID, same thing. 82 00:06:21,660 --> 00:06:31,680 We will say populate and comments author added 83 00:06:31,680 --> 00:06:37,320 into the dishes find by id in 84 00:06:37,320 --> 00:06:43,395 the get of the /dish ID endpoint. 85 00:06:43,395 --> 00:06:54,350 Similarly, in the comments also when we retrieve the dish, 86 00:06:54,520 --> 00:07:02,370 we'll say populate comments author here and the 87 00:07:02,370 --> 00:07:09,900 same thing also in the dish router, 88 00:07:09,900 --> 00:07:13,695 dish ID comments, comment ID also. 89 00:07:13,695 --> 00:07:16,530 The bigger populating this information there. 90 00:07:16,530 --> 00:07:22,620 Now of course, what this means is that when you are posting the dish, 91 00:07:22,620 --> 00:07:30,090 earlier you are including the author information in the body of the message. 92 00:07:30,090 --> 00:07:35,120 So, now here when we try to push the comment into that, 93 00:07:35,120 --> 00:07:41,370 so this post corresponds to the dish ID comments field. 94 00:07:41,370 --> 00:07:46,280 So, this is how we were posting a comment to a specific dish. 95 00:07:46,280 --> 00:07:48,570 So, now in this post, 96 00:07:48,570 --> 00:07:53,890 since we are not storing the information about the author anymore, 97 00:07:53,890 --> 00:08:02,400 so what we need to do is when we push the item into the author field there. 98 00:08:02,400 --> 00:08:06,720 So, here when you're populating the information into the dish, 99 00:08:06,720 --> 00:08:10,680 we will have to first- 100 00:08:12,010 --> 00:08:16,430 Recall that the body contains the comment already, 101 00:08:16,430 --> 00:08:21,505 but the author property will not be there in the body of the message in the book, 102 00:08:21,505 --> 00:08:26,020 but depending on which user is posting this information, 103 00:08:26,020 --> 00:08:29,250 we can immediately populate the author field. 104 00:08:29,250 --> 00:08:32,535 Now, how do we know which user is posting this information? 105 00:08:32,535 --> 00:08:38,165 The fact that we have done the verify user here for the post, 106 00:08:38,165 --> 00:08:42,115 means that a specific user is posting this information, 107 00:08:42,115 --> 00:08:44,250 and by doing the verify user, 108 00:08:44,250 --> 00:08:50,415 we would have already loaded in the req.user into the request object. 109 00:08:50,415 --> 00:08:51,925 In the request object, 110 00:08:51,925 --> 00:08:55,565 we can go in and say wreck user, 111 00:08:55,565 --> 00:08:59,010 and then underscore ID here. 112 00:08:59,010 --> 00:09:01,910 So, again let me reiterate this point, 113 00:09:01,910 --> 00:09:05,760 how are we obtaining the author's information here? 114 00:09:05,760 --> 00:09:10,470 Now, recall that we updated the dishes schema, 115 00:09:10,470 --> 00:09:13,875 so that the author field in the comment will simply store 116 00:09:13,875 --> 00:09:20,915 the object ID referring to the user that is posting this comment. 117 00:09:20,915 --> 00:09:24,450 Now, how do we know which user is posting this comment? 118 00:09:24,450 --> 00:09:27,085 Now again, to reiterate this point, 119 00:09:27,085 --> 00:09:31,825 recall that when we verified the user here by calling authenticate verify user, 120 00:09:31,825 --> 00:09:37,590 the passport authorized JWT would have loaded 121 00:09:37,590 --> 00:09:45,120 the user information into the request body in the form of req.user. 122 00:09:45,120 --> 00:09:48,470 So, that user will contain the ID of 123 00:09:48,470 --> 00:09:52,520 the specific user that is actually posting this comment. 124 00:09:52,520 --> 00:09:55,730 So, we have already verified the authenticity of the user, 125 00:09:55,730 --> 00:10:01,400 and so the user ID can simply be obtained by saying req.user. 126 00:10:01,400 --> 00:10:04,400 _ID, and that user's ID, 127 00:10:04,400 --> 00:10:09,380 I will assign this to the author field off the comment. 128 00:10:09,380 --> 00:10:10,990 Now when the comment comes in, 129 00:10:10,990 --> 00:10:13,880 the comment in the body of the request message will 130 00:10:13,880 --> 00:10:17,355 only contain the rating field and the comment field. 