Html, thymleaf radiobutton th:field="" fails if data is null - html

Question

I´d like to autofill receipt data. If my receipt is not null it should pick the right gender to a radio button with thymeleaf. There are no errors if the receipt is not null, but if receipt is null the errors are thrown
<div class="form-group">
<div id="genderReceipt">
<label for="genderMaleReceipt" class="radio-inline">
<input type="radio" name="genderReceipt" id="genderMaleReceipt" value="MALE" th:field="*{receipt.gender}"/>
Herr
</label>
<label for="genderFemaleReceipt" class="radio-inline">
<input type="radio" name="genderReceipt" id="genderFemaleReceipt" value="FEMALE" th:field="*{receipt.gender}"/>
Frau
</label>
</div>
<label for="genderReceipt" class="error" style="display: none;"> Bitte gib eine Anrede an.</label>
</div>
The result should be like: if receipt == null both are unchecked... if receipt != null the right gender is checked
error log says:
java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'receipt' available as request attribute

Answer 1

My Solution for this problem is to duplicate the code and insert th:if statements like here in the example
<div th:if="${receipt} == null">
<label for="genderFemaleReceipt" class="radio-inline">
<input type="radio" name="genderReceipt" id="genderMaleReceipt" value="MALE" />
Herr
</label>
<label for="genderFemaleReceipt" class="radio-inline">
<input type="radio" name="genderReceipt" id="genderFemaleReceipt" value="FEMALE" />
Frau
</label>
</div>
<div th:if="${receipt} != null">
<label for="genderFemaleReceipt" class="radio-inline">
<input type="radio" name="genderReceipt" id="genderMaleReceipt" value="MALE" th:field="*{receipt.gender}"/>
Herr
</label>
<label for="genderFemaleReceipt" class="radio-inline">
<input type="radio" name="genderReceipt" id="genderFemaleReceipt" value="FEMALE" th:field="*{receipt.gender}"/>
Frau
</label>
</div>
I know thats not best practice ;( but i didn´t know a other way to do it.