WEBVTT 00:00.290 --> 00:06.950 So we need to do all the steps from this list that I have created here inside our router PHP file. 00:06.950 --> 00:10.640 Let's begin by normalizing the URI. 00:10.640 --> 00:16.190 And as I write this function, I'm going to explain what does it exactly means and what needs to be 00:16.190 --> 00:16.700 done. 00:16.700 --> 00:22.160 So let's create a function that we're gonna call normalize URI. 00:22.190 --> 00:28.670 It accepts the URI as a parameter and it returns a string. 00:28.670 --> 00:31.910 So the URI let's make some changes to it. 00:31.910 --> 00:37.250 First I'd like to make it lowercase as our files our route handlers. 00:37.250 --> 00:38.840 They're also going to be lowercase. 00:38.840 --> 00:44.060 So to be able to find a file we need to care about the character case. 00:44.060 --> 00:50.030 Because on Unix systems the character case in file names matter. 00:50.270 --> 00:57.710 Next up I'd like to use trim to remove all the white spaces from the URI and also remove some additional 00:57.710 --> 01:00.140 characters, which would be slashes. 01:00.140 --> 01:03.400 We want to get rid of those completely. 01:03.460 --> 01:08.770 Next up, we've got this URI and we're going to return a value. 01:08.770 --> 01:12.550 But there is one special case that we need to think of. 01:12.580 --> 01:17.050 If the URI is empty, this means we are on the main page. 01:17.050 --> 01:21.940 That's why we need to look for a route handler that will be called index. 01:21.970 --> 01:25.630 Otherwise we just return the URI. 01:25.660 --> 01:28.960 Now it's time to see this in action. 01:29.200 --> 01:31.360 So let's move to the dispatch function. 01:31.360 --> 01:34.420 And we are implementing the first step. 01:34.420 --> 01:44.080 So the URI is the result of calling the normalize URI function we've just defined on the URI that is 01:44.080 --> 01:45.910 passed to this function. 01:45.910 --> 01:50.260 Now at this point it would be useful to see what that actually is. 01:50.260 --> 01:54.490 For that I'm going to just do var dump with uri and die. 01:54.520 --> 01:58.540 So we stop this function and we see what is the effect. 01:58.570 --> 02:04.910 Now this dispatch function it needs to be called inside the index, the front controller. 02:04.940 --> 02:06.800 So let's call dispatch. 02:06.800 --> 02:09.050 And what do we pass in here. 02:09.080 --> 02:14.900 Well we can get something from our server super global that we already know. 02:14.900 --> 02:19.250 And this is simply the request URI. 02:19.280 --> 02:21.440 That would be our URI. 02:21.440 --> 02:25.280 And the method we also get from the node server. 02:25.280 --> 02:28.280 But server super global. 02:28.280 --> 02:32.600 And that is on the other hand called request method. 02:32.630 --> 02:35.240 That's everything that we need to do in here. 02:35.240 --> 02:37.730 The next thing to do is to start the server. 02:37.730 --> 02:43.970 So let's make sure that we jump into the public folder and we start the server from there. 02:44.600 --> 02:56.270 So I run php dash s localhost 8000 and the file name is index php. 02:56.360 --> 02:58.430 Now we should have the server running. 02:58.430 --> 03:03.060 And let's now head to localhost 8000 to see what's the output. 03:03.090 --> 03:10.440 So now I have magically moved into the browser, and when I just type localhost 8000, the result is 03:10.440 --> 03:11.100 index. 03:11.100 --> 03:14.010 Let me try with slash contact. 03:14.160 --> 03:18.150 So you see that this works fine for the guestbook. 03:18.150 --> 03:20.130 It should also work fine. 03:20.130 --> 03:26.220 So we are getting the route handler name without the method attached. 03:26.250 --> 03:32.700 We're going to be working on this a little bit later, but we can see that our edge case is also working 03:32.700 --> 03:33.480 fine. 03:34.080 --> 03:40.560 By the way, you might have probably noticed that I have the documentation for the stream function open, 03:40.560 --> 03:42.570 and I'm not ashamed of that. 03:42.570 --> 03:47.400 I don't remember the names and order of every function parameters. 03:47.400 --> 03:55.680 That's why I make sure that I have the documentation open on every single project, language, or framework 03:55.680 --> 03:58.950 that I work with, and I suggest you do the same. 03:59.010 --> 04:04.190 Okay, so let's enlarge the working space, the code editor again and then jump to router. 04:04.370 --> 04:05.150 PHP file. 04:05.150 --> 04:07.940 So we've got this first step handled. 04:07.940 --> 04:09.680 I can comment out this line. 04:09.680 --> 04:16.010 By the way, this combination of VAR dumping and dying is a common practice in PHP. 04:16.040 --> 04:18.530 I use it for debugging all the time. 04:18.530 --> 04:21.110 We might as well extract it to a function. 