From 7946b4883e8dcc3796ee3bd142c6c0b74032416d Mon Sep 17 00:00:00 2001
From: Sara <sarasdj@stud.ntnu.no>
Date: Fri, 5 Apr 2024 13:54:09 +0200
Subject: [PATCH] update: loading from file if no internet connection
---
app/lib/consts.dart | 2 +-
app/lib/controller/network_controller.dart | 4 ++
app/lib/server_requests/fetch_markers.dart | 29 ++++++-----
app/lib/server_requests/fetch_relation.dart | 29 ++++++-----
app/lib/server_requests/init_state.dart | 58 +++++++++++++--------
5 files changed, 74 insertions(+), 48 deletions(-)
diff --git a/app/lib/consts.dart b/app/lib/consts.dart
index d1c7751a..1e79c722 100644
--- a/app/lib/consts.dart
+++ b/app/lib/consts.dart
@@ -17,7 +17,7 @@ List<Measurement> selectedMarkerList = [];
LatLng mapCenter = LatLng(60.8000, 10.8471);
DateTime ?lastUpdate; // Last time data was fetched from server
List<String> lakeSearchOptions = []; // Init empty
-bool internetConnection = true;
+bool internetConnection = false;
// Font settings
const textColor = Colors.white;
diff --git a/app/lib/controller/network_controller.dart b/app/lib/controller/network_controller.dart
index e0992f06..7da8a58b 100644
--- a/app/lib/controller/network_controller.dart
+++ b/app/lib/controller/network_controller.dart
@@ -18,6 +18,8 @@ class NetworkController extends GetxController {
// If no network connection, show snack-bar
if (connectivityResult == ConnectivityResult.none) {
+ internetConnection = false;
+
Get.rawSnackbar(
messageText: Text(
'No internet connection. The displayed information may be outdated!',
@@ -35,6 +37,8 @@ class NetworkController extends GetxController {
snackStyle: SnackStyle.GROUNDED,
);
} else {
+ internetConnection = true;
+
if (Get.isSnackbarOpen) { // Close snack-bar upon establishing internet connection
Get.closeCurrentSnackbar();
}
diff --git a/app/lib/server_requests/fetch_markers.dart b/app/lib/server_requests/fetch_markers.dart
index cd67bc7b..80cbc172 100644
--- a/app/lib/server_requests/fetch_markers.dart
+++ b/app/lib/server_requests/fetch_markers.dart
@@ -62,18 +62,23 @@ Future<FetchResult> fetchMeasurements() async {
}
Future<FetchResult> loadSavedData() async {
- // Get latest saved data from file if the server does not respond
- Directory appDocumentsDirectory = await getApplicationDocumentsDirectory();
- String filePath = '${appDocumentsDirectory.path}/last_data.json';
+ try {
+ // Get latest saved data from file if the server does not respond
+ Directory appDocumentsDirectory = await getApplicationDocumentsDirectory();
+ String filePath = '${appDocumentsDirectory.path}/last_data.json';
- // Read file contents
- File file = File(filePath);
- if (await file.exists()) {
- String contents = await file.readAsString();
- List<dynamic> jsonData = json.decode(contents); // Parse JSON string from file
- List<Measurement> measurements = jsonData.map((data) => Measurement.fromJson(data)).toList();
- return FetchResult(measurements, false);
- } else {
- throw Exception('File does not exist');
+ // Read file contents
+ File file = File(filePath);
+ if (await file.exists()) {
+ String contents = await file.readAsString();
+ List<dynamic> jsonData = json.decode(contents); // Parse JSON string from file
+ List<Measurement> measurements = jsonData.map((data) => Measurement.fromJson(data)).toList();
+ return FetchResult(measurements, false);
+ } else {
+ throw Exception('File does not exist');
+ }
+ } catch (error) {
+ print('Error in reading measurements from file: $error');
+ return FetchResult([], false);
}
}
diff --git a/app/lib/server_requests/fetch_relation.dart b/app/lib/server_requests/fetch_relation.dart
index 88e1ca20..3f723fae 100644
--- a/app/lib/server_requests/fetch_relation.dart
+++ b/app/lib/server_requests/fetch_relation.dart
@@ -46,19 +46,24 @@ Future<Uint8List> fetchRelation() async {
}
Future<Uint8List> loadSavedRelation() async {
