Gauge Plugin

Introduction

This plugin can be used to build dashboards that contain graphical image gauges or non-graphical gauges like (target measure gauge) and (trend icons).

Two types of gauges are currently available, a target measure bar and a trend icon.

Type of Gauge	Name	What it Does	Example
Target Measure Bar	tambar	Shows the actual state of a measure in a bar. The bar has two parts, the upper thick bar shows the actual value, the lower thin bar shows the scale of the gauge. For example regions with a relative distribution of bad (red), acceptable (yellow) and good (green) values
	simple	This is identical to tambar with the exception that instead of creating a graphic it uses the HTML <table> tag to create the measure bar.
Trend Icon	trend	Shows the up trend, no change and down trend of a measure

The Target Measure Bar has scale regions (the lower thin bar) like red, yellow and green. Each region has a start and end boundary, the end boundary of one region is the start of the next. The scale determines the boundaries, e.g. a scale of 0, 10, 20, 40 has a red region with range 0...10, a yellow one with range 10...20 and a green one with range 20...40.

The upper value region (the thick bar) has two colors, a dark color used for actual value and a light color for filling out the rest of the gauge with a lighter color.

The %GAUGE{...}% variable gets expanded to either an image representing the gauge or HTML <table> representing the gauge. Parameters and global settings determine the type of gauge, dimensions, scale and values.

GaugePlugin Global Settings

Plugin settings are stored as preferences variables. To reference a plugin setting write %<plugin>_<setting>%, for example, %INTERWIKIPLUGIN_SHORTDESCRIPTION%

• One line description, shown in the TextFormattingRules topic:
  • Set SHORTDESCRIPTION = Create gauges (graphical or not), typically used for dashboards

• Set DEBUG to 1 to get debug messages in data/debug.txt. Default: 0
  • Set DEBUG = 0

• Default gauge used. Possible values are: tambar, simple, or trend. Default: tambar
  • Set TYPE = tambar

• Default way to access gauge data: inline or file.
  inline means the gauge image data is accessed via <img src="data:image/png;base64,<base64_data>" />
  file means the gauge image data is accessed from a created file.
  Caution should be used since depending on the age of browsers, there might be a max length limit to inline data or no support at all for inline images (i.e. IE7 and earlier don't support inline images). No limit is imposed in this plugin leaving this up to users to keep track of.
  • Set TAMBAR_ACCESS = file

• Default dimensions, scale and colors for Target Measure Bar. See details in the syntax rules.
  • Set TAMBAR_WIDTH = 60
  • Set TAMBAR_HEIGHT = 16
  • Set TAMBAR_SCALE = 0, 33, 67, 100
  • Set TAMBAR_COLORS = #FF0000, #FFCCCC, #FFFF00, #FFFFCC, #00FF00, #CCFFCC
  • Set TAMBAR_SCALE_HEIGHT_PERCENTAGE = 20

• Default dimensions for Trend Icon
  • Set TREND_WIDTH = 16
  • Set TREND_HEIGHT = 16

Syntax Rules

The %GAUGE{...}% variable gets expanded to either an image representing the gauge or HTML <table> representing the gauge.

Examples

Type of gauge	You type	You should get...	...if installed
Target Measure Bar (tambar)	%GAUGE{type="tambar" name="tambarTest1" scale="0, 10, 20, 40" value="27"}%
Target Measure Bar (simple)	%GAUGE{type="simple" name="simpleTest1" scale="0, 10, 20, 40" value="27"}%
Trend Icon	%GAUGE{type="trend" name="trendTest1" value="-3"}%

The "if installed" column shows images instead of variables in case the plugin is installed correctly.

Output

• For tambar and trend
  • access="file"
    • A PNG graphics file is created containing the gauge results. The file is placed in %PUBURLPATH%/%WEB%/%TOPIC%/_GaugePlugin_<type>_<name>.png
    • %GAUGE{...}% gets expanded to an <img ... /> image tag.
  • access="inline"
    • No image file is created, instead the image is sent inline in base64 format. %GAUGE{...}% gets expanded to an inline <img ... /> image tag like:
      • <img src="data:image/png;base64,<base64_data>" />
• For simple
  • An HTML <table> is used to create the requested gauge. No file is created.

