Table of Contents

Pentaho ChartBeans

In this article, This article provides you with an introduction to the Pentaho ChartBeans ¹ project is introduced. Pentaho ChartBeans is a wrapper around existing "chart engines" (such as JFreeChart and Open Flash Chart). Wrapping these chart engines creates a single way of expressing charts.

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To eliminate confusion in documentation, the Pentaho ChartBeans project has documented its preferred charting terminology has been provided. In addition to standardizing on terms for the purpose of the Pentaho ChartBeans project, this terminology page provides an excellent introduction to charting in general. Please review this page before proceeding.

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The first design was based on JavaBeans and is the source from which the term "beans" derives. The proposal was for classes for each of the structural components of a chart (such as the plot, series, and title). We'll refer to this design This design will be referred to as the ChartModel API.

ChartDocument API

The second design was based on a Document Object Model (DOM). A chart DOM is an object model that consists of elements which can have attributes and child elements. Elements have an associated namespace. Core chart elements, like title and plot would go into the Pentaho ChartBeans namespace. Other, chart engine-specific elements would go into their own namespaces. For example, Open Flash Chart-specific properties would go into a "openflashchart" namespace, while JFreeChart-specific properties would go into a "jfreechart" namespace. We'll refer to this design This design will be referred to as the ChartDocument API.

Tale of Two APIs

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Example from a Java Developer Perspective

Let's use In this example Pentaho ChartBeans is used to render a standalone PNG image and an HTML page with an embedded Flash chart object.

Chart Data

In this example, we create a ChartTableModel consisting of 21 rows and 3 columns. In addition, we add The full source of this example is attached. It is a zipped Eclipse project called pentaho-chartbeans-demo. An included readme file instructs you how to run the example.

Chart Data

In this example, a ChartTableModel is created consisting of 21 rows and 3 columns. This example also adds some row and column metadata.

Code Block

	java
	java
title	createChartTableModel: Dummy Data


 
private static ChartTableModel createChartTableModel() {
    // 21 rows and 3 columns
    Object[][] dataArray = { 
                             {   5.55,  10.11,  20.22 }, 
                             {  30.33,  40.44,  50.55 }, 
                             {  31.33,  99.44, 150.55 },
        { 32.33, 1.44, 30.55 }, { 34                 {  32.33,   881.44, 77 30.55 }, { 35.33, 22.44, 54.55 }, { 36.33, 33.44, 52.55 }, 
                             { 37 34.33, 76 88.44, 54 77.55 }, { 38
                             {  35.33, 7 22.44,  5954.55 }, { 39
                             {  36.33, 48 33.44, 56.55 }, { 40.33, 19.44, 57.55 }, 52.55 },
                             {  37.33,  76.44,  54.55 }, 
                             {  38.33,   7.44,  59.55 }, 
                             {  39.33,  48.44,  56.55 }, 
                             {  40.33,  19.44,  57.55 },
                             {  50.33, 104.44,  36.55 }, 
                             {  60.33,  23.44,  74.55 }, 
                             {  20.33,  90.44,  80.55 }, 
                             {  60.33,  18.44,  27.55 },
                             {  10.33,  22.44,  97.55 }, 
                             {  20.33,  59.44,  55.55 }, 
                             { 50 90.33, 104140.44, 36 22.55 }, { 60.33, 23.44, 74.55 }, { 20
                             { 100.33, 90 56.44,  8076.55 }, { 60.33, 18.44, 27.55 },
                             { 10 40.33, 22 50.44,  9750.55 }, {
 20.33, 59.44, 55.55 }, { 90.33, 140.44, 22.55 }, { 100.33, 56.44, 76.55 },             { 40.33, 50.44, 50.55 }, {  60.66,  70.77,  80.88 } 
                           };

    ChartTableModel data = new ChartTableModel();
    data.setData(dataArray);

    // give names to the categories
    data.setColumnName(0, "budget");
    data.setColumnName(1, "sales");
    data.setColumnName(2, "forecast");

    // give names to the series
    final String ROW_NAME_KEY = "row-name";
    data.setRowMetadata(0, ROW_NAME_KEY, "1");
    data.setRowMetadata(1, ROW_NAME_KEY, "2");
    // ----- lines omitted -----
    data.setRowMetadata(20, ROW_NAME_KEY, "21");
    return data;
  }

Chart Structure

Here we add the This example adds 21 series to the plot which in turn gets added to the chart.

