1 00:00:00,840 --> 00:00:06,270 So this time around, we want to work with layouts that allow us to simplify our templates, and if 2 00:00:06,270 --> 00:00:11,400 you look at your templates folder right now, we have to about which looks like this, let me hide the 3 00:00:11,400 --> 00:00:17,460 terminal at home, which looks almost exactly the same. 4 00:00:17,490 --> 00:00:21,360 And this information at the top and then this little bit at the bottom. 5 00:00:21,360 --> 00:00:27,010 These are the things we want to have existed in one place and not on every single page of our site. 6 00:00:27,030 --> 00:00:28,850 The rationale for this is pretty straightforward. 7 00:00:28,860 --> 00:00:34,970 If I need to make a change to the top of the site, like here, for example, I'm importing the bootstrap 8 00:00:34,970 --> 00:00:40,950 success if I want it to use some other success, I don't want to have to change it on every single page 9 00:00:40,950 --> 00:00:41,490 of the site. 10 00:00:41,490 --> 00:00:43,060 That's just extremely time consuming. 11 00:00:43,440 --> 00:00:49,020 So what we're going to do is we're going to create a new file in the templates folder and we're going 12 00:00:49,020 --> 00:00:49,830 to call that. 13 00:00:50,040 --> 00:00:50,940 It's just a file. 14 00:00:51,270 --> 00:00:54,960 We're going to call it base layout template. 15 00:00:55,560 --> 00:00:58,830 And it is important that you have this middle part layout. 16 00:00:58,890 --> 00:01:01,830 OK, I would actually use the temporal extension. 17 00:01:01,830 --> 00:01:06,720 You can use HTML or whatever you want to, but HTML is the standard, at least in my world. 18 00:01:06,840 --> 00:01:08,940 So I'm going to create that and it's a new empty file. 19 00:01:09,630 --> 00:01:12,960 Then I'm going to copy everything from the homepage. 20 00:01:12,990 --> 00:01:14,160 I'm going to copy all of it. 21 00:01:14,690 --> 00:01:20,390 I'm going to paste it in here and then I'm going to add a couple of things at the very top. 22 00:01:20,400 --> 00:01:27,600 I'm going to create a new blank line and I'm going to in double curly braces, I'm going to say define 23 00:01:27,870 --> 00:01:29,790 and then in quotes face. 24 00:01:30,560 --> 00:01:37,110 And then at the very bottom of this, right after the closing HTML tag, I'm going to put in double 25 00:01:37,110 --> 00:01:40,050 curly brackets and OK. 26 00:01:40,050 --> 00:01:43,920 And then just to make things format nicely, I will indent everything in between. 27 00:01:44,280 --> 00:01:49,260 All I've done here and this is something you're going to become very familiar with is I've used inside 28 00:01:49,260 --> 00:01:54,470 those double curly braces directives that are specific to go laying templates. 29 00:01:55,080 --> 00:01:58,470 So before these were added, this was just an HTML. 30 00:01:58,800 --> 00:02:00,120 There was nothing special about it all. 31 00:02:00,150 --> 00:02:05,580 It was passed as a goal line template where it looked for these double curly braces and things in between 32 00:02:05,580 --> 00:02:09,270 them to do things didn't find any, so it just served up the HTML5. 33 00:02:09,570 --> 00:02:15,390 And all I've done here is define everything between this tag, define base and this tag. 34 00:02:15,390 --> 00:02:17,850 And I've said everything in between. 35 00:02:17,850 --> 00:02:23,290 That is a as is defined with the name base and it's going to be a layer. 36 00:02:23,490 --> 00:02:26,570 OK, now I'm going to add some other things in here. 37 00:02:26,580 --> 00:02:31,020 Clearly, I don't want this is the home page on every page of the site. 38 00:02:31,200 --> 00:02:34,650 In fact, I'm going to delete everything between those body tags. 39 00:02:34,680 --> 00:02:37,740 I'm just going to delete it and I'm going instead. 40 00:02:37,740 --> 00:02:39,720 I'm going to put a little directive in there. 41 00:02:40,170 --> 00:02:42,510 And that directive is a block. 42 00:02:42,510 --> 00:02:43,770 A content block. 43 00:02:44,790 --> 00:02:46,650 Block is my directive. 44 00:02:47,010 --> 00:02:49,020 And the name is content. 