How to load data into a DataGrid for each page using JSON in Flutter DataTable (SfDataGrid).

In this article, we will show you how to load data into a DataGrid for each page using JSON in Flutter DataTable.

STEP 1:

Refer to this KB link to populate Flutter DataTable (DataGrid) with JSON API.

STEP 2:

Initialize the SfDataGrid and SfDataPager widgets with all the required properties. Instead of supplying the entire data to the DataGrid, provide only the data corresponding to the current page to the DataGridSource.

Future generateProductList() async {
  // Here we have get the entire data asynchronously.
  var response = await http.get(Uri.parse(
      'https://ej2services.syncfusion.com/production/web-services/api/Orders?'));
  var list = json.decode(response.body).cast<Map<String, dynamic>>();
  productlist =
      await list.map<Product>((json) => Product.fromJson(json)).toList();
  jsonDataGridSource =
      JsonDataGridSource(productlist.getRange(0, rowsPerPage).toList());

  return productlist;
}

@override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: const Text('Flutter DataGrid Sample'),
        ),
        body: FutureBuilder(
            future: generateProductList(),
            builder: (BuildContext context, AsyncSnapshot<dynamic> snapshot) {
              return snapshot.hasData
                  ? LayoutBuilder(builder: (context, constraints) {
                      return Column(children: [
                        SizedBox(
                            height: constraints.maxHeight - 60,
                            width: constraints.maxWidth,
                            child: buildDataGrid()),
                        SizedBox(
                          height: 60,
                          width: constraints.maxWidth,
                          child: SfDataPager(
                            pageCount: (productlist.length / rowsPerPage)
                                .ceil()
                                .toDouble(),
                            delegate: jsonDataGridSource,
                            availableRowsPerPage: const [10, 20, 30],
                            onRowsPerPageChanged: (int? rowsPerPages) {
                              setState(() {
                                rowsPerPage = rowsPerPages!;
                                jsonDataGridSource.updateDataGriDataSource();
                              });
                            },
                          ),
                        )
                      ]);
                    })
                  : const Center(
                      child: CircularProgressIndicator(strokeWidth: 3));
            }));
  }

  Widget buildDataGrid() {
    return SfDataGrid(
        columns: getColumns(),
        source: jsonDataGridSource,
        columnWidthMode: ColumnWidthMode.fill);
  }

STEP 3:

Then, load the relevant data for the specific page within the handlePageChange method. This method is invoked whenever the page is changed through the data pager.

class JsonDataGridSource extends DataGridSource {
 ...

@override
  Future<bool> handlePageChange(int oldPageIndex, int newPageIndex) async {
    int startIndex = newPageIndex * rowsPerPage;
    int endIndex = startIndex + rowsPerPage;
    if (endIndex > productlist.length) {
      endIndex = productlist.length;
    }
    if (startIndex < productlist.length && endIndex <= productlist.length) {
      buildDataGridRow(productlist.getRange(startIndex, endIndex).toList());
      notifyListeners();
    } else {
      dataGridRows = [];
    }

    return true;
  }
}

You can download this example on GitHub.