Json Table Widget

This Flutter package provides a Json Table Widget for directly showing table from a json(Map). Supports Column toggle also.

Live Demo: https://apgapg.github.io/json_table/

Live Data Testing: https://apgapg.github.io/json_table/#/customData

Features

• The table constructed isn’t the flutter’s native DataTable.
• The table is manually coded hence serves a great learning purpose on how to create simple tables manually in flutter
• Supports vertical & horizontal scroll
• Supports custom columns includes default value, column name, value builder
• Supports nested data showing
• Supports pagination
• Supports row select color, callback

 Installation

In the dependencies: section of your pubspec.yaml, add the following line:

dependencies:
  json_table: <latest version>

 Usage

Import this class

import 'package:json_table/json_table.dart';

– Vanilla Implementation

//Decode your json string
final String jsonSample='[{"id":1},{"id":2}]';
var json = jsonDecode(jsonSample);

//Simply pass this json to JsonTable
child: JsonTable(json)

– Implementation with HEADER and CELL widget builders

JsonTable(
   json,
   tableHeaderBuilder: (String header) {
     return Container(
       padding: EdgeInsets.symmetric(horizontal: 8.0, vertical: 4.0),
       decoration: BoxDecoration(border: Border.all(width: 0.5),color: Colors.grey[300]),
       child: Text(
         header,
         textAlign: TextAlign.center,
         style: Theme.of(context).textTheme.display1.copyWith(fontWeight: FontWeight.w700, fontSize: 14.0,color: Colors.black87),
       ),
     );
   },
   tableCellBuilder: (value) {
     return Container(
       padding: EdgeInsets.symmetric(horizontal: 4.0, vertical: 2.0),
       decoration: BoxDecoration(border: Border.all(width: 0.5, color: Colors.grey.withOpacity(0.5))),
       child: Text(
         value,
         textAlign: TextAlign.center,
         style: Theme.of(context).textTheme.display1.copyWith(fontSize: 14.0, color: Colors.grey[900]),
       ),
     );
   },
 )

Head over to example code: simple_table.dart

– Implementation with custom COLUMNS list

• Pass custom column list to control what columns are displayed in table
• The list item must be constructed using JsonTableColumn class
• JsonTableColumn provides 4 parameters, namely,

JsonTableColumn("age", label: "Eligible to Vote", valueBuilder: eligibleToVote, defaultValue:"NA")

• First parameter is the field/key to pick from the data
• label: The column header label to be displayed
• defaultValue: To be used when data or key is null
• valueBuilder: To get the formatted value like date etc

//Decode your json string
final String jsonSample='[{"name":"Ram","email":"ram@gmail.com","age":23,"DOB":"1990-12-01"},'
                              '{"name":"Shyam","email":"shyam23@gmail.com","age":18,"DOB":"1995-07-01"},'
                              '{"name":"John","email":"john@gmail.com","age":10,"DOB":"2000-02-24"},'
                              '{"name":"Ram","age":12,"DOB":"2000-02-01"}]';
var json = jsonDecode(jsonSample);
//Create your column list
var columns = [
      JsonTableColumn("name", label: "Name"),
      JsonTableColumn("age", label: "Age"),
      JsonTableColumn("DOB", label: "Date of Birth", valueBuilder: formatDOB),
      JsonTableColumn("age", label: "Eligible to Vote", valueBuilder: eligibleToVote),
      JsonTableColumn("email", label: "E-mail", defaultValue: "NA"),
    ];
//Simply pass this column list to JsonTable
child: JsonTable(json,columns: columns)

//Example of valueBuilder
String eligibleToVote(value) {
    if (value >= 18) {
      return "Yes";
    } else
      return "No";
}

Head over to example code: custom_column_table.dart

– Implementation with nested data list

Suppose your json object has nested data like email as shown below:

{"name":"Ram","email":{"1":"ram@gmail.com"},"age":23,"DOB":"1990-12-01"}

• Just use email.1 instead of email as key

JsonTableColumn("email.1", label: "Email", defaultValue:"NA")

//Decode your json string
final String jsonSample='[{"name":"Ram","email":{"1":"ram@gmail.com"},"age":23,"DOB":"1990-12-01"},'
                               '{"name":"Shyam","email":{"1":"shyam23@gmail.com"},"age":18,"DOB":"1995-07-01"},'
                               '{"name":"John","email":{"1":"john@gmail.com"},"age":10,"DOB":"2000-02-24"}]';
var json = jsonDecode(jsonSample);
//Create your column list
var columns = [
      JsonTableColumn("name", label: "Name"),
      JsonTableColumn("age", label: "Age"),
      JsonTableColumn("DOB", label: "Date of Birth", valueBuilder: formatDOB),
      JsonTableColumn("age", label: "Eligible to Vote", valueBuilder: eligibleToVote),
      JsonTableColumn("email.1", label: "E-mail", defaultValue: "NA"),
    ];
//Simply pass this column list to JsonTable
child: JsonTable(json,columns: columns)

Head over to example code: custom_column_nested_table.dart

Column toggle

Option for toggling column(s) also. User can customise which columns are to be shown

 showColumnToggle: true

Row Highlighting

Add row highlighting with custom color support

allowRowHighlight: true,
rowHighlightColor: Colors.yellow[500].withOpacity(0.7),

Row Select Callback

Get the index and data map of a particular selected row. Note index might return incorrect value in case of pagination

onRowSelect: (index, map) {
    print(index);
    print(map);
  },

Pagination

Just provide an int value to ‘paginationRowCount’ parameter

paginationRowCount: 4,

TODO

•  Custom header list parameter. This will help to show only those keys as mentioned in header list
•  Add support for keys missing in json object
•  Add support for auto formatting of date
•  Extracting column headers logic must be change. Not to depend on first object
•  Nested data showing support
•  Row highlight support
•  Row select callback
•  Wrap filters in expansion tile
•  Pagination support
•  Add option to change header row to vertical row on left

 Contribution

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -m ‘Add some feature’)
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

Download Json Table Widget source code on GitHub

https://github.com/apgapg/json_table