WEBVTT 00:00.200 --> 00:00.770 Okay, guys. 00:00.770 --> 00:05.090 So in this video I'd like us to have the router class implemented. 00:05.120 --> 00:09.560 We're gonna be implementing it from bottom to the top. 00:09.590 --> 00:16.400 Additionally, I'd like to have a separate routes file where we're gonna be adding routes using this 00:16.430 --> 00:17.390 add method. 00:17.390 --> 00:25.130 And the way we're gonna implement routing would probably be the closest to how it's done in the Laravel 00:25.130 --> 00:26.060 framework. 00:26.090 --> 00:32.000 Now, I generally do think that the router is a complex piece of code. 00:32.030 --> 00:34.310 So you would need to focus. 00:34.310 --> 00:39.530 And also I think you're gonna learn some interesting tricks and practices. 00:39.530 --> 00:48.560 And I think it is also very useful to just try and solve a complex problem, which definitely the routing 00:48.560 --> 00:49.460 is. 00:50.060 --> 00:54.110 So maybe let's start from this call action method. 00:54.110 --> 00:58.760 In this method we would like to create a class. 00:58.760 --> 01:07.650 The controller class that we point to in this controller string and call a method of this class, which 01:07.650 --> 01:09.840 also is passed as a string parameter. 01:10.020 --> 01:11.970 So that's interesting. 01:11.970 --> 01:16.140 We haven't done anything like this before. 01:16.170 --> 01:22.680 Now let's see how can we create a class by just having the class name, the controller class name, 01:22.680 --> 01:25.560 and the action name, which is a method. 01:25.920 --> 01:32.700 So first let's figure out the namespace of the class. 01:32.700 --> 01:37.770 So we know that the app code will be stored inside the app folder. 01:38.310 --> 01:44.730 I'm going to create a controller folder inside because this is where we're going to be keeping the controller 01:44.730 --> 01:45.840 classes. 01:46.170 --> 01:52.560 Let's quickly jump to Composer.json to remind ourselves that inside the app directory, the namespace 01:52.560 --> 01:54.540 prefix is app. 01:55.830 --> 01:58.770 Okay, so we can start with the app prefix. 01:58.800 --> 02:05.140 Now I'm adding two slashes because one slash is an escape character for special characters. 02:05.440 --> 02:14.770 Then we go with controller namespace again slash, and only then we've got the actual controller class 02:14.770 --> 02:18.910 name, and I can directly use this controller variable here. 02:19.120 --> 02:21.430 So this would be our class name. 02:21.430 --> 02:27.760 Now what's interesting is I can create a new class in PHP by using a variable. 02:30.220 --> 02:35.350 So in this place PHP will just figure out what's the value of this variable. 02:35.350 --> 02:39.910 It will try to find the class using this name using autoloader. 02:39.910 --> 02:44.170 And if it succeeds it will just create this controller class. 02:44.170 --> 02:48.760 So I would just need to create a specific controller class first. 02:49.600 --> 02:55.450 Now, I've said previously that action is a method of a controller. 02:55.450 --> 03:01.120 That's why I can also use the action variable in place of the method name. 03:01.120 --> 03:09.170 Again, PHP will resolve the value of this variable, and whatever the name is, it will try to find 03:09.200 --> 03:13.400 such method in this created object and run it. 03:13.430 --> 03:17.060 Okay, but controllers can also have some parameters. 03:17.060 --> 03:18.590 What do we do about that? 03:18.650 --> 03:27.350 Finally, let's use array unpacking using the params, which is an array, because we're going to collect 03:27.350 --> 03:34.070 the passed parameters of every defined route in the order they were defined. 03:34.070 --> 03:41.210 And that's also a requirement of our method that it should have those parameters defined in the same 03:41.210 --> 03:45.080 order as we can find them in the route. 03:46.100 --> 03:46.940 I need to fix this. 03:46.940 --> 03:51.110 This is return and this method is complete. 03:51.110 --> 03:55.640 This is how we're going to be calling the specific controller method. 03:55.640 --> 04:01.520 Once we are able to identify the route and was its matching controller. 