131 00:10:17,355 --> 00:10:23,425 Now we don't want to explicitly send the author field anymore from the client side, 132 00:10:23,425 --> 00:10:26,090 instead that should be automatically inserted 133 00:10:26,090 --> 00:10:28,990 on the server side based upon the authenticity of 134 00:10:28,990 --> 00:10:32,180 the user That's the point that I had been 135 00:10:32,180 --> 00:10:36,830 reiterating in this modification that I have done here. 136 00:10:36,830 --> 00:10:43,400 So, that users information is automatically obtained from the req.user that is 137 00:10:43,400 --> 00:10:50,200 loaded into the body of the request message by the authenticate verify user, 138 00:10:50,200 --> 00:10:55,250 which is going to use Passport authenticate with the JWT strategy there. 139 00:10:55,250 --> 00:10:59,795 In addition, now when we receive the updated dish here, 140 00:10:59,795 --> 00:11:03,695 we need to populate the author's information into the dish. 141 00:11:03,695 --> 00:11:05,500 So, at this point, 142 00:11:05,500 --> 00:11:08,675 when we receive the dish here, 143 00:11:08,675 --> 00:11:15,370 we are then going to search the dishes here. 144 00:11:15,370 --> 00:11:20,150 So, we'll say Dishes.findByID 145 00:11:21,000 --> 00:11:28,090 and then supply the dish ID as the parameter here, 146 00:11:28,090 --> 00:11:30,190 so we'll say find by ID, 147 00:11:30,190 --> 00:11:33,175 dish ID, and then, 148 00:11:33,175 --> 00:11:43,405 we need to populate the comments author here, 149 00:11:43,405 --> 00:11:55,600 and then we'll say then dish. 150 00:11:55,600 --> 00:12:04,370 Inside there, we're going to be sending this dish information back to the user here. 151 00:12:04,370 --> 00:12:07,260 So, let me cut that and paste that in here. 152 00:12:07,260 --> 00:12:12,670 So, this modification is required because now I need to populate 153 00:12:12,670 --> 00:12:15,190 the author's information back into 154 00:12:15,190 --> 00:12:18,760 the comment before I can send the current back to the user. 155 00:12:18,760 --> 00:12:22,220 So, this is the additional modification that we need to 156 00:12:22,220 --> 00:12:26,105 do when we use the Mongoose population here. 157 00:12:26,105 --> 00:12:29,950 Similarly, now going into the put, 158 00:12:29,950 --> 00:12:34,450 when we modify a specific comment with the comment ID, 159 00:12:34,450 --> 00:12:40,830 so this is under the dish ID comments comment ID part. 160 00:12:40,830 --> 00:12:42,890 So, when we do the put here, 161 00:12:42,890 --> 00:12:49,230 so we first find the dishes find by id req params dish ID, 162 00:12:49,230 --> 00:12:50,840 then in the dish. 163 00:12:50,840 --> 00:12:57,160 So, the first thing that we check is to ensure that if the dish is not null, 164 00:12:57,160 --> 00:13:01,430 and the dish comments ID is not null, 165 00:13:01,430 --> 00:13:08,665 so we checked to make sure that the comment is indeed present in the dish, 166 00:13:08,665 --> 00:13:12,320 and then when the dish itself is returned, 167 00:13:12,320 --> 00:13:16,385 then we need to search again for 168 00:13:16,385 --> 00:13:21,230 the dish because we need to populate the comments author into the dish. 169 00:13:21,230 --> 00:13:27,950 So here, we'll say dishes.findByID (dish ID), 170 00:13:31,750 --> 00:13:36,880 the reason we need to do one more search is because 171 00:13:36,880 --> 00:13:42,240 we need to populate the comments.author here, 172 00:13:42,240 --> 00:13:46,355 so that's the only reason why we need to do one more search here. 173 00:13:46,355 --> 00:13:50,720 Then when we receive the dish here, 174 00:13:52,260 --> 00:13:57,700 obviously because we just updated the dish so the dish information should be 175 00:13:57,700 --> 00:14:03,640 found in the database, 176 00:14:03,640 --> 00:14:07,490 so that should work fine and then inside there will say 177 00:14:07,490 --> 00:14:12,215 risk status code 200 res set header content type application json, 178 00:14:12,215 --> 00:14:14,960 and then return the dish here, 179 00:14:14,960 --> 00:14:16,740 and then we'll handle error here, 180 00:14:16,740 --> 00:14:19,630 and then the other ones if the dishes 181 00:14:19,630 --> 00:14:24,095 now and also the other errors that we have set up earlier, 182 00:14:24,095 --> 00:14:27,050 they will be handled as usual here. 183 00:14:27,050 --> 00:14:32,790 So, these are the additional changes that we need to make sure when you update the dish, 184 00:14:32,790 --> 00:14:39,175 when you're sending back the updated comment or updated dish, 185 00:14:39,175 --> 00:14:44,485 then we will populate the comment in the dish here. 186 00:14:44,485 --> 00:14:48,160 Similarly, going to the delete here, 187 00:14:48,160 --> 00:14:50,575 and then after the delete the comment, 188 00:14:50,575 --> 00:14:59,310 again we're going to be fetching the dish and populating the author information. 189 00:14:59,310 --> 00:15:01,275 So, let me just copy this part, 190 00:15:01,275 --> 00:15:04,130 and then we'll be doing exactly the same thing here, 191 00:15:04,130 --> 00:15:06,770 so we'll say dish save, 192 00:15:06,770 --> 00:15:16,210 then we're going to be then checking dish.findByID (dish author), 193 00:15:16,210 --> 00:15:19,760 and then we'll populate the comments author, 194 00:15:19,760 --> 00:15:21,925 and then we'll say (then) dish, 195 00:15:21,925 --> 00:15:24,920 and then res.statusCode, and so on, 196 00:15:24,920 --> 00:15:29,350 and the remaining error handling just like before here. 197 00:15:29,350 --> 00:15:33,040 So, with this modification to the dish router, 198 00:15:33,040 --> 00:15:41,420 now the last point that we need to consider is the fact that in the user.js file, 199 00:15:41,420 --> 00:15:43,740 we have now added into fields, 200 00:15:43,740 --> 00:15:49,050 the first name and last name field which by default will be empty strings. 201 00:15:49,050 --> 00:15:51,880 So, when the user is registering, 202 00:15:51,880 --> 00:15:54,670 we should allow the user to supply the first name and 203 00:15:54,670 --> 00:15:58,040 last name in the registration process. 204 00:15:58,040 --> 00:16:00,040 Now, where does that take place? 205 00:16:00,040 --> 00:16:03,025 That takes place in the user's.js. 206 00:16:03,025 --> 00:16:05,390 So, going to users users.js, 207 00:16:05,390 --> 00:16:09,885 when the user posts on the slash signup, 208 00:16:09,885 --> 00:16:13,050 earlier we were only posting the username and password. 209 00:16:13,050 --> 00:16:15,105 In addition to those two, 210 00:16:15,105 --> 00:16:21,785 in the json object that we include in the body of the request message coming in, 211 00:16:21,785 --> 00:16:25,530 the post request message coming in from the client side, 212 00:16:25,530 --> 00:16:29,590 we can also include the first name and last name for the user. 213 00:16:29,590 --> 00:16:33,740 So, when the first name and last name for the user is included, 214 00:16:33,740 --> 00:16:35,590 so what am I going to do here? 215 00:16:35,590 --> 00:16:42,450 So, recall that when you say user.register at this point the user information comes in, 216 00:16:42,450 --> 00:16:45,785 and then you have submitted the username here, 217 00:16:45,785 --> 00:16:49,460 and you have also assigned the password here which will be 218 00:16:49,460 --> 00:16:53,380 turned into the hash and salt by the passport local mongoose. 219 00:16:53,380 --> 00:17:00,000 Now, if there is no error that means that the user's registration was successful, 220 00:17:00,000 --> 00:17:08,740 and so at this point what we will do is we'll say if req.body. 221 00:17:08,740 --> 00:17:13,420 First name. So, which means that the body of the incoming request message, 222 00:17:13,420 --> 00:17:16,345 if it contains the first name, 223 00:17:16,345 --> 00:17:24,770 then we'll say user.firstname is equal to req.body.firstname. 224 00:17:26,160 --> 00:17:29,675 Similarly, for the last name also. 225 00:17:29,675 --> 00:17:32,040 So at this point, 226 00:17:32,040 --> 00:17:34,780 we would have the user available here. 227 00:17:34,780 --> 00:17:40,125 See the user is coming in as the second parameter to this callback function here. 228 00:17:40,125 --> 00:17:43,455 So, we are setting up the first name by changing 229 00:17:43,455 --> 00:17:51,490 the first name property inside the user document here saying, req.body.firstname. 