45 00:02:49,320 --> 00:02:51,660 And this seems odd, but I'll explain it to you. 46 00:02:51,840 --> 00:02:53,550 I'm going to put a period after that. 47 00:02:54,150 --> 00:03:00,900 So there's an opening block tag and now I'll put a closing block tag, which is basically nothing more 48 00:03:00,900 --> 00:03:01,430 than the word. 49 00:03:01,440 --> 00:03:10,110 And so I've just defined a section in this layout that says to the goal line and Googling it says to 50 00:03:10,110 --> 00:03:10,620 go line. 51 00:03:11,670 --> 00:03:15,600 What will you see between this opening block and this envelope, this instatement? 52 00:03:15,930 --> 00:03:18,300 This will change on a per template basis. 53 00:03:18,300 --> 00:03:24,060 I might have content I want to stick in there and that content might be just HTML, in which case I 54 00:03:24,060 --> 00:03:26,430 wouldn't need this dot more often. 55 00:03:26,430 --> 00:03:33,360 It's going to include data that I pass from my handlers to the template renderer to render on the template. 56 00:03:33,360 --> 00:03:39,390 And all that DOT means is include whatever data you have with this template and send it to this block 57 00:03:39,390 --> 00:03:41,040 so we can use it if it has to. 58 00:03:42,240 --> 00:03:43,200 Now I define that. 59 00:03:43,200 --> 00:03:47,340 And just to make things simpler, because I'm going to use this later on, I'm going to find two more 60 00:03:47,340 --> 00:03:48,600 blocks up on the top. 61 00:03:48,900 --> 00:03:56,430 I'm going to find a new block, which I'll call success, and I will pass it data as well, and then 62 00:03:56,430 --> 00:03:57,570 I'll have an ending tag for it. 63 00:03:58,350 --> 00:04:05,370 And and then at the bottom, just before the closing body tag, I'm going to have another block called 64 00:04:05,370 --> 00:04:07,170 Jazz for JavaScript. 65 00:04:07,500 --> 00:04:09,280 And again, I need a closing tag. 66 00:04:09,570 --> 00:04:12,990 Now, the reason I'm doing this is that it's entirely possible. 67 00:04:12,990 --> 00:04:14,250 Block j ust dot. 68 00:04:14,340 --> 00:04:15,650 I want to pass it data as well. 69 00:04:16,590 --> 00:04:22,680 It's entirely possible, in fact, likely that I'm going to have some custom access for one page, but 70 00:04:22,680 --> 00:04:23,460 not for another. 71 00:04:23,460 --> 00:04:24,840 And this gives me a place to put it. 72 00:04:24,850 --> 00:04:26,480 That's the only reason it exists. 73 00:04:26,880 --> 00:04:32,460 It's also extremely likely that I'll have some JavaScript which is specific to some pages, but not 74 00:04:32,460 --> 00:04:34,350 others, and this gives me a place to put it. 75 00:04:35,010 --> 00:04:41,310 So all I've done here is to find a template, a layout for our templates that says here's the base template. 76 00:04:41,820 --> 00:04:47,880 Everything might have access entry, it might have a JavaScript entry and it might have a content entry. 77 00:04:48,240 --> 00:04:49,400 And I can say that. 78 00:04:49,410 --> 00:04:51,300 So now I've created this template. 79 00:04:51,630 --> 00:04:54,770 The obvious question is how do I use it? 80 00:04:55,080 --> 00:04:59,360 Well, to start with, let's go back and say simplify our homepage. 81 00:04:59,850 --> 00:05:00,330 Now this. 82 00:05:00,460 --> 00:05:05,710 Hard here from d'Hiv container and to the ending, Dave and all that stuff in between. 83 00:05:05,800 --> 00:05:08,500 That's the only content I want on this template. 84 00:05:08,530 --> 00:05:09,430 I don't want the rest of it. 85 00:05:09,430 --> 00:05:10,680 So I'm going to copy that, too. 86 00:05:10,700 --> 00:05:11,290 So I have it. 87 00:05:12,040 --> 00:05:14,560 And then I'm going to select all of this text and delete it. 88 00:05:14,830 --> 00:05:19,930 And I'm going to start this template with a directive, a go line template directive. 89 00:05:20,320 --> 00:05:22,510 And it's simply the word template. 90 00:05:22,540 --> 00:05:28,750 Use this template, use the template called base and include the data that's passed and then I'll have 91 00:05:28,750 --> 00:05:29,200 an end. 92 00:05:31,360 --> 00:05:33,020 Actually, you don't need an end for that one. 93 00:05:33,040 --> 00:05:34,840 I'm going to delete that just to say don't confuse you. 94 00:05:34,930 --> 00:05:36,680 This is a simple directive that's not closing. 95 00:05:36,700 --> 00:05:38,730 This just says it has no closing tag. 96 00:05:38,740 --> 00:05:41,800 It just says use the template named base. 97 00:05:41,800 --> 00:05:48,050 And this word right here, base corresponds to this word in base layout template. 98 00:05:49,360 --> 00:05:50,500 So now I have to find that. 99 00:05:50,860 --> 00:05:52,030 And when am I going to have it here? 100 00:05:52,060 --> 00:05:56,340 Well, I could have defined and I want to define content. 