dot

README

dot

Golang package for formatting graphs as dot-code. The package uses an external dot executable to generate SVG or PNG images.

You can set a custom dot exectuable during compilation using go build -ldflags "-X dot.Exe=/path/to/dot/exe".

Documentation

Overview

Package dot implements a simple interface to encode graphs/digraphs as dot files.

Index

• Constants
• func Execute(in io.Reader, out io.Writer, args ...string) error
• func ToPNG(in io.Reader, out io.Writer) error
• func ToSVG(in io.Reader, out io.Writer) error
• type Encoder
  • func NewEncoder(out io.Writer) *Encoder
  • func (e *Encoder) Done() error
  • func (e *Encoder) EncodeEdge(src, dest string, args ...interface{}) error
  • func (e *Encoder) EncodeKeyVal(key, val string) error
  • func (e *Encoder) EncodeNode(id string, args ...interface{}) error
• type HTML

Constants

const (
	RankDir     = "rankdir"
	LR          = "LR"
	RL          = "RL"
	TB          = "TB"
	BT          = "BT"
	Label       = "label"
	Peripheries = "peripheries"
)

Often used Configuration options.

const Exe = "/usr/bin/dot"

Exe defines the full path of the dot executable that will be used. Change this at compile time using `go build -ldflags "-X dot.Exe=/path/to/dot/exe"`.

Functions

func Execute

func Execute(in io.Reader, out io.Writer, args ...string) error

Execute executes a dot command with the given arguments.

func ToPNG

func ToPNG(in io.Reader, out io.Writer) error

ToPNG formats the given dot input as PNG encoded image into the output. It is equivalent to `Execute(in, out, "-Tpng"`.

func ToSVG

func ToSVG(in io.Reader, out io.Writer) error

ToSVG formats the given dot input as SVG encoded image into the given output. It is equivalent to `Execute(in, out, "-Tsvg")`.

Types

type Encoder

type Encoder struct {
	Digraph bool // weather to use a graph or a digraph for the output
	// contains filtered or unexported fields
}

Encoder writes dot code into a writer.

func NewEncoder

func NewEncoder(out io.Writer) *Encoder

NewEncoder creates a new encoder that writes in the given writer.

func (*Encoder) Done

func (e *Encoder) Done() error

Done writes the last closing bracet into the writer.

func (*Encoder) EncodeEdge

func (e *Encoder) EncodeEdge(src, dest string, args ...interface{}) error

EncodeEdge encodes an edge from src id to dest id.

func (*Encoder) EncodeKeyVal

func (e *Encoder) EncodeKeyVal(key, val string) error

EncodeKeyVal encodes key = val.

func (*Encoder) EncodeNode

func (e *Encoder) EncodeNode(id string, args ...interface{}) error

EncodeNode encodes node id.

type HTML

type HTML string

HTML can be used to inject html encoded strings. E.g. EncodeEdge("edge", "label", HTML("<b>foo</b>").