230 00:17:51,490 --> 00:17:55,395 If it exists, then we'll set the user's first name to that. 231 00:17:55,395 --> 00:18:03,220 Similarly, if the req.body.last name is available, 232 00:18:03,220 --> 00:18:09,630 so we'll also update the user's last name as req.body.lastname. 233 00:18:09,770 --> 00:18:16,650 And once we have done these two changes to the first name and the last name, 234 00:18:16,650 --> 00:18:23,160 then we need to save the modification that we have done to the user. 235 00:18:23,160 --> 00:18:25,030 So, we have just updated the user. 236 00:18:25,030 --> 00:18:30,550 So, we'll say user.save then this will 237 00:18:30,550 --> 00:18:37,190 return the error or the user. 238 00:18:37,190 --> 00:18:41,025 So, if the modification has been saved properly, 239 00:18:41,025 --> 00:18:43,765 then it will return the error, 240 00:18:43,765 --> 00:18:49,380 otherwise it will return the user value and this passport authenticate we will 241 00:18:49,380 --> 00:18:55,710 do it inside this user here. 242 00:18:55,710 --> 00:19:00,505 So, we'll say, user.save(err, user). 243 00:19:00,505 --> 00:19:04,740 And then also we need to cross check to make sure that 244 00:19:04,740 --> 00:19:10,660 if there is an error in saving the changes to the user, 245 00:19:10,660 --> 00:19:15,180 then we'll say res status code 500, 246 00:19:15,180 --> 00:19:18,485 so let me copy this from there. 247 00:19:18,485 --> 00:19:23,275 So, we'll say res status code 500, 248 00:19:23,275 --> 00:19:30,220 res set header content type application json and res.jason here. 249 00:19:30,220 --> 00:19:35,995 Then, and we'll return to this point. 250 00:19:35,995 --> 00:19:37,960 If there is no error, 251 00:19:37,960 --> 00:19:40,480 then of course you authenticate the user by calling 252 00:19:40,480 --> 00:19:43,550 passport authenticate with the local to ensure that 253 00:19:43,550 --> 00:19:48,835 the user registration has been successful and this should be 254 00:19:48,835 --> 00:19:56,390 correctly done and when which case you will return this message back to the client side. 255 00:19:56,390 --> 00:20:03,215 We need to close this user.save here. 256 00:20:03,215 --> 00:20:07,520 So, make sure that you close this endpoint correctly. 257 00:20:07,520 --> 00:20:11,005 So, user.save is closed here, and that's it. 258 00:20:11,005 --> 00:20:14,730 These are the changes that we need to make to the user. 259 00:20:14,730 --> 00:20:21,740 So thereby, after the user is registered with the given username and the given password, 260 00:20:21,740 --> 00:20:24,940 then after the user is successfully registered, 261 00:20:24,940 --> 00:20:28,235 then we will set the first name and last name field 262 00:20:28,235 --> 00:20:32,925 of the user document by using these two here. 263 00:20:32,925 --> 00:20:35,900 We want to make sure that the user is successfully 264 00:20:35,900 --> 00:20:39,160 registered before we sent the first name and last name for that. 265 00:20:39,160 --> 00:20:42,540 So, that's why we are carrying out this operation after the user 266 00:20:42,540 --> 00:20:46,360 is successfully registered. That's it. 267 00:20:46,360 --> 00:20:53,785 Let's save the changes and go and check out the server. 268 00:20:53,785 --> 00:20:56,185 After saving the changes, 269 00:20:56,185 --> 00:20:59,980 let's now go to the terminal and 270 00:20:59,980 --> 00:21:06,925 then before I start the server, 271 00:21:06,925 --> 00:21:16,690 let me first check out my MongoDB and delete the user that we have registered earlier. 272 00:21:16,690 --> 00:21:25,640 So, we'll say use confusion and then we'll say db.usersfind. 