Code Block

	java
	java
title	createChartModel: Dummy Chart Structure


 
private static ChartModel createChartModel() {

    List<Series> seriesList = new ArrayList<Series>();
    Series series1 = new Series();
    series1.setForegroundColor(0x2D00FF);
    seriesList.add(series1);
    Series series2 = new Series();
    series2.setForegroundColor(0x11FFE4);
    seriesList.add(series2);

    // lines omitted

    Series series21 = new Series();
    series21.setForegroundColor(0x0596FF);
    seriesList.add(series21);

    CategoricalBarPlot plot = new CategoricalBarPlot();
    plot.setSeries(seriesList);
    plot.setOrientation(Orientation.HORIZONTAL);

    ChartModel chartModel = new ChartModel();
    chartModel.setTitle("Bar Chart Using Pentaho ChartBeans");
    chartModel.setPlot(plot);
    return chartModel;
  }

Chart Styling

For now, styling is included in the chart structure when using ChartModel API.

Generating Charts

Now let's pull all of the pieces can be pulled together. First we have there is a main method that "boots" Pentaho ChartBeans. This reads various configuration files and otherwise readies the system for chart processing requests. Next we render , one chart is rendered using the JFreeChart plugin for Pentaho ChartBeans and then we render another chart is rendered using the Open Flash Chart plugin for Pentaho ChartBeans. Note that both use the same ChartModel and ChartTableModel.

Code Block

	java
	java
title	main method


 
public static void main(String[] args) throws Exception {
    // "boot" ChartBeans
    ChartBoot.getInstance().start();

    // remove any output from previous runs
    cleanOutput();

    // render chart using JFreeChart plugin for Pentaho ChartBeans
    renderUsingJFreeChartPlugin(createChartModel(), createChartTableModel(), "chartoutput/Bar.png");

    // render same chart using Open Flash Chart plugin for Pentaho ChartBeans
    renderUsingOpenFlashChartPlugin(createChartModel(), createChartTableModel(), "chartoutput/Bar.html");
  }

See how we specify one specifies the plugin class in the first line?

Code Block

	java
	java
title	renderUsingJFreeChartPlugin method


 
private static void renderUsingJFreeChartPlugin(final ChartModel chartModel, final ChartTableModel chartTableModel,
      final String chartOutputFilename) throws Exception {
    final IChartPlugin plugin = ChartPluginFactory.getInstance("org.pentaho.chart.plugin.jfreechart.JFreeChartPlugin");
    ChartDocumentContext cdc = ChartFactory.generateChart(chartModel, chartTableModel);
    IOutput output = plugin.renderChartDocument(cdc, chartTableModel);
    OutputUtils.persistChart(output, chartOutputFilename, IOutput.OutputTypes.FILE_TYPE_PNG, 400/*px*/, 400/*px*/);
  }

The Open Flash Chart example is a little more complicated because we have to embed the chart data must be embedded in an HTML document. Whereas in the JFreeChart example, the bytes for the PNG image went to the chartOutputFilename, in this example, we write the Pentaho ChartBeans output is written to a String which contains the JSON that will configure the Open Flash Chart object when rendered by the browser.

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Code Block

	java
	java
title	renderUsingOpenFlashChartPlugin method

  private static void renderUsingOpenFlashChartPlugin(final ChartModel chartModel,
      final ChartTableModel chartTableModel, final String chartOutputFilename) throws Exception {
    final IChartPlugin plugin = ChartPluginFactory
        .getInstance("org.pentaho.chart.plugin.openflashchart.OpenFlashChartPlugin");

    ChartDocumentContext cdc = ChartFactory.generateChart(chartModel, chartTableModel);
    IOutput output = plugin.renderChartDocument(cdc, chartTableModel);

    ByteArrayOutputStream tmpOut = new ByteArrayOutputStream();
    output.persistChart(tmpOut, IOutput.OutputTypes.DATA_TYPE_STREAM, 400, 400);
    final String ENCODING = "UTF-8";
    ByteArrayInputStream in = new ByteArrayInputStream(tmpOut.toByteArray());
    IOUtils.closeQuietly(tmpOut);
    String openFlashChartJson = IOUtils.toString(in, ENCODING);
    IOUtils.closeQuietly(in);

