1 00:00:00,240 --> 00:00:00,760 Beautiful. 2 00:00:00,780 --> 00:00:06,780 And once we have looked at the Synchronoss approach like promised, I also would want to show you the 3 00:00:06,810 --> 00:00:11,700 asynchronous and as always, let's start by creating a new file can. 4 00:00:11,700 --> 00:00:18,690 In my case, that is going to be 10 hyphen and then I'm going to go with F.A.A. Sync Andrius. 5 00:00:19,020 --> 00:00:24,800 I'll grab everything in the objets and then just copy and paste back in the address. 6 00:00:24,810 --> 00:00:31,500 I would want to change these names so I'm not looking anymore for the red files and I'm actually looking 7 00:00:31,500 --> 00:00:33,990 for a method by the name of red file. 8 00:00:34,320 --> 00:00:38,820 So this is going to be the asynchronous one and the same goes with right file. 9 00:00:39,120 --> 00:00:42,830 Now, of course, we can remove all of this code as well. 10 00:00:43,260 --> 00:00:48,240 And the way the synchronous method works, we need to provide a callback. 11 00:00:48,480 --> 00:00:55,590 And if you're familiar with callback, essentially what it means is that we run that callback when we 12 00:00:55,590 --> 00:00:56,030 are done. 13 00:00:56,760 --> 00:01:04,769 So when whatever functionality we're doing is complete, then we run that callback just like we normally 14 00:01:04,769 --> 00:01:07,560 would do with adventitious there on a button. 15 00:01:07,840 --> 00:01:13,230 Remember, we go with the listener, we add whatever the event, of course, with a button that would 16 00:01:13,230 --> 00:01:16,500 be a click event and then pass in the callback function. 17 00:01:16,650 --> 00:01:20,400 And that callback function will run every time we click on a button. 18 00:01:20,730 --> 00:01:25,170 So this is the same thing where we have the read file function. 19 00:01:26,150 --> 00:01:30,920 And we can simply use it, since we have the structure that we need to provide a path. 20 00:01:31,220 --> 00:01:37,030 So again, we go forward slash content and the file name is first. 21 00:01:38,120 --> 00:01:42,050 And this is where we provide that second argument. 22 00:01:42,230 --> 00:01:44,190 And that is going to be a callback. 23 00:01:44,780 --> 00:01:47,930 Now, in that callback function, we pass into more arguments. 24 00:01:47,970 --> 00:01:54,380 First one is going to be error if there is one, as well as the result online instead of the body. 25 00:01:54,590 --> 00:02:00,680 First, I would want to check if there is an error and then I can just return null as well as maybe 26 00:02:00,710 --> 00:02:01,350 console log. 27 00:02:01,640 --> 00:02:08,419 So we go with F error and then we say return now or simply return whatever you want. 28 00:02:08,630 --> 00:02:11,330 And if you want, you can log the error. 29 00:02:11,870 --> 00:02:19,520 So and then if everything is correct, then I'll have access to my data, which of course has the name, 30 00:02:19,520 --> 00:02:21,680 the parameter name of Russell. 31 00:02:21,890 --> 00:02:28,100 And since I would simply want to log the result, I'm going to go with console log and the result, 32 00:02:28,120 --> 00:02:32,440 keep in mind that this is where you would set up the functionality. 33 00:02:32,720 --> 00:02:39,950 So let's go back and we're going to go with node abcess and in this case, something really interesting 34 00:02:40,340 --> 00:02:43,480 where we don't get the text right. 35 00:02:43,640 --> 00:02:45,010 So we're getting this buffer. 36 00:02:45,350 --> 00:02:51,690 So this is what's going to happen where if we don't provide that UTF coding, we'll get the buffer. 