273 00:21:25,650 --> 00:21:30,690 So, we know that this particular user has been registered earlier, 274 00:21:30,690 --> 00:21:32,580 but when we register that user, 275 00:21:32,580 --> 00:21:35,700 we did not register the first name and last name for the user. 276 00:21:35,700 --> 00:21:39,155 So, I'm going to delete this user and then re- register the user. 277 00:21:39,155 --> 00:21:48,370 So, to do that using the Mongo ripple,I will say db users drop, 278 00:21:48,370 --> 00:21:52,220 and then we'll say db users find, 279 00:21:52,220 --> 00:21:54,620 and that should return an empty. 280 00:21:54,620 --> 00:22:01,685 No users registered there and then we'll exit the Mongo ripple. 281 00:22:01,685 --> 00:22:05,285 And so, once we have removed that registered user, 282 00:22:05,285 --> 00:22:08,760 then, let me start my server. 283 00:22:09,490 --> 00:22:12,275 And once the server is up and running, 284 00:22:12,275 --> 00:22:16,240 let's go to Postman and then register 285 00:22:16,240 --> 00:22:20,930 a new user along with the first name and last name of the user. 286 00:22:20,930 --> 00:22:26,845 Then, they will log in as that user and then we'll look at how 287 00:22:26,845 --> 00:22:31,650 the Mongoose population helps us to populate the information about 288 00:22:31,650 --> 00:22:37,000 the user automatically into the document there. 289 00:22:37,000 --> 00:22:40,029 Now going to Postman, 290 00:22:40,029 --> 00:22:42,660 let me do a sign up of a new user. 291 00:22:42,660 --> 00:22:48,310 So, I'm doing a post localhost: 3000 users sign up. 292 00:22:48,310 --> 00:22:50,715 In the body of the message, 293 00:22:50,715 --> 00:22:54,910 we had the username and the password already in there. 294 00:22:54,910 --> 00:22:59,199 Let me add in two additional fields: 295 00:22:59,199 --> 00:23:09,350 first name, last name. 296 00:23:14,880 --> 00:23:18,530 Then, register that user. 297 00:23:20,850 --> 00:23:23,680 So, once I register the user, 298 00:23:23,680 --> 00:23:26,350 you can see that the registration was successful. 299 00:23:26,350 --> 00:23:29,810 Now, let me login as this user. 300 00:23:29,820 --> 00:23:32,640 So, to log in as the user, 301 00:23:32,640 --> 00:23:37,620 let me do a post and cross check to make sure. 302 00:23:37,620 --> 00:23:40,475 So, I'm doing a post to users login. 303 00:23:40,475 --> 00:23:45,725 Let me cross check and I see that the username and password is correctly typed in there. 304 00:23:45,725 --> 00:23:47,775 So when I log in, 305 00:23:47,775 --> 00:23:53,165 I should be successfully logged in and I should be able to obtain this token there. 306 00:23:53,165 --> 00:24:02,660 Because this token is essential for us to be able to add in a dish to our server site. 307 00:24:02,660 --> 00:24:05,915 So, after you obtain the token, 308 00:24:05,915 --> 00:24:10,250 copy this token string and save it because you will need that in 309 00:24:10,250 --> 00:24:13,220 the authorization header for the post 310 00:24:13,220 --> 00:24:16,910 put and delete operations that you're going to perform later. 311 00:24:16,910 --> 00:24:20,540 So let me copy that token. 312 00:24:20,540 --> 00:24:23,890 Now, normally the way I would keep these tokens is, 313 00:24:23,890 --> 00:24:28,400 that I'll just open a text document and then copy and paste it into the text document. 314 00:24:28,400 --> 00:24:31,190 So that for subsequent postman requests, 315 00:24:31,190 --> 00:24:34,230 I can simply copy this string and then paste it into 316 00:24:34,230 --> 00:24:37,770 the authorization header, if required. 317 00:24:37,770 --> 00:24:44,070 So, let me copy that token and here I have a text document open here. 318 00:24:44,070 --> 00:24:50,815 So, I'm going to paste that string into this text document. 319 00:24:50,815 --> 00:24:57,170 So, here we have the token that we have obtained. 320 00:24:57,170 --> 00:25:03,120 Let's now go and post a dish to our server. 321 00:25:03,120 --> 00:25:05,135 Going back to postman, 322 00:25:05,135 --> 00:25:07,535 let me post a dish to the server. 323 00:25:07,535 --> 00:25:12,690 So, this is where I will choose the post here. 324 00:25:12,690 --> 00:25:21,334 Inside here, I have the dish information that I had used earlier but for the comments, 325 00:25:21,334 --> 00:25:25,345 now, recall that earlier we had author field which was storing a string. 