- // Get latest saved relation from file if the server does not respond
- Directory appDocumentsDirectory = await getApplicationDocumentsDirectory();
- String filePath = '${appDocumentsDirectory.path}/last_relation.json';
+ try {
+ // Get latest saved relation from file if the server does not respond
+ Directory appDocumentsDirectory = await getApplicationDocumentsDirectory();
+ String filePath = '${appDocumentsDirectory.path}/last_relation.json';
- // Read file contents
- File file = File(filePath);
- if (await file.exists()) {
- String contents = await file.readAsString();
- List<dynamic> jsonData = json.decode(contents); // Parse JSON string from file
- Uint8List relation = Uint8List.fromList(utf8.encode(jsonData.toString()));
- return relation;
- } else {
- throw Exception('File does not exist');
+ // Read file contents
+ File file = File(filePath);
+ if (await file.exists()) {
+ String contents = await file.readAsString();
+ List<dynamic> jsonData = json.decode(contents); // Parse JSON string from file
+ Uint8List relation = Uint8List.fromList(utf8.encode(jsonData.toString()));
+ return relation;
+ } else {
+ throw Exception('File does not exist');
+ }
+ } catch (error) {
+ print('Error in reading relation from file: $error');
+ return Uint8List(0);
}
}
diff --git a/app/lib/server_requests/init_state.dart b/app/lib/server_requests/init_state.dart
index a5c90d44..b2e2182b 100644
--- a/app/lib/server_requests/init_state.dart
+++ b/app/lib/server_requests/init_state.dart
@@ -4,6 +4,7 @@ import 'dart:convert';
import 'dart:typed_data';
import 'package:app/consts.dart';
+import '../consts.dart';
import '../data_classes.dart';
import '../server_requests/fetch_markers.dart';
import '../server_requests/fetch_relation.dart';
@@ -19,30 +20,41 @@ Future<void> initialiseState() async {
late Future<Uint8List> relationFuture;
try {
- // Try to fetch measurement data from server
- markerListFuture = fetchMeasurements().then((fetchResult) {
+
+ // Read data from files if no internet connection
+ if (!internetConnection) {
+ selectedRelation = Uint8List(0); // NB update once fixed
+
+ FetchResult fetchResult = await loadSavedData();
List<Measurement> measurements = fetchResult.measurements;
- serverConnection = fetchResult.connected;
-
- // Return measurements
- return measurements;
- }).catchError((error) {
- serverConnection = false;
- throw Exception("Failed to fetch measurements: $error");
- });
-
- // If measurements were fetched successfully, request relation
- if (serverConnection) {
- relationFuture = fetchRelation();
- } /*else { // Read last saved data
- relationFuture = loadSavedRelation();
- }*/
-
- initSearchOptions();
-
- //selectedRelation = await relationFuture;
- selectedRelation = Uint8List(0);
- selectedMarkerList = await markerListFuture;
+ selectedMarkerList = measurements;
+
+ lakeSearchOptions = ["Mjøsa"];
+ } else { // Try to fetch measurement data from server
+ markerListFuture = fetchMeasurements().then((fetchResult) {
+ List<Measurement> measurements = fetchResult.measurements;
+ serverConnection = fetchResult.connected;
+
+ // Return measurements
+ return measurements;
+ }).catchError((error) {
+ serverConnection = false;
+ throw Exception("Failed to fetch measurements: $error");
+ });
+
+ // If measurements were fetched successfully, request relation
+ if (serverConnection) {
+ relationFuture = fetchRelation();
+ } /*else { // Read last saved data
+ relationFuture = loadSavedRelation();
+ }*/
+
+ initSearchOptions();
+
+ //selectedRelation = await relationFuture;
+ selectedRelation = Uint8List(0); // NB update once fixed
+ selectedMarkerList = await markerListFuture;
+ }
} catch (e) {
// Handle any errors that occur during the initialization process
print("Error during initialization: $e");
--
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