From 8a7dfa0972c83fd811a4296e7373574bea4a28d0 Mon Sep 17 00:00:00 2001 From: Nguyễn Gia Phong Date: Sun, 19 Jul 2020 20:34:40 +0700 Subject: [usth/ICT2.7] Remove Udacity transcribes --- .../4 - Adding Attributes - lang_en.srt | 352 --------------------- 1 file changed, 352 deletions(-) delete mode 100644 usth/ICT2.7/P3L2 A Tale of Analysis and Design Subtitles/4 - Adding Attributes - lang_en.srt (limited to 'usth/ICT2.7/P3L2 A Tale of Analysis and Design Subtitles/4 - Adding Attributes - lang_en.srt') diff --git a/usth/ICT2.7/P3L2 A Tale of Analysis and Design Subtitles/4 - Adding Attributes - lang_en.srt b/usth/ICT2.7/P3L2 A Tale of Analysis and Design Subtitles/4 - Adding Attributes - lang_en.srt deleted file mode 100644 index 0a48aae..0000000 --- a/usth/ICT2.7/P3L2 A Tale of Analysis and Design Subtitles/4 - Adding Attributes - lang_en.srt +++ /dev/null @@ -1,352 +0,0 @@ -1 -00:00:00,240 --> 00:00:02,880 -Okay, so let me look at the requirements and - -2 -00:00:05,500 --> 00:00:09,150 -it's something that I can see here that we didn't point out before is that - -3 -00:00:09,150 --> 00:00:13,540 -there seems to be clearly some concept of a due date. And I'm telling you why - -4 -00:00:13,540 --> 00:00:17,610 -I'm saying that because here, for example, I notice that it says when items are - -5 -00:00:17,610 --> 00:00:22,580 -due. We mention overdue several times, so is - -6 -00:00:22,580 --> 00:00:24,410 -this something we need to keep track of? - -7 -00:00:24,410 --> 00:00:27,510 ->> Yeah remember when we used to stamp them on the books? In the stamp pad? - -8 -00:00:27,510 --> 00:00:28,240 ->> Oh yeah yeah yeah! Oh course! - -9 -00:00:28,240 --> 00:00:30,600 ->> Right? Yeah we definitely keep track of, - -10 -00:00:30,600 --> 00:00:32,390 -the system has to keep track of when books are due. - -11 -00:00:32,390 --> 00:00:35,300 ->> Okay. So it seems to me that one good way - -12 -00:00:35,300 --> 00:00:39,660 -of doing that is by basically adding an attribute to the, item. - -13 -00:00:39,660 --> 00:00:40,590 ->> Okay. - -14 -00:00:40,590 --> 00:00:41,910 ->> And I'll just call it due date. - -15 -00:00:41,910 --> 00:00:42,400 ->> Okay. - -16 -00:00:42,400 --> 00:00:45,360 ->> So basically for each item in case it's loaned - -17 -00:00:45,360 --> 00:00:48,315 -there will be this attribute that will contain the value of - -18 -00:00:48,315 --> 00:00:48,520 ->> Okay. - -19 -00:00:48,520 --> 00:00:55,710 ->> Of when, when the item is due. And then, something else that I noticed - -20 -00:00:55,710 --> 00:00:58,734 -here is that down here, it seems like - -21 -00:00:58,734 --> 00:01:00,900 -the requirements are saying that an item can - -22 -00:01:00,900 --> 00:01:04,190 -be renewed only once. So, I guess, that's - -23 -00:01:04,190 --> 00:01:05,933 -something we need to keep track of, right? - -24 -00:01:05,933 --> 00:01:06,056 ->> Yeah. - -25 -00:01:06,056 --> 00:01:06,700 ->> The system needs to know. - -26 -00:01:06,700 --> 00:01:08,360 ->> We have to know whether they've renewed it or not. - -27 -00:01:08,360 --> 00:01:14,132 ->> Okay so, I'll do a similar thing here. I think I want to go and add a an - -28 -00:01:14,132 --> 00:01:19,140 -attribute that we'd call number of times renewed, and add it to the item class. - -29 -00:01:19,140 --> 00:01:19,760 ->> Okay. - -30 -00:01:19,760 --> 00:01:21,140 ->> And this is kind of more generic - -31 -00:01:21,140 --> 00:01:23,180 -than what you need, because here it says only once, but - -32 -00:01:23,180 --> 00:01:25,800 -let's say that in the future you want to allow it to, - -33 -00:01:25,800 --> 00:01:28,690 -kind of renew twice, you'll be able to use these attributes again - -34 -00:01:28,690 --> 00:01:31,090 -because, we can just count how many times it was renewed. Okay? - -35 -00:01:31,090 --> 00:01:31,680 ->> Makes sense. - -36 -00:01:31,680 --> 00:01:35,980 ->> Alright. And one last thing I want to point out. - -37 -00:01:35,980 --> 00:01:38,310 -And this seems obvious but I'm going to check with - -38 -00:01:38,310 --> 00:01:43,150 -you anyways. And seems like there is a basically the - -39 -00:01:43,150 --> 00:01:46,090 -need to keep track of whether an item is checked - -40 -00:01:46,090 --> 00:01:48,210 -out or not. If you look at the text here, - -41 -00:01:48,210 --> 00:01:51,080 -the requirements here, I can see that check out and checked out are - -42 -00:01:51,080 --> 00:01:55,070 -mentioned five times. So, I'm assuming that that's something also - -43 -00:01:55,070 --> 00:01:58,080 -that we want to know about an item, whether it's checked out or not. - -44 -00:01:58,080 --> 00:01:59,970 ->> We have to keep track of whether they're checked out. - -45 -00:01:59,970 --> 00:02:01,930 ->> Okay, so I'll add an - -46 -00:02:01,930 --> 00:02:04,340 -additional attribute there. So I'm going to again go - -47 -00:02:04,340 --> 00:02:06,480 -back to the diagram and I'm - -48 -00:02:06,480 --> 00:02:10,139 -just going to write here also the checked out attribute. - -49 -00:02:12,260 --> 00:02:14,590 -And, I think that's it as far as I'm - -50 -00:02:14,590 --> 00:02:16,330 -concerned. Is there anything that you think is missing? - -51 -00:02:16,330 --> 00:02:21,077 ->> Well, I do have a question. Would checked out, - -52 -00:02:21,077 --> 00:02:27,140 -better not be the case that someone can check out a reference book. - -53 -00:02:27,140 --> 00:02:28,400 ->> Oh, I see, I see. - -54 -00:02:28,400 --> 00:02:30,120 ->> Okay. I mean, it's only the books and - -55 -00:02:30,120 --> 00:02:31,780 -the audio visual material that can be checked out. - -56 -00:02:31,780 --> 00:02:37,790 ->> Right, right, right. Okay, so I, I guess, well the way I will fix that is, - -57 -00:02:37,790 --> 00:02:42,300 -I'll probably put yet another attribute in the item class, and I'll - -58 -00:02:42,300 --> 00:02:45,860 -call it loanable. And basically, this attribute is just telling us whether - -59 -00:02:45,860 --> 00:02:49,580 -an item is loanable or not. So, when it's not true and - -60 -00:02:49,580 --> 00:02:53,480 -loanable is not on. Basically, that item can be checked out. - -61 -00:02:53,480 --> 00:02:55,174 ->> Okay. And, the system would know this. - -62 -00:02:55,174 --> 00:02:56,450 ->> The system will know that. - -63 -00:02:56,450 --> 00:02:57,160 ->> And prevent it from happening. - -64 -00:02:57,160 --> 00:02:58,240 ->> And prevent it from happening. Okay? - -65 -00:02:58,240 --> 00:02:58,750 ->> Alright. - -66 -00:02:58,750 --> 00:03:02,918 ->> Perfect. So, we're going to do that and, any other objections, - -67 -00:03:02,918 --> 00:03:04,035 -any other? - -68 -00:03:04,035 --> 00:03:05,730 ->> No, that was my question. - -69 -00:03:05,730 --> 00:03:08,040 ->> Okay, perfect, so what I'm going to do next, I - -70 -00:03:08,040 --> 00:03:11,130 -mean, I haven't mentioned that yet, but you know classes right - -71 -00:03:11,130 --> 00:03:12,890 -now we just looked at the attributes right that give - -72 -00:03:12,890 --> 00:03:16,140 -you sort of the state of the class. And there's something - -73 -00:03:16,140 --> 00:03:19,185 -else, there's a second part of the class that is kind of - -74 -00:03:19,185 --> 00:03:22,520 -an orthogonal aspect, which is what the class can do. And we - -75 -00:03:22,520 --> 00:03:25,640 -call those operations. So normally these kinds also have operations, I - -76 -00:03:25,640 --> 00:03:28,000 -guess you know it would make sense to you as well. - -77 -00:03:28,000 --> 00:03:30,070 -And one way, one very natural way to - -78 -00:03:30,070 --> 00:03:33,310 -identify operations is to look at the requirements and - -79 -00:03:33,310 --> 00:03:36,850 -look for verbs. Because verbs associated with an item - -80 -00:03:36,850 --> 00:03:38,480 -will tell you basically what the item can do. - -81 -00:03:38,480 --> 00:03:38,900 ->> Okay. - -82 -00:03:38,900 --> 00:03:41,250 ->> So I, I'd like to go back to the requirements and - -83 -00:03:41,250 --> 00:03:45,110 -start, the same way in which we underlined, nouns, we're going to underline - -84 -00:03:45,110 --> 00:03:49,340 -verbs and we're going to see which ones of those verbs actually represent - -85 -00:03:49,340 --> 00:03:53,120 -actions that we want to represent explicitly, we want to model explicitly in - -86 -00:03:53,120 --> 00:03:53,950 -our class diagram. - -87 -00:03:53,950 --> 00:03:54,490 ->> Okay. - -88 -00:03:54,490 --> 00:03:54,750 ->> Okay. - -- cgit 1.4.1