R – Problem with auto page break in iReport

I have found the solution. I created 3 detail bands and put one subreport per detail band! It worked fine!

Place your sub-report field in the any other band other than detail band and add whenNoDataType="AllSectionsNoDetail" to your xml file.
Add it among the other report properties in <JasperReport> tag.
You can also add using the GUI Designer.
Open your sub report and in the properties editor, at the end of the options you will find
When No Data option. Select All Sections with No Detail from the list of available options.


Mainreport :

<?xml version="1.0" encoding="UTF-8"?>
<jasperReport xmlns="http://jasperreports.sourceforge.net/jasperreports" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports http://jasperreports.sourceforge.net/xsd/jasperreport.xsd" name="report1" pageWidth="595" pageHeight="842" columnWidth="555" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20">
<property name="ireport.zoom" value="1.0"/>
<property name="ireport.x" value="0"/>
<property name="ireport.y" value="12"/>
<parameter name="SUBREPORT_DIR" class="java.lang.String" isForPrompting="false">
    <defaultValueExpression><![CDATA["/home/qualian/Desktop/gopi/prjreport/"]]></defaultValueExpression>
</parameter>
<queryString>
    <![CDATA[]]>
</queryString>
<background>
    <band splitType="Stretch"/>
</background>
<title>
    <band height="79" splitType="Stretch"/>
</title>
<pageHeader>
    <band height="35" splitType="Stretch"/>
</pageHeader>
<columnHeader>
    <band height="61" splitType="Stretch"/>
</columnHeader>
<detail>
    <band height="125" splitType="Stretch">
        <subreport>
            <reportElement x="33" y="56" width="208" height="36"/>
            <connectionExpression><![CDATA[$P{REPORT_CONNECTION}]]></connectionExpression>
            <subreportExpression class="java.lang.String"><![CDATA[$P{SUBREPORT_DIR}+"report3_subreport1.jasper"]]></subreportExpression>
        </subreport>
        <staticText>
            <reportElement x="33" y="15" width="100" height="20"/>
            <textElement/>
            <text><![CDATA[Main Report]]></text>
        </staticText>
    </band>
</detail>
<columnFooter>
    <band height="45" splitType="Stretch"/>
</columnFooter>
<pageFooter>
    <band height="54" splitType="Stretch"/>
</pageFooter>
<summary>
    <band height="42" splitType="Stretch"/>
</summary>

Sub report:

<?xml version="1.0" encoding="UTF-8"?>
<jasperReport xmlns="http://jasperreports.sourceforge.net/jasperreports" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports http://jasperreports.sourceforge.net/xsd/jasperreport.xsd" name="report1_subreport3" language="groovy" pageWidth="555" pageHeight="802" whenNoDataType="AllSectionsNoDetail" columnWidth="555" leftMargin="0" rightMargin="0" topMargin="0" bottomMargin="0">
<property name="ireport.zoom" value="1.0"/>
<property name="ireport.x" value="0"/>
<property name="ireport.y" value="0"/>
<background>
    <band splitType="Stretch"/>
</background>
<columnHeader>
    <band height="40" splitType="Stretch">
        <staticText>
            <reportElement x="107" y="12" width="100" height="20"/>
            <textElement/>
            <text><![CDATA[Sub Report]]></text>
        </staticText>
    </band>
</columnHeader>

This worked like a charm. Hope this helps.