如何动态选择县级城市

Question

我正在尝试使用域类从我的数据库中获取country，state和city。但我需要更简单的方法来获取它们。有没有办法通过使用Grails标签获得这些？

<g:countrySelect/>

<div class="form-group">
    <div class="col-lg-2"></div>
    <div class="fieldcontain ${hasErrors(bean: accountInstance, field: 'country', 'error')} ">
        <label class="col-lg-3 control-label" for="country">
        <g:message code="account.country.label" default="Country" />
        </label>

        <g:select id="country" name="country.id" from="${org.preva.Country.list()}"
                  optionKey="id" value="${accountInstance?.country?.id}"
                  class="many-to-one" noSelection="['null': 'Choose Country']"
                  style="width:160px"/>
    </div>
</div>

<div class="form-group">
    <div class="col-lg-2"></div>
    <div class="fieldcontain ${hasErrors(bean: accountInstance, field: 'state', 'error')} ">
        <label class="col-lg-3 control-label" for="state">
        <g:message code="account.state.label" default="State" />
        </label>
        <g:select id="state" name="state.id" from="${org.preva.State.list()}"
                  optionKey="id" value="${accountInstance?.state?.id}"
                  class="many-to-one" noSelection="['null': 'Choose State']"
                  style="width:160px"/>
    </div>
</div>

<div class="form-group">
    <div class="col-lg-2"></div>
    <div class="fieldcontain ${hasErrors(bean: accountInstance, field: 'city', 'error')} ">
        <label class="col-lg-3 control-label" for="city">
        <g:message code="account.city.label" default="City" />
        </label>
        <g:select id="city" name="city.id" from="${org.preva.City.list()}"
                  optionKey="id" value="${accountInstance?.city?.id}"
                  class="many-to-one" noSelection="['null': 'Choose City']"
                  style="width:160px"/>
    </div>
</div>

有没有默认标签？