1 00:00:00,810 --> 00:00:05,790 That guys in this video we're going to look at the factory pattern also called the factory method in 2 00:00:05,790 --> 00:00:13,020 javascript which is a way of creating an interface for creating objects but we can let subclasses define 3 00:00:13,020 --> 00:00:21,600 which classes to instantiate and factory methods are often used in applications to manage and maintain 4 00:00:21,900 --> 00:00:24,840 and manipulate collections of objects that are different. 5 00:00:24,840 --> 00:00:30,740 But at the same time have many common characteristics and a good example of that would be a member. 6 00:00:30,840 --> 00:00:36,480 Let's say some kind of paid membership application or web site where your members may have different 7 00:00:36,480 --> 00:00:40,460 types but still have the same properties and methods. 8 00:00:40,470 --> 00:00:42,540 So that's what we're going to get into in this video. 9 00:00:42,540 --> 00:00:48,930 We're going to create a member factory that takes a member type in creates a new object based on that 10 00:00:48,930 --> 00:00:49,630 type. 11 00:00:49,830 --> 00:00:53,760 OK so let's go ahead and create a function here. 12 00:00:53,760 --> 00:01:01,640 This is just a blank blank app J S file and we're going to call this member factory and we're going 13 00:01:01,640 --> 00:01:02,550 to set this. 14 00:01:02,550 --> 00:01:07,500 Actually we're just going to say function member factory it's just a declaration and then we're going 15 00:01:07,500 --> 00:01:08,730 to do this stot 16 00:01:11,220 --> 00:01:12,340 create member. 17 00:01:12,360 --> 00:01:15,280 And that will be a function expression. 18 00:01:19,190 --> 00:01:24,110 So this function is going to take in two things it's going to take in a name and it's going to take 19 00:01:24,110 --> 00:01:26,040 in a membership type. 20 00:01:26,390 --> 00:01:26,860 OK. 21 00:01:26,870 --> 00:01:31,850 Now here we're going to define a member variable. 22 00:01:32,360 --> 00:01:38,870 And we want to check the types here that are passed in or the type that's passed in and basically going 23 00:01:38,870 --> 00:01:46,610 by that type we want to create a new object or a certain type of object so we'll have a simple membership 24 00:01:46,940 --> 00:01:49,140 a standard and a super membership. 25 00:01:49,160 --> 00:01:54,020 Maybe it's a web hosting application web site or something like that. 26 00:01:54,050 --> 00:02:05,600 So let's test the type and we'll see if it's equal to simple then we're going to set member equal to 27 00:02:05,630 --> 00:02:09,230 new and then we're going to instantiate simple 28 00:02:11,930 --> 00:02:16,320 membership and we'll pass in the name. 29 00:02:16,320 --> 00:02:23,770 All right and then we'll do an LCF. 30 00:02:24,620 --> 00:02:30,070 So LCF that I'm just going to copy this up. 31 00:02:30,070 --> 00:02:31,210 This should be else. 32 00:02:31,340 --> 00:02:34,460 Type is equal to standard 33 00:02:37,160 --> 00:02:45,070 then we want to instantiate new standard membership. 34 00:02:45,230 --> 00:02:46,190 Else if 35 00:02:49,990 --> 00:03:06,970 the type is equal to Super then we want the member equal to new super membership. 36 00:03:06,970 --> 00:03:14,270 So we're testing out whatever that type is now now down here we want to set after the if statement. 37 00:03:14,310 --> 00:03:27,390 We want to set the member Daut type equal to type and then I'm just going to have one function or one 38 00:03:27,390 --> 00:03:33,450 method associated with this object called define that that's going to spit out the name the type the 39 00:03:33,450 --> 00:03:36,210 membership type and the cost of the membership. 40 00:03:36,210 --> 00:03:39,190 So let's call that define. 