implementing API graphs and getting frustrated at async stuff

To Do List.txt

@@ -1,17 +0,0 @@
-TODO
-	⁃	Show username
-	⁃	add ‘confirm logout’
-
-		Splash Screen
-	⁃	Splash screen transition - fade
-
-	Login
-	⁃	save login details option (checkbox or something)
-
-	Navigation
-	⁃	Make it look good
-
-	Submit Receipt
-	⁃	Categories
-	⁃	Recurring
-	⁃	'organisation name' dialog works

android/build.gradle

@@ -26,4 +26,4 @@ subprojects {
 
 task clean(type: Delete) {
     delete rootProject.buildDir
-}
+}

lib/common/apifunctions/get_graph_data.dart

@@ -2,13 +2,12 @@ import 'dart:convert';
 import 'dart:async';
 import 'package:http/http.dart' as http;
 import 'package:shared_preferences/shared_preferences.dart';
-
+import 'package:charts_flutter/flutter.dart' as charts;
-enum DataPoint {date, String}
 
 class GraphData {
-  List<DataPoint> data = new List<DataPoint>();
+  List<charts.Series> data = new List<charts.Series>();
 
-  Future<List<DataPoint>> getGraphData(String graphType) async {
+  Future<List<charts.Series>> getGraphData(String graphType) async {
     /// Graph types:
     /// - total_last_week
     /// - avg_spend_last_week
@@ -18,6 +17,7 @@ class GraphData {
     /// HTTP POST request sample:
     /// {"graph":"total_last_week","session_key":"blahblahblah"}
 
+    charts.Series dataSeries = new charts.Series();
     final url = "https://dev.peartrade.org/api/v1/customer/graphs";
     SharedPreferences preferences = await SharedPreferences.getInstance();
 
@@ -33,17 +33,62 @@ class GraphData {
 
     if (response.statusCode == 200) {
       final responseJson = jsonDecode(response.body);
-      final labels = responseJson['graph']['labels'];
+      final List<dynamic> labels = responseJson['graph']['labels'];
-      final data = responseJson['graph']['data'];
+      final List<dynamic> data = responseJson['graph']['data'];
-//      final bounds = responseJson['graph']['bounds']; // why is this even returned?
+//      final List<String> bounds = responseJson['graph']['bounds']; // why is this even returned?
+
+      /*
+      final data = [
+        new TimeSeriesSales(new DateTime(2017, 9, 19), 5),
+        new TimeSeriesSales(new DateTime(2017, 9, 26), 25),
+        new TimeSeriesSales(new DateTime(2017, 10, 3), 100),
+        new TimeSeriesSales(new DateTime(2017, 10, 10), 75),
+      ];
+       */
+
+      List<TimeSeriesSpend> timeSeriesSpendList = new List<TimeSeriesSpend>();
+
+      for (int i = 0; i < labels.length; i++) {
+        print(DateTime(labels[i]));
+        timeSeriesSpendList.add(new TimeSeriesSpend(data[i], DateTime(labels[i])));
+      }
+
+      return [
+        new charts.Series<TimeSeriesSpend, DateTime>(
+          id: 'Spend',
+          colorFn: (_, __) => charts.MaterialPalette.blue.shadeDefault,
+          domainFn: (TimeSeriesSpend spend, _) => spend.time,
+          measureFn: (TimeSeriesSpend spend, _) => spend.spend,
+          data: timeSeriesSpendList,
+        )
+      ];
+
+      /*
+        new charts.Series<TimeSeriesSales, DateTime>(
+        id: 'Sales',
+        colorFn: (_, __) => charts.MaterialPalette.blue.shadeDefault,
+        domainFn: (TimeSeriesSales sales, _) => sales.time,
+        measureFn: (TimeSeriesSales sales, _) => sales.sales,
+        data: data,
+      )*/
+
 //      print(labels[5]);
 //      print(data[5]);
     } else {
       final errorMessage = json.decode(response.body)['message'];
       print("Error: " + errorMessage);
+
+      return null;
     }
   }
 