04:01.520 --> 04:04.830 So let's go to the match root method next. 04:05.460 --> 04:08.610 Now this match root method has only one job. 04:08.610 --> 04:12.690 Its job is to compare the root URI to request URI. 04:12.720 --> 04:18.780 Now this means that we're going to run this for every single root we have defined, unless we earlier 04:18.780 --> 04:20.460 find the proper root. 04:20.640 --> 04:22.890 So here is a reminder. 04:24.180 --> 04:30.390 So first we need to divide all those URIs into segments. 04:31.080 --> 04:34.920 So as you see those two will match in our case. 04:35.010 --> 04:36.840 So we've got the static part. 04:36.870 --> 04:38.010 We've got a parameter. 04:38.010 --> 04:39.510 And this is matching. 04:39.540 --> 04:45.930 That's why first let's cover dividing those URIs into segments. 04:45.930 --> 04:48.720 And the segment separator is a forward slash. 04:49.560 --> 04:49.800 Okay. 04:49.830 --> 04:53.940 So let's define a variable called root segments. 04:53.970 --> 04:57.570 We're talking about the current root that we are processing. 04:57.570 --> 05:01.530 And another one would be the request segments. 05:01.530 --> 05:03.120 So we can compare them. 05:04.080 --> 05:07.950 Okay, so I've said that the forward slash is a separator. 05:07.950 --> 05:13.380 And in PHP to get the strings separated by something we use explode. 05:13.590 --> 05:15.420 This is our separator. 05:15.420 --> 05:18.690 And I'm going to stream to remove Whitespaces. 05:18.690 --> 05:21.900 So first I'm using the root URI. 05:21.900 --> 05:28.350 And additionally when using trim to remove white spaces I can remove some additional characters like 05:28.500 --> 05:30.510 the forward slash itself. 05:30.540 --> 05:37.140 Now, you might have guessed that we're going to call the same function for the request URI. 05:37.170 --> 05:39.060 Just need to fix the name here. 05:39.090 --> 05:41.100 That's request URI. 05:41.130 --> 05:42.990 Okay, we've got the segments. 05:43.440 --> 05:47.580 So the algorithm let's take a look at it. 05:47.610 --> 05:53.580 We need to first see if we have the same segment count and then match individual segments. 05:54.810 --> 05:58.920 So the count of arrays because those will now be erased. 05:58.920 --> 06:00.960 The root segments and request segments. 06:00.960 --> 06:06.670 We can just compare the result of count of route segments. 06:06.700 --> 06:13.360 If it's different than the count of request segments. 06:13.390 --> 06:17.620 If it's different, we return null and null in. 06:17.620 --> 06:28.450 This function is used to return that we haven't matched the actual route URI to a defined route, because 06:28.450 --> 06:32.530 if we would match it, then something would be returned in the array. 06:32.530 --> 06:38.560 And this something is either an empty array or list of all the found parameters. 06:38.590 --> 06:47.200 Now, if we don't eliminate this right route right away, then let's add the params variable, which 06:47.200 --> 06:52.810 would be an empty array and then return it. 06:52.810 --> 06:56.920 But first we need to go through every single route part and compare it. 06:56.950 --> 07:03.490 Okay, so let's use a for each loop to go through all the route segments. 07:03.490 --> 07:09.320 Immense and let me get the index as it might be handy. 07:09.320 --> 07:13.220 And then we've got the route segment. 07:14.390 --> 07:20.090 Okay, now our first job is to check if this segment is a parameter. 07:20.090 --> 07:21.470 How can we do that? 07:21.770 --> 07:24.230 Some extra functions in PHP. 07:24.830 --> 07:34.010 So one is called str startswith where we can check if the root part which is haystack. 07:34.040 --> 07:42.500 That's the parameter name starts with curly brace opening because this is how we begin a parameter. 07:43.370 --> 07:47.840 And also we check if the same string ends with. 07:47.840 --> 07:55.010 So there is another function called endswith where haystack is also the root part. 07:55.730 --> 07:59.000 And here we are looking for a closing brace. 07:59.030 --> 08:04.320 Now if that would be the case then we just add a parameter. 08:05.550 --> 08:07.110 So two parameters. 08:07.140 --> 08:14.490 We're going to add the parameters using the parameters defined name which we can get from the root part 08:14.520 --> 08:16.740 excluding the curly braces. 08:16.740 --> 08:21.390 So we can just use trim get the root part. 08:22.200 --> 08:26.640 And what we exclude is white spaces and curly braces. 08:28.740 --> 08:33.660 And the value of it is the request. 08:35.880 --> 08:37.110 Segments. 