101 00:05:58,620 --> 00:06:04,110 And it has a closing time, and in between those, I'll post what I copied a little a few minutes ago. 102 00:06:04,620 --> 00:06:07,620 So now look how simple and short this template is. 103 00:06:07,650 --> 00:06:09,390 It says use the base template. 104 00:06:09,600 --> 00:06:14,160 And anywhere on that base template where you find a block name content put this content. 105 00:06:14,970 --> 00:06:20,180 And the fact that I have the dot here means that my data is available for the entire template. 106 00:06:21,510 --> 00:06:23,430 So that's all that I have to do for that. 107 00:06:23,430 --> 00:06:27,570 And I can do exactly the same thing for base layout or so for about Page. 108 00:06:27,580 --> 00:06:31,290 So I come in here, I find the things that I want to be specific to this. 109 00:06:31,290 --> 00:06:41,970 I cut it, delete everything, say use the template base and pass the data to it and then define content. 110 00:06:45,080 --> 00:06:54,330 Paste in my HTML specific to the Web page and close that define tag, and now that is a lot less HTML 111 00:06:54,330 --> 00:06:56,200 to maintain on a per page basis. 112 00:06:56,460 --> 00:07:01,400 So I defined this base layout, I defined the home page and define the about page. 113 00:07:01,590 --> 00:07:09,600 But if I run the application right now, which I'm going to so go run command web Stargirl, there's 114 00:07:09,600 --> 00:07:13,770 only one file so I could put Mango, but I like to get the habit of going Stargirl because I know him 115 00:07:13,770 --> 00:07:15,870 and have more files in there later and run it. 116 00:07:18,340 --> 00:07:24,730 Then switch to my favorite Web browser, open up a browser window and go to local eighty. 117 00:07:26,020 --> 00:07:27,740 Well, I didn't seem to work very well. 118 00:07:27,940 --> 00:07:28,650 What's in there? 119 00:07:28,690 --> 00:07:34,080 If I view the source on this view the while, I'll just go view source. 120 00:07:35,500 --> 00:07:36,490 There's nothing in there. 121 00:07:36,520 --> 00:07:37,220 It's empty. 122 00:07:37,270 --> 00:07:37,810 Why? 123 00:07:37,930 --> 00:07:43,470 Well, because although I've told this template for the homepage, so let's find home again. 124 00:07:44,140 --> 00:07:46,750 I've said use the template base. 125 00:07:46,750 --> 00:07:48,280 Well, I can't find the template base. 126 00:07:48,300 --> 00:07:54,070 And if I look down here, the error messages in the console in my terminal, it says error parsing, 127 00:07:54,070 --> 00:07:59,380 template, template, homepage, template, no such template base. 128 00:07:59,680 --> 00:08:07,210 I need to actually tell go how to render this template that I'm using layouts and that fortunately is 129 00:08:07,210 --> 00:08:08,630 not all that difficult. 130 00:08:09,040 --> 00:08:10,900 So how are we going to do that? 131 00:08:10,930 --> 00:08:14,190 Well, we already know we have a package here called Render. 132 00:08:14,230 --> 00:08:14,550 Right. 133 00:08:15,190 --> 00:08:18,010 And inside of that is where I actually render the template. 134 00:08:18,970 --> 00:08:22,030 So name starts with package name, and that's OK, I don't mind that. 135 00:08:23,420 --> 00:08:27,320 How do I actually make this thing do what I want it to do? 136 00:08:27,590 --> 00:08:29,770 Well, let's think about this for a minute. 137 00:08:30,440 --> 00:08:35,690 So what I need to do is something more sophisticated than simply saying go to the templates directory 138 00:08:35,690 --> 00:08:38,790 right here, find the template with that name and render it. 139 00:08:39,020 --> 00:08:46,730 I actually need to somehow tell it, find all of the based on all of the pages in this folder, whatever 140 00:08:46,730 --> 00:08:53,810 they may be, find the layouts associated with them and combine those into a template that I can actually 141 00:08:53,810 --> 00:08:54,170 serve. 142 00:08:54,350 --> 00:08:54,790 All right. 143 00:08:54,920 --> 00:09:03,770 So what I'm going to do is I'm going to create a new function and I'll call it a render template test 144 00:09:03,890 --> 00:09:06,770 just so I don't overwrite what I have already. 145 00:09:06,950 --> 00:09:13,270 And I'll give it now in my response writer and give it my tampoe string. 146 00:09:13,280 --> 00:09:14,510 So the same arguments. 