XForms

<div class="control-group">
        <div class="control-label">What is your date of birth? (DD/MM/YYYY)</div>
        <div>
          <div class="pull-left mtop">
            <xf:select1 bind="P_DateOfBirth_Day">
              {
              for $i in 1 to 31 
              let $v := if ($i < 10) then "0" || $i else $i
              return
              <xf:item>
                <xf:value>{$v}</xf:value><xf:label>{$i}</xf:label>
              </xf:item>
              }
              
              
              
              <xf:action 
                ev:event="xforms-value-changed" 
                if="instance('extra')/Day/text() != '' and instance('extra')/Month/text() != '' and instance('extra')/Year/text() != ''">
                <xf:setvalue 
                  ref="instance('data')/m:properties/d:P_DateOfBirth" 
                  value="concat(instance('extra')/Year, '-', instance('extra')/Month, '-', instance('extra')/Day)" />
              </xf:action>
            </xf:select1>
          </div>
          
        </div>
      </div>

Angular

Forms Markup

<group>
    <element>
      <id>dateofbirth</id>
      <label>Date Of Birth</label>
      <input type="date" bind="application.P_DateOfBirth" required="true" />
      <help>Please state your date of birth in YYYY-MM-DD format.<br /> Example: <span class="g">1979-06-27</span>.</help>
    </element>
    <element>
      <id>nationality</id>
      <label>Nationality</label>
      <input type="select" bind="application.P_Nationality" options="c.value as c.label for c in countries" required="true">
        <option value="">---</option>
      </input>
      <help>Please state your nationality. If you have more than one, please state the one you would like to be associated with. <br /> Note: You may be required to prove your nationality during the visa/immigration process.</help>
    </element>
    <element>
      <id>qscanphotoid</id>
      <label>ID/Passport Scan</label>
      <input type="file" bind="application.photo" target="/restxq/json/oa/file/photoid" filetype="jp?g|pdf" required="true" />
      <help>Please upload a scan of your ID or passport (JPEG or PDF).</help>
    </element>
    </group>