ChartDirector 6.0 (Ruby Edition)

Percentage Bar Chart




This example demonstrates creating a percentage bar chart with a legend box. It also demonstrates gradient background color, rounded frame, soft drop shadow, and using CDML to include custom icons in the legend box.

A percentage bar chart is like a stacked bar chart, except the bars are individually scaled so that they stacked up to 100.

The key features demonstrated in this example are:

Note that by default, the data label format is {percent}% (showing the percentage) for a percentage bar layer, as opposed to {value} (showing the data value) for other types of bar layer. The data label format can be modified using Layer.setDataLabelFormat.

Source Code Listing

[Ruby On Rails Version - Controller] app/controllers/percentbar_controller.rb
require("chartdirector")

class PercentbarController < ApplicationController

    def index()
        @title = "Percentage Bar Chart"
        @ctrl_file = File.expand_path(__FILE__)
        @noOfCharts = 1
        render :template => "templates/chartview"
    end

    #
    # Render and deliver the chart
    #
    def getchart()
        # The data for the bar chart
        data0 = [100, 125, 245, 147, 67]
        data1 = [85, 156, 179, 211, 123]
        data2 = [97, 87, 56, 267, 157]

        # The labels for the bar chart
        labels = ["Mon", "Tue", "Wed", "Thu", "Fri"]

        # Create a XYChart object of size 500 x 320 pixels. Use a vertical gradient color from pale
        # blue (e8f0f8) to sky blue (aaccff) spanning half the chart height as background. Set
        # border to blue (88aaee). Use rounded corners. Enable soft drop shadow.
        c = ChartDirector::XYChart.new(500, 320)
        c.setBackground(c.linearGradientColor(0, 0, 0, c.getHeight() / 2, 0xe8f0f8, 0xaaccff),
            0x88aaee)
        c.setRoundedFrame()
        c.setDropShadow()

        # Set directory for loading images to current script directory
        c.setSearchPath(File.dirname(__FILE__))

        # Add a title to the chart using 15 points Arial Italic. Set top/bottom margins to 15
        # pixels.
        title = c.addTitle("Weekly Product Sales", "ariali.ttf", 15)
        title.setMargin2(0, 0, 15, 15)

        # Tentatively set the plotarea to 50 pixels from the left edge, and to just under the title.
        # Set the width to 60% of the chart width, and the height to 50 pixels from the bottom edge.
        # Use pale blue (e8f0f8) background, transparent border, and grey (aaaaaa) grid lines.
        c.setPlotArea(50, title.getHeight(), c.getWidth() * 6 / 10, c.getHeight() - title.getHeight(
            ) - 50, 0xe8f0f8, -1, ChartDirector::Transparent, 0xaaaaaa)

        # Add a legend box where the top-right corner is anchored at 10 pixels from the right edge,
        # and just under the title. Use vertical layout and 8 points Arial font.
        legendBox = c.addLegend(c.getWidth() - 10, title.getHeight(), true, "arial.ttf", 8)
        legendBox.setAlignment(ChartDirector::TopRight)

        # Set the legend box background and border to transparent
        legendBox.setBackground(ChartDirector::Transparent, ChartDirector::Transparent)

        # Set the legend box icon size to 16 x 32 pixels to match with custom icon size
        legendBox.setKeySize(16, 32)

        # Set axes to transparent
        c.xAxis().setColors(ChartDirector::Transparent)
        c.yAxis().setColors(ChartDirector::Transparent)

        # Set the labels on the x axis
        c.xAxis().setLabels(labels)

        # Add a percentage bar layer
        layer = c.addBarLayer2(ChartDirector::Percentage)

        # Add the three data sets to the bar layer, using icons images with labels as data set names
        layer.addDataSet(data0, 0x66aaee,
            "<*block,valign=absmiddle*><*img=service.png*> Service<*/*>")
        layer.addDataSet(data1, 0xeebb22,
            "<*block,valign=absmiddle*><*img=software.png*> Software<*/*>")
        layer.addDataSet(data2, 0xcc88ff,
            "<*block,valign=absmiddle*><*img=computer.png*> Hardware<*/*>")

        # Use soft lighting effect with light direction from top
        layer.setBorderColor(ChartDirector::Transparent, ChartDirector::softLighting(
            ChartDirector::Top))

        # Enable data label at the middle of the the bar
        layer.setDataLabelStyle().setAlignment(ChartDirector::Center)

        # For a vertical stacked chart with positive data only, the last data set is always on top.
        # However, in a vertical legend box, the last data set is at the bottom. This can be
        # reversed by using the setLegend method.
        layer.setLegend(ChartDirector::ReverseLegend)

        # Adjust the plot area size, such that the bounding box (inclusive of axes) is 15 pixels
        # from the left edge, just below the title, 10 pixels to the right of the legend box, and 15
        # pixels from the bottom edge.
        c.packPlotArea(15, title.getHeight(), c.layoutLegend().getLeftX() - 10, c.getHeight() - 15)