04:21.110 --> 04:22.430 That's for later. 04:22.460 --> 04:25.070 Now we need to handle the second point. 04:25.070 --> 04:30.470 The only allowed HTTP methods that we allow is get or post. 04:31.580 --> 04:41.090 So another good practice that I'd like to introduce is to not hide the magic values inside functions. 04:41.150 --> 04:45.920 So we've got two examples right now this get and post method. 04:45.950 --> 04:48.170 Those are the ones that we handle. 04:48.170 --> 04:55.730 We should not hide this detail inside the dispatch function, because this might be an interesting knowledge 04:55.730 --> 04:59.000 that might be used across the whole project. 04:59.000 --> 05:02.150 That's why we should go with a constant. 05:02.360 --> 05:08.800 So we should define that the allowed methods is get and post. 05:08.830 --> 05:12.730 Now this can be accessed in different places. 05:12.760 --> 05:20.140 Another thing that we should be extracting into constants is maybe the index URI. 05:20.170 --> 05:22.300 This is an empty string. 05:22.300 --> 05:27.040 This might look trivial, but believe me, this is really a good practice. 05:27.070 --> 05:34.780 Now I'm not comparing that to an empty string, and I can configure the behavior of the project without 05:34.780 --> 05:38.410 changing the implementation of the functions. 05:39.580 --> 05:50.380 I can also do index route to say that if we are looking at this main page without any specific URI, 05:50.410 --> 05:52.570 the route name is index. 05:53.110 --> 05:55.840 I can use this constant right here. 05:55.840 --> 05:57.970 This would be index route. 05:57.970 --> 06:04.690 So now every single time you go back to this file or any other developer on your team. 06:04.690 --> 06:11.860 They don't have to scan the implementation of every single function and try to understand what is happening. 06:11.860 --> 06:20.140 And it might feel a lot safer to just change one of those values, to change the behavior of the app, 06:20.140 --> 06:24.760 instead of changing it directly inside the function. 06:24.760 --> 06:29.350 So this is a very good practice. 06:29.380 --> 06:32.290 Now let's jump to this second step. 06:32.290 --> 06:37.930 Let's make sure that we only handle specific HTTP methods. 06:37.930 --> 06:45.070 So we're going to add an if statement and use an in array function to check if the method that was passed 06:45.070 --> 06:48.940 here is one of the allowed methods. 06:49.450 --> 07:00.130 Now if it's not, we should return a 404 response that can be summarized as a not found response. 07:00.130 --> 07:03.640 Now also, we need to normalize the method. 07:03.810 --> 07:09.210 So the method variable, well let's convert it to uppercase. 07:09.210 --> 07:17.250 On the other hand, because this is how we have defined those methods inside this constant like this. 07:18.390 --> 07:25.260 So let's go back into this if statement and let's call a non-existing Notfound function. 07:25.260 --> 07:31.560 So we need to add this function because this is something that might really be reusable across the whole 07:31.560 --> 07:32.670 application. 07:33.030 --> 07:38.520 So by calling this function it immediately returns the response from PHP. 07:38.550 --> 07:46.920 It stops the execution and it returns an HTTP response code that is specific to this case. 07:46.920 --> 07:50.310 404 means that the page wasn't found. 07:51.420 --> 07:59.730 Next we can echo 404 not found and the exit statement will stop the execution of the script. 08:01.950 --> 08:05.330 So you might be wondering how do I test that? 08:05.330 --> 08:12.470 If we have the allowed methods as get and post and get is the default method of the browser. 08:12.470 --> 08:19.010 When you just go to a website and post is the method that you typically use with forms. 08:19.040 --> 08:24.950 Well, it's easy to test that we can temporarily remove the get from allowed methods. 08:24.950 --> 08:28.640 And now you can see that this was working fine. 08:28.640 --> 08:33.980 And if I now go to the main page we've got 404 not found. 08:34.010 --> 08:39.110 So this was just a temporary measure to try this out to test the functionality. 08:39.140 --> 08:40.190 It worked fine. 08:40.190 --> 08:43.610 Let's bring back the get method from the allowed methods. 08:43.610 --> 08:49.190 And when I refresh the page we don't see anything, which actually is a good sign. 08:49.190 --> 08:55.760 It means that this dispatch function went to the very end and it didn't stop at this point. 