1 00:00:02,070 --> 00:00:03,890 So did you succeed? 2 00:00:03,890 --> 00:00:06,983 Let's implement, updating and deleting together. 3 00:00:08,000 --> 00:00:09,040 Now for that, 4 00:00:09,040 --> 00:00:11,980 I'll start with updating and therefore 5 00:00:11,980 --> 00:00:13,403 this posts edit route. 6 00:00:14,650 --> 00:00:16,280 What we're doing in there in the end, 7 00:00:16,280 --> 00:00:20,260 is we are calling this updateOne method 8 00:00:20,260 --> 00:00:22,450 and we're selecting a post by postId, 9 00:00:22,450 --> 00:00:25,653 and then we're setting the updated title and content. 10 00:00:26,790 --> 00:00:30,140 So I will grab this part here of the code 11 00:00:30,140 --> 00:00:31,400 and go to my model. 12 00:00:31,400 --> 00:00:35,210 And now in there we could add a new method, 13 00:00:35,210 --> 00:00:38,793 an async method called update, for example. 14 00:00:39,970 --> 00:00:44,950 But actually we could also reuse the safe method here, 15 00:00:44,950 --> 00:00:48,010 and in there, we can use the fact 16 00:00:48,010 --> 00:00:51,470 that the ID won't always be set. 17 00:00:51,470 --> 00:00:54,930 And check if this thought ID is truthy, 18 00:00:54,930 --> 00:00:56,580 so it's not undefined. 19 00:00:56,580 --> 00:00:58,870 It is set instead. 20 00:00:58,870 --> 00:01:01,780 Then this means that we created this post 21 00:01:01,780 --> 00:01:04,019 with an existing ID. 22 00:01:04,019 --> 00:01:08,870 And when we call save on a post that already has an ID, 23 00:01:08,870 --> 00:01:11,550 we're definitely not creating a new post 24 00:01:11,550 --> 00:01:15,070 because when we do that, we don't have an ID yet. 25 00:01:15,070 --> 00:01:18,790 We only have IDs on posts that were already stored 26 00:01:18,790 --> 00:01:20,610 in the database before. 27 00:01:20,610 --> 00:01:23,480 So when we call, save on such an existing post, 28 00:01:23,480 --> 00:01:26,430 we must be doing that because we wanna update 29 00:01:26,430 --> 00:01:28,713 that post instead of creating it. 30 00:01:29,680 --> 00:01:33,170 So therefore if we have an ID here in the save method, 31 00:01:33,170 --> 00:01:38,090 I'll execute this update code and only else. 32 00:01:38,090 --> 00:01:42,220 If we don't have an ID, I know that I'm creating a post. 33 00:01:42,220 --> 00:01:44,203 So then I'll do it like that. 34 00:01:45,700 --> 00:01:47,750 Now either way we'll get a result. 35 00:01:47,750 --> 00:01:51,830 So I will actually create result as a standalone variable 36 00:01:51,830 --> 00:01:55,390 and set result equal here in the update case, 37 00:01:55,390 --> 00:01:59,160 and set it equal here, not as a new constant, 38 00:01:59,160 --> 00:02:02,000 but instead as a value for this variable. 39 00:02:02,000 --> 00:02:03,610 So that either way in the end, 40 00:02:03,610 --> 00:02:05,853 we can return the result if we need that. 41 00:02:07,900 --> 00:02:11,880 So that's how we can utilize this ID for updating. 42 00:02:11,880 --> 00:02:16,340 And that also means that here for finding the correct post, 43 00:02:16,340 --> 00:02:18,230 we can use this ID, 44 00:02:18,230 --> 00:02:20,640 assuming that the ID that is stored 45 00:02:20,640 --> 00:02:23,380 in this post object based on this class, 46 00:02:23,380 --> 00:02:24,893 has the right format. 47 00:02:25,830 --> 00:02:27,490 And to ensure this, 48 00:02:27,490 --> 00:02:30,783 we should go back to the post constructor. 49 00:02:31,650 --> 00:02:34,440 Instead of assigning the ID like that here, 50 00:02:34,440 --> 00:02:37,600 we should check if ID is set. 51 00:02:37,600 --> 00:02:38,870 If we're not getting an ID, 52 00:02:38,870 --> 00:02:41,030 I don't wanna do anything. 53 00:02:41,030 --> 00:02:42,750 But if I do get an ID, 54 00:02:42,750 --> 00:02:46,500 then we probably get it as a raw string 55 00:02:46,500 --> 00:02:51,450 and we wanna transform it to this ObjectId thing. 56 00:02:51,450 --> 00:02:52,283 So then here, 57 00:02:52,283 --> 00:02:56,060 I wanna set this ID equal to new ObjectId 58 00:02:57,260 --> 00:03:00,530 just as I'm doing it here in blog.js, 59 00:03:00,530 --> 00:03:04,913 when I transform the post ID I'm getting into an ObjectId. 