1 00:00:00,210 --> 00:00:02,160 -: The next part of the URL 2 00:00:02,160 --> 00:00:06,840 and this is also an optional part, is the sub entity. 3 00:00:06,840 --> 00:00:09,210 Now, what is sub entity? 4 00:00:09,210 --> 00:00:12,840 The sub entity is used for accessing entities 5 00:00:12,840 --> 00:00:16,110 that are dependent on other entities. 6 00:00:16,110 --> 00:00:19,020 And if this sounds a little bit complicated 7 00:00:19,020 --> 00:00:22,620 then I hope the example will help clear things up. 8 00:00:22,620 --> 00:00:27,620 So for example, get all the items of order no. 17. 9 00:00:28,560 --> 00:00:31,740 So in this case, the order is the entity 10 00:00:31,740 --> 00:00:35,670 and the items of the order are the sub entities. 11 00:00:35,670 --> 00:00:38,400 So we will need the URL to specify 12 00:00:38,400 --> 00:00:41,730 that we don't want to retrieve the order itself 13 00:00:41,730 --> 00:00:46,380 but the items of the order and let's see how it's done. 14 00:00:46,380 --> 00:00:49,410 But first let's see how it shouldn't be done. 15 00:00:49,410 --> 00:00:53,688 So a common mistake I see in a lot of organizations 16 00:00:53,688 --> 00:00:56,190 is something like this. 17 00:00:56,190 --> 00:00:57,450 So you see here the APIs 18 00:00:57,450 --> 00:01:01,290 the version and the entity is items in order. 19 00:01:01,290 --> 00:01:03,060 And the number of the order. 20 00:01:03,060 --> 00:01:05,337 This is a mistake and you should not implement 21 00:01:05,337 --> 00:01:06,870 the URL like this. 22 00:01:06,870 --> 00:01:09,840 Why? First it's not very readable. 23 00:01:09,840 --> 00:01:14,250 Notice how long the text part of the URL is. 24 00:01:14,250 --> 00:01:17,070 So you actually need to concentrate to 25 00:01:17,070 --> 00:01:20,370 understand what exactly is going to be retrieved here. 26 00:01:20,370 --> 00:01:22,980 And as a result, this is not simple, 27 00:01:22,980 --> 00:01:27,980 and we always try to make a URL as simple as possible. 28 00:01:27,990 --> 00:01:32,990 So what is the correct way to use the sub entity in the URL? 29 00:01:33,330 --> 00:01:37,470 So the sub entity should come after the ID parameter 30 00:01:37,470 --> 00:01:39,573 and it should look something like this. 31 00:01:40,770 --> 00:01:44,220 So you see here again the API, the version, the entity 32 00:01:44,220 --> 00:01:46,890 the ID parameter, and this is the ID 33 00:01:46,890 --> 00:01:51,780 of the entity and after the ID parameter, the sub entity 34 00:01:51,780 --> 00:01:53,820 the items, in this case. 35 00:01:53,820 --> 00:01:56,640 So when looking at the URL like this 36 00:01:56,640 --> 00:01:59,790 then we see that the URL is hierarchical 37 00:01:59,790 --> 00:02:03,450 and it is very easy to understand we are actually going 38 00:02:03,450 --> 00:02:08,009 from all the entities to a specific entity 39 00:02:08,009 --> 00:02:11,009 to the sub entities of the specific entity. 40 00:02:11,009 --> 00:02:14,160 So what we are having here is a very simple 41 00:02:14,160 --> 00:02:16,533 and very easy to understand URL. 42 00:02:18,090 --> 00:02:22,260 Now, same goes also for sub-sub-entity, etc. 43 00:02:22,260 --> 00:02:24,030 which is not a very common case, but 44 00:02:24,030 --> 00:02:26,940 in theory you can add another ID parameters 45 00:02:26,940 --> 00:02:30,360 after the sub entity and after this ID parameter, 46 00:02:30,360 --> 00:02:33,300 add sub-sub-entity, etc. 47 00:02:33,300 --> 00:02:36,480 Again, not very common, but can be used. 48 00:02:36,480 --> 00:02:38,550 So let's see how the sub entity fits 49 00:02:38,550 --> 00:02:40,503 in the URL that we are building. 50 00:02:41,820 --> 00:02:43,110 Back to our receptor. 51 00:02:43,110 --> 00:02:48,110 All we need to do is add forward slash and items. 52 00:02:50,400 --> 00:02:51,900 So look at what we have here. 53 00:02:51,900 --> 00:02:53,280 We have a GET. 54 00:02:53,280 --> 00:02:56,760 So we understand that this API should return something. 55 00:02:56,760 --> 00:03:00,140 It is retrieving something and what does it retrieve? 56 00:03:00,140 --> 00:03:04,680 It retrieve from the order it goes to order number 17. 57 00:03:04,680 --> 00:03:06,600 And for this specific order 58 00:03:06,600 --> 00:03:09,243 it should return all the items of the order.