326 00:25:25,345 --> 00:25:28,770 So, all these comments are not valid. 327 00:25:28,770 --> 00:25:35,110 So, I'm going to delete all these comments from submission because, 328 00:25:35,110 --> 00:25:42,570 now, we expect the user to post comments on their own. 329 00:25:42,570 --> 00:25:44,460 When the user posts comments, 330 00:25:44,460 --> 00:25:52,155 we will automatically add in the ID of the user into the author field of the comments. 331 00:25:52,155 --> 00:25:55,390 So, let me post this dish here. 332 00:25:55,390 --> 00:25:57,325 Going to the header, 333 00:25:57,325 --> 00:26:01,550 in the authorization header, I'm going to say, 334 00:26:02,310 --> 00:26:12,785 bearer and then, paste the token and then submit. 335 00:26:12,785 --> 00:26:17,055 I should do a post on that. 336 00:26:17,055 --> 00:26:21,950 So, I will say post and so when I post now, 337 00:26:21,950 --> 00:26:26,785 you see that this dish has been posted on the server side, 338 00:26:26,785 --> 00:26:31,340 and with the comments array being empty at this moment. 339 00:26:31,340 --> 00:26:34,450 So, after I post this dish, 340 00:26:34,450 --> 00:26:37,660 let me copy the ID of this dish. 341 00:26:37,660 --> 00:26:40,835 So, let me copy this ID for the dish because I will 342 00:26:40,835 --> 00:26:44,735 need that to post comments for this dish. 343 00:26:44,735 --> 00:26:47,075 Then, going to my text editor, 344 00:26:47,075 --> 00:26:51,485 I'm going to save that ID of the dish here. 345 00:26:51,485 --> 00:26:54,550 Now, of course, once you build your client side, 346 00:26:54,550 --> 00:26:57,770 your client will automatically have all this information. 347 00:26:57,770 --> 00:27:02,565 So, your client will automatically be able to send the token and so on. 348 00:27:02,565 --> 00:27:06,385 So, you don't need to do this cut-and-paste thing but with postman, 349 00:27:06,385 --> 00:27:11,750 this is the only way that we can add any information to our postman requests, 350 00:27:11,750 --> 00:27:17,185 that go out from postman to the server. 351 00:27:17,185 --> 00:27:22,090 Now, in order to convince ourselves that this dish actually exists, 352 00:27:22,090 --> 00:27:26,310 let me do a get on the local hostcolon:3000/dishes. 353 00:27:26,570 --> 00:27:30,750 When I do a get, you can actually see that 354 00:27:30,750 --> 00:27:34,175 this particular dish exists on the server side. 355 00:27:34,175 --> 00:27:37,600 So, let's now try to post a comment. 356 00:27:37,600 --> 00:27:39,515 So, to post a comment, 357 00:27:39,515 --> 00:27:45,550 let's do a post and we'll say, 358 00:27:49,940 --> 00:27:54,950 localhost:3000/dishes, slash and the ID of the dish that 359 00:27:54,950 --> 00:27:59,910 I just copied, and slash comments. 360 00:27:59,910 --> 00:28:03,090 When you post on the comments, 361 00:28:03,090 --> 00:28:11,285 you need to make sure that in the body we will add in the comment here. 362 00:28:11,285 --> 00:28:13,605 So, a typical comment contains 363 00:28:13,605 --> 00:28:20,555 a rating of say 364 00:28:20,555 --> 00:28:26,140 five and then comment. 365 00:28:29,030 --> 00:28:33,535 So, let me just type in some random comment, 366 00:28:33,535 --> 00:28:34,915 just to demonstrate to you. 367 00:28:34,915 --> 00:28:41,085 So, this should be in the body of the post for the comments and in the header, 368 00:28:41,085 --> 00:28:44,665 we should add the authorization header. 369 00:28:44,665 --> 00:28:50,525 So, for the authorization header, we'll say, bearer. 370 00:28:50,525 --> 00:28:54,875 I need to paste the token here, 371 00:28:54,875 --> 00:28:59,065 pasting the token value that I have saved earlier. 372 00:28:59,065 --> 00:29:02,575 Let's now post this comment. 373 00:29:02,575 --> 00:29:05,265 Then, when the comment is posted, 374 00:29:05,265 --> 00:29:07,705 let's look at the returned value here. 375 00:29:07,705 --> 00:29:09,510 So, as you browse down, 376 00:29:09,510 --> 00:29:14,975 you can see that the dish to which the comment has been added, has been returned. 