60 00:03:07,038 --> 00:03:09,660 Therefore, just as in blog.js, 61 00:03:09,660 --> 00:03:13,270 we wanna get the ObjectId like this 62 00:03:13,270 --> 00:03:17,580 by importing mongodb, and using the ObjectId like that. 63 00:03:17,580 --> 00:03:20,820 And therefore in the post.js file, at the very top, 64 00:03:20,820 --> 00:03:25,820 I will import mongodb by requiring mongodb. 65 00:03:25,870 --> 00:03:28,450 And then once we imported all those things, 66 00:03:28,450 --> 00:03:31,950 I will get my ObjectId Constructor, 67 00:03:31,950 --> 00:03:34,990 my ObjectId class by accessing it 68 00:03:34,990 --> 00:03:38,820 on the imported mongodb package like that. 69 00:03:38,820 --> 00:03:42,560 And then here we can indeed create a new ObjectId 70 00:03:42,560 --> 00:03:46,280 and pass the ID, which we got as a parameter value 71 00:03:46,280 --> 00:03:47,763 into this constructor. 72 00:03:49,040 --> 00:03:52,260 And with that, we'll set the ID only if we get one 73 00:03:52,260 --> 00:03:54,490 and we therefore only have one down there 74 00:03:54,490 --> 00:03:58,133 if we did set one when we created the post before. 75 00:04:00,210 --> 00:04:02,820 This also means that the transformation 76 00:04:02,820 --> 00:04:06,780 from string to ObjectId, now happens in the model 77 00:04:06,780 --> 00:04:08,990 and hence back in blog.js, 78 00:04:08,990 --> 00:04:13,990 we can actually go to this update post route. 79 00:04:14,860 --> 00:04:19,800 So to this route and get rid of this line of code here. 80 00:04:19,800 --> 00:04:23,670 And instead after checking that the input is correct 81 00:04:23,670 --> 00:04:25,850 before we redirect, 82 00:04:25,850 --> 00:04:29,760 we now create our post based on that model. 83 00:04:29,760 --> 00:04:34,710 So we create a new post here based on this post class, 84 00:04:34,710 --> 00:04:38,094 but now we create it by passing in the enteredTitle 85 00:04:38,094 --> 00:04:39,860 and the enteredContent. 86 00:04:39,860 --> 00:04:43,500 And we now also do pass in an ID here 87 00:04:43,500 --> 00:04:46,220 because here we wanna create a post object 88 00:04:46,220 --> 00:04:50,023 for a post that already exists in the database. 89 00:04:50,980 --> 00:04:54,510 And the ID here is req.params.id 90 00:04:54,510 --> 00:04:56,880 because we're using the ID, which we extract 91 00:04:56,880 --> 00:04:58,633 from the URL path. 92 00:05:00,090 --> 00:05:04,670 And then again, we can call post.save here 93 00:05:04,670 --> 00:05:07,910 to save that and await this here. 94 00:05:07,910 --> 00:05:11,110 Since save actually is a async function, 95 00:05:11,110 --> 00:05:14,420 it will therefore automatically return a promise. 96 00:05:14,420 --> 00:05:19,420 All functions decorated with async, do return promises. 97 00:05:19,760 --> 00:05:22,330 So therefore we can await this here to wait 98 00:05:22,330 --> 00:05:25,003 until it was saved before we redirect. 99 00:05:26,870 --> 00:05:29,530 And actually that's the wrong place I just noticed. 100 00:05:29,530 --> 00:05:31,670 I, of course, wanna do that down here. 101 00:05:31,670 --> 00:05:35,440 Here, I was in the place where I was checking for errors. 102 00:05:35,440 --> 00:05:37,883 I wanna do that after I checked this. 103 00:05:39,480 --> 00:05:42,890 Now with that, I also implemented the updating logic 104 00:05:42,890 --> 00:05:44,410 with help of a model. 105 00:05:44,410 --> 00:05:47,670 And hence, if we now try that again, 106 00:05:47,670 --> 00:05:50,650 and we go to the admin page and I try updating 107 00:05:50,650 --> 00:05:55,650 this first post, this crashes, and let's see why. 108 00:05:55,680 --> 00:05:59,950 If I expand this, enteredTitle is not the defined, 109 00:05:59,950 --> 00:06:01,950 that's of course, my fault. 110 00:06:01,950 --> 00:06:04,800 I have an error in that save logic. 111 00:06:04,800 --> 00:06:07,630 When I set the data for updating the post, 112 00:06:07,630 --> 00:06:11,010 this should not be enteredTitle and enteredContent. 113 00:06:11,010 --> 00:06:13,790 instead we're inside of the post class. 