How to handle Twitter Bootstrap fields with Thymeleaf Spring and less code - thymeleaf

Question

I need some advice how is a recommended way to handle Twitter Bootstrap fields with Thymeleaf. I know that recommendations are not so easy, so I wrote my thoughts about it and hope you can comment it. At the end there a some concrete questions.
First I tried a fragment which shows what is needed to generate
<div th:fragment="textfield">
<div class="control-group"
th:classappend="${#fields.hasErrors('__${fId}__')}? 'error'">
<label class="control-label" th:for="${fId}"
th:text="#{model.__*{class.simpleName}__.__${fId}__}+':'">
FirstName
</label>
<div class="controls">
<input type="text" th:class="${inputclass}" th:field="*{__${fId}__}" th:disabled="${disabled}"/>
<span class="help-inline" th:if="${#fields.hasErrors('__${fId}__')}"
th:errors="*{__${fId}__}"></span>
</div>
</div>
</div>
which can be used with
<div class="control-group replace" th:include="templates::textfield" th:with="fId='userId'" th:remove="tag">
<label class="control-label replace">Benutzer-Id</label>
<div class="controls replace">
<input type="text" value=""/>
</div>
</div>
or in short
<div class="control-group replace" th:include="templates::textfield" th:with="fId='userId'" th:remove="tag"/>
It's not very flexible about the input, so you need for a checkbox an own fragment.
Next I choose the layout-approach:
<div layout:fragment="bsfield">
<div class="control-group" th:classappend="${#fields.hasErrors('__${fId}__')}? 'error'">
<label class="control-label" th:for="${fId}"
th:text="#{model.__*{class.simpleName}__.__${fId}__}+':'">
FirstName </label>
<div class="controls">
<span layout:fragment="bsinput" th:remove="tag">
<input type="text" class="replace" th:field="*{__${fId}__}" th:disabled="${disabled}"/>
</span>
<span class="help-inline" th:if="${#fields.hasErrors('__${fId}__')}"
th:errors="*{__${fId}__}"></span>
</div>
</div>
</div>
Which is very flexible because I can define my input directly.
I can use it shortly with
<div layout:include="templates::bsfield" th:with="fId='firstName'" th:remove="tag">
<div layout:fragment="bsinput">
<input type="text" th:field="*{__${fId}__}" th:disabled="${disabled}"/>
</div>
</div>
or more prototype style
<div class="control-group" layout:include="templates::bsfield" th:with="fId='lastName'" th:remove="tag">
<label class="control-label" th:remove="all">Last Name</label>
<div class="controls" th:remove="tag">
<div layout:fragment="bsinput">
<input type="text" th:field="*{__${fId}__}" th:disabled="${disabled}"/>
</div>
</div>
</div>
Both variants has still a lot of boilerplate. So I think about the following solution inspired by Playframework helper.
<input type="text" th:bsfield="firstName" th:disabled="${disabled}"/>
and writing a Processor which creates
<div class="control-group"
th:classappend="${#fields.hasErrors('${fId}')}? 'error'">
<label class="control-label" th:for="${fId}"
th:text="#{model.__*{class.simpleName}__.${fId}}+':'">
FirstName </label>
<div class="controls">
<input type="text" th:class="${inputclass}" th:field="*{${fId}}" th:disabled="${disabled}"/>
<span class="help-inline" th:if="${#fields.hasErrors('${fId}')}"
th:errors="*{${fId}}"></span>
</div>
</div>
and replace ${fId} with the value of bsfield in this example "firstname". After that Thymeleaf should recompute it (setRecomputeProcessorsImmediately (true);) For the prototype I think it's necessary to write a JS-Solution.
I'm unsure if this is really clever or a misuse of Processors. Furthermore I'm unsure how much time a beginner need to write such a processor. Are 4 hours realistic or more a few days?
Would appreciate if someone can give me a hint.

Answer 1

In the meantime I did it. As a beginner you must calculate 4-8 hours, without JUnit tests (it looks difficult to test processors) and DTD and editor-support. The most problems I had was that it's difficult to reuse an existing node after changing attributes. Here it's better to clone it.
Next time I think I can do it in 1 or 2 hours.
The experience is very good, you have clean and short code. With the JS-File you don't lose the prototyping experience.