147 00:09:15,080 --> 00:09:17,600 And I'm going to do things a little bit differently to start with. 148 00:09:17,840 --> 00:09:20,840 I'm going to create something that you may not be familiar with. 149 00:09:21,140 --> 00:09:23,420 It is a go langue map. 150 00:09:23,420 --> 00:09:24,770 It's just a data structure. 151 00:09:24,770 --> 00:09:28,880 Some people call these associative arrays and that would be the closest corresponding thing. 152 00:09:28,880 --> 00:09:35,060 And this is just a data structure that holds whatever I tell it to hold so I can look up things very, 153 00:09:35,060 --> 00:09:35,690 very quickly. 154 00:09:36,140 --> 00:09:39,290 So I'm going to do that by creating something I'm going to call a cache. 155 00:09:39,290 --> 00:09:45,110 When I'm going to create is a template cache that holds all of my templates and it creates it at the 156 00:09:45,110 --> 00:09:46,190 start of the application. 157 00:09:46,700 --> 00:09:54,530 So I create a variable, my cache, and I'm going to assign that the type of map string. 158 00:09:56,750 --> 00:10:02,030 And that I'm going to put in a point or two template, dot template. 159 00:10:03,060 --> 00:10:08,630 And I need to close that with opening and closing curly brackets, which is pretty straightforward. 160 00:10:08,670 --> 00:10:12,060 OK, so that is something that I've just created. 161 00:10:12,060 --> 00:10:15,210 My cache is a map string template template. 162 00:10:17,140 --> 00:10:18,550 All right, so what am I going to do with that? 163 00:10:19,210 --> 00:10:26,710 Well, the first thing I need to do is to tell it you need to go and get all of the files at a particular 164 00:10:26,710 --> 00:10:27,280 location. 165 00:10:27,550 --> 00:10:30,190 OK, so how do I tell you to do that? 166 00:10:30,220 --> 00:10:32,000 Well, first of all, what am I going to get? 167 00:10:32,020 --> 00:10:37,720 I'm going to go get all of the pages, all of the things in this template folder that actually have 168 00:10:37,720 --> 00:10:39,180 the name page in there. 169 00:10:39,190 --> 00:10:42,970 So before the template, I have a I have a page. 170 00:10:44,170 --> 00:10:46,060 Let's go get those so pages. 171 00:10:46,060 --> 00:10:48,250 I'm going to go get those and error. 172 00:10:48,250 --> 00:10:52,180 I'm going to be checking for errors is going to be assigned. 173 00:10:52,750 --> 00:11:00,790 And this is a built in function found in go file path dot Glaube strange name galore, but it actually 174 00:11:00,790 --> 00:11:02,200 kind of makes sense to me to think it through. 175 00:11:02,500 --> 00:11:03,670 And I want to find. 176 00:11:05,040 --> 00:11:13,680 Everything that exists in dot slash templates and then star dot page, dot tempo. 177 00:11:14,670 --> 00:11:20,190 Now all that really does is say go to the templates folder, find everything the templates folder that's 178 00:11:20,190 --> 00:11:26,070 at the root level of my application and get all of the files that start with anything but definitely 179 00:11:26,070 --> 00:11:28,410 end with dot page, dot tempo. 180 00:11:28,440 --> 00:11:35,460 So this is going to select about Dot Page, Dot Temple and home page Tapio and then I'll check for errors. 181 00:11:35,490 --> 00:11:40,910 OK, so if error is not equal to nil then I want to do what. 182 00:11:40,960 --> 00:11:42,930 Well what do I want to do here. 183 00:11:43,170 --> 00:11:44,100 Let's return an error. 184 00:11:44,970 --> 00:11:47,370 So return an error. 185 00:11:47,370 --> 00:11:50,760 Which means up here I have to say it returns the type of error. 186 00:11:51,150 --> 00:11:51,540 OK. 187 00:11:51,630 --> 00:11:54,840 And it's not called er it's called e r r try that again. 188 00:11:55,860 --> 00:11:57,830 Erm all right. 189 00:11:57,840 --> 00:12:02,300 So now I've got my pages, I haven't done anything with them yet so I've got to do something with it. 190 00:12:02,490 --> 00:12:05,720 So now I'm going to use another control structure that you haven't seen yet. 191 00:12:05,730 --> 00:12:09,150 You may have seen it if you've done some work at other programming languages but you haven't seen it 192 00:12:09,150 --> 00:12:09,720 in go. 193 00:12:10,440 --> 00:12:16,230 It's a for loop and the way that for loops working go is really straightforward for and then the first 194 00:12:16,230 --> 00:12:18,480 thing would be index, which I'm going to get rid of in a minute. 