1
00:00:00,770 --> 00:00:01,820
Welcome back again.

2
00:00:01,820 --> 00:00:08,630
This lesson is going to be a very simple lesson we learn how to use a pull refresh control to refresh

3
00:00:08,630 --> 00:00:10,030
the content of a table view.

4
00:00:10,400 --> 00:00:12,530
So I'm going to school in here.

5
00:00:12,530 --> 00:00:14,330
I'm going to add a new application.

6
00:00:14,330 --> 00:00:17,240
I'm going to call it table view.

7
00:00:17,300 --> 00:00:20,850
I think that table view refresh control.

8
00:00:21,420 --> 00:00:26,330
And again we have to do the basic stuff what I'm going to try to do them as quickly as they can in their

9
00:00:26,330 --> 00:00:27,110
storyboard.

10
00:00:27,110 --> 00:00:28,750
I don't have this file.

11
00:00:29,240 --> 00:00:32,200
Instead I have an actual table view controller.

12
00:00:32,330 --> 00:00:37,490
My table view controller has a cell that has an I.D. called Cell I.D..

13
00:00:37,910 --> 00:00:38,980
It is basic.

14
00:00:38,990 --> 00:00:48,260
This is the initial view controller and I do have a class for it called my table view controller which

15
00:00:48,320 --> 00:00:55,100
in this storyboard is connected to here is all the things that we have done so many times so far and

16
00:00:55,100 --> 00:00:58,510
I'm trying to get through them as quickly as I can.

17
00:00:58,640 --> 00:01:09,290
And I have a valuable called my array which has only two cities in it Vancouver and New York and then

18
00:01:09,470 --> 00:01:14,740
in the number of the rows I have my array count.

19
00:01:14,870 --> 00:01:18,310
These are the only thing that matter in this particular application.

20
00:01:18,590 --> 00:01:26,960
And then I also have a cell for row that uses the cell a D doesn't need the index part because I'm not

21
00:01:26,960 --> 00:01:29,300
really using that for anything.

22
00:01:29,480 --> 00:01:36,440
I'm trying to cut down on the amount of code and come up with the simplest possible stuff and then they

23
00:01:36,440 --> 00:01:46,400
have to do in here is this I have to say cell that fixed table dot text becomes my array object that

24
00:01:46,400 --> 00:01:53,540
index part DOT rule and that's all I have to do to just show some stuff in my table view.

25
00:01:53,570 --> 00:01:58,610
Now this is something that we have done so many times before then new we want to happen in here is we

26
00:01:58,610 --> 00:02:05,690
want to be able to pull our people view using a UI refresh control and refresh the content of the table

27
00:02:05,690 --> 00:02:06,010
view.

28
00:02:06,380 --> 00:02:12,950
So to do that I'm going to go ahead and say I have a value event called My refresh control which is

29
00:02:12,950 --> 00:02:20,170
of the type you I refresh control and then of course I have to initialize it in my view did load.

30
00:02:20,200 --> 00:02:27,440
So in my view that Lord I'm going to go ahead and say My refresh control is a you I refresh control

31
00:02:27,950 --> 00:02:33,320
and then my refresh control essentially has to do something when it gets pulled.

32
00:02:33,350 --> 00:02:39,620
So we have to essentially add a target for it and I'm going to say add the target on the target for

33
00:02:39,620 --> 00:02:48,470
it is this I'm gonna go ahead and say at Target within self and the action for it is selector let's

34
00:02:48,470 --> 00:02:58,310
find an action for it I'm going to add something for it call it function refresh function and then it

35
00:02:58,310 --> 00:03:07,010
is called fine Shen then it is called is gonna call that one for the White event obviously that value

36
00:03:07,040 --> 00:03:14,960
changed value changed so when the refresh controller gets pulled it has to essentially call this one

37
00:03:15,530 --> 00:03:17,330
now I still have to do two things.

38
00:03:17,330 --> 00:03:23,090
One of them is to get rid of the error I have to say this is an art objective c kind of function so

39
00:03:23,090 --> 00:03:29,900
it exposes the selector and the other thing is we have made the refresh control but we haven't really

40
00:03:29,950 --> 00:03:37,820
added this to anyone and for that I'm going to go ahead and say self dot table view dot the sub view

41
00:03:38,030 --> 00:03:44,210
and I'm going to add the refresh control as a sub view to my table view to my table view will have that

42
00:03:44,780 --> 00:03:51,450
rotating you know bar that shows our study is being refreshed at the time the last thing that we're

43
00:03:51,470 --> 00:03:58,460
doing here before I can do an actual test with new data is once we come to the refresh control and we

44
00:03:58,460 --> 00:04:05,240
deal with the refresh or whatever we're trying to do when I'm going to do in here is it say self doubt

45
00:04:05,270 --> 00:04:14,080
table view data reload the data and then also my refresh control we have to and refreshing.

46
00:04:14,440 --> 00:04:16,280
So let's go ahead and run this application.

47
00:04:16,310 --> 00:04:23,210
He doesn't really do anything right now but he's gonna show us visually how refresh control works once

48
00:04:23,240 --> 00:04:30,590
we know that we can actually add extra data to our table view array as well so we now have this table

49
00:04:30,590 --> 00:04:37,400
view and if we pull it we can see the refresh happening up there it doesn't stay there for a very long

50
00:04:37,400 --> 00:04:44,000
time but it shows us that it is refreshing itself now the refresh usually happens when you are trying

51
00:04:44,000 --> 00:04:48,410
to pull new information from a network or somewhere.

52
00:04:48,440 --> 00:04:54,740
So because of that I'm going to actually try to simulate that even though this isn't a very good way

53
00:04:54,740 --> 00:05:03,030
of doing it but I'm going to say my array not append lets up and the few new cities to say I have a

54
00:05:03,030 --> 00:05:08,370
new city this one and I'm going to have another one.

55
00:05:08,370 --> 00:05:15,720
Let's say that is going to be real and then I'm going to go ahead and say even let's let's talk details

56
00:05:15,720 --> 00:05:19,800
about this I'm going to say my array dot sort them as well.

57
00:05:19,830 --> 00:05:25,200
So by now then the refresh happens some new information appears.

58
00:05:25,200 --> 00:05:31,350
Like I said this is a process that usually happens through a network and you will have to wait for the

59
00:05:31,350 --> 00:05:37,080
network to finish its work using a completion block and victim the completion block.

60
00:05:37,080 --> 00:05:43,390
We often actually run the table view reload and refresh control if we wait for those to happen.

61
00:05:43,420 --> 00:05:48,120
We will see more of these when we talk about networking in a few sections from now.

62
00:05:48,120 --> 00:05:54,240
But for now every time that we refresh it has to add the two new cities sort everything reload table

63
00:05:54,240 --> 00:05:56,310
view and end the refresh.

64
00:05:56,400 --> 00:05:57,860
Let's see that.

65
00:05:57,870 --> 00:05:59,040
Yes.

66
00:05:59,060 --> 00:06:05,220
And once again it does the same thing obviously it keeps adding new Delhi and Rio because every time

67
00:06:05,220 --> 00:06:09,470
it comes in here and appends to them it doesn't know that they already exist in there.

68
00:06:09,870 --> 00:06:17,850
So that's a very simple refresh contour for a table view used primarily when your data changes depending

69
00:06:17,850 --> 00:06:20,040
on a network status.

70
00:06:20,070 --> 00:06:22,980
Let's keep it up to here and we'll move on to our next lesson.