114 00:06:13,790 --> 00:06:18,790 So this is this.title and this here is this.content, 115 00:06:20,400 --> 00:06:23,960 referring to the title and content that we do set up 116 00:06:23,960 --> 00:06:26,913 when we instantiate this post class. 117 00:06:28,010 --> 00:06:30,510 Now with that, if we saved that, 118 00:06:30,510 --> 00:06:35,510 if I do click save again here, this was updated like this. 119 00:06:37,270 --> 00:06:38,980 So that worked. 120 00:06:38,980 --> 00:06:42,060 Let's now implement the deletion logic as well. 121 00:06:42,060 --> 00:06:46,360 And for this, I will go to the delete route, this one. 122 00:06:46,360 --> 00:06:48,520 And it's now this line of code that we 123 00:06:48,520 --> 00:06:50,383 wanna outsource in the end. 124 00:06:51,530 --> 00:06:55,330 In post.js, I will add a new method 125 00:06:55,330 --> 00:06:57,760 because now it's not the save method, 126 00:06:57,760 --> 00:06:59,630 instead it's a new async method, 127 00:06:59,630 --> 00:07:03,440 which could be called delete because that's what we'll do. 128 00:07:03,440 --> 00:07:06,113 And in there, I wanna execute this logic. 129 00:07:07,450 --> 00:07:11,560 Now for the ID, I will use this.id, 130 00:07:11,560 --> 00:07:15,600 assuming that we are calling delete on a post object 131 00:07:15,600 --> 00:07:19,403 that did get an ID when it was instantiated. 132 00:07:20,510 --> 00:07:24,773 And therefore, we might wanna check if not this thought ID, 133 00:07:25,700 --> 00:07:30,500 if this is not set, in that case we know we have no ID, 134 00:07:30,500 --> 00:07:32,600 so deleting won't work. 135 00:07:32,600 --> 00:07:35,910 And in that case, we could throw a custom error 136 00:07:35,910 --> 00:07:39,680 with the throw keyword, which I also mentioned before, 137 00:07:39,680 --> 00:07:43,500 or we just return and don't do anything. 138 00:07:43,500 --> 00:07:46,060 Either way, we wanna make sure that this line 139 00:07:46,060 --> 00:07:48,880 of code doesn't execute because this relies 140 00:07:48,880 --> 00:07:50,450 on the existence of an ID. 141 00:07:50,450 --> 00:07:53,203 And therefore it won't work if we don't have one. 142 00:07:55,740 --> 00:07:58,520 But with that, we should now be able to call delete 143 00:07:58,520 --> 00:08:00,440 to delete a post. 144 00:08:00,440 --> 00:08:02,610 We also get back a result here, 145 00:08:02,610 --> 00:08:06,610 which we can return in case we should be interested 146 00:08:06,610 --> 00:08:09,980 in that in the place where we called the delete method 147 00:08:11,300 --> 00:08:13,900 and with all of that, back in blog.js, 148 00:08:13,900 --> 00:08:16,660 here in the delete route, 149 00:08:16,660 --> 00:08:20,763 I will just create my post by instantiating it. 150 00:08:21,720 --> 00:08:26,720 And now here, I'm not really interested in the title 151 00:08:27,050 --> 00:08:29,250 and the content. 152 00:08:29,250 --> 00:08:32,693 Instead here, I'm really just interested in the ID. 153 00:08:33,900 --> 00:08:37,730 What we can do in this case is we can pass in empty strings 154 00:08:37,730 --> 00:08:42,730 for title and content and just pass in req.params.id. 155 00:08:45,320 --> 00:08:50,320 Alternatively, we pass null as values for title and content 156 00:08:51,940 --> 00:08:55,620 to make it clear that here I don't have any title 157 00:08:55,620 --> 00:08:58,950 or content because I'm not creating this instance 158 00:08:58,950 --> 00:09:03,140 of the post class to work on that existing post. 159 00:09:03,140 --> 00:09:07,123 Instead, I'm creating it like this, just to delete it. 160 00:09:08,120 --> 00:09:12,510 So here we can then call post.delete and await that. 161 00:09:12,510 --> 00:09:13,963 And that should do the trick. 162 00:09:15,730 --> 00:09:18,890 If we now save all of that, 163 00:09:18,890 --> 00:09:21,160 and I reload here and I delete, 164 00:09:21,160 --> 00:09:25,520 let's say the last post here, that seems to work. 165 00:09:25,520 --> 00:09:27,690 If I reload, it's still gone. 166 00:09:27,690 --> 00:09:32,580 I also have no error here. So that did the trick. 167 00:09:32,580 --> 00:09:35,803 And that is how we can delete a post as well.