Package org.apache.struts2.components

Interface HtmlConstraintProvider

All Known Implementing Classes:

StrutsHtmlConstraintProvider

public interface HtmlConstraintProvider

Maps a field's validators onto the HTML attributes a theme should render for it.

The default implementation is deliberately conservative — see StrutsHtmlConstraintProvider. Applications wanting a less conservative mapping (a rewritten pattern for a case-insensitive regex, say) should register their own implementation instead.

A type entry in the returned map is discarded: the templates have already written the input's type by the time the map renders, so changing it needs a template override, not a provider. Any entry whose name matches an attribute the developer set on the tag is discarded too — the developer's own value always wins.

Since:

7.4.0

Method Summary

Modifier and Type	Method	Description
Map<String,String>	constraintsFor(List<Validator> validators, HtmlControlType control, Object action, Object value)

Method Details

constraintsFor

Map<String,String> constraintsFor(List<Validator> validators,
 HtmlControlType control,
 Object action,
 Object value)

Parameters:

validators - the field's validators; may be null or empty

control - the kind of control being rendered

action - the object the field's validators run against, used to resolve i18n validator messages: the action, or the visited object for a field reached through a visitor validator; may be null

value - the field's current value as the tag resolved it — what the page renders and, for a control that omits its parameter when left empty, what the server will validate on such a submit; may be null

Returns:

attribute name to value; never null, possibly empty