        # Output the chart
        send_data(c.makeChart2(ChartDirector::PNG), :type => "image/png", :disposition => "inline")

    end

end

[Ruby On Rails Version - View] app/views/templates/chartview.html.erb
<html>
<body style="margin:5px 0px 0px 5px">

<!-- Title -->
<div style="font-size:18pt; font-family:verdana; font-weight:bold">
    <%= @title %>
</div>
<hr style="border:solid 1px #000080" />

<!-- Source Code Listing Link -->
<div style="font-size:9pt; font-family:verdana; margin-bottom:1.5em">
    <%= link_to "Source Code Listing", 
        :controller => "cddemo", :action => "viewsource",
        :ctrl_file => @ctrl_file, :view_file => File.expand_path(__FILE__) %>
</div>

<!-- Create one or more IMG tags to display the demo chart(s) -->
<% 0.upto(@noOfCharts - 1) do |i| %>
    <img src="<%= url_for(:action => "getchart", :img => i) %>">
<% end %>

</body>
</html>

[Command Line Version] rubydemo/percentbar.rb
#!/usr/bin/env ruby
require("chartdirector")

# The data for the bar chart
data0 = [100, 125, 245, 147, 67]
data1 = [85, 156, 179, 211, 123]
data2 = [97, 87, 56, 267, 157]

# The labels for the bar chart
labels = ["Mon", "Tue", "Wed", "Thu", "Fri"]

# Create a XYChart object of size 500 x 320 pixels. Use a vertical gradient color from pale blue
# (e8f0f8) to sky blue (aaccff) spanning half the chart height as background. Set border to blue
# (88aaee). Use rounded corners. Enable soft drop shadow.
c = ChartDirector::XYChart.new(500, 320)
c.setBackground(c.linearGradientColor(0, 0, 0, c.getHeight() / 2, 0xe8f0f8, 0xaaccff), 0x88aaee)
c.setRoundedFrame()
c.setDropShadow()

# Add a title to the chart using 15 points Arial Italic. Set top/bottom margins to 15 pixels.
title = c.addTitle("Weekly Product Sales", "ariali.ttf", 15)
title.setMargin2(0, 0, 15, 15)

# Tentatively set the plotarea to 50 pixels from the left edge, and to just under the title. Set the
# width to 60% of the chart width, and the height to 50 pixels from the bottom edge. Use pale blue
# (e8f0f8) background, transparent border, and grey (aaaaaa) grid lines.
c.setPlotArea(50, title.getHeight(), c.getWidth() * 6 / 10, c.getHeight() - title.getHeight() - 50,
    0xe8f0f8, -1, ChartDirector::Transparent, 0xaaaaaa)

# Add a legend box where the top-right corner is anchored at 10 pixels from the right edge, and just
# under the title. Use vertical layout and 8 points Arial font.
legendBox = c.addLegend(c.getWidth() - 10, title.getHeight(), true, "arial.ttf", 8)
legendBox.setAlignment(ChartDirector::TopRight)

# Set the legend box background and border to transparent
legendBox.setBackground(ChartDirector::Transparent, ChartDirector::Transparent)

# Set the legend box icon size to 16 x 32 pixels to match with custom icon size
legendBox.setKeySize(16, 32)

# Set axes to transparent
c.xAxis().setColors(ChartDirector::Transparent)
c.yAxis().setColors(ChartDirector::Transparent)

# Set the labels on the x axis
c.xAxis().setLabels(labels)

# Add a percentage bar layer
layer = c.addBarLayer2(ChartDirector::Percentage)

# Add the three data sets to the bar layer, using icons images with labels as data set names
layer.addDataSet(data0, 0x66aaee, "<*block,valign=absmiddle*><*img=service.png*> Service<*/*>")
layer.addDataSet(data1, 0xeebb22, "<*block,valign=absmiddle*><*img=software.png*> Software<*/*>")
layer.addDataSet(data2, 0xcc88ff, "<*block,valign=absmiddle*><*img=computer.png*> Hardware<*/*>")

# Use soft lighting effect with light direction from top
layer.setBorderColor(ChartDirector::Transparent, ChartDirector::softLighting(ChartDirector::Top))

# Enable data label at the middle of the the bar
layer.setDataLabelStyle().setAlignment(ChartDirector::Center)

# For a vertical stacked chart with positive data only, the last data set is always on top. However,
# in a vertical legend box, the last data set is at the bottom. This can be reversed by using the
# setLegend method.
layer.setLegend(ChartDirector::ReverseLegend)

# Adjust the plot area size, such that the bounding box (inclusive of axes) is 15 pixels from the
# left edge, just below the title, 10 pixels to the right of the legend box, and 15 pixels from the
# bottom edge.
c.packPlotArea(15, title.getHeight(), c.layoutLegend().getLeftX() - 10, c.getHeight() - 15)

# Output the chart
c.makeChart("percentbar.png")