08:37.890 --> 08:40.740 And this is where we needed the index. 08:41.310 --> 08:45.600 So that's the root part I've used the wrong name. 08:45.600 --> 08:48.810 This is the root segment okay. 08:50.730 --> 08:53.850 So again this is a parameter. 08:53.850 --> 08:58.110 It's always starting with a curly brace and ending with a curly brace. 08:58.110 --> 09:02.910 So everything inside it is the parameter name. 09:02.910 --> 09:10.660 That's why here we are trimming white spaces and curly braces by using the root segment, which is from 09:10.660 --> 09:12.160 the root definition. 09:12.340 --> 09:15.880 And that's the key to the parameters. 09:15.880 --> 09:23.650 And then as a value, we use the segment at the same place from the request which will contain this 09:23.650 --> 09:25.150 parameter value. 09:25.180 --> 09:28.360 So that's the first condition that we have for a segment. 09:28.870 --> 09:34.660 Another one is checking if maybe the static segments don't match. 09:34.660 --> 09:42.160 Because if we don't have a parameter then this means we have a static segment that's a static segment 09:42.160 --> 09:45.970 like the text that is saying literally posts. 09:46.000 --> 09:47.890 That's just an example. 09:47.920 --> 10:02.680 So if the root segment is different than the request segments with the given index, remember we can 10:02.710 --> 10:09.920 safely use the Indexes for both arrays because first we have checked if they have the equal. 10:09.950 --> 10:12.290 Length and if that's the case. 10:12.290 --> 10:17.900 So if the static segment has a mismatch then again we can return null. 10:17.900 --> 10:23.720 This means that we didn't have a match and this route just doesn't match. 10:23.720 --> 10:30.710 So maybe this is a little bit complex because it is a kind of an algorithm. 10:30.710 --> 10:38.810 But anyway I think we really need to practice all kinds of problems and solving them anyway. 10:38.810 --> 10:41.540 This should match one specific route. 10:41.540 --> 10:49.880 And now our job is to call this match route function for every defined route that we have inside the 10:49.880 --> 10:50.480 app. 10:51.890 --> 11:00.770 Next up, this find route method will use the match route method to compare all the routes defined to 11:00.770 --> 11:03.920 the current URI and the method. 11:04.830 --> 11:09.450 So let's use foreach again going through all the routes. 11:12.330 --> 11:18.870 And then we are calling this match route and we are getting the parameters. 11:20.610 --> 11:25.980 So here we'll be passing the route URI. 11:30.810 --> 11:33.240 And the URI of the request. 11:33.240 --> 11:35.190 So we are comparing those. 11:35.190 --> 11:43.650 Now the result as you might remember if we get anything else then null it means we have found a matching 11:43.650 --> 11:44.550 route. 11:45.810 --> 11:47.250 But that's not everything. 11:47.250 --> 11:53.430 So first we need to check if params is different than null. 11:53.970 --> 11:58.080 This means we've got something that is almost what we are looking for. 11:58.080 --> 12:03.030 But remember that we've also got a method and this wasn't checked anywhere. 12:04.840 --> 12:12.790 So it needs to match the expected method of the request that's either Get or post or whatever you'd 12:12.790 --> 12:13.900 like to use. 12:14.380 --> 12:22.090 Only then we can return something from Findroot method, which as you see, is also a nullable array. 12:25.600 --> 12:34.030 So we go through every single route and if we can't match anything, then we just return null from this 12:34.030 --> 12:34.840 method. 12:35.470 --> 12:43.990 But we need to tell the dispatch method what is the name of the controller class and the action as well. 12:44.020 --> 12:51.610 That's why from this find route method, we're going to return all the info about the route itself, 12:51.610 --> 12:54.940 about this route we are currently investigating. 12:56.980 --> 13:01.480 And only then we're going to add another parameter called params. 13:01.570 --> 13:07.280 Getting the parameters that were passed through this route. 13:08.780 --> 13:15.530 So at this point, it might be getting complicated why we construct this return type this way, but 13:15.530 --> 13:21.500 we are just returning all the data that will be required in an array. 13:21.860 --> 13:30.320 So maybe it would be more clear once we see that this add method is adding routes that have the method, 13:30.350 --> 13:32.510 the URI, the controller. 