 
 }
 
+class TimeSeriesSpend {
+  final DateTime time;
+  final int spend;
+
+  TimeSeriesSpend(this.spend, this.time);
+}
+

lib/common/widgets/charts/time_series_simple.dart

@@ -0,0 +1,60 @@
+/// Timeseries chart example
+import 'package:charts_flutter/flutter.dart' as charts;
+import 'package:flutter/material.dart';
+
+class SimpleTimeSeriesChart extends StatelessWidget {
+  final List<charts.Series> seriesList;
+  final bool animate;
+
+  SimpleTimeSeriesChart(this.seriesList, {this.animate});
+
+  /// Creates a [TimeSeriesChart] with sample data and no transition.
+  factory SimpleTimeSeriesChart.withSampleData() {
+    return new SimpleTimeSeriesChart(
+      _createSampleData(),
+      // Disable animations for image tests.
+      animate: true,
+    );
+  }
+
+
+  @override
+  Widget build(BuildContext context) {
+    return new charts.TimeSeriesChart(
+      seriesList,
+      animate: animate,
+      // Optionally pass in a [DateTimeFactory] used by the chart. The factory
+      // should create the same type of [DateTime] as the data provided. If none
+      // specified, the default creates local date time.
+      dateTimeFactory: const charts.LocalDateTimeFactory(),
+    );
+  }
+
+  /// Create one series with sample hard coded data.
+  static List<charts.Series<TimeSeriesSales, DateTime>> _createSampleData() {
+    final data = [
+      new TimeSeriesSales(new DateTime(2017, 9, 19), 5),
+      new TimeSeriesSales(new DateTime(2017, 9, 26), 25),
+      new TimeSeriesSales(new DateTime(2017, 10, 3), 100),
+      new TimeSeriesSales(new DateTime(2017, 10, 10), 75),
+    ];
+
+    return [
+      new charts.Series<TimeSeriesSales, DateTime>(
+        id: 'Sales',
+        colorFn: (_, __) => charts.MaterialPalette.blue.shadeDefault,
+        domainFn: (TimeSeriesSales sales, _) => sales.time,
+        measureFn: (TimeSeriesSales sales, _) => sales.sales,
+        data: data,
+      )
+    ];
+  }
+}
+
+/// Sample time series data type.
+class TimeSeriesSales {
+  final DateTime time;
+  final int sales;
+
+  TimeSeriesSales(this.time, this.sales);
+}

lib/main.dart

@@ -15,8 +15,8 @@ void main() {
 class MyApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
-    GraphData gd = new GraphData();
+//    GraphData gd = new GraphData();
-    gd.getGraphData('total_last_week');
+//    gd.getGraphData('total_last_week');
 
     //var config = ConfigWrapper.of(context);
     return new MaterialApp(

lib/pages/receipt_page.dart

@@ -204,7 +204,7 @@ class ReceiptPageState extends State<ReceiptPage> {
 
   List<String> getRecurringOptions() {
     var options = new List<String>(7);
-    options[0] = "None";
+    options[0] = "None";  // this should not be hardcoded and should be fetched from API instead
     options[1] = "Daily";
     options[2] = "Weekly";
     options[3] = "Fortnightly";
@@ -556,7 +556,7 @@ class ReceiptPageState extends State<ReceiptPage> {
                               value: value,
                               child: Text(value),
                             );
-                          }).toList(),
+                          }).toList(),    // fix errors here by [items] being an empty container while _categoryDropDownItems is null
                         )
                     ),
                   ],

lib/pages/stats_page.dart

@@ -12,6 +12,9 @@ import 'package:local_spend/common/widgets/charts/grouped_bar_chart.dart';
 import 'package:local_spend/common/widgets/charts/scatter_bucketingAxis_legend.dart';
 import 'package:local_spend/common/widgets/charts/numeric_line_bar_combo.dart';
 import 'package:local_spend/common/widgets/charts/series_legend_with_measures.dart';
+import 'package:local_spend/common/widgets/charts/time_series_simple.dart';
+import 'package:local_spend/common/apifunctions/get_graph_data.dart';
+import 'package:charts_flutter/flutter.dart' as charts;
 
 const URL = "https://flutter.io/";
 const demonstration = false;
@@ -25,6 +28,9 @@ class StatsPage extends StatefulWidget {
 
 class StatsPageState extends State<StatsPage> {
 
+  GraphData graphData = new GraphData();
+  List<charts.Series> totalLastWeek;
+
   @override
   void initState() {
     super.initState();
@@ -43,6 +49,15 @@ class StatsPageState extends State<StatsPage> {
 
   @override
   Widget build(BuildContext context) {
+    if (graphData.data != null) {
+      graphData.getGraphData('total_last_week').then((val) {
+        totalLastWeek = val;
+        setState(() {
+          // update view
+        });
+      });
+    }
+
     return PlatformScaffold(
       appBar: AppBar(
         backgroundColor: Colors.blue[400],
@@ -63,30 +78,11 @@ class StatsPageState extends State<StatsPage> {
         padding: EdgeInsets.fromLTRB(0, 0, 0, 0),
         child: ListView(
           children: <Widget>[
-            // some graphs and charts here etc
-//            Container(
-//              padding: EdgeInsets.fromLTRB(0.0,17,0.0,0.0),
-//              child : Text(
-//                "Really Cool Chart",
-//                textAlign: TextAlign.center,
-//                style: TextStyle(
-//                  fontSize: 22.0,
-//                  color: Colors.black,
-//                  fontWeight: FontWeight.bold,
-//                ),
-//              ),
-//            ),
-//
-//            Container(
-//              height: 250,
-////              width: 250,
-//              child: new DonutPieChart.withSampleData()
-//            ),
 
