A package for managing data as a set of (tabular) records.

Each RecordSet is made up of Records which, in turn, are made up of Fields.

If you're looking to parse delimited files into a RecordSet, check out the betto_codec_csv package.

A range of approaches are available for loading data into a RecordSet. The most basic approach is to just add a list of Records, each built from a list of Objects, to the RecordSet. In this approach all data is treated as Strings.

For more complex data structures, a RecordSetHeader can be provided that describes FieldSchema for each field. The FieldSchema provides a range of information, including:

• The [FieldSchema.name] is the column name
• The [FieldSchema.type] is the data type
• [FieldSchema.defaultValue] is the default value to use if a null is provided
• [FieldSchema.isNullable] indicates if the field can be null
• [FieldSchema.validators] can be used to validate the field value. A set of pre-defined Validators is provided in the betto_schema package.

The RecordSetHeader can also be configured with a set of FieldParsers. These provide a way to convert data from an incoming data type (usually a String) to the intended data type. The FieldParser class provides a set of static methods to help here, including [FieldParser.stringToInt] and [FieldParser.stringToDateTime]. The FieldParsers class provides a base set of FieldParsers for converting from a String to another type.

The approach is based on creating a RecordSet with a defined RecordSetHeader and then adding Records to it. The RecordSet will then handle type changes and validation of the incoming Records.

A RecordSet can then be rendered as HTML, JSON, or CSV using the Renderer class. These are basic but can be readily extended.

Basic example demonstrating reading in comma-separated data and printing out HTML (see example.dart in the example/ directory):

import 'package:betto_recordset/betto_recordset.dart';
import 'package:collection/collection.dart';

void main() {
  const csvData = [
    'id,name,rating',
    '1,Black Forest Cake,5.0',
    '2,Trifle,3.5',
    '3,Ice cream cake,2.0',
    '4,Tiramisu,4.5',
    '5,Chocolate cake,3.0,Very Dry',
    '6,Fruit Pizza,0.5',
  ];

  final rs = RecordSet(
    header: RecordSetHeader.fromStrings(
      csvData[0].split(','),
    ),
  );

  for (final row in csvData.slice(1)) {
    rs.newRecord(
      row.split(','),
    );
  }

  final html = Renderer(formatHtml).render(rs);
  print(html);
}

Will create HTML as follows:

<table>
  <thead>
    <tr>
      <th>id</th>
      <th>name</th>
      <th>rating</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>1</td>
      <td>Black Forest Cake</td>
      <td>5.0</td>
    </tr>
    <tr>
      <td>2</td>
      <td>Trifle</td>
      <td>3.5</td>
    </tr>
    <tr>
      <td>3</td>
      <td>Ice cream cake</td>
      <td>2.0</td>
    </tr>
    <tr>
      <td>4</td>
      <td>Tiramisu</td>
      <td>4.5</td>
    </tr>
    <tr>
      <td>5</td>
      <td>Chocolate cake</td>
      <td>3.0</td>
    </tr>
    <tr>
      <td>6</td>
      <td>Fruit Pizza</td>
      <td>0.5</td>
    </tr>
  </tbody>
</table>

Which, when rendered appears as:

You'll find example usage in the example/ directory and in test/. The test/example_test.dart test file provides a more in-depth example of the package.

This package is part of the Bettongia project.