37 00:02:51,980 --> 00:02:59,030 Now, where do we have this encoding value right here in between in between the content as well as the 38 00:02:59,030 --> 00:02:59,360 path. 39 00:02:59,660 --> 00:03:04,490 So let's just go with string and we're looking for the UTF. 40 00:03:04,820 --> 00:03:12,740 So let's say UTF eight and seven, and let's run it one more time and of course, have no Rapture's. 41 00:03:12,950 --> 00:03:16,410 And then hello, this is the first text file. 42 00:03:16,880 --> 00:03:18,410 Now, the million dollar question. 43 00:03:18,860 --> 00:03:21,110 Well, how we can set up the same functionality. 44 00:03:21,980 --> 00:03:22,550 Check it out. 45 00:03:22,880 --> 00:03:29,660 We have read file, read file and then we simply create a new file with both of these routers. 46 00:03:29,990 --> 00:03:37,100 So if you're familiar with callbacks, you know that we would need to set up that functionality inside 47 00:03:37,100 --> 00:03:39,740 of this callback where I'm getting this result. 48 00:03:40,400 --> 00:03:45,590 Otherwise, there's going to be an error, because the only way for me to access this result, if I'm 49 00:03:45,590 --> 00:03:49,310 setting this as a callback, is, of course, inside of this function. 50 00:03:49,640 --> 00:03:56,780 And this is what I was saying before, where, yes, eventually I'll show you a different approach because 51 00:03:56,990 --> 00:03:59,690 inevitably we will set up a callback. 52 00:03:59,690 --> 00:04:01,890 Hell, and you'll see that in a second. 53 00:04:02,150 --> 00:04:08,960 So what I would want to do right now, when I get back my first text file, well, I would want to assign 54 00:04:08,960 --> 00:04:12,910 it to some kind of variable and then I would want to read that second file. 55 00:04:12,920 --> 00:04:13,190 Right. 56 00:04:13,550 --> 00:04:18,769 And then eventually, once I read the second file, then, of course, I would want to create that new 57 00:04:18,769 --> 00:04:19,120 file. 58 00:04:19,550 --> 00:04:26,330 And the way it's going to look like I'm going to go with const, I'll say first and you can name it 59 00:04:26,330 --> 00:04:26,680 first. 60 00:04:27,230 --> 00:04:31,090 I'm just going to go first and this will be equal to my result. 61 00:04:31,340 --> 00:04:31,720 Awesome. 62 00:04:32,060 --> 00:04:38,440 And then right after that, the result again I'm going to go with read file and then the same thing. 63 00:04:39,020 --> 00:04:45,960 We provide a path so we go with content and then in this case we're looking for second and then the 64 00:04:46,670 --> 00:04:48,650 then we need to provide the encoding. 65 00:04:49,010 --> 00:04:51,770 So Node knows how to decode that. 66 00:04:51,770 --> 00:04:56,560 And we'll go at UTF eight and then we need to provide our callback again. 67 00:04:56,570 --> 00:04:57,380 Same deal. 68 00:04:57,380 --> 00:05:00,110 We go with error and result. 69 00:05:00,320 --> 00:05:03,100 And in order to speed this up, I will copy and paste. 70 00:05:03,320 --> 00:05:07,070 So just grab everything starting with F and ending with the result. 71 00:05:07,440 --> 00:05:09,040 Copy and paste. 72 00:05:09,230 --> 00:05:12,620 Again, this is the case where we're checking for error. 73 00:05:12,620 --> 00:05:18,530 First, if there is an error, we cancel it and if everything is successful, we assign this one to 74 00:05:18,530 --> 00:05:23,450 the second one and then eventually now we want to set up my right file. 75 00:05:23,660 --> 00:05:29,830 So again, it is a function we need to provide that value and we already have a result sync. 76 00:05:30,770 --> 00:05:35,300 That's why I'll create a new one and I'll call this result and async. 77 00:05:35,570 --> 00:05:40,940 So again, we're looking for the content and we'll go with the file line, which is going to be a result 78 00:05:40,940 --> 00:05:46,610 and async text, since there is no file node will create that for us. 79 00:05:46,970 --> 00:05:47,660 All right away. 80 00:05:47,660 --> 00:05:48,510 Set up my data. 81 00:05:48,590 --> 00:05:52,130 Now, if you want, you can copy and paste this functionality. 