Interface DataSource

Returns Promise<Array<TableSummary>>

An array of table summary objects that are currently used in the data source.

Returns Promise<Array<ConnectionSummary>>

An array of descriptions of the connections within this data source.

Parameters

• logicalTableId: string

• Optional options: DataSourceUnderlyingDataOptions

  Collection of options to change the behavior of the call.

Returns Promise<DataTable>

A data table containing the underlying data of the data source.

Parameters

• logicalTableId: string

  logical table id.

• Optional pageRowCount: undefined | number

  The number of rows per page. The default and maximum is 10,000 rows.

• Optional options: DataSourceUnderlyingDataOptions

  Collection of options to change the behavior of the reader.

Returns Promise<DataTableReader>

A data table reader to access the logical table data in the data source.

getLogicalTableDataReaderAsync attempts to prepare all the rows of the table to be read as pages. There is a limit to the number of rows that can be prepared. The default limit is about 1 million rows of data. However, if the data source has many columns, this number will be adjusted downward. You can change the default limit with the Tableau Server (Cloud) or Tableau Desktop option: ExtensionsAndEmbeddingReaderCellLimit. If the data source has many columns, getLogicalTableDataReaderAsync can be sped up by only requesting native data values in the DataSourceUnderlyingDataOptions.

The following example shows use of the getLogicalTableDataReaderAsync and getAllPagesAsync to prepare pages of 10,000 rows each, and then to get a maximum of 150,000 rows of native data from a specific logical table in a data source.

const dataSources = await worksheet.getDataSourcesAsync();
const dataSource = dataSources.find(datasource => datasource.name === "Sample - Superstore");
const logicalTables = await dataSource.getLogicalTablesAsync()
const dataTableReader = await dataSource.getLogicalTableDataReaderAsync(logicalTables[0].id, 10000,
    { includeDataValuesOption: tableau.IncludeDataValuesOption.OnlyNativeValues });
const dataTable = await dataTableReader.getAllPagesAsync(150000);
console.log(dataTable);
await dataTableReader.releaseAsync();

Returns Promise<Array<LogicalTable>>

An array of logical tables that are currently used in the data source.

The following example uses the getLogicalTablesAsync method to print the names of the the logical tables to the console.

dataSource.getLogicalTablesAsync().then(function (logicalTables) {
  // Loop through each table that was used in creating this data source
  logicalTables.forEach(function (table) {
     console.log(table.caption);
  });
});

Parameters

• Optional options: DataSourceUnderlyingDataOptions

  Collection of options to change the behavior of the call.

Returns Promise<DataTable>

Returns a promise containing a page of data from the underlying data of the data source.

The following example shows use of the getUnderlyingDataAsync() method to get the underlying data from a specific data source. The example uses the JavaScript find() method to select the workbook and data source.

const dataSources = await worksheet.getDataSourcesAsync();
const dataSource = dataSources.find(datasource => datasource.name === "Sample - Superstore");
const dataTable = await dataSource.getUnderlyingDataAsync();
let field = dataTable.columns.find(column => column.fieldName === "Sub-Category");
let list = [];
for (let row of dataTable.data) {
    list.push(row[field.index].value);
}
let values = list.filter((el, i, arr) => arr.indexOf(el) === i);
console.log(values);

Returns Promise<void>

Promise that resolves when the data source has finished refreshing.