WEBVTT 00:00.080 --> 00:05.600 Maybe you are wondering why we use retrofit with Google Maps. 00:05.840 --> 00:14.840 Again, retrofit is not strictly required to use directions API, but it offers several advantages over 00:14.840 --> 00:17.120 the traditional Google Maps services. 00:17.160 --> 00:18.280 Java client. 00:18.560 --> 00:26.760 So again guys, if you use this library, it's sufficient and there is no need to use retrofit with 00:26.880 --> 00:27.960 API calls. 00:27.960 --> 00:37.960 But in as I told you, for more efficient and professional and reliable calls and responses and network 00:37.960 --> 00:40.720 calls, I'm using retrofit. 00:40.760 --> 00:49.240 Retrofit is type safe HTTP client for Android and Java, handling all low level HTTP work. 00:49.280 --> 00:51.400 I want to show you something. 00:51.440 --> 00:59.560 If you go to directions API overview or the new documentation documentations with directions API, you 00:59.560 --> 01:06.680 can get directions for several modes of transportation such as transit, driving, walking, and bicycle. 01:06.800 --> 01:14.230 The most important part here is how the directions API work. 01:14.510 --> 01:21.270 The directions API returns the most efficient routes when calculating directions. 01:21.470 --> 01:29.230 The product factors in the following travel elements when determining the most efficient route the travel 01:29.270 --> 01:32.350 time, distance, and number of turns. 01:32.630 --> 01:40.470 This depends on the algorithm of the directions API and how to calculate the most efficient route using 01:40.510 --> 01:47.710 these three variables the travel time, which is the primary distance, and the number of turns. 01:47.750 --> 01:51.110 Now I want from you to focus with me. 01:51.270 --> 01:52.950 Please pay attention. 01:52.990 --> 01:56.070 Here we have this API call. 01:56.230 --> 02:05.630 The following example request returns driving directions from Toronto, Ontario to Montreal, Quebec 02:05.630 --> 02:07.070 in JSON format. 02:07.110 --> 02:11.030 Here I am requesting this is the base URL. 02:11.230 --> 02:18.750 Did you remember base URL when working with retrofits with retrofit and API calls, the response we 02:18.850 --> 02:23.450 have the base URL and the endpoint and the variables of course. 02:23.610 --> 02:25.610 So this is the endpoint. 02:25.610 --> 02:30.610 And here we have the variable destination Montreal. 02:30.730 --> 02:33.450 The origin is Toronto. 02:33.610 --> 02:36.810 And the key your API key. 02:36.930 --> 02:40.930 Let me copy this code sample copy it. 02:41.170 --> 02:49.330 And I want from you to focus with me here please please guys let me make here a new package. 02:49.370 --> 02:51.690 Name it as retrofit. 02:51.690 --> 02:56.770 Inside this retrofit create a new Kotlin interface. 02:56.810 --> 03:01.170 Name it as directions, services or service. 03:01.210 --> 03:04.650 Please write those notes down. 03:04.810 --> 03:08.290 And here we have this API call. 03:08.330 --> 03:10.490 This is the base URL. 03:10.610 --> 03:13.170 So this is the base URL. 03:13.410 --> 03:17.170 And those are the variables okay. 03:17.330 --> 03:26.010 Now let me change this API key with the API key that we have in the Google Maps platform. 03:26.010 --> 03:27.530 Click show key. 03:27.800 --> 03:31.120 copy it and replace it with this. 03:31.240 --> 03:35.880 Let's copy this API call and to here click go. 03:35.880 --> 03:37.080 And here we go. 03:37.120 --> 03:41.600 We have a JSON response that Geocoder status okay. 03:41.880 --> 03:46.280 The types locality political and other variables. 03:46.280 --> 03:55.240 The routes we have the description for the North East and the South West copyrights powered by Google 03:55.440 --> 03:56.240 legs. 03:56.280 --> 04:05.880 We have endpoints start point and the points between the location Toronto and Montreal. 04:06.000 --> 04:12.240 So the origin is Toronto and the Montreal is destination. 04:12.280 --> 04:12.760 Okay. 04:13.040 --> 04:24.840 All these codes, all these variables, all the JSON response will be transformed into something visible 04:24.840 --> 04:25.800 on the map. 04:25.800 --> 04:28.880 This is what we're going to create. 04:28.880 --> 04:36.640 This is our job to transform this response into the route displayed on the map.