Spring MVC: Difference between spring:bind and form:form

Question

I am looking to find out the difference between the spring:bind and form:form tag libraries when submitting a form.

A snippet of my JSP is as follows:

<form:form modelAttribute="testRulesForm">
....
<td>
    <form:checkbox path="rules[${counter.index}].isActive" value="rules[${counter.index}].isActive"/>
</td>
<td>
    <form:select path="rules[${counter.index}].leftCondition.name">
        <form:options items="${testRulesForm.ruleAttributes}" itemLabel="name" itemValue="name" />
    </form:select>
</td>
<td>
    <form:select path="rules[${counter.index}].operator">
        <form:options itemLabel="operator" itemValue="operator" />
    </form:select>
</td>
....

Seeing as I have my path variable specified and this will be bound to my modelAttribute, does this mean that I do not need spring:bind?

Thanks

Answer 1

Normally you don't need to use <spring:bind> if you already use form taglib.

They do basically the same with respect to model attributes, but tags from form taglib also generate HTML form markup, whereas with <spring:bind> you need to generate markup yourself.

The following code with form tags:

<form:form modelAttribute = "foo">
    <form:input path = "bar" />
</form:form>

is similar to the following code with <spring:bind>:

<spring:bind path = "foo">
    <form method = "get">
        <spring:bind path = "bar">
            <input name = "bar" value = "${status.displayValue}" />
        </spring:bind>
    </form>
</spring:bind>

<spring:bind> is useful when you need something customized, that cannot be achieved by form taglib.