Last year's start and end dates

form.xml

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         fr:data-format-version="4.0.0">
    <xh:head>
        <xh:title>Last year's start and end dates</xh:title>
        <xf:model id="fr-form-model" xxf:expose-xpath-types="true" xxf:analysis.calculate="true">

            
            <xf:instance id="fr-form-instance" xxf:exclude-result-prefixes="#all" xxf:index="id">
                <form>
                    <section-1>
                        <grid-1>
                            <date/>
                            <control-1/>
                            <control-2/>
                        </grid-1>
                        
                    </section-1>
                </form>
            </xf:instance>

            
            <xf:bind id="fr-form-binds" ref="instance('fr-form-instance')">
                <xf:bind id="section-1-bind" name="section-1" ref="section-1">
                    <xf:bind id="grid-1-bind" ref="grid-1" name="grid-1">
                        <xf:bind id="date-bind" ref="date" name="date" type="xf:date"
                                 xxf:default="current-date()"/>
                        <xf:bind id="control-1-bind" ref="control-1" name="control-1" type="xf:date"
                                 calculate="concat(year-from-date($date) - 1, '-01-01')"
                                 readonly="false()"/>
                        <xf:bind id="control-2-bind" ref="control-2" name="control-2" type="xf:date"
                                 calculate="concat(year-from-date($date) - 1, '-12-31')"
                                 readonly="false()"/>
                    </xf:bind>
                    
                </xf:bind>
            </xf:bind>

            
            <xf:instance id="fr-form-metadata" xxf:readonly="true" xxf:exclude-result-prefixes="#all">
                <metadata>
                    <application-name>a</application-name>
                    <form-name>a</form-name>
                    <title xml:lang="en">Last year's start and end dates</title>
                    <description xml:lang="en"/>
                    <created-with-version>2020.1-SNAPSHOT PE</created-with-version>
                    <updated-with-version>2020.1-SNAPSHOT PE</updated-with-version>
                    <library-versions>
                        <app>2</app>
                    </library-versions>
                </metadata>
            </xf:instance>

            
            <xf:instance id="fr-form-attachments" xxf:exclude-result-prefixes="#all">
                <attachments/>
            </xf:instance>

            
            <xf:instance xxf:readonly="true" id="fr-form-resources" xxf:exclude-result-prefixes="#all">
                <resources>
                    <resource xml:lang="en">
                        <date>
                            <label>Date</label>
                            <hint/>
                        </date>
                        <control-1>
                            <label>Previous year start</label>
                            <hint/>
                        </control-1>
                        <control-2>
                            <label>Previous year end</label>
                            <hint/>
                        </control-2>
                        <section-1>
                            <label>Untitled Section</label>
                        </section-1>
                        
                    </resource>
                </resources>
            </xf:instance>

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                <fr:section id="section-1-section" bind="section-1-bind">
                    <xf:label ref="$form-resources/section-1/label"/>
                    <fr:grid id="grid-1-grid" bind="grid-1-bind">
                        <fr:c y="1" x="1" w="3">
                            <fr:date xmlns:xxbl="http://orbeon.org/oxf/xml/xbl"
                                     xmlns:DateSupport="java:org.orbeon.xbl.DateSupportJava"
                                     id="date-control"
                                     bind="date-bind">
                                <xf:label ref="$form-resources/date/label"/>
                                <xf:hint ref="$form-resources/date/hint"/>
                                <xf:alert ref="$fr-resources/detail/labels/alert"/>
                        
                        
                            </fr:date>
                                
                            </fr:c>
                        <fr:c y="1" x="4" w="9"/>
                        <fr:c x="1" y="2" w="3">
                            <fr:date xmlns:xxbl="http://orbeon.org/oxf/xml/xbl"
                                     xmlns:DateSupport="java:org.orbeon.xbl.DateSupportJava"
                                     id="control-1-control"
                                     bind="control-1-bind">
                                <xf:label ref="$form-resources/control-1/label"/>
                                <xf:hint ref="$form-resources/control-1/hint"/>
                                <xf:alert ref="$fr-resources/detail/labels/alert"/>
                        
                        
                            </fr:date>
                        </fr:c>
                        <fr:c x="4" y="2" w="3">
                            <fr:date xmlns:xxbl="http://orbeon.org/oxf/xml/xbl"
                                     xmlns:DateSupport="java:org.orbeon.xbl.DateSupportJava"
                                     id="control-2-control"
                                     bind="control-2-bind">
                                <xf:label ref="$form-resources/control-2/label"/>
                                <xf:hint ref="$form-resources/control-2/hint"/>
                                <xf:alert ref="$fr-resources/detail/labels/alert"/>
                        
                        
                            </fr:date>
                        </fr:c>
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