195 00:12:18,480 --> 00:12:21,630 But this is for index and then page. 196 00:12:21,630 --> 00:12:23,430 That's just a name that I'm giving. 197 00:12:23,430 --> 00:12:27,600 It is a signed range through pages and then I do something. 198 00:12:28,440 --> 00:12:30,660 So I have two things that are happening here. 199 00:12:30,840 --> 00:12:36,570 For every page that I find, I am going to get the index and the first time through will be zero. 200 00:12:37,050 --> 00:12:40,020 And then then I'm going to get the actual page itself. 201 00:12:40,020 --> 00:12:46,680 Will the page that I get here is a collection or a selection of all the files that is found in this 202 00:12:46,680 --> 00:12:47,610 variable pages. 203 00:12:47,880 --> 00:12:51,840 So it might find about first, therefore I will equal zero. 204 00:12:51,840 --> 00:12:58,980 The first iteration and page will equal about Page Tampoe and then the second time through this will 205 00:12:58,980 --> 00:13:04,020 go to one because we start counting at zero and four loops and the second one and the second value would 206 00:13:04,020 --> 00:13:05,910 be home page temple. 207 00:13:06,060 --> 00:13:11,660 It will not include based on layout because well, it doesn't end in page two. 208 00:13:12,810 --> 00:13:16,110 Now when I do this, what I what am I going to do when I start looping through this? 209 00:13:16,110 --> 00:13:17,400 Well, I've got this information. 210 00:13:17,400 --> 00:13:23,970 The first thing you get is the actual base name of the page, because what it's returning here is actually 211 00:13:23,970 --> 00:13:29,250 not just about page that template, it's turning the full path to that. 212 00:13:29,250 --> 00:13:31,410 And what I want, it's returning the full path to that. 213 00:13:31,410 --> 00:13:33,360 And what I want is the actual name of the page. 214 00:13:33,360 --> 00:13:39,530 And I can get that by saying name is assigned file path, not base page. 215 00:13:40,110 --> 00:13:40,580 All right. 216 00:13:40,590 --> 00:13:43,860 So now I've used this page variable and it's used here. 217 00:13:44,100 --> 00:13:48,920 And from that I've extracted the actual name, which is just about page template. 218 00:13:49,200 --> 00:13:50,280 I don't want the index. 219 00:13:50,280 --> 00:13:50,940 I'm not going to use it. 220 00:13:50,940 --> 00:13:53,520 So I'm actually going to say don't do anything with the index. 221 00:13:53,850 --> 00:13:56,890 Now that I have this name, what do I want to do with it? 222 00:13:57,600 --> 00:14:02,070 Well, I'm going to create a template set and a template set. 223 00:14:02,070 --> 00:14:03,780 It sounds ever so complicated. 224 00:14:03,780 --> 00:14:08,550 It's not all I'm going to do is give it create a new variable test for template set. 225 00:14:08,970 --> 00:14:16,050 And I'm going to check for an error that's assigned the value of template, not new. 226 00:14:17,730 --> 00:14:24,690 And the name I want to use for that template is the actual name I just extracted name and then I want 227 00:14:24,690 --> 00:14:25,770 to give it Funk's. 228 00:14:26,310 --> 00:14:31,320 This template might have some functions and I'm going to give it a word functions which we haven't defined 229 00:14:31,320 --> 00:14:31,470 yet. 230 00:14:31,470 --> 00:14:32,400 But don't worry about that. 231 00:14:32,880 --> 00:14:35,340 And I want to pass files page. 232 00:14:35,350 --> 00:14:38,760 Wow, that's a lot of text, but what is it actually doing? 233 00:14:38,770 --> 00:14:40,590 Well, first of all, let me just do this. 234 00:14:41,190 --> 00:14:44,730 Copy this error check and paste it here. 235 00:14:44,910 --> 00:14:46,770 OK, what's this function. 236 00:14:46,770 --> 00:14:51,030 Well, we haven't seen that what what that actually is yet, but it is something that I am going to 237 00:14:51,030 --> 00:14:51,510 use. 238 00:14:51,510 --> 00:14:57,720 OK, what I'm going to do up here is outside of this function and outside of that function, just out 239 00:14:57,720 --> 00:15:06,720 to the input statement that I'm going to create a new function, OK, a new variable, I'm going to 240 00:15:06,720 --> 00:15:07,680 call it functions. 241 00:15:08,190 --> 00:15:11,520 And all it's going to do, it's equal to template dot. 242 00:15:11,520 --> 00:15:13,890 Func Map will be seeing this shortly. 