             Container(
               padding: EdgeInsets.fromLTRB(0.0,17,0.0,0.0),
               child : Text(
-                "GroupedBarChart",
+                "This Week's Spend",
                 textAlign: TextAlign.center,
                 style: TextStyle(
                   fontSize: 22.0,
@@ -100,127 +96,8 @@ class StatsPageState extends State<StatsPage> {
               padding: EdgeInsets.symmetric(horizontal: 10),
               height: 200,
 //              width: 250,
-              child: new GroupedBarChart.withSampleData()
-            ),
 
-            Container(
+                child: new SimpleTimeSeriesChart(totalLastWeek),//seriesList: List<charts.Series>
-              padding: EdgeInsets.fromLTRB(0.0,17,0.0,0.0),
-              child : Text(
-                "BucketingAxisScatterPlotChart",
-                textAlign: TextAlign.center,
-                style: TextStyle(
-                  fontSize: 22.0,
-                  color: Colors.black,
-                  fontWeight: FontWeight.bold,
-                ),
-              ),
-            ),
-
-            Container(
-                padding: EdgeInsets.symmetric(horizontal: 10),
-                height: 200,
-//              width: 250,
-                child: new BucketingAxisScatterPlotChart.withSampleData()
-            ),
-
-            Container(
-              padding: EdgeInsets.fromLTRB(0.0,20,0.0,0.0),
-              child : Text(
-                "PieOutsideLabelChart",
-                textAlign: TextAlign.center,
-                style: TextStyle(
-                  fontSize: 22.0,
-                  color: Colors.black,
-                  fontWeight: FontWeight.bold,
-                ),
-              ),
-            ),
-
-            Container(
-                padding: EdgeInsets.symmetric(horizontal: 10),
-                height: 200,
-//              width: 250,
-                child: new PieOutsideLabelChart.withSampleData()
-            ),
-
-            Container(
-              padding: EdgeInsets.fromLTRB(0.0,17,0.0,0.0),
-              child : Text(
-                "DonutAutoLabelChart",
-                textAlign: TextAlign.center,
-                style: TextStyle(
-                  fontSize: 22.0,
-                  color: Colors.black,
-                  fontWeight: FontWeight.bold,
-                ),
-              ),
-            ),
-
-            Container(
-                padding: EdgeInsets.symmetric(horizontal: 10),
-                height: 200,
-//              width: 250,
-                child: new DonutAutoLabelChart.withSampleData()
-            ),
-
-            Container(
-              padding: EdgeInsets.fromLTRB(0.0,17,0.0,0.0),
-              child : Text(
-                "DonutPieChart",
-                textAlign: TextAlign.center,
-                style: TextStyle(
-                  fontSize: 22.0,
-                  color: Colors.black,
-                  fontWeight: FontWeight.bold,
-                ),
-              ),
-            ),
-
-            Container(
-                padding: EdgeInsets.symmetric(horizontal: 10),
-                height: 200,
-//              width: 250,
-                child: new DonutPieChart.withSampleData()
-            ),
-
-            Container(
-              padding: EdgeInsets.fromLTRB(0.0,17,0.0,0.0),
-              child : Text(
-                "NumericComboLineBarChart",
-                textAlign: TextAlign.center,
-                style: TextStyle(
-                  fontSize: 22.0,
-                  color: Colors.black,
-                  fontWeight: FontWeight.bold,
-                ),
-              ),
-            ),
-
-            Container(
-                padding: EdgeInsets.symmetric(horizontal: 10),
-                height: 200,
-//              width: 250,
-                child: new NumericComboLineBarChart.withSampleData()
-            ),
-
-            Container(
-              padding: EdgeInsets.fromLTRB(0.0,17,0.0,0.0),
-              child : Text(
-                "LegendWithMeasures",
-                textAlign: TextAlign.center,
-                style: TextStyle(
-                  fontSize: 22.0,
-                  color: Colors.black,
-                  fontWeight: FontWeight.bold,
-                ),
-              ),
-            ),
-
-            Container(
-                padding: EdgeInsets.symmetric(horizontal: 10),
-                height: 200,
-//              width: 250,
-                child: new LegendWithMeasures.withSampleData()
             ),
 
           ],