Mediawiki/Erweiterung/Gnuplot

Die Mediawiki-Erweiterung Gnuplot (auch: GNUPlot) erlaubt die Erzeugung und Anzeige von grafischen Darstellungen. Dabei wird das Programm Gnuplot verwendet.

Installation

1. Voraussetzung ist die Installation des Pakets "gnuplot".

# apt-get install gnuplot

2. Anlegen der Datei "extensions/Gnuplot.php" und Einfügen des folgenden PHP-Codes (Stand: 8. Februar 2009).

<?php /** * Parser hook extension adds a <gnuplot> tag and <dataset> tag to wiki markup for rendering gnuplot plots! * * * Usage is something like this: * <gnuplot> * set title "Text" * set yrange [0:60] * set xtics (0,1,2,3,4,5,6,7,8,9,10) * set xrange [0:10] * plot <dataset>0 1 * 2 10 * 3 15 * </dataset> using 1:2 title "Burndown" with lines * </gnuplot> * * Options should be heroicly wide open.. if you can wrap your head around all the possibilities listed in the * gnuplot documentation. * **/ // Make sure we are being called properly if( !defined( 'MEDIAWIKI' ) ) { echo(" This file is an extension to the MediaWiki software and cannot be used standalone.\n" ); die( -1 ); } $wgExtensionFunctions[] = "wfGnuplotExtension"; /** * You should refer to the gnuplot documentation for the different output types * Honestly, only image types will work without some other changes */ $image_format = "png"; $gnuplot_path = "/usr/bin/gnuplot"; /** * The function links its methods as * hooks for the Parser */ function wfGnuplotExtension() { global $wgParser; # register the extension with the WikiText parser # the first parameter is the name of the new tag. # the second parameter is the callback function for # processing the text between the tags $wgParser->setHook( "dataset", "saveDATA" ); $wgParser->setHook( "gnuplot", "renderPLOT" ); } /** * This method setups up the output of the plot script, which * has a few things that we dont want to repeat EVERYTIME someone * wants to make a graph * * @param String $plot_source - we have to have the full source to wrap * @param String $output_filename - we have to tell gnuplot where to output the graph * @return the script with output stuff wrapped in it */ function wrap_script($plot_source, $output_filename) { global $image_format; $something = "set terminal ".$image_format."\n"; $something .= "set output \"".$output_filename."\"\n"; $something .= $plot_source; return $something; } /** * Caches the command script and calls the gnuplot executable to render the * graph image * * @param String $plot_script * @return Nothing.. we assume this all goes correctly. */ function renderGnuPlot(&$plot_script) { global $wgMathDirectory, $wgMathPath, $wgTmpDirectory, $image_format, $gnuplot_path; // hash our script $script_hash = md5($plot_script); // make the output of the command be in the math directory $filename = $wgMathDirectory."/plot-".$script_hash.".".$image_format; //fill in the extras our consumer doesn't care about $full_plot_script = wrap_script($plot_script,$filename); $current_dir = getcwd(); chdir($wgTmpDirectory); // create temporary file for the plot script $winPath = $wgTmpDirectory."/".$script_hash.".plot"; $fp = fopen($winPath,"a+"); $w= fputs($fp,$full_plot_script); fclose($fp); // run gnuplot to create our file $command = $gnuplot_path." ".$script_hash.".plot "; //I had a problem with the status code always being false. so, stopped using it $status_code = exec($command); //delete the plot file unlink($wgTmpDirectory."/".$script_hash.".plot"); chdir($current_dir); } /** * Determins if a graph file has already been rendered * if not, calls to render one and returns the root host url to the image. * * @param String $plot_script * @return images/math/plot-.... file reference for the image tag */ function getPlotImageURL($plot_script) { global $wgMathDirectory, $wgMathPath, $image_format; //unique our script $formula_hash = md5($plot_script); $filename = 'plot-' . $formula_hash.".".$image_format; $full_path_filename = $wgMathDirectory."/".$filename; if (is_file($full_path_filename)) { //nothing to do //we've already made this image before } else { renderGnuPlot($plot_script); } return $wgMathPath."/".$filename; } /** * The callback function for converting the input text to HTML output * * @param String $input * @param Array<String> $argv * @param Parser $parser * @return HTML image tag to the graph itself */ function renderPLOT( &$input, $argv, &$parser ) { //get our parser to finish up its parse and recover the real data-set data (the UNIQ QINU problem) $input = $parser->recursiveTagParse( $input ); $input = $parser->mStripState->unstripBoth($input); $url = getPlotImageURL($input); return "<img src='$url'>"; } /** * This method takes in the raw tuple input of the dataset, and any arguments, and saves it to a random * file on the system. The return is the absolute path to the data file, so that it can be * embedded into the plot command. * * @param String $input * @param Array<String> $argv * @param Parser $parser * @return unknown */ function saveDATA( $input, $argv, &$parser){ global $wgMathDirectory, $wgMathPath, $wgTmpDirectory; //make a temp filename with a hash of the input $filename = md5($input); //we dont wanna create toooo many of these guys either if (!is_file($wgTmpDirectory."/".$filename.".dat")) { //know where we are $current_dir = getcwd(); //than change it chdir($wgTmpDirectory); // saving this data set as a temporary RANDOM file $winPath = $wgTmpDirectory."/".$filename.".dat"; $fp = fopen($winPath,"a+"); $w=fputs($fp,$input); fclose($fp); chdir($current_dir); } return "\"".$wgTmpDirectory."/".$filename.".dat\""; } ?>

3. Anpassung der Rechte.

# chown wiki:wiki extensions/gnuplot.php

4. Pfad zu Gnuplot in der Datei "extensions/gnuplot.php" anpassen.

$gnuplot_path   = "/usr/bin/gnuplot";

5. Einfügen der folgenden Zeile in die Datei "LocalSettings.php".

## Extension: Gnuplot
require_once('extensions/gnuplot.php');

Die Standardeinstellungen in der Datei "gnuplot.php" sind die folgenden.

set terminal png color
set size 0.5,0.5

Passendere Einstellungen sind z. B.

set terminal png color
set size 1.5,1.0

Weblinks

• Extension:Gnuplot (Mediawiki.org) - auch bekannt als "Gnuplot-2"

• Gnuplot homepage (Gnuplot.info)
• Gnuplot
• Grundkurs Gnuplot
• Gnuplot (meta.Wikimedia.org)