243 00:15:13,890 --> 00:15:19,140 I'll explain it in a moment, but let's get it typed out first and it's going to be empty, OK, it 244 00:15:19,140 --> 00:15:19,560 has nothing. 245 00:15:20,190 --> 00:15:23,010 So I've created a variable called functions. 246 00:15:23,160 --> 00:15:24,630 It's a type template. 247 00:15:24,630 --> 00:15:25,470 Func map. 248 00:15:25,650 --> 00:15:27,200 What does this do? 249 00:15:27,210 --> 00:15:32,430 Well, I think map is nothing more than a map of functions that I can use in a template. 250 00:15:32,430 --> 00:15:38,070 I am going to, at some point in this course, need to do something in a go line template that is not 251 00:15:38,070 --> 00:15:39,210 built into the language. 252 00:15:39,330 --> 00:15:46,230 Maybe I want to format a date, maybe I want to return the current year, whatever it may be. 253 00:15:46,440 --> 00:15:52,770 It's not built into the templating language, but go allows us to create our own functions and pass 254 00:15:52,770 --> 00:15:53,880 those to the template. 255 00:15:54,030 --> 00:15:55,920 We don't have any yet, but we'll get some later. 256 00:15:55,920 --> 00:15:58,080 Let's just set it up right now because we know we're going to use it. 257 00:15:58,710 --> 00:16:02,100 So now I've created my template set based upon this page. 258 00:16:02,100 --> 00:16:04,110 I've passed an empty variable function. 259 00:16:04,530 --> 00:16:07,450 That will eventually have some functions in there that we can use. 260 00:16:07,770 --> 00:16:10,680 I've checked for errors, so, so far so good. 261 00:16:11,130 --> 00:16:12,330 What happens next? 262 00:16:13,500 --> 00:16:18,720 Well, first of all, we need to find out, does this template match any layouts? 263 00:16:18,720 --> 00:16:24,750 In other words, should I use a layout that's defined for this template with this particular template? 264 00:16:24,930 --> 00:16:28,420 OK, so we're going to check and see if it matches something. 265 00:16:29,130 --> 00:16:33,930 So let's look for the existence of any layouts in this particular folder called templates. 266 00:16:33,930 --> 00:16:35,700 And we can do that by saying matches. 267 00:16:35,950 --> 00:16:37,310 That's a variable that I'm picking. 268 00:16:37,320 --> 00:16:41,330 And I just like it because actually we're checking to see if something matches again. 269 00:16:41,340 --> 00:16:42,510 We'll check for an error. 270 00:16:42,840 --> 00:16:49,710 And that's going to be assigned the value of, once again, this glob thing, file path globe. 271 00:16:51,150 --> 00:17:00,880 And we're going to look in the folder, dot slash, star layout star, dot layout, dot temple. 272 00:17:01,890 --> 00:17:07,980 So that's going to say look for anything, any file in that directory specified here, which is actually 273 00:17:07,980 --> 00:17:10,330 supposed to be dot templates. 274 00:17:10,350 --> 00:17:11,070 Try that again. 275 00:17:11,670 --> 00:17:17,430 Templates start looking the templates directory for any file that ends and layout HTML. 276 00:17:17,910 --> 00:17:20,510 And if you can find one, we're going to do something with it. 277 00:17:20,700 --> 00:17:24,510 But first, let's check for errors to make sure that everything works the way it's supposed to, because 278 00:17:24,510 --> 00:17:28,470 maybe I had a typo in here where I left the letter out and I can't find the necessary directory, but 279 00:17:28,470 --> 00:17:33,720 whatever it's good practice to check for errors, then we're going to look at this variable matches. 280 00:17:34,140 --> 00:17:40,740 If there's at least one thing that it finds in there, then the length of matches will be greater than 281 00:17:40,740 --> 00:17:41,120 zero. 282 00:17:41,190 --> 00:17:48,390 So I can say if Len, which is a built in function go matches, is greater than zero, then I want to 283 00:17:48,390 --> 00:17:48,920 do something. 284 00:17:49,230 --> 00:17:50,830 And what do I want to do? 285 00:17:51,270 --> 00:18:00,540 Well, I want to actually again go to my template set, which I've already created, check for an error 286 00:18:01,470 --> 00:18:06,750 and I want to pass that Glaube so pass Glaube. 287 00:18:09,220 --> 00:18:13,060 And it's going to be, once again, just the path to the templates. 288 00:18:14,250 --> 00:18:18,000 Templates start up template, sort of layout. 289 00:18:20,500 --> 00:18:21,280 Tampoe. 290 00:18:24,480 --> 00:18:30,800 We're going to pass it will check for errors once again, if there's an error, just return the error. 