08:57.050 --> 09:05.150 So the next step is to figure out what is the actual file name for that, let's define a function that 09:05.150 --> 09:07.730 will be called Getfile path. 09:08.540 --> 09:11.570 Now this function might be super simple. 09:11.570 --> 09:14.060 It depends on our requirements. 09:14.090 --> 09:21.980 Now, if I pass the URI to it and the method, I expect to have a string returned, that would be the 09:21.980 --> 09:26.690 full path to the PHP file that can match the route. 09:26.870 --> 09:32.390 So let's jump to the index file because I think we need another constant. 09:32.390 --> 09:34.700 We've got the includes directory. 09:34.730 --> 09:41.270 Now let's also have the routes directory in a constant that we can use everywhere. 09:41.270 --> 09:45.290 And we're gonna have a new folder called routes. 09:45.320 --> 09:47.540 Let's create this folder now. 09:47.900 --> 09:49.670 So this is routes. 09:49.670 --> 09:52.970 This would contain all the routes that we define. 09:52.970 --> 09:54.830 Let's go back to router. 09:55.610 --> 10:01.010 Now I think that here we can just return a value. 10:01.040 --> 10:13.150 This would be the routes directory If I remember the constant name properly, then a directory separator, 10:13.690 --> 10:22.210 then I think that we can directly translate the URI into the pathname, but we might normalize it first. 10:22.210 --> 10:30.190 So let's do normalize URI to just make sure it's matching the case of the path names. 10:31.180 --> 10:32.560 So this is this. 10:32.590 --> 10:38.140 Next up we should append the method after an underscore. 10:38.140 --> 10:41.770 So first we are we are adding the underscore. 10:41.920 --> 10:49.900 Next up I'm concatenating the method which by the way I might have to lowercase. 10:49.900 --> 10:59.200 So I do str two lower because all of our path names and file names should be in lower case. 10:59.200 --> 11:05.050 And finally I concatenate the extension the PHP. 11:05.160 --> 11:08.580 Now let's just see if this works. 11:08.580 --> 11:14.190 If this is fine, I'm gonna var dump the. 11:14.670 --> 11:15.690 What's the function name? 11:15.690 --> 11:18.480 Get file path okay. 11:18.600 --> 11:20.130 Get file path. 11:20.130 --> 11:28.440 Passing the URI and method that we already have here and calling die to stop the execution. 11:28.680 --> 11:30.750 Let me refresh the page. 11:34.140 --> 11:35.640 Now this looks fine. 11:35.640 --> 11:42.420 I really expect to have this directory and I expect to have this file inside once I create it. 11:42.450 --> 11:43.320 Of course. 11:43.440 --> 11:46.440 And this also works on windows. 11:46.440 --> 11:54.420 If I refresh this script and zoom out a little bit, even though we've got a mixture of slashes and 11:54.420 --> 12:02.070 forward slashes, they both work on windows, so you should be fine on windows as well. 12:03.150 --> 12:11.390 Now the next step should be to create a file and see if it really works, if we can really load a specific 12:11.600 --> 12:12.710 PHP file. 12:14.840 --> 12:18.230 Okay, now let me open the files. 12:18.230 --> 12:23.900 And here let's create the contact get PHP. 12:23.930 --> 12:27.080 One file is more than enough. 12:27.110 --> 12:29.240 It can do echo. 12:29.270 --> 12:33.170 Hello something super simple. 12:33.590 --> 12:36.320 Now let's jump back to the router. 12:36.950 --> 12:41.660 And at this point we should just check if this file exists. 12:41.660 --> 12:52.430 So let me remove the var dump and just leave this fragment and assign it to the file path variable. 12:52.610 --> 12:58.490 And next up we're going to do a check using file exists function from PHP. 12:58.640 --> 13:08.900 We're going to check if this file exists because if it does I'm just going to use include And I'm going 13:08.930 --> 13:14.120 to include this file so it can run and I can return to. 13:14.150 --> 13:20.090 Just make sure we stop at this point because if this file won't be found. 13:20.900 --> 13:26.240 I run the not found which would display a 404 not found page. 13:26.300 --> 13:29.750 Okay, it's time for a final test. 13:30.230 --> 13:35.090 So let me go to this URL and as expected, I see the text. 13:35.120 --> 13:35.960 Hello. 13:36.830 --> 13:39.380 Let's also verify that on windows. 13:40.610 --> 13:44.420 And if I go to main page well this was expected. 13:44.420 --> 13:46.370 The index file is not created. 13:46.370 --> 13:51.710 But if I jump to contact page I see the same text. 13:51.740 --> 13:52.580 Hello. 13:52.940 --> 13:56.780 All right so we've created a working router. 13:57.710 --> 14:03.350 So our next steps should be to start implementing some specific logic. 14:03.350 --> 14:07.040 Some specific pages of this application.