1 00:00:00,990 --> 00:00:04,470 So let's play with Sessions and make sure that they work the way that we want them to. 2 00:00:04,500 --> 00:00:10,810 And I'm going to come up with a completely arbitrary and artificial test to make sure that things work. 3 00:00:10,830 --> 00:00:11,730 So here's what I'm going to do. 4 00:00:11,740 --> 00:00:13,920 I'm looking in the handler's folder right now. 5 00:00:13,920 --> 00:00:14,880 I have two handlers. 6 00:00:14,970 --> 00:00:18,960 I have one for the home page and I have one for the about page. 7 00:00:19,470 --> 00:00:21,270 So what I'm going to do is this. 8 00:00:21,270 --> 00:00:28,080 I am going to grab the remote IP address of the person visiting my site and store it in the home page. 9 00:00:28,080 --> 00:00:30,390 And I'm going to do that on the home a stored in the session. 10 00:00:30,390 --> 00:00:33,380 I'm going to do that in the home handler and that's really quite easy to do. 11 00:00:33,900 --> 00:00:36,010 So I first of all, I need the remote IP address. 12 00:00:36,030 --> 00:00:36,630 Well, that's easy. 13 00:00:36,630 --> 00:00:43,290 I can pull that right out of the request, so I'll call a variable remote IP is assigned the value of 14 00:00:43,560 --> 00:00:45,150 our remote address. 15 00:00:45,570 --> 00:00:53,880 OK, so that's built right into the standard library is part of the http http package and I can just 16 00:00:53,880 --> 00:00:54,770 pull the remote address. 17 00:00:54,780 --> 00:00:59,120 So that'll be an IP version four or an IP version six address and that's returned as a string. 18 00:00:59,130 --> 00:01:00,440 So I have a string here right now. 19 00:01:00,980 --> 00:01:05,850 I want to put that in the session and I know I have access to the session from the site where I config 20 00:01:05,850 --> 00:01:12,660 and I can get to the site where I config from this M variable that's part of the receiver M app session. 21 00:01:13,140 --> 00:01:16,290 Put and put, as you can see, takes three arguments. 22 00:01:16,590 --> 00:01:22,740 The context a key to look up the value if I want to get it out of the session and the actual value that 23 00:01:22,740 --> 00:01:24,620 I'm storing in that session, larible. 24 00:01:24,630 --> 00:01:27,000 So I'll put our context. 25 00:01:28,590 --> 00:01:32,160 The name will be remote IP and this can be whatever I want it to be. 26 00:01:32,160 --> 00:01:33,810 But that may that may make sense. 27 00:01:34,200 --> 00:01:40,440 And the value is remote IP, which I just thought, OK, so if you think about this, all I'm doing 28 00:01:40,680 --> 00:01:46,020 is the first time somebody hits that home page or actually every time somebody hits that home page for 29 00:01:46,020 --> 00:01:53,280 that user session, I'm storing the remote IP as a string in the session with the key to look it up 30 00:01:53,280 --> 00:01:54,640 being remote IP. 31 00:01:54,840 --> 00:01:55,290 All right. 32 00:01:55,380 --> 00:01:56,930 Well, that doesn't seem terribly helpful. 33 00:01:57,180 --> 00:01:58,150 What am I going to do with this? 34 00:01:58,800 --> 00:02:03,060 Well, in the other handler, I'm going to pull that value out of the session. 35 00:02:03,330 --> 00:02:12,720 So I will say remote IP is assigned and app session get and I'm going to use get string so I don't have 36 00:02:12,720 --> 00:02:13,560 to typecast it. 37 00:02:14,100 --> 00:02:21,660 Get the string from the context arg context and the key to look it up is remote IP. 38 00:02:22,170 --> 00:02:28,800 And the thing to remember here is that this value will be an empty string if there is nothing in the 39 00:02:28,800 --> 00:02:31,080 session named remote IP. 40 00:02:31,660 --> 00:02:33,930 So now that I have that, I need to put it in my string. 41 00:02:33,930 --> 00:02:49,200 That string map oops map and I'll call it remote IP is given the value of remote IP and now I'm going 42 00:02:49,200 --> 00:02:50,670 to go to my vote page template. 43 00:02:50,700 --> 00:02:54,810 So let's find that about Page and we'll put a little bit logic in here. 44 00:02:56,270 --> 00:03:01,940 In a new paragraph, I'm going to put an if statement in here, so this is a and if statement as part 45 00:03:01,940 --> 00:03:03,170 of the template package. 46 00:03:03,170 --> 00:03:09,350 So it doesn't follow the standard go syntax, but it's really simple, if not equal to. 47 00:03:09,380 --> 00:03:11,650 I'm going to make sure that things are not equal. 48 00:03:12,050 --> 00:03:22,070 So if not equal to and then look up the first value index dot string map, remote IP and it has to match 49 00:03:22,070 --> 00:03:25,250 case if that's not equal to nothing. 