/*
* Copyright (c) 1998-2011 Caucho Technology -- all rights reserved
*
* This file is part of Resin(R) Open Source
*
* Each copy or derived work must preserve the copyright notice and this
* notice unmodified.
*
* Resin Open Source is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Resin Open Source is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
* of NON-INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with Resin Open Source; if not, write to the
* Free SoftwareFoundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*
* $Id: TagExtraInfo.java,v 1.2 2004/09/29 00:12:48 cvs Exp $
*/
package javax.servlet.jsp.tagext;
/**
* Extra tag information for a custom tag. It performs a similar function
* to BeanInfo classes, but for tag libraries. The TagExtraInfo class will
* be called at JSP compile time to:
* <ol>
* <li>instantiate and initialize runtime variables
* <li>validate tags
* </ol>
*
* <p/>The TagExtraInfo class is specified in the TLD
* using the teiclass attribute:
*
* <code><pre>
* <tag>
* <name>foo</name>
* <tagclass>com.caucho.tags.FooTag</tagclass>
* <teiclass>com.caucho.tags.FooTagInfo</teiclass>
* </tag>
* </pre></code>
*/
public abstract class TagExtraInfo {
private TagInfo _tagInfo;
/**
* Implementing classes must implement a zero-arg constructor.
*/
public TagExtraInfo()
{
}
/**
* Returns information needed to instantiate runtime variables.
*
* <p>The default implementation returns null.
*
* <p>For example, if the tag initializes a nested integer named by
* the foo attribute, getVariableInfo might return the following:
* <code><pre>
* public VariableInfo []getVariableInfo(TagData data)
* {
* VariableInfo []info = new VariableInfo[1];
* String foo = data.getAttribute("foo");
* info[0] = new VariableInfo(foo, "int", true, VariableInfo.NESTED);
* return info;
* }
* </pre></code>
*
* @param data The tag's static attributes and values.
*/
public VariableInfo []getVariableInfo(TagData data)
{
return null;
}
/**
* Validates the tag, so errors can be caught at compile-time instead of
* waiting for runtime.
*
* <p>The default implementation returns true.
*/
public boolean isValid(TagData data)
{
return true;
}
/**
* Sets the TLD tag info for this tag.
*/
public final void setTagInfo(TagInfo tagInfo)
{
_tagInfo = tagInfo;
}
/**
* Gets the TLD tag info for this tag.
*/
public final TagInfo getTagInfo()
{
return _tagInfo;
}
/**
* Validates the tag.
*/
public ValidationMessage []validate(TagData data)
{
if (isValid(data))
return null;
else {
ValidationMessage msg;
String prefix = getTagInfo().getTagLibrary().getShortName();
String name = getTagInfo().getTagName();
if (prefix != null)
name = prefix + ':' + name;
msg = new ValidationMessage(null, "tag <" + name + "> was not valid according to validator `" + getClass().getName() + "'");
return new ValidationMessage[] { msg };
}
}
}