Java Reference
In-Depth Information
Group
: The chart expression is evaluated when the group specified by
evaluationGroup
changes.
Now
: The chart expression is evaluated when its containing band is filled. This
is the default value for this attribute.
Page
: The chart expression is evaluated when rendering all other elements in
the same page is finished.
Report
: The chart expression is evaluated when rendering all other elements
in the report is finished.
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isShowLegend
This attribute is used to determine if a chart legend will be displayed on the report.
The valid values for this attribute are listed below:
true
: A legend will be displayed on the report. This is the default value.
false
: A legend will not be displayed on the report.
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Chart Customization
JasperReports uses
JFreeChart
as the underlying charting library.
JFreeChart
contains features not directly supported by JasperReports. By supplying a
customizer class via the
customizerClass
attribute, we can take advantage of
JFreeChart
features.
All customizer classes must implement
net.sf.jasperreports.engine.
JRChartCustomizer
. This interface contains a single method. The method signature is:
customize(org.jfree.chart.JFreeChart
chart
,
JRChart jasperChart)
org.jfree.chart.JFreeChart
is
JFreeChart
is representation of a
chart
;
JRChart
is JasperReports representation of a
jasperChart
. Since the
customize()
method is
automatically called by JasperReports when filling a report, we don't need to worry
about instantiating and initializing instances of these classes.
Chart customization is more of a
JFreeChart
feature rather than a JasperReports
feature. Therefore, an example has not been shown.
More information about
JFreeChart
can be found at
http://www.jfree.org/
jfreechart/
.
The JRXML
<chart>
element contains some attributes used to support bookmarks
and hyperlinks. These attributes are discussed in detail in Chapter 8.
