Function WriteTable

utils/table_writer.go:64–119

WriteTable renders a tabular representation from underlying data source. If there is no column for this data source, it will return an empty string. All elements of the table will be right justify (left padding). Column splitter is "|" for now.

(dataSource TableDataSource)

// All elements of the table will be right justify (left padding). Column
// splitter is "|" for now.
func WriteTable(dataSource TableDataSource) string {
	columnHeaders := dataSource.ColumnHeaders()
	numCols := len(columnHeaders)

	// Return empty string if no columns.
	if numCols == 0 {
		return ""
	}
	// Compute column widths.
	columnWidths := make([]int, numCols)

	// Then compare with the length of each value.
	numRows := dataSource.NumRows()
	for c := 0; c < numCols; c++ {
		header := columnHeaders[c]
		columnWidths[c] = len(header)
		for r := 0; r < numRows; r++ {
			value := dataSource.GetValue(r, c)
			expandColumnWidth(columnWidths, value, c)
		}
	}

	// string buffer for final result.
	var buffer bytes.Buffer
	// Prepare format for header.
	headerFormat := "|"
	for _, columnWidth := range columnWidths {
		headerFormat += fmt.Sprintf("%%%ds|", columnWidth)
	}
	headerFormat += "\n"

	// Write column header.
	buffer.WriteString(sprintfStrings(headerFormat, columnHeaders))

	if numRows > 0 {
		// Prepare format for rows.
		rowFormat := "|"
		for c := 0; c < numCols; c++ {
			// get formatter of first row.
			value := dataSource.GetValue(0, c)
			modifier := getFormatModifier(value)
			rowFormat += fmt.Sprintf("%%%d%s|", columnWidths[c], modifier)
		}
		rowFormat += "\n"

		// Write rows.
		for r := 0; r < numRows; r++ {
			row := make([]interface{}, numCols)
			for c := 0; c < numCols; c++ {
				row[c] = dataSource.GetValue(r, c)
			}
			buffer.WriteString(fmt.Sprintf(rowFormat, row...))
		}
	}
	return buffer.String()
}