377 00:29:14,975 --> 00:29:19,300 Notice that the dish information is there but note in particular, 378 00:29:19,300 --> 00:29:22,620 what is contained in the comment that has been posted here. 379 00:29:22,620 --> 00:29:25,740 So, as you can see, you already know that the updated and 380 00:29:25,740 --> 00:29:29,050 created at fields are automatically added in by mongoose. 381 00:29:29,050 --> 00:29:31,900 The rating and the comment that we submitted are 382 00:29:31,900 --> 00:29:34,780 right there but note how the author field 383 00:29:34,780 --> 00:29:40,675 now contains the ID corresponding to the user. 384 00:29:40,675 --> 00:29:47,190 Now, as we saw in the code how the author field information is added, now, 385 00:29:47,190 --> 00:29:49,965 if you do a get on the dishes, 386 00:29:49,965 --> 00:29:52,900 you will notice that this author field will be 387 00:29:52,900 --> 00:29:56,890 automatically filled in by the users information here. 388 00:29:56,890 --> 00:30:02,180 So, let's now do a get on the localhost:3000/dishes. 389 00:30:02,300 --> 00:30:06,820 So, when we now do a get on this point, 390 00:30:06,820 --> 00:30:12,215 you'll now notice that in the dishes here, 391 00:30:12,215 --> 00:30:15,460 right there, the information about the dish is already 392 00:30:15,460 --> 00:30:20,110 present but note how the comment is now constructed. 393 00:30:20,110 --> 00:30:23,500 The comment now contains, 394 00:30:23,500 --> 00:30:27,240 the rating comment fields as we saw earlier, 395 00:30:27,240 --> 00:30:28,780 the updated and created at, 396 00:30:28,780 --> 00:30:32,910 but note what happened to the author field here. 397 00:30:32,910 --> 00:30:36,890 So, when you do a get request because we did a populate on 398 00:30:36,890 --> 00:30:42,230 the server side when the get operation is invoked, 399 00:30:42,230 --> 00:30:45,750 the populate has automatically populated 400 00:30:45,750 --> 00:30:51,390 the author information into position in the author field here. 401 00:30:51,390 --> 00:30:54,215 So, in there, you can see that from the author, 402 00:30:54,215 --> 00:30:56,260 you can now look up the last name and 403 00:30:56,260 --> 00:30:58,970 the first name information automatically from the author field. 404 00:30:58,970 --> 00:31:01,645 So, if you need to construct a comment, 405 00:31:01,645 --> 00:31:04,050 you now have the rating, 406 00:31:04,050 --> 00:31:08,210 the comment, and also the first name and last name of 407 00:31:08,210 --> 00:31:12,485 the author automatically included into this document. 408 00:31:12,485 --> 00:31:15,645 Also, the user name also is included into this document. 409 00:31:15,645 --> 00:31:21,495 So, this is how you can add in information from another document and populate 410 00:31:21,495 --> 00:31:27,905 a second document with that information before you reply back from the server site. 411 00:31:27,905 --> 00:31:32,315 So, this is the use of mongoose population and how we 412 00:31:32,315 --> 00:31:37,580 can automatically populate information into a mongoose document. 413 00:31:37,580 --> 00:31:41,280 With this, we complete this exercise. 414 00:31:41,280 --> 00:31:46,075 In this exercise, we have seen the use of mongoose population and we have also seen 415 00:31:46,075 --> 00:31:51,785 how we can populate information from one document into another document. 416 00:31:51,785 --> 00:31:57,340 Whereby, when we modify the server to do the population for the requests, 417 00:31:57,340 --> 00:32:02,200 mongoose will automatically take care of populating this information for us. 418 00:32:02,200 --> 00:32:04,190 All that we need to do, 419 00:32:04,190 --> 00:32:10,900 is to store the reference to the other document in the form of the object ID, 420 00:32:10,900 --> 00:32:16,240 in the document into which you want to populate this information. 421 00:32:16,240 --> 00:32:18,965 With this, we complete this exercise. 422 00:32:18,965 --> 00:32:25,230 This is a good time for you to do a git-commit with the message, mongoose population.