Data.GraphViz.Commands

This module defines functions to call the various Graphviz commands. It is based upon code originally written for version 0.5 of Graphalyze: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/Graphalyze-0.5

Whilst various output formats are supported (see GraphvizOutput for a complete list), it is not yet possible to choose a desired renderer and formatter. Being able to determine which renderers and formatters are applicable for a specific GraphvizOutput is not easy (there is no listing of available renderers or formatters on the Graphviz website), and for the most part the default ones do the job well.

Please note that for GraphvizOutput and GraphvizCanvas, you will see that they are instances of a GraphvizResult class; this is an internal class that should not be visible outside this module, but Haddock is being too helpful for its own good.

The different Graphviz tools available.

data GraphvizCommand

The available Graphviz commands. The following directions are based upon those in the Graphviz man page (available online at http://graphviz.org/pdf/dot.1.pdf, or if installed on your system man graphviz). Note that any command can be used on both directed and undirected graphs.

Constructors

Dot

For hierachical graphs (ideal for directed graphs).

Neato

For symmetric layouts of graphs (ideal for undirected graphs).

TwoPi

For radial layout of graphs.

Circo

For circular layout of graphs.

Fdp

For symmetric layout of graphs.

Instances

Eq GraphvizCommand

Ord GraphvizCommand

Read GraphvizCommand

Show GraphvizCommand

dirCommand :: GraphvizCommand

The default command for directed graphs.

undirCommand :: GraphvizCommand

The default command for undirected graphs.

commandFor :: DotRepr dg n => dg n -> GraphvizCommand

The appropriate (default) Graphviz command for the given graph.

The possible outputs that Graphviz supports.

The list of output types supported by Graphviz is dependent upon how it is built on your system. To determine which actual formats are available on your system, run dot -T?. Trying to use an output type that is not supported by your installation of Graphviz will result in an error.

The outputs defined here in GraphvizOutput and GraphvizCanvas are those from the default list of available outputs. For more information, see: http://graphviz.org/doc/info/output.html

data GraphvizOutput

The possible Graphviz output formats (that is, those that actually produce a file).

Constructors

Bmp

Windows Bitmap Format.

Canon

Pretty-printed Dot output with no layout performed.

DotOutput

Reproduces the input along with layout information.

XDot

As with DotOutput, but provides even more information on how the graph is drawn.

Eps

Encapsulated PostScript.

Fig

FIG graphics language.

Gd

Internal GD library format.

Gd2

Compressed version of Gd.

Gif

Graphics Interchange Format.

Ico

Icon image file format.

Imap

Server-side imagemap.

Cmapx

Client-side imagemap.

ImapNP

As for Imap, except only rectangles are used as active areas.

CmapxNP

As for Cmapx, except only rectangles are used as active areas.

Jpeg

The JPEG image format.

Pdf

Portable Document Format.

Plain

Simple text format.

PlainExt

As for Plain, but provides port names on head and tail nodes when applicable.

Png

Portable Network Graphvics format.

Ps

PostScript.

Ps2

PostScript for PDF.

Svg

Scalable Vector Graphics format.

SvgZ

Compressed SVG format.

Tiff

Tagged Image File Format.

Vml

Vector Markup Language; Svg is usually preferred.

VmlZ

Compressed VML format; SvgZ is usually preferred.

Vrml

Virtual Reality Modeling Language format; requires nodes to have a Z attribute.

WBmp

Wireless BitMap format; monochrome format usually used for mobile computing devices.

Instances

Eq GraphvizOutput

Ord GraphvizOutput

Read GraphvizOutput

Show GraphvizOutput

GraphvizResult GraphvizOutput

data GraphvizCanvas

Unlike GraphvizOutput, these items do not produce an output file; instead, they directly draw a canvas (i.e. a window) with the resulting image.

Constructors

Gtk

Xlib

Instances

Eq GraphvizCanvas

Ord GraphvizCanvas

Read GraphvizCanvas

Show GraphvizCanvas

GraphvizResult GraphvizCanvas

Running Graphviz.

data RunResult

Represents the result of running a command.

Constructors

Error String

Success

Instances

Eq RunResult

Ord RunResult

Read RunResult

Show RunResult

maybeErr :: Either String a -> RunResult

Return the error if there is one, otherwise return Success.

runGraphviz :: DotRepr dg n => dg n -> GraphvizOutput -> FilePath -> IO (Either String FilePath)

Run the recommended Graphviz command on this graph, saving the result to the file provided (note: file extensions are not checked).

runGraphvizCommand :: DotRepr dg n => GraphvizCommand -> dg n -> GraphvizOutput -> FilePath -> IO (Either String FilePath)

Run the chosen Graphviz command on this graph, saving the result to the file provided (note: file extensions are not checked).

addExtension :: (GraphvizOutput -> FilePath -> a) -> GraphvizOutput -> FilePath -> a

Append the default extension for the provided GraphvizOutput to the provided FilePath for the output file.

runGraphvizCanvas :: DotRepr dg n => GraphvizCommand -> dg n -> GraphvizCanvas -> IO RunResult

Run the chosen Graphviz command on this graph and render it using the given canvas type.

runGraphvizCanvas' :: DotRepr dg n => dg n -> GraphvizCanvas -> IO RunResult

Run the recommended Graphviz command on this graph and render it using the given canvas type.

graphvizWithHandle

Arguments

:: (DotRepr dg n, Show a)

=> GraphvizCommand

Which command to run

-> dg n

The DotRepr to use

-> GraphvizOutput

The GraphvizOutput type

-> (Handle -> IO a)

Extract the output

-> IO (Either String a)

The error or the result.

Run the chosen Graphviz command on this graph, but send the result to the given handle rather than to a file.

Note that the Handle -> IO a function must fully consume the input from the Handle; hGetContents' is a version of hGetContents that will ensure this happens.

If the command was unsuccessful, then Left error is returned.

Helper utilities.

hGetContents' :: Handle -> IO String

A version of hGetContents that fully evaluates the contents of the Handle (that is, until EOF is reached). The Handle is not closed.