82 00:05:52,460 --> 00:05:55,790 This is totally up to you where basically we use two of them. 83 00:05:56,000 --> 00:06:00,410 And in my case, this is exactly what I'm going to do in order to speed this up if you want to create 84 00:06:00,410 --> 00:06:03,410 something from scratch, because that is also an option. 85 00:06:03,590 --> 00:06:05,330 And I'm just going to copy and paste. 86 00:06:05,330 --> 00:06:06,610 That's my template string. 87 00:06:06,830 --> 00:06:11,480 And again, if you want this flag, you can definitely do so. 88 00:06:11,660 --> 00:06:14,100 In my case, I'm just going home at that. 89 00:06:14,390 --> 00:06:15,440 So here's the result. 90 00:06:15,440 --> 00:06:23,270 I have first and second and the reason why I have access to them, because I'm looking in the outside 91 00:06:23,270 --> 00:06:24,740 scope of this. 92 00:06:25,820 --> 00:06:32,500 And then again, we have a callback function in the right, while I know there's tons of callback functions, 93 00:06:32,510 --> 00:06:37,760 that's why we'll have to set up a better setup when we're handling these callbacks. 94 00:06:38,030 --> 00:06:39,590 But we'll do that a little bit later. 95 00:06:39,620 --> 00:06:46,280 So for now, let's just add a comment here where we have a first or second parameter and then third 96 00:06:46,280 --> 00:06:46,830 parameter. 97 00:06:47,120 --> 00:06:54,210 This is going to be, again, our callback where we have error and result and then in-service callback. 98 00:06:54,470 --> 00:07:00,530 Finally, we can take a look at the value and of course, the value will be in this result. 99 00:07:00,560 --> 00:07:05,210 Now, of course, we're creating the file and all that, but hopefully you get the gist that if you 100 00:07:05,210 --> 00:07:09,320 would be doing something where you're looking for this result, it would be over here. 101 00:07:09,650 --> 00:07:11,930 So, again, let's check for Eric quickly. 102 00:07:12,170 --> 00:07:19,340 If there is an error that I would want to return, as well as log the error just in case. 103 00:07:19,550 --> 00:07:23,510 And if everything is correct, let me just cancel the result. 104 00:07:23,810 --> 00:07:24,830 So save it here. 105 00:07:25,280 --> 00:07:28,130 And two things we need to watch out for. 106 00:07:28,430 --> 00:07:30,530 Maybe there is an error on second one. 107 00:07:30,650 --> 00:07:35,030 We should create a new file by the result, async the day. 108 00:07:35,300 --> 00:07:39,860 Let me clear the console and we're going to run node abcess. 109 00:07:40,100 --> 00:07:48,110 And I do get an error and are simply tells me that I did not add the dot in front of the content, so 110 00:07:48,110 --> 00:07:52,250 I would need to go back to the right file and just add up. 111 00:07:52,610 --> 00:07:59,570 And once we have the dot, we are going to be in good place where I'll clear the console all on one 112 00:07:59,570 --> 00:08:03,780 more time node dress and then the result will be undefined. 113 00:08:04,130 --> 00:08:05,450 OK, that's fine. 114 00:08:05,720 --> 00:08:11,780 Like I said, in this case, we're not expecting anything back, but that's really cool that in the 115 00:08:11,780 --> 00:08:16,110 result async we should have our next year is the result. 116 00:08:16,130 --> 00:08:19,190 Hello, this is first text and then the second text. 117 00:08:19,520 --> 00:08:24,400 So hopefully it is clear this is how we would use the async pattern. 118 00:08:24,740 --> 00:08:30,310 So let me zoom out right now here and you'll see this famous callback hell. 119 00:08:30,560 --> 00:08:38,120 And in the next video, I would want to give you a brief description of what our differences between 120 00:08:38,120 --> 00:08:45,320 the asynchronous approach or non blocking approach and the blocking on the synchronous one, as well 121 00:08:45,320 --> 00:08:49,220 as what are the alternatives to the callback.