41 00:03:39,270 --> 00:03:42,900 So say member define equals function 42 00:03:46,540 --> 00:03:53,760 an inside here we're just going to console log on to Prince and back text we use template literals and 43 00:03:53,760 --> 00:03:54,990 all say the name. 44 00:03:55,110 --> 00:04:04,130 So they start name in and right after that let's put in parentheses the membership type so will say 45 00:04:04,170 --> 00:04:10,940 this type and then let's put a colon right here and then we'll put the cost of the number of ships of 46 00:04:10,950 --> 00:04:17,770 this dot cost and then we just want to return the member. 47 00:04:18,450 --> 00:04:24,960 So now we need to do is create our constructors for these subclasses. 48 00:04:24,960 --> 00:04:27,740 The simple standard and super membership's. 49 00:04:27,750 --> 00:04:35,970 So we're going to go down here create a variable called simple membership and we're going to set that 50 00:04:35,970 --> 00:04:41,950 to a function that's going to take in a name. 51 00:04:42,720 --> 00:04:45,990 And we're going to set this dog name 52 00:04:48,990 --> 00:04:51,350 equal to the name that's passed in. 53 00:04:51,360 --> 00:05:02,250 And then we're also going to set the cost of this to let's say $15 actual to $5 and then I'm just going 54 00:05:02,250 --> 00:05:07,740 to copy this and this one will be the standard membership 55 00:05:10,880 --> 00:05:19,010 and this one will be $15 this one will be the super and this one will be $25. 56 00:05:19,070 --> 00:05:26,080 So now let's go down here and let's create a variable called members and just set it to an empty array 57 00:05:26,960 --> 00:05:28,860 and then we want to define our factory. 58 00:05:28,940 --> 00:05:37,460 So I will say Konst factory equals new member factory. 59 00:05:38,330 --> 00:05:45,610 And then what we can do is we can add members by simply saying members Daut push. 60 00:05:46,490 --> 00:05:54,620 And then we can pass in that factory variable and we want to call create member. 61 00:05:55,560 --> 00:06:03,080 And what does create member take is right here takes in the name and it takes in the type ok and the 62 00:06:03,080 --> 00:06:06,530 type should be the simple standard or super. 63 00:06:07,190 --> 00:06:21,520 So let's say John Doe signs up for a simple membership and then down here we'll go ahead and cons. dot 64 00:06:21,580 --> 00:06:27,070 blog the members so save. 65 00:06:28,200 --> 00:06:36,840 All right so if we if we look at it this way it's just going to show us membership in the index it'll 66 00:06:36,840 --> 00:06:43,980 show us the cost the name simple what I'm going to do though is loop through the members so we'll say 67 00:06:43,980 --> 00:06:54,480 members Daut for each and put a function in here and then and here we'll see a member. 68 00:06:55,350 --> 00:06:59,460 And then let's call our member define K.M.. 69 00:06:59,520 --> 00:07:05,190 Remember we have that defined method right here and that's going to log the name the type the cost and 70 00:07:05,190 --> 00:07:05,760 so on. 71 00:07:05,760 --> 00:07:13,590 So let me just comment this log out and save and there we go John Doe has a simple membership which 72 00:07:13,590 --> 00:07:17,670 is five dollars and we can create as many of these as we want. 73 00:07:17,670 --> 00:07:32,130 So if we want to create some more of these let's say Chris Jackson and let's say he purchased a super 74 00:07:32,490 --> 00:07:46,140 membership we have Janice Williams who will say she got a simple membership and Tom Smith got a standard 75 00:07:47,520 --> 00:07:49,200 membership so we'll save that. 76 00:07:49,200 --> 00:07:51,120 Now you can see that they're all getting added. 77 00:07:51,120 --> 00:07:54,380 We have the name the membership type and the price. 78 00:07:54,540 --> 00:08:00,210 So this is a pretty good example of a fact of how the Factory pattern works. 79 00:08:00,390 --> 00:08:06,570 It's really good for when you have you know different objects they're different but they have the they 80 00:08:06,570 --> 00:08:10,580 share a lot of the same properties and methods and all of that. 81 00:08:10,620 --> 00:08:14,400 So we have just different memberships. 82 00:08:14,400 --> 00:08:18,530 All right guys that's it for the factory pattern and I will see you in the next video.