50 00:03:25,490 --> 00:03:28,640 In other words, if there's a value stored in that string, that's not an empty string. 51 00:03:28,640 --> 00:03:30,740 I want to do something else. 52 00:03:30,950 --> 00:03:32,090 I want to do something else. 53 00:03:33,620 --> 00:03:34,040 And 54 00:03:37,100 --> 00:03:37,490 all right. 55 00:03:37,760 --> 00:03:46,340 So if my value stored in the string map is not equal to an empty string, then I want to say your remote 56 00:03:46,580 --> 00:03:52,090 IP address is and then I'll just look up that value again. 57 00:03:52,100 --> 00:03:56,480 So I'll just copy and paste this copy and paste. 58 00:03:58,190 --> 00:04:00,080 Otherwise I got at the wrong spot. 59 00:04:01,610 --> 00:04:13,310 Paste, otherwise, I don't know your IP address yet, visit the atrip equals slash homepage. 60 00:04:16,990 --> 00:04:21,560 So I can set it all right now, this should all work. 61 00:04:21,580 --> 00:04:22,760 Let's give this a try. 62 00:04:22,780 --> 00:04:26,380 First of all, let me go back to my Web browser, make sure I'm not on the homepage. 63 00:04:26,380 --> 00:04:27,690 Slug's close that tab out. 64 00:04:27,700 --> 00:04:32,570 I'll open New Initech and then close this one and close this one and close this one. 65 00:04:32,590 --> 00:04:32,870 All right. 66 00:04:32,870 --> 00:04:35,980 So I'm starting from a known place. 67 00:04:37,200 --> 00:04:41,580 Go run command web, me or StarTalk, go. 68 00:04:45,030 --> 00:04:52,830 It compiles good and now I'm going to go to localhost, but I want to go to the vote page because I 69 00:04:52,830 --> 00:04:58,940 don't want to set that sectional variable yet, I hit it and it does not connect rom part number eighty 70 00:04:58,950 --> 00:04:59,300 eighty. 71 00:05:02,160 --> 00:05:03,140 This is the vote page. 72 00:05:03,150 --> 00:05:04,710 I don't know your IP address yet. 73 00:05:04,710 --> 00:05:06,580 Visit the home page so I can set it. 74 00:05:06,600 --> 00:05:07,590 So I'll go to the homepage. 75 00:05:08,130 --> 00:05:14,790 And now that I visited that home page, when I go back I should get a different message because it should 76 00:05:14,790 --> 00:05:20,910 be able to pull a non-empty string out of this session that has my remote IP address and there it is, 77 00:05:21,090 --> 00:05:24,930 one two seven zero zero one and then appart number after. 78 00:05:25,470 --> 00:05:29,280 So that is exactly what I wanted to do and that's how sessions work. 79 00:05:29,640 --> 00:05:33,930 So we have just so you know, let me go back to the record, not the roots, the handlers. 80 00:05:34,320 --> 00:05:39,630 We have a bunch of ways of getting things out of a session or putting things or one way to put it in, 81 00:05:39,630 --> 00:05:41,010 but a bunch of ways of getting it out. 82 00:05:41,550 --> 00:05:45,390 So up here, when I said Aptos session, get string. 83 00:05:45,390 --> 00:05:47,760 Let's look at some of the other things that are built into the session. 84 00:05:47,760 --> 00:05:55,710 Package Emden after session dot I can get direct access to the cookie I can find the lifetime of the 85 00:05:55,710 --> 00:05:56,250 session. 86 00:05:56,550 --> 00:05:58,980 I can look for the codec which are never going to do. 87 00:05:58,980 --> 00:06:00,000 But it's there if you want it. 88 00:06:00,330 --> 00:06:04,260 I can get a string, I can get anything I want out of the session. 89 00:06:04,260 --> 00:06:11,670 So often I'll store something that's not a string, it's not a an integer, one of the default primitive 90 00:06:11,670 --> 00:06:12,090 types. 91 00:06:12,270 --> 00:06:14,280 I can put whatever I want in the session. 92 00:06:14,280 --> 00:06:15,990 To do that I have to make one extra step. 93 00:06:15,990 --> 00:06:17,370 But we're not going to do that for a little while. 94 00:06:17,580 --> 00:06:21,330 But just so you know, the session package is pretty simple to use. 95 00:06:21,690 --> 00:06:24,480 And I like Alex Edwards excession. 96 00:06:24,480 --> 00:06:27,870 It works extremely well if you want to experiment with another one. 97 00:06:27,870 --> 00:06:29,040 Well, it's not that difficult. 98 00:06:29,040 --> 00:06:30,660 You already know how to install a package. 99 00:06:31,050 --> 00:06:33,180 Give it a try if you're so interested. 100 00:06:33,630 --> 00:06:35,280 Anyway, that's it for Sessions for right now. 101 00:06:35,280 --> 00:06:40,290 We'll be coming back to the usage of sessions on a regular basis as our application takes shape. 102 00:06:40,680 --> 00:06:43,170 But I think we've covered the basics for now.