Error Handling

If the required parameters are not defined, then an error message is returned. If tambar, then the error might be returned in an <img ... /> image or as plan text. If simple, then the error will be returned inside of a <table%gt;.

Plugin Installation Instructions

Note: You do not need to install anything on your browser to use this plugin. The following instructions are for the administrator who installs the plugin on the server where TWiki is running.

• Download the ZIP file from the Plugin web (see below)
• Unzip GaugePlugin.zip in your twiki installation directory. Content:

  File:	Description:
  lib/TWiki/Plugins/GaugePlugin.pm	Plugin Perl module
  data/TWiki/GaugePlugin.txt	Plugin topic
  data/TWiki/GaugePluginTests.txt	Test page containing many examples of the GaugePlugin in action. Also shows various error conditions
  data/TWiki/VarGAUGE.txt	Variable documentation topic
  pub/TWiki/GaugePlugin/tambar1.gif	Sample tambar image
  pub/TWiki/GaugePlugin/trenddn.gif	trend down arrow
  pub/TWiki/GaugePlugin/trendeq.gif	trend no change arrow
  pub/TWiki/GaugePlugin/trendup.gif	trend up arrow
  pub/TWiki/GaugePlugin/trendnd.gif	trend error message if value is not specified

• TWiki 4 and up: Visit configure in your TWiki installation, and enable the plugin in the {Plugins} section.
• Test if the plugin is correctly installed:
  • Check above examples if the "if installed" column shows images instead of variables.
  • Check GaugePluginTests for some more test

Plugin Info

Plugin Author:	TWiki:Main.PeterThoeny, TWiki:Main.TaitCyrus
Copyright:	© 2002-2011, TWiki:Main.PeterThoeny; © 2008-2011, TWiki:TWiki.TWikiContributor
License:	GPL (GNU General Public License)
Plugin Version:	2011-07-10
Change History:
2011-07-10:	TWikibug:Item6725: Change global package variables from "use vars" to "our" -- TWiki:Main.PeterThoeny
2011-05-20:	TWikibug:Item6726 - Add new type="simple" which creates a gauge only using HTML <table> instead of creating a PNG image. This allows this plugin to be run without having to install the gd library TWikibug:Item6728 - Add new option of access which defaults to file, but allows access="inline" to embed the image in HTML (no image needs to be created). TWikibug:Item6729 - Fix bug with umask not getting reset after use. -- TWiki:Main/TaitCyrus
2011-05-13:	TWikibug:Item6722 - Add ability to control scale height (from 0% to 100% of the gauge) TWikibug:Item6723 - Fix data parsing issues that limited the use of very small values (like 0.01) -- TWiki:Main/TaitCyrus
2010-05-06:	TWikibug:Item6433 - Doc fixes -- TWiki:Main/PeterThoeny
2010-05-05:	TWikibug:Item6419 - Validate and untaint input values -- TWiki:Main/PeterThoeny
2010-04-08:	TWikibug:Item6420 - Added VarGAUGE variable documentation page; other doc improvements -- TWiki:Main/PeterThoeny
01 May 2003:	Added time stamp to image to prevent browser from caching images; ignore non-numerical chars in value parameter; fixed warnings (V1.002)
08 Sep 2002:	Added missing binmode (for Windows); pass parameters also to error image (V1.001)
23 May 2002:	Initial version (V1.0)
16 May 2002:	Initial spec (V1.0)
Dependencies:	(optional) gd graphics library, http://www.libgd.org/ libpng PNG graphics library, http://www.libpng.org/pub/png/libpng.html
CPAN Dependencies	(optional) CPAN:GD, CPAN:POSIX, MIME::Base64
Perl Version:	5.005
Plugin Home:	http://TWiki.org/cgi-bin/view/Plugins/GaugePlugin
Feedback:	http://TWiki.org/cgi-bin/view/Plugins/GaugePluginDev

Related Topics: VarGAUGE, TWikiPreferences, TWikiPlugins