13:33.230 --> 13:37.160 So basically here we are returning those three values. 13:37.160 --> 13:39.500 The method that you write the controller name. 13:39.500 --> 13:42.980 Plus we are adding the parameters on top of it. 13:43.160 --> 13:48.950 Maybe it will make sense if I just implement the add method right now. 13:49.070 --> 13:53.810 So we can add two routes by using this square operator. 13:54.800 --> 14:04.670 And every item is an array itself where we've got the method which equals method. 14:04.670 --> 14:12.200 Then we've got the You or I, which also equals the value of your variable and the controller. 14:12.230 --> 14:20.000 You can also optionally replace this with a call to a compact function, which I've probably used before. 14:20.030 --> 14:22.250 So this is how a route looks like. 14:22.250 --> 14:24.380 It has a method you write controller. 14:24.410 --> 14:32.840 So basically in this place where we return the response from find route, we're going to be getting 14:32.840 --> 14:40.100 those three elements of the array plus the parameters that we got from the actual URI. 14:40.130 --> 14:41.120 Okay. 14:41.600 --> 14:47.120 Next up we've got the final step the dispatch function. 14:47.240 --> 14:56.360 So here our job is to just find the route for the URI and the method that we received. 14:56.390 --> 15:02.270 If we've got a null so it wasn't found it might happen. 15:02.270 --> 15:10.770 If someone enters an incorrect URL we can return the result of not found method. 15:11.190 --> 15:18.930 This doesn't exist yet, but we can easily copy this from the previous code. 15:23.160 --> 15:25.290 So let me just quickly add this. 15:25.290 --> 15:30.450 This is public function not found. 15:31.410 --> 15:34.260 For now, let's just echo this text not found. 15:34.260 --> 15:38.280 We're going to be changing that to an actual view later on. 15:38.370 --> 15:43.830 And the final thing here is to call the controller and the action. 15:44.550 --> 15:48.420 So we can use array destructuring and call explode. 15:48.960 --> 15:55.080 Because this directly stems from how we're going to be defining the controller. 15:55.080 --> 15:57.540 So let me show you how we're going to do that. 15:57.630 --> 16:02.580 So when we point to a controller let it be a post controller class. 16:02.670 --> 16:05.880 The action will be marked after an at sign. 16:05.880 --> 16:13.450 So this would should be index action in post controller class or this example. 16:13.480 --> 16:17.590 Here would be a show action in post controller class. 16:17.590 --> 16:21.250 So that's the name of a method inside this class. 16:21.250 --> 16:27.580 That's why with explode I'm going to use the at sign up separator. 16:27.580 --> 16:35.230 And from root controller we are getting the controller class and the method name the action. 16:35.980 --> 16:45.670 So with destructuring I'm getting separately the controller and the action because this will just return 16:45.670 --> 16:47.410 an array with two items. 16:47.410 --> 16:48.970 So that's the first item. 16:48.970 --> 16:50.410 That's the second one. 16:51.340 --> 17:03.850 And finally we return the result of this call action which accepts the controller, the action and the 17:03.850 --> 17:08.960 parameters which we get from the route under the key palms. 17:08.990 --> 17:15.650 Now the logic is complete and it's time that we define some roots and try this out. 17:17.060 --> 17:23.510 Okay, so since this is a pretty long lecture, I think we might take a short break and do it in the 17:23.510 --> 17:24.410 next one. 17:24.440 --> 17:27.620 For now, let's just quickly review what we have done. 17:27.620 --> 17:31.460 So using this add method you can add more roots. 17:31.820 --> 17:33.590 This is a not found function. 17:33.590 --> 17:36.650 We had a previously something very similar. 17:36.680 --> 17:44.420 But the main entry point to this class is the dispatch method to which you pass the URI and the method. 17:44.420 --> 17:52.700 It then tries to find a root and call the specific controller if obviously one is found. 17:52.700 --> 18:00.380 So here we dynamically create a class and try to call its method also dynamically by using a variable. 18:00.380 --> 18:03.830 So maybe this was something we haven't done before. 18:03.830 --> 18:08.090 And I think it's interesting to know that this is possible.