291 00:18:31,890 --> 00:18:33,110 So we've passed it now. 292 00:18:33,660 --> 00:18:35,100 And what do we do with it next? 293 00:18:35,130 --> 00:18:37,750 Well, we're all set off right now for that part. 294 00:18:37,770 --> 00:18:38,490 For that part. 295 00:18:38,850 --> 00:18:44,820 All we need to do at this point is to take that template set that we've just spent all this time creating. 296 00:18:45,150 --> 00:18:48,150 And we need to add it to the cash that we created up here. 297 00:18:48,160 --> 00:18:50,460 We're finally going to use this map we created. 298 00:18:51,150 --> 00:18:52,820 And the way that it works is very simple. 299 00:18:52,950 --> 00:19:00,350 My cash name, which is the actual name of the template, equals the template set I just created. 300 00:19:01,020 --> 00:19:01,680 So I've got that. 301 00:19:01,680 --> 00:19:02,400 I've created it. 302 00:19:03,000 --> 00:19:05,750 And now because I have a function here, return no. 303 00:19:06,780 --> 00:19:13,050 So we've gone to all this trouble of creating render template test, which is going to become rendered 304 00:19:13,050 --> 00:19:13,980 template in just a minute. 305 00:19:14,550 --> 00:19:15,680 And let's go through this again. 306 00:19:15,690 --> 00:19:21,360 What I've done is create a map and a map is just something I can look up very look up a value in very 307 00:19:21,360 --> 00:19:21,800 quickly. 308 00:19:22,020 --> 00:19:26,040 This happens to have a string as its first parameter, the map index. 309 00:19:26,550 --> 00:19:30,190 And I'm using for the index the name of the template in question. 310 00:19:30,210 --> 00:19:34,500 So when I run this, my cache will actually have two entries. 311 00:19:35,010 --> 00:19:43,380 The first one is called about Page Tampoe and the second one is called Home Page Template. 312 00:19:43,560 --> 00:19:45,180 So that's how I can look things up. 313 00:19:45,570 --> 00:19:50,580 And when I look it up, it's going to give me a fully parsed and ready to use template. 314 00:19:50,700 --> 00:19:54,360 So and it's actually a pointer to a template, but same idea for our purposes. 315 00:19:55,470 --> 00:20:01,230 When I need to render a template, I need to have access to this cache and I need to be able to do that 316 00:20:01,710 --> 00:20:02,370 in some way. 317 00:20:02,370 --> 00:20:03,480 That kind of makes sense. 318 00:20:03,510 --> 00:20:08,910 Now, if you look at the way I've built this variable right now, I've actually got this scoped. 319 00:20:08,910 --> 00:20:13,320 So it only exists within this particular function. 320 00:20:13,320 --> 00:20:14,420 And that's not very helpful. 321 00:20:14,670 --> 00:20:16,720 So maybe I should return that as well. 322 00:20:16,740 --> 00:20:19,740 So let me put brackets around this and return to values. 323 00:20:20,970 --> 00:20:25,800 And the first value of their return is exactly what I have right here, a map, string, template, 324 00:20:25,800 --> 00:20:26,280 template. 325 00:20:26,280 --> 00:20:27,090 So let's get that. 326 00:20:29,450 --> 00:20:30,440 And pasted in there. 327 00:20:32,290 --> 00:20:36,490 And we don't need this after, of course, because we're not actually this is how we're referring to 328 00:20:36,490 --> 00:20:36,940 the type. 329 00:20:36,940 --> 00:20:41,950 This is just a type, it's a map with an index of string and the contents are going to be a pointer 330 00:20:41,950 --> 00:20:43,150 to template template. 331 00:20:43,540 --> 00:20:44,830 And we're returning error. 332 00:20:45,460 --> 00:20:50,860 And here we can just return that before the error. 333 00:20:50,860 --> 00:20:53,380 So we'll compile and return that before the error. 334 00:20:53,380 --> 00:20:57,010 So we'll compile return that before the error one more time. 335 00:20:59,830 --> 00:21:04,480 And down here, if everything works the way that it's supposed to, I can now return this cash. 336 00:21:04,510 --> 00:21:04,950 All right. 337 00:21:05,380 --> 00:21:06,490 So we've got this function. 338 00:21:06,490 --> 00:21:07,210 It's all set. 339 00:21:07,210 --> 00:21:10,920 It's going to go through and pass our templates and return something. 340 00:21:11,980 --> 00:21:14,800 Well, let's test it and make sure it actually works. 