/*******************************************************************************
*
* Copyright (c) 2004-2010 Oracle Corporation.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
*
*
*******************************************************************************/
package hudson.util.jelly;
import org.apache.commons.jelly.JellyContext;
import org.apache.commons.jelly.JellyException;
import org.apache.commons.jelly.JellyTagException;
import org.apache.commons.jelly.Tag;
import org.apache.commons.jelly.TagLibrary;
import org.apache.commons.jelly.XMLOutput;
import org.apache.commons.jelly.expression.Expression;
import org.apache.commons.jelly.impl.ExpressionAttribute;
import org.apache.commons.jelly.impl.TagScript;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Map;
/**
* Jelly tag library for literal-like tags, with an ability to add arbitrary
* attributes taken from a map.
*
* <p> Tags from this namespace ("jelly:hudson.util.jelly.MorphTagLibrary")
* behaves mostly like literal static tags, except it interprets two attributes
* "ATTRIBUTES" and "EXCEPT" in a special way.
*
* The "ATTRIBUTES" attribute should have a Jelly expression that points to a
* {@link Map} object, and the contents of the map are added as attributes of
* this tag, with the exceptions of entries whose key values are listed in the
* "EXCEPT" attribute.
*
* The "EXCEPT" attribute takes a white-space separated list of attribute names
* that should be ignored even if it's in the map.
*
* <p> The explicit literal attributes, if specified, always take precedence
* over the dynamic attributes added by the map.
*
* <p> See textbox.jelly as an example of using this tag library.
*
* @author Kohsuke Kawaguchi
* @since 1.342
*/
public class MorphTagLibrary extends TagLibrary {
/**
* This code is really only used for dealing with dynamic tag libraries, so
* no point in implementing this for statically used tag libraries.
*/
@Override
public Tag createTag(final String name, Attributes attributes) throws JellyException {
return null;
}
@Override
public TagScript createTagScript(final String tagName, Attributes attributes) throws JellyException {
return new TagScript() {
private Object evalAttribute(String name, JellyContext context) {
ExpressionAttribute e = attributes.get(name);
if (e == null) {
return null;
}
return e.exp.evaluate(context);
}
private Collection<?> getExclusions(JellyContext context) {
Object exclusion = evalAttribute(EXCEPT_ATTRIBUTES, context);
if (exclusion == null) {
return Collections.emptySet();
}
if (exclusion instanceof String) {
return Arrays.asList(exclusion.toString().split("\\s+")); // split by whitespace
}
if (exclusion instanceof Collection) {
return (Collection) exclusion;
}
throw new IllegalArgumentException("Expected collection for exclusion but found :" + exclusion);
}
@Override
public void run(JellyContext context, XMLOutput output) throws JellyTagException {
AttributesImpl actual = new AttributesImpl();
Collection<?> exclusions = getExclusions(context);
Map<String, ?> meta = (Map) evalAttribute(META_ATTRIBUTES, context);
if (meta != null) {
for (Map.Entry<String, ?> e : meta.entrySet()) {
String key = e.getKey();
// @see jelly.impl.DynamicTag.setAttribute() -- ${attrs} has duplicates with "Attr" suffix
if (key.endsWith("Attr") && meta.containsKey(key.substring(0, key.length() - 4))) {
continue;
}
// @see http://github.com/hudson/jelly/commit/4ae67d15957b5b4d32751619997a3cb2a6ad56ed
if (key.equals("ownerTag")) {
continue;
}
if (!exclusions.contains(key)) {
Object v = e.getValue();
if (v != null) {
actual.addAttribute("", key, key, "CDATA", v.toString());
}
}
}
} else {
meta = Collections.emptyMap();
}
for (Map.Entry<String, ExpressionAttribute> e : attributes.entrySet()) {
String name = e.getKey();
if (name.equals(META_ATTRIBUTES) || name.equals(EXCEPT_ATTRIBUTES)) {
continue; // already handled
}
if (meta.containsKey(name)) {
// if the explicit value is also generated by a map, delete it first.
// this is O(N) operation, but we don't expect there to be a lot of collisions.
int idx = actual.getIndex(name);
if (idx >= 0) {
actual.removeAttribute(idx);
}
}
Expression expression = e.getValue().exp;
actual.addAttribute("", name, name, "CDATA", expression.evaluateAsString(context));
}
try {
output.startElement(tagName, actual);
getTagBody().run(context, output);
output.endElement(tagName);
} catch (SAXException x) {
throw new JellyTagException(x);
}
}
};
}
private static final String META_ATTRIBUTES = "ATTRIBUTES";
private static final String EXCEPT_ATTRIBUTES = "EXCEPT";
}