    final String HTML_TEMPLATE = "<html>\n" + "  <head>\n"
        + "    <title>Bar Chart Using Open Flash Chart Plugin</title>\n"
        + "    <script type=\"text/javascript\">window.getChartData = function() '{' return ''{0}''; '}'</script>\n"
        + "  </head>\n" + "  <body>\n"
        + "    <object id=\"ofco00b1c87708fe11dea97da1e1ba5b86bc\" height=\"100%\" align=\"middle\" width=\"100%\" \n"
        + "    codebase=\"http://fpdownload.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=8,0,0,0\" \n"
        + "    classid=\"clsid:D27CDB6E-AE6D-11cf-96B8-444553540000\"> \n"
        + "    <param value=\"sameDomain\" name=\"allowScriptAccess\"/><param value=\"opaque\" name=\"wmode\"/> \n"
        + "    <param value=\"open-flash-chart.swf?get-data=getChartData\" name=\"movie\"/> \n"
        + "    <param value=\"high\" name=\"quality\"/><embed id=\"ofce00b1c87708fe11dea97da1e1ba5b86bc\" \n"
        + "    height=\"100%\" align=\"middle\" width=\"100%\" \n"
        + "    pluginspage=\"http://www.macromedia.com/go/getflashplayer\" type=\"application/x-shockwave-flash\" \n"
        + "    allowscriptaccess=\"sameDomain\" bgcolor=\"#FFFFFF\" quality=\"high\" wmode=\"opaque\" \n"
        + "    src=\"open-flash-chart.swf?get-data=getChartData\"/></object>\n" + "  </body>\n" + "</html>";

    String html = MessageFormat.format(HTML_TEMPLATE, new String[] { openFlashChartJson });
    FileUtils.writeStringToFile(new File(chartOutputFilename), html, "UTF-8");
  }

The full source of this example is attached. It is a zipped Eclipse project called pentaho-chartbeans-demo. An included readme file instructs you how to run the example.

Example from an End User Perspective

An end user is anyone who will be using the Pentaho BI Platform. Because the unit of work in the Pentaho BI Platform is the action sequence, we're going to show an example using an xaction is shown that queries using MQL to get the data and then renders a chart using Pentaho ChartBeans.

Note: The ChartComponent mentioned below is not complete! It is a work in progress and cannot be used as is. This example is for illustration only.

Chart Data

In this example, we're just going to query against example, a database is queried using an MQL query. See Generating Charts in this section.

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The ChartBeans XML document for this example is below. Its relatively brief because our the data and styling is separate from the chart structure. The elements in this document define a stylesheet reference, a chart title, the series, and the chart orientation.

Code Block

	xml
	xml
title	Bar.xml: The Chart Document

<chart xmlns="http://reporting.pentaho.org/namespaces/charting/1.0">

  <!-- external style sheet -->
  <stylesheet href="theme.css" />

  <!-- chart title -->
  <title>Bar Chart Using Pentaho ChartBeans</title>
     

  <!-- styling on individual series using style and class attributes -->
  <series style="-x-pentaho-chart-series-type: bar; -x-pentaho-chart-bar-style: bar;" class="series1" />
  <series class="series2" />
  <!-- lines omitted -->
  <series class="series18" />


   <!-- wrap colors because there are more series than colors in the theme -->
  <series class="series1" />
  <series class="series2" />
  <series class="series3" />

  <!-- styling on plot using style attribute -->
  <plot style="-x-pentaho-chart-orientation: horizontal"/>
</chart>

...

Here is the external style sheet referenced above. Here we're using class selectors are being used. Note the W3C standard color property as well as a custom Pentaho ChartBeans' -x-pentaho-chart-line-width property.

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Code Block

	xml
	xml
title	Pentaho Action Sequence (for use in the Pentaho BI Platform)

<?xml version="1.0" encoding="UTF-8"?>
<action-sequence> 
  <name>chartbeans_demo.xaction</name>
  <title>chartbeans_demo.xaction</title>
  <version>1</version>
  <logging-level>debug</logging-level>
  <documentation>
    <description>Generate a chart through ChartBeans from an MQL statement.</description> 
     <help>Pass in an MQL statement that returns a table of three columns. The first column is the series, the second is the category and the third is the data.</help>
    <result-type>rule</result-type>
    </documentation>

  <inputs>
    <query type="string"> 
      <sources> 
        <request>query</request>
       </sources>
      </query> 
    <chart-model type="string">
      <sources>
        <request>chart-model</request>
      </sources>
    </chart-model>
    <chart-width type="integer">
      <sources>
        <request>chart-width</request>
      </sources>
      <default-value>-1</default-value> 
    </chart-width>
    <chart-height type="integer">
      <sources>
        <request>chart-height</request>
      </sources>
      <default-value>-1</default-value>
    </chart-height>
    <series-column type="string">
      <sources>
        <request>series-column</request>
      </sources>
      <default-value/>
     </series-column>
    <category-column type="string">
      <sources>
        <request>category-column</request>
      </sources>
      <default-value/>
     </category-column>
    <value-column type="string">
      <sources>
        <request>value-column</request>
      </sources>
      <default-value/>
    </value-column>
  </inputs>