341 00:21:14,830 --> 00:21:20,740 So what I'm going to do for just the sake of argument to make sure this works is I am going to every 342 00:21:20,740 --> 00:21:23,670 time I render a template, I'm going to create that template set. 343 00:21:24,040 --> 00:21:35,230 So put in here a template cache, I'll call it template cache and all error is assigned render template 344 00:21:35,230 --> 00:21:35,740 test. 345 00:21:36,100 --> 00:21:37,450 And that takes arguments. 346 00:21:37,450 --> 00:21:42,520 It takes a W and it takes uh, we don't even need the template string. 347 00:21:42,520 --> 00:21:43,270 Let's get rid of that. 348 00:21:47,960 --> 00:21:50,010 Let's just leave it right now. 349 00:21:50,030 --> 00:21:54,560 We're not using the writer at the moment, but we will later on and we'll just check for errors. 350 00:21:54,560 --> 00:21:57,020 So I'm going to copy an error check down here. 351 00:21:57,820 --> 00:21:58,550 Just type it out. 352 00:21:58,580 --> 00:22:08,510 It's not going to take that long if error is not equal to nil format, print line error, getting template 353 00:22:08,510 --> 00:22:11,300 cache and the error. 354 00:22:12,010 --> 00:22:12,490 All right. 355 00:22:12,620 --> 00:22:13,460 So that's it. 356 00:22:14,360 --> 00:22:19,210 And if you're not doing anything with that right now, so I better just do this instead. 357 00:22:19,970 --> 00:22:21,250 They're all right. 358 00:22:21,470 --> 00:22:25,090 And now, because we have an error in two places, I don't need to initialize it twice. 359 00:22:25,730 --> 00:22:33,620 So in theory, if I actually run this code, just hit a page on the Web browser, it's going to execute 360 00:22:33,620 --> 00:22:33,890 this. 361 00:22:33,890 --> 00:22:35,580 But I want to make sure it's actually doing it. 362 00:22:35,600 --> 00:22:46,380 So what I'm going to do here is put another format, dot print line page is currently on the page. 363 00:22:46,430 --> 00:22:51,140 So what's going to happen when I every time I hit a page on the website, it's going to call render 364 00:22:51,150 --> 00:22:55,640 template to render it that it's going to execute this code, which I just have here, just to demonstrate 365 00:22:55,640 --> 00:22:58,550 that it's actually building a template cache or finding out if it's not. 366 00:22:59,360 --> 00:23:03,890 And every time that you render a page, this function gets called down here. 367 00:23:03,980 --> 00:23:05,960 It will create our map. 368 00:23:06,290 --> 00:23:12,440 It will go through the find all the necessary pages in template, in the templates folder, and then 369 00:23:12,440 --> 00:23:17,090 it will loop through that range, arrange for those pages and print out the name of the current page, 370 00:23:17,210 --> 00:23:22,070 and that will return a template cache if there are no errors, which we don't use at the moment. 371 00:23:22,070 --> 00:23:23,630 But let's try this out and see if it works. 372 00:23:23,690 --> 00:23:26,360 OK, so let's compile it. 373 00:23:29,500 --> 00:23:35,410 Good, and I'll hit enter a few times just to get blank lines, go back to this page, reload that page 374 00:23:36,010 --> 00:23:36,870 and come back here. 375 00:23:37,180 --> 00:23:40,600 So it said, look at the error passing template. 376 00:23:40,600 --> 00:23:41,830 That's the error we saw last time. 377 00:23:41,830 --> 00:23:42,790 So we can ignore that. 378 00:23:43,150 --> 00:23:48,190 But it actually found the about page and it found the the home page. 379 00:23:48,490 --> 00:23:49,950 So that's exactly what I need. 380 00:23:50,200 --> 00:23:50,700 Perfect. 381 00:23:51,250 --> 00:23:52,660 So let's go back to our code here. 382 00:23:53,950 --> 00:23:56,470 Stop this down or shut this down. 383 00:23:56,500 --> 00:24:01,270 So I'll stop the application and think about what we're going to do next. 384 00:24:01,280 --> 00:24:07,690 What I need to do is somehow to get my cash and use that to render a template. 385 00:24:08,230 --> 00:24:08,580 Hmm. 386 00:24:09,100 --> 00:24:10,000 How am I going to do that? 387 00:24:10,450 --> 00:24:12,150 I think this is long enough for one lecture. 388 00:24:12,160 --> 00:24:18,130 Let's break this one up into two and in the next one will actually make our template, set our cache 389 00:24:18,130 --> 00:24:24,430 of templates, make that usable and show pages using that nice layout we created at the start of this 390 00:24:24,430 --> 00:24:24,730 lecture. 391 00:24:24,760 --> 00:24:25,090 All right. 392 00:24:25,090 --> 00:24:27,670 I'll see you in the next one and we'll actually make this thing work.