Table

Small, easy to use library, that renders arbitrary data as table in console.

How it works

Library operates with two interfaces - table.Cell and table.Inteface. First one used to describe cell rendering contents while the second describes whole table structure (same as Go native sort.Interface)

Tables

Method table.Print works only with table.Interface, so you have to create structure, that implements it:

type Interface interface {
	// Returns list of headers
	Headers() []string
	// Iterates over own contents, supplying each data row to provided callback function
	EachRow(func(...Cell))
}

Example:

package main

import (
	"github.com/mono83/table"
	"github.com/mono83/table/cells"
	"io/ioutil"
	"os"
)

func main() {
	files, err := ioutil.ReadDir(".")
	if err != nil {
		panic(err)
	}

	table.Print(filesTable(files), table.PrintOptions{
		ColumnSeparator: " ",
		NoHeader:        true,
	})
}

// filesTable is proxy structure, that implements table.Interface
type filesTable []os.FileInfo

func (f filesTable) Headers() []string {
	return []string{
		"Name",
		"Type",
		"Size",
	}
}

func (f filesTable) EachRow(callback func(...table.Cell)) {
	for _, info := range f {
		var nodeType table.Cell
		nodeType = cells.Empty{}
		if info.IsDir() {
			nodeType = cells.ColoredYellowHi(cells.String("dir"))
		}

		callback(
			cells.ColoredString(cells.String(info.Name())),
			nodeType,
			cells.Bytes(info.Size()),
		)
	}
}

Cells

All cells in table must implement table.Cell interface:

type Cell interface {
	// Returns cell width
	Width() int
	// Returns plain string representation of cell contents
	String() string
	// Returns formatted value of cell
	PrintFormat(width int) string
}

Implementations

There are some implementations in cells package, most of them can be obtained using simple type casting:

Type	Casts from	Usecase
cells.Empty	none	Empty cells
cells.String	string	String values
cells.Int	int	int values
cells.Int64	int64	int64 values
cells.Bytes	int64	Byte size of something. This implementation will format value and append suffixes like Kb, Mb, Gb

Formatting adapters

Coloring

There are some useful coloring adapters, designed as function, that takes table.Cell as argument. Suffix hi stands for high-intensity.

• cells.ColoredRed and cells.ColoredRedHi - red cell coloring
• cells.ColoredGreen and cells.ColoredGreenHi - green cell coloring
• cells.ColoredCyan and cells.ColoredCyanHi - cyan cell coloring
• cells.ColoredYellow and cells.ColoredYellowHi - yellow cell coloring
• cells.ColoredBlue and cells.ColoredBlueHi - blue cell coloring
• cells.ColoredWhite and cells.ColoredWhiteHi - white cell coloring
• cells.ColoredString - standard color for strings (currently - green)
• cells.ColoredInt - standard color for integers (currently - cyan)

Alignment

• cells.AlignLeft
• cells.AlignRight
• cells.AlignCenter

Cell helpers

• cells.Sprintf - shortcut to string cell, built using fmt.Sprintf

Print options

• Writer - io.Writer to use. If omitted, os.Stdout will be chosen
• ColumnSeparator - string, used as column separator
• NoDecoration - if true, color formatting disabled
• NoHeader - if true, table header with column names won't be rendered
• HeaderBorder - string, used to render border between header and data