Spring Roo MVC Read-Only Inputs

I've recently been using Spring Roo quite regularly and also recommended it as part of the development tool stack at a client to boost productivity. It provides a lot of nice features and generates a lot of boiler-plate code for CRUD functionality. Obviously it has its limitations and when you start trying to do things differently then Roo will start having problems. Nevertheless, as long as you are willing to accept the limitations and customize where necessary, you can use it to your benefit.

Recently, I came across an issue where I wanted to update an entity from the web UI, but have some fields marked as readonly so that the user cannot modify them from the update view. Unfortunately, the custom jsp tags that the Spring Roo web mvc add-on provides doesn't support readonly input fields. The input.tagx provides a number of attributes such as render, disableFormBinding and disabled but none of these fulfilled the requirement. Using the disabled attribute, marks the input field as disabled which renders fine and doesn't allow editing of the field, but it also doesn't get submitted with the form and consequently the entity's validation fails or the field's value is replaced by an empty value.

The solution I found was to create a new inputreadonly tag by copying and customizing the input.tagx file.

I added a new jsp directive:

<jsp:directive.attribute name="readonly" type="java.lang.Boolean" required="false" rtexprvalue="true" description="Specify if this field should be readonly" />

and modified the body where it generates the input field:

<c:otherwise>
<c:choose>
<c:when test="${readonly eq true}">
<form:input disabled="${disabled}" id="_${sec_field}_id" path="${sec_field}" readonly="${readonly}"></form:input></c:when>
<c:otherwise>
<form:input disabled="${disabled}" id="_${sec_field}_id" path="${sec_field}

Then I modified the update.jspx file to use the new jsp tag.

<field:inputreadonly field="businessType" id="c_com_changesoft_samples_domain_Business_businessType" z="user-managed>" readonly="true"/>

The result is an html read-only input field.