WEBVTT 00:00.080 --> 00:03.080 Congratulations for this big success. 00:03.240 --> 00:13.800 We succeeded in inserting San Francisco marker inside Marker's collection in Firebase Firestore database. 00:14.080 --> 00:16.640 Now we need to fetch the markers. 00:16.640 --> 00:21.120 We need to get all markers in the database. 00:21.320 --> 00:25.600 So for this we need to create a new function. 00:25.600 --> 00:28.120 Let's go to the repository. 00:28.120 --> 00:34.680 So whenever you have any new function you need to create it in repository. 00:34.720 --> 00:43.800 As said before the interface marker repository defines what you can do add marker, get markers, and 00:43.800 --> 00:44.440 so on. 00:44.640 --> 00:50.920 Inside marker repository implementation we define how you do it. 00:50.920 --> 01:02.160 So the first step here is to create and use suspend function called get all Markers from Firestore. 01:02.200 --> 01:05.960 This function returns a list of. 01:06.320 --> 01:12.240 We can create lat long to make it simple to display latitude and longitude. 01:12.440 --> 01:16.360 But I prefer to make it as customized. 01:16.360 --> 01:25.840 So we're going to create a new class a new data class that it is a customized and display latitude longitude 01:26.000 --> 01:28.440 plus title plus document ID. 01:28.680 --> 01:32.800 So we can add more variables to the marker. 01:32.840 --> 01:42.200 Since we upload inside the add marker, the latitude and the name latitude and longitude and the name. 01:42.200 --> 01:48.840 So we have three things marker latitude, marker longitude, and marker name. 01:48.840 --> 01:57.200 If we specify lat long like this, we only get two parameters the latitude and longitude okay. 01:57.400 --> 02:05.990 So we don't need like this We need to get three parameters the ID or the title latitude and longitude. 02:06.030 --> 02:06.510 Okay. 02:06.670 --> 02:12.390 For this let's go to create here Inside Utilities package. 02:12.470 --> 02:14.750 Create a new Kotlin class. 02:14.950 --> 02:18.350 Name it as destination marker. 02:18.390 --> 02:20.750 We can make it as data class. 02:20.910 --> 02:34.590 So data class and define the parameters val id it's of type string val latitude double val longitude 02:34.750 --> 02:37.310 double val title. 02:37.350 --> 02:39.190 It's of type string. 02:39.310 --> 02:45.910 Also we can add a function to convert to lat long if needed. 02:46.190 --> 02:48.150 So let long. 02:48.190 --> 02:53.470 And here put latitude and longitude as parameters okay. 02:53.630 --> 03:00.110 Import class lat long from Google Maps Okay, so remove this. 03:00.150 --> 03:05.070 I always make mistakes here and import from Google Maps model. 03:05.070 --> 03:05.750 Lat long. 03:05.790 --> 03:07.670 Okay, this is if needed. 03:07.670 --> 03:10.590 This is optional to convert it to lat long. 03:10.630 --> 03:13.830 Okay back to the marker repository. 03:13.830 --> 03:18.110 And here it's a list of destination marker. 03:18.150 --> 03:21.990 Now let's move to the marker repository implementation. 03:21.990 --> 03:24.630 And let's implement the method. 03:24.630 --> 03:27.630 Get all markers from Firestore. 03:27.910 --> 03:28.350 Here. 03:28.350 --> 03:38.510 Inside the implementation we need to define how to do how to get all markers from Firestore. 03:38.630 --> 03:49.150 So for this we need to get val result equals to Firestore dot collection markers. 03:49.150 --> 03:57.460 Firebase which is the instance we passed as a parameter that collection markers Dot. 03:57.500 --> 03:58.260 Get. 03:58.300 --> 03:59.020 Dot. 03:59.220 --> 03:59.980 Await. 03:59.980 --> 04:01.940 This is a suspend function. 04:02.060 --> 04:04.980 Get all markers from Fhir store. 04:05.180 --> 04:08.140 Reads all marker documents from Firestore. 04:08.140 --> 04:14.300 Markers collection maps them to a list of destination markers object. 04:14.300 --> 04:21.780 So the returning type of this function is a list of destination markers and the result here. 04:21.940 --> 04:27.220 Access the markers collection in your Firebase Firestore database. 04:27.420 --> 04:30.060 Dot get tells Firestore. 04:30.100 --> 04:32.700 Get all documents in this collection. 04:32.940 --> 04:37.900 Await is a function used to return a task. 04:37.900 --> 04:45.420 And since Firestore returns a task which is asynchronous, await suspends the coroutine until the data 04:45.420 --> 04:46.340 is loaded. 04:46.540 --> 04:52.460 This makes the code look asynchronous and safe to call in Co-routines. 04:52.500 --> 04:58.380 After this line result holds a query snapshot containing all the documents. 04:58.380 --> 05:06.820 So if I hover here, result is a query snapshot containing all the your documents. 05:06.860 --> 05:15.660 Now we need to get every document inside our Firebase Firestore collection and map every document to 05:15.740 --> 05:19.100 a destination marker instance. 05:19.220 --> 05:24.980 For this reuse return result dot map. 05:24.980 --> 05:35.060 Here I can use the map function in order to map every document to a destination marker for every document 05:35.060 --> 05:36.300 document. 05:36.340 --> 05:45.940 Go and create a destination marker and set for the parameters of this destination marker. 05:46.260 --> 05:48.660 The document data. 05:48.700 --> 05:49.940 Let me show you guys. 05:50.100 --> 05:52.500 At first we need to specify the ID. 05:52.540 --> 05:54.460 I'll use document query. 05:54.500 --> 05:57.810 Document snapshot.id latitude. 05:58.050 --> 06:04.930 It's document dot get double and the field is latitude. 06:04.930 --> 06:06.810 Please pay attention here. 06:06.970 --> 06:11.010 Here we have latitude field and longitude. 06:11.050 --> 06:12.610 This is case sensitive. 06:12.610 --> 06:16.890 So please write them exactly as your database. 06:17.010 --> 06:21.490 If it is not found go and put it 0.0. 06:21.610 --> 06:24.890 Longitude equals to document dot. 06:24.930 --> 06:29.930 Get double the field longitude 0.0. 06:29.970 --> 06:36.490 The last thing we need to get is document dot get string and the title. 06:36.610 --> 06:42.690 If it is null and not found, go and create an empty string. 06:42.730 --> 06:50.450 In the next video, we're gonna modify our view model and test our code to get the markers in the collection.