  <outputs>
    <outputstream type="content">
       <destinations>
         <response>content</response>
       </destinations>
     </outputstream>
   </outputs>

  <resources/>

  <actions> 
 

    <action-definition>
      <action-inputs>
        <query />
      </action-inputs>
      <action-outputs>
        <rule-result type="result-set" mapping="chartdata"/>
      </action-outputs>
      <component-name>MQLRelationalDataComponent</component-name>
      <action-type>rule</action-type>
      <component-definition>
        <live>true</live>
        <display-names>false</display-names>
      </component-definition>
    </action-definition>

    <action-definition>
      <component-name>org.pentaho.platform.engine.services.solution.PojoComponent</component-name>
      <action-inputs>
         <chart-model type="string"/>
        <chartdata type="result-set" />
        <chart-width type="integer"/>
        <chart-height type="integer"/>
        <series-column type="string"/>
        <category-column type="string"/>
        <value-column type="string"/>
      </action-inputs>
      <action-outputs>
        <outputstream/>
      </action-outputs>
      <component-definition>
         <class>org.pentaho.platform.plugin.action.chartbeans.ChartComponent</class>
       </component-definition>
      <action-name>Test the test POJO</action-name>  
      <logging-level>DEBUG</logging-level>
     </action-definition>
   

  </actions>

</action-sequence>

Results

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Panel

bgColor	#FFFFFF
title	Bar chart using JFreeChart plugin for Pentaho ChartBeans

Here is the result (in the form of a screenshot) using the Open Flash Chart plugin for Pentaho ChartBeans:

Panel

bgColor	#FFFFFF
title	Bar chart using Open Flash Chart plugin for Pentaho ChartBeans

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Status

ChartComponent (In Progress)

Access to Pentaho ChartBeans in the Pentaho BI Platform is provided by the Pentaho ChartBeans ChartComponent. You can use ChartComponent in your action sequences to generate charts. Documentation on Pentaho ChartBeans ChartComponent is currently in progress.

CDF Widget (Planned)

A Community Dashboard Framework (CDF) widget is planned. This will allow the dashboard to render a Pentaho ChartBeans chart.

Contributing

SVN locations appear at the bottom of this document. Building the project projects follows the Pentaho Common Build. Run ant -projecthelp for a list of the most common targets.

To discuss Pentaho ChartBeans, please post in the Pentaho Forums. Use the BI Server and Platform forum.

To create defect reports, improvement requests please use Pentaho JIRA. Use the Pentaho BI Server project and the ChartBeans component when creating JIRA cases.

Related Items

Pentaho ChartBeans Developer Documentation ²
JFreeChart
Open Flash Chart
Pentaho ChartBeans Subversion repository: svn://source.pentaho.org/svnroot/pentaho-commons/pentaho-chartbeans/trunk
Pentaho ChartBeans ChartComponent Subversion repository: svn://source.pentaho.org/svnroot/bi-platform-v2/trunk/bi-platform-plugin-actions

¹ Pentaho ChartBeans name is subject to change.
² Be very careful when wading through the Pentaho ChartBeans developer documentation. It was created while Pentaho ChartBeans was being architected and therefore could have inaccurate information. We Pentaho developers are in the process of bringing it up to date to reflect the current code.

Versions Compared

Old Version 25

New Version Current

Key

Pentaho ChartBeans

ChartDocument API

Tale of Two APIs

Example from a Java Developer Perspective

Chart Data

Chart Data

Chart Structure

Chart Styling

Generating Charts

Example from an End User Perspective

Chart Data

Results

Status

ChartComponent (In Progress)

CDF Widget (Planned)

Contributing

Related Items

Page Comparison

Versions Compared

Old Version 25

New Version Current

Key

Pentaho ChartBeans

ChartDocument API

Tale of Two APIs

Example from a Java Developer Perspective

Chart Data

Chart Data

Chart Structure

Chart Styling

Generating Charts

Example from an End User Perspective

Chart Data

Results

Status

ChartComponent (In Progress)

CDF Widget (Planned)

Contributing

Related Items