una/template/location_field_plain.html

<div class="bx-form-input-location-__name__ __minimized__ bx-form-input-location-cont bx-clearfix">
    __inputs__
    <div class="bx-form-input-location-status-cont bx-def-font-small bx-def-font-grayed bx-def-margin-thd-top bx-clearfix">
        <div class="bx-form-input-location-status ok"><i class="sys-icon sys-colored col-green1-dark check-circle"></i> <bx_text:_sys_location_status_ok /></div>
        <div class="bx-form-input-location-status fail"><i class="sys-icon sys-colored col-red1-dark times-circle"></i> <bx_text:_sys_location_status_fail /></div>
        <div class="bx-form-input-location-status undef"><i class="sys-icon sys-colored question-circle"></i> <bx_text:_sys_location_status_undef /></div>
        <div class="bx-form-input-location-status loading"><i class="sys-icon sys-colored sync-alt"></i> <bx_text:_sys_loading /></div>
        <div class="bx-form-input-location-copyright"></div>
    </div>
</div>

<script>
(function () {

    var eForm = $('#__form_id__');
    eForm.on('submit', function (ev) {
        if (typeof(glBxLocationDisableFormSubmit) !== 'undefined' && glBxLocationDisableFormSubmit)
            ev.preventDefault();
    });

    var disableFormSubmit = function (b) {
        glBxLocationDisableFormSubmit = b;
        if (b)
            eForm.find('[type=submit]').addClass('bx-btn-disabled').attr('disabled', true);
        else
            eForm.find('[type=submit]').removeClass('bx-btn-disabled').attr('disabled', false);
    }

    var getLocationParams = function (sMode) {
        var sCountry = eForm.find('select[name="__name___country"] :selected').text();
        var sCountryCode = eForm.find('select[name="__name___country"]').val();
        var sZip = eForm.find('input[name="__name___zip"]').val();
        var sState = eForm.find('input[name="__name___state"]').val();
        var sCity = eForm.find('input[name="__name___city"]').val();
        var sStreet = eForm.find('input[name="__name___street"]').val();
        var sNum = eForm.find('input[name="__name___street_number"]').val();

        if (!sCountryCode || !sCountryCode.length)
            return '';

        sRet = '&country=' + encodeURIComponent(sCountry);

        if (sZip !== undefined && sZip.length && sMode !== 'no_street_no_zip')
            sRet += '&postalcode=' + encodeURIComponent(sZip);

        if (sZip !== undefined && 'zip_only' == sMode)
            return sZip.length ? sRet : '';

        if (sState.length)
            sRet += '&state=' + encodeURIComponent(sState);

        if (sCity.length)
            sRet += ('county_as_city' == sMode ? '&county=' : '&city=') + encodeURIComponent(sCity);
        
        if (sStreet !== undefined && sStreet.length && sMode !== 'no_street_no_zip')
            sRet += '&street=' + (sNum.length ? encodeURIComponent(sNum) + ' ' : '') + encodeURIComponent(sStreet);

        return sRet;
    }

    var geocode = function (a, i) {
        var s = a[i];
        $.getJSON('__nominatim_server__/search?addressdetails=1' + s + '&format=json&limit=1&email=__nominatim_email__', function (oResult) {
            glBxLocationFieldPlainGeocodingRequest = false;
            if (('object' === typeof oResult) && oResult.length && ('undefined' !== typeof oResult[0].lat) && ('undefined' !== typeof oResult[0].lon)) {

                eForm.find('input[name="__name___lat"]').val(oResult[0].lat);
                eForm.find('input[name="__name___lng"]').val(oResult[0].lon);
                if ('undefined' !== typeof(oResult[0].address)) {
                    if ('undefined' !== typeof(oResult[0].address.state) && 0 == eForm.find('input[name="__name___state"]').val().length)
                        eForm.find('input[name="__name___state"]').val(oResult[0].address.state);
                    else if (__normalize_names__ && eForm.find('input[name="__name___state"]').val() != oResult[0].address.state)
                        eForm.find('input[name="__name___state"]').val(oResult[0].address.state);

                    var sCity = '';
                    if ('undefined' !== typeof(oResult[0].address.city))
                        sCity = oResult[0].address.city;
                    else if ('undefined' !== typeof(oResult[0].address.town))
                        sCity = oResult[0].address.town;
                    else if ('undefined' !== typeof(oResult[0].address.village))
                        sCity = oResult[0].address.village;

                    if (sCity && 0 == $('input[name="__name___city"]').val().length)
                        eForm.find('input[name="__name___city"]').val(sCity);
                    else if (__normalize_names__ && sCity && eForm.find('input[name="__name___city"]').val() != sCity)
                        eForm.find('input[name="__name___city"]').val(sCity);
                }
                if ('undefined' !== typeof(oResult[0].licence))
                    $('.bx-form-input-location-__name__ .bx-form-input-location-copyright').html(oResult[0].licence);
                setLocationStatus('ok');
            } 
            else {
                i += 1;
                if ('undefined' !== typeof(a[i])) {
                    geocode(a, i);
                }
                else {
                    eForm.find('input[name="__name___lat"]').val(0);
                    eForm.find('input[name="__name___lng"]').val(0);
                    setLocationStatus('fail');
                }
            }
        });
    }

    var setLocationStatus = function (s) {
        eForm.find('.bx-form-input-location-__name__ .bx-form-input-location-status').hide();
        eForm.find('.bx-form-input-location-__name__ .bx-form-input-location-status.' + s).show();
        if ('loading' !== s)
            disableFormSubmit(false);
    }

    setLocationStatus('undef');

    $(document).ready(function () {
        eForm.find('input[name^="__name__"],select[name^="__name__"]').on('change', function () {
            if ('undefined' !== typeof(glBxLocationFieldPlainGeocodingRequest) && glBxLocationFieldPlainGeocodingRequest) { // cancel previous request
                clearTimeout(glBxLocationFieldPlainGeocodingRequest);
                glBxLocationFieldPlainGeocodingRequest = null;
            }

            if ('hidden' == this.type)
                return;
            
            var s = getLocationParams();
            if (!s) {
                setLocationStatus('undef');
                return;
            }
            var a = [s];

            if (s = getLocationParams('zip_only'))
                 a.push(s);

            if (s = getLocationParams('no_street_no_zip'))
                 a.push(s);
 
            disableFormSubmit(true);
            glBxLocationFieldPlainGeocodingRequest = setTimeout(function () {
                setLocationStatus('loading');
                geocode(a, 0);
            }, 1500);
        });

        if (getLocationParams()) {
            if (parseFloat(eForm.find('input[name="__name___lat"]').val()) && parseFloat(eForm.find('input[name="__name___lng"]').val()))
                setLocationStatus('ok');
            else
                setLocationStatus('fail');
        } 
        else {
            setLocationStatus('undef');
        }
    });
})();
</script>