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Please make sure you have read the Tag Syntax document and understand how tag attribute syntax works.

Within the form tags, there are two classes of tags: the form tag itself, and all other tags, which make up the individual form elements. The behavior of the form tag is different than the elements enclosed within it.

Form Tag Themes

As explained in Themes and Templates, the HTML Tags (which includes Form Tags) are all driven by templates. Templates are grouped together to create themes. The framework bundles three themes in the distribution.

simple

Sometimes too simple

xhtml

Extends simple

(default)

ajax

Extends xhtml

The predefined themes can be used "as is" or customized.

xhtml layout

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The xhtml theme renders out a two-column table. If a different layout is needed, do not write your own HTML. Create a new theme or utilize the simple theme.

Simple theme caveats

The downside of using the simple theme is that it doesn't support as many of the attributes that the other themes do. For example, the label attribute does nothing in the simple theme, and the automatic display of error messages is not supported.

Common Attributes

All the form tags extend the UIBean class. This base class provides a set of common attributes, that can be grouped in to three categories: templated-related, javascript-related, and general attributes. The individual attributes are documented on each tag's reference page.

In addition to the common attributes, a special attribute exists for all form element tags: form (${parameters.form}). The form property represents the attributes used to render the form tag, such as the form's id. In a template, the form's ID can be found by calling ${parameters.form.id}.

Template-Related Attributes

AttributeThemeData TypesDescription
templateDirn/aStringdefine the template directory
themen/aStringdefine the theme name
templaten/aStringdefine the template name
themeExpansionTokenn/aStringspecial token (defined with struts.ui.theme.expansion.token) used to search for template in parent theme (don't use it separately!)
expandThemen/aStringconcatenation of themeExpansionToken and theme which tells internal template loader mechanism to try load template from current theme and then from parent theme (and parent theme, and so on) when used with <#include/> directive

Javascript-Related Attributes

AttributeThemeData TypesDescription
onclicksimpleStringhtml javascript onclick attribute
ondblclicksimpleStringhtml javascript ondbclick attribute
onmousedownsimpleStringhtml javascript onmousedown attribute
onmouseupsimpleStringhtml javascript onmouseup attribute
onmouseoversimpleStringhtml javascript onmouseover attribute
onmouseoutsimpleStringhtml javascript onmouseout attribute
onfocussimpleStringhtml javascript onfocus attribute
onblursimpleStringhtml javascript onblur attribute
onkeypresssimpleStringhtml javascript onkeypress attribute
onkeyupsimpleStringhtml javascript onkeyup attribute
onkeydownsimpleStringhtml javascript onkeydown attribute
onselectsimpleStringhtml javascript onselect attribute
onchangesimpleStringhtml javascript onchange attribute

Tooltip Related Attributes

AttributeData TypeDefaultDescription
tooltipStringnoneSet the tooltip of this particular component
jsTooltipEnabledStringfalseEnable js tooltip rendering
tooltipIconString/struts/static/tooltip/tooltip.gifThe url to the tooltip icon
tooltipDelayString500Tooltip shows up after the specified timeout (miliseconds). A behavior similar to that of OS based tooltips.
keysimpleStringThe name of the property this input field represents. This will auto populate the name, label, and value

General Attributes

AttributeThemeData TypesDescription
cssClasssimpleStringdefine html class attribute
cssStylesimpleStringdefine html style attribute
cssClasssimpleStringerror class attribute
cssStylesimpleStringerror style attribute
titlesimpleStringdefine html title attribute
disabledsimpleStringdefine html disabled attribute
labelxhtmlStringdefine label of form element
labelPositionxhtmlStringdefine label position of form element (top/left), default to left
requiredPositionxhtmlStringdefine required label position of form element (left/right), default to right
errorPositionxhtmlStringdefine error position of form element (top|bottom), default to top
namesimpleStringForm Element's field name mapping
requiredxhtmlBooleanadd * to label (true to add false otherwise)
tabIndexsimpleStringdefine html tabindex attribute
valuesimpleObjectdefine value of form element

When some attributes don't apply

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Some tag attributes may not be utilized by all, or any, of the templates. For example, the form tag supports the tabindex attribute, but none of the themes render the tabindex.

Value/Name Relationship

In many of the tags (except for the form tag) there is a unique relationship between the name and value attributes. The name attribute provides the name for the tag, which in turn is used as the control attribute when the form is submitted. The value submitted is bound to the name. In most cases, the name maps to a simple JavaBean property, such as "postalCode". On a submit, the value would be set to the property by calling the setPostalCode mutator.

Likewise, a form control could be populated by calling a JavaBean accessor, like getPostalCode. In the expression language, we can refer to the JavaBean property by name. An expression like "%{postalCode}" would in turn call getPostalCode.

Using Expressions to populate a form for editing

However, since the tags imply a relationship between the name and value, the value attribute is optional. If a value is not specified, by default, the JavaBean accessor is used instead.

Populating a form for editing, the easy way

While most attributes are exposed to the underlying templates as the same key as the attribute (${parameters.label}), the value attribute is not. Instead, it can be accessed via the nameValue key (${parameters.nameValue}). The nameValue key indicates that the value may have been generated from the name attribute rather than explicitly defined in the value attribute.

ID Name Assignment

All form tags automatically assign an ID to the control, but the ID can be overridden if needed.

Forms

The default ID is the action name. For example, "updateAddress".

Controls

The default ID is the form's name concatenated with the tag name. For example, "updateAddress_postalCode".

Form labelposition propagation

When labelposition attribute was defined for <s:form> tag it will be propagated to all form elements, but if form element defines its own labelposition it will take precedence over <s:form>'s attribute. Since 2.3.17.

Required Attribute

The required attribute on many UI tags defaults to true only if you have client-side validation enabled, and a validator is associated with that particular field.

Tooltip

tooltipConfig is deprecated, use individual tooltip configuration attributes instead

Every Form UI component (in xhtml / css_xhtml or any other that extends them) can have tooltips assigned to them. The Form component's tooltip related attribute, once defined, will be applied to all form UI components that are created under it unless explicitly overriden by having the Form UI component itself defined with their own tooltip attribute.

In Example 1, the textfield will inherit the tooltipDelay and tooltipIconPath attribte from its containing form. In other words, although it doesn't define a tooltipIconPath attribute, it will have that attribute inherited from its containing form.

In Example 2, the textfield will inherite both the tooltipDelay and tooltipIconPath attribute from its containing form, but the tooltipDelay attribute is overriden at the textfield itself. Hence, the textfield actually will have its tooltipIcon defined as /myImages/myIcon.gif, inherited from its containing form, and tooltipDelay defined as 5000.

Example 3, 4 and 5 show different ways of setting the tooltip configuration attribute.
Example 3: Set tooltip config through the body of the param tag
Example 4: Set tooltip config through the value attribute of the param tag
Example 5: Set tooltip config through the tooltip attributes of the component tag

Next: UI Tag Reference