WEBVTT 00:00.160 --> 00:08.720 The next step after creating the directions repository is to create the class that implements this interface. 00:08.920 --> 00:16.560 So here, as we learned before, we need to create directions repository implementation. 00:16.680 --> 00:29.080 This class implements the directions repository and we need to add some parameters for the constructor. 00:29.120 --> 00:36.520 Also, we need to use the inject annotation in order to inject the constructor. 00:36.720 --> 00:41.840 So alt plus enter to import the inject from Javax dot inject. 00:41.880 --> 00:42.760 Inject. 00:42.760 --> 00:48.240 And we need to inject the constructor with two parameters. 00:48.480 --> 00:59.280 The first one is the private val api key, which is of type string, and the second one is of type directions. 00:59.280 --> 01:04.010 Surface Alt+ enter to import the direction surface. 01:04.050 --> 01:09.330 We need to implement the two functions Alt+ enter to implement the members. 01:09.370 --> 01:12.970 Get root and get root for multiple markers. 01:13.010 --> 01:13.850 Here we go. 01:14.210 --> 01:16.610 Those are the two functions. 01:16.730 --> 01:21.890 Let's start with the first one which is the get root return. 01:21.930 --> 01:22.730 Try. 01:22.770 --> 01:27.530 Let's start with val origin str which is string. 01:27.530 --> 01:37.930 And here we need to fetch the origin as a string because when making an API call and we need to get 01:37.930 --> 01:44.010 the strings, we use strings and not any other objects like lat longs. 01:44.010 --> 01:49.290 So we need to convert the lat long which is the origin into string. 01:49.330 --> 01:50.490 It's very simple. 01:50.530 --> 01:56.890 Here we get the first coordinate which is latitude and the second is the longitude. 01:56.930 --> 01:57.370 Okay. 01:57.610 --> 01:59.930 This is for origin. 01:59.970 --> 02:02.770 Let's start with destination str. 02:03.050 --> 02:07.010 Destination latitude and destination dot longitude. 02:07.050 --> 02:14.610 We are converting the origin and destination which are of type latitude and longitude. 02:14.610 --> 02:15.250 Lat long. 02:15.290 --> 02:20.090 Objects into strings in order to put them into the API call. 02:20.130 --> 02:25.690 Here close it with catch exception and return null. 02:25.730 --> 02:27.490 Then close this. 02:27.530 --> 02:28.290 Here we go. 02:28.330 --> 02:30.730 Let's continue with return a try. 02:30.770 --> 02:33.930 We need to return a list of lat long. 02:33.970 --> 02:39.130 So here inside the try we need to get the response. 02:39.330 --> 02:41.730 So response equals to. 02:41.770 --> 02:51.930 Let's call the direction service interface dot get directions function specifying three parameters the 02:51.930 --> 02:55.290 origin destination and the API key. 02:55.410 --> 03:01.460 Again guys this is the first step converting origin and destination into strings for API call. 03:01.700 --> 03:12.100 The second step is the API call itself by calling the response that the directions service dot get directions 03:12.100 --> 03:16.060 function, and we have to pass three parameters. 03:16.420 --> 03:22.900 This function makes a network request to get directions between the points. 03:23.020 --> 03:30.100 Uses the previously created directions service, including an API key for authentication. 03:30.220 --> 03:35.020 The third step here is response processing. 03:35.140 --> 03:42.700 We request this from the server and we get the response into the response variable. 03:42.700 --> 03:47.100 So here we store this call inside this response variable. 03:47.300 --> 03:50.300 And let's process this response. 03:50.300 --> 03:59.100 So let's use this variable in order to extract the points and the strings and transform every point 03:59.100 --> 04:01.260 into a lat long object. 04:01.260 --> 04:09.180 So response dot which is a list of roots dot first or null. 04:09.220 --> 04:12.620 Overview polyline dot points. 04:12.660 --> 04:18.860 Dot lat polyline or polyline util dot code. 04:19.100 --> 04:21.620 Don't worry, we're gonna explain everything. 04:21.820 --> 04:29.300 The encoded path dot map and set lat long for every point. 04:29.300 --> 04:35.020 Create a lat long object having the latitude and longitude. 04:35.060 --> 04:37.940 The response dot dot first or null. 04:38.180 --> 04:44.980 Overview polyline dot points accesses the first route in the response. 04:44.980 --> 04:51.100 So this is the function that allows us to access the first route in the response if available. 04:51.100 --> 04:58.430 Getting the overview polyline which contains encoded Polly points. 04:58.470 --> 05:03.590 Okay, so this will access the first route in the response. 05:03.590 --> 05:10.950 I want from you to write those notes down please, because these are very important and helps you, 05:11.070 --> 05:19.030 uh, to recognize and remember what are and, uh, how why we used those codes. 05:19.070 --> 05:19.550 Okay. 05:19.710 --> 05:26.110 This will get the overview polyline containing encoded points. 05:26.310 --> 05:29.990 The encoded points are of type string. 05:30.150 --> 05:38.670 We need to extract the points string encoded polyline format and access this string and transform every 05:38.670 --> 05:41.070 point into lat long. 05:41.270 --> 05:46.070 So here we are using the polyline encoding. 05:46.070 --> 05:50.830 So the first the fourth step is polyline decoding. 05:50.950 --> 05:54.470 Uses Polly utils decode. 05:54.510 --> 05:57.190 This is from Google Maps util. 05:57.230 --> 06:05.910 To decode the polyline string maps each decoded point to a lat long object. 06:06.150 --> 06:12.590 The lat block ensures this only happens if points exist. 06:12.590 --> 06:16.830 If there is an error here, we need to return null. 06:16.870 --> 06:21.110 For example, if the network call fails, response has no routes. 06:21.270 --> 06:23.750 Polyline is missing or invalid. 06:23.870 --> 06:26.110 Any other exception occurs. 06:26.310 --> 06:34.790 Polyline encoding using Google efficient polyline encoding algorithm to represent the route with minimal 06:34.790 --> 06:35.470 data. 06:35.510 --> 06:44.190 Okay, so this is a very important thing we should use in order to get the response in form of strings. 06:44.470 --> 06:53.910 Then processing this response and transform the strings into latitude and longitude lat long points.