org.databene.webdecs.xml.AbstractXMLElementParser Maven / Gradle / Ivy
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'databene webdecs' is an open source software library for
WEB Data Extraction, Conversion and Scripting, written by Volker Bergmann.
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/*
* (c) Copyright 2010-2011 by Volker Bergmann. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, is permitted under the terms of the
* GNU General Public License (GPL).
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* WITHOUT A WARRANTY OF ANY KIND. ALL EXPRESS OR IMPLIED CONDITIONS,
* REPRESENTATIONS AND WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE
* HEREBY EXCLUDED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
package org.databene.webdecs.xml;
import java.util.Collections;
import java.util.Map;
import java.util.Set;
import org.databene.commons.ArrayFormat;
import org.databene.commons.ArrayUtil;
import org.databene.commons.CollectionUtil;
import org.databene.commons.ConfigurationError;
import org.databene.commons.StringUtil;
import org.databene.commons.SyntaxError;
import org.databene.commons.xml.XMLUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Element;
/**
* Abstract implementation of the {@link XMLElementParser} interface.
* Created: 05.12.2010 10:46:38
* @since 0.5.4
* @author Volker Bergmann
*/
public abstract class AbstractXMLElementParser implements XMLElementParser {
private static final Logger LOGGER = LoggerFactory.getLogger(AbstractXMLElementParser.class);
protected final String elementName;
protected final Set> supportedParentTypes;
protected Set requiredAttributes;
protected Set optionalAttributes;
public AbstractXMLElementParser(String elementName,
Set requiredAttributes,
Set optionalAttributes,
Class... supportedParentTypes) {
this.elementName = elementName;
this.requiredAttributes = (requiredAttributes != null ? requiredAttributes : Collections.emptySet());
this.optionalAttributes = (optionalAttributes != null ? optionalAttributes : Collections.emptySet());
this.supportedParentTypes = CollectionUtil.toSet(supportedParentTypes);
}
public boolean supports(Element element, E[] parentPath) {
if (!this.elementName.equals(element.getNodeName()))
return false;
return CollectionUtil.isEmpty(this.supportedParentTypes) || parentPath == null ||
this.supportedParentTypes.contains(ArrayUtil.lastElementOf(parentPath).getClass());
}
public final E parse(Element element, E[] parentPath, org.databene.webdecs.xml.ParseContext context) {
checkAttributeSupport(element);
return doParse(element, parentPath, context);
}
protected abstract E doParse(Element element, E[] parentPath, ParseContext context);
protected void checkAttributeSupport(Element element) {
for (String attribute : XMLUtil.getAttributes(element).keySet()) {
if (!requiredAttributes.contains(attribute) && !optionalAttributes.contains(attribute))
syntaxError("attribute '" + attribute + "' is not supported", element); // TODO v0.6.x print supported attributes
}
for (String requiredAttribute : requiredAttributes) {
if (StringUtil.isEmpty(element.getAttribute(requiredAttribute)))
syntaxError("Required attribute '" + requiredAttribute + "' is missing", element);
}
}
protected static void checkSupportedAttributes(Element element, String... supportedAttributes) {
for (String actualAttribute : XMLUtil.getAttributes(element).keySet()) {
if (!ArrayUtil.contains(actualAttribute, supportedAttributes))
syntaxError("attribute '" + actualAttribute + "' is not supported", element);
}
}
protected static void assertElementName(String expectedName, Element element) {
if (!element.getNodeName().equals(expectedName))
throw new RuntimeException("Expected element name '" + expectedName + "', " +
"found: '" + element.getNodeName());
}
protected void excludeAttributes(Element element, String... attributeNames) {
String usedAttribute = null;
for (String attributeName : attributeNames) {
if (!StringUtil.isEmpty(element.getAttribute(attributeName))) {
if (usedAttribute == null)
usedAttribute = attributeName;
else
syntaxError("The attributes '" + usedAttribute + "' and '" + attributeName + "' " +
"exclude each other", element);
}
}
}
protected void assertAtLeastOneAttributeIsSet(Element element, String... attributeNames) {
boolean ok = false;
for (String attributeName : attributeNames)
if (!StringUtil.isEmpty(element.getAttribute(attributeName)))
ok = true;
if (!ok)
syntaxError("At least one of these attributes must be set: " + ArrayFormat.format(attributeNames), element);
}
protected void assertAttributeIsSet(Element element, String attributeName) {
if (StringUtil.isEmpty(element.getAttribute(attributeName)))
syntaxError("Attribute '" + attributeName + "' is missing", element);
}
protected void assertAttributeIsNotSet(Element element, String attributeName) {
if (!StringUtil.isEmpty(element.getAttribute(attributeName)))
syntaxError("Attributes '" + attributeName + "' must not be set", element);
}
protected Object parent(E[] parentPath) {
if (ArrayUtil.isEmpty(parentPath))
return null;
else
return ArrayUtil.lastElementOf(parentPath);
}
protected static String parseRequiredName(Element element) {
String name = parseOptionalName(element);
if (StringUtil.isEmpty(name))
syntaxError("'name' attribute is missing", element);
return name;
}
protected static String parseOptionalName(Element element) {
return getOptionalAttribute("name", element);
}
protected static Integer parseOptionalInteger(String attributeName, Element element) {
String spec = getOptionalAttribute(attributeName, element);
return (spec != null ? Integer.parseInt(spec) : null);
}
protected static Boolean parseOptionalBoolean(String attributeName, Element element) {
String spec = getOptionalAttribute(attributeName, element);
return (spec != null ? Boolean.parseBoolean(spec) : null);
}
protected static Long parseOptionalLong(String attributeName, Element element) {
String spec = getOptionalAttribute(attributeName, element);
return (spec != null ? Long.parseLong(spec) : null);
}
public static String getRequiredAttribute(String name, Element element) {
String value = getOptionalAttribute(name, element);
if (value == null)
syntaxError("'" + name + "' attribute expected", element);
return value;
}
protected static String getOptionalAttribute(String name, Element element) {
return StringUtil.emptyToNull(element.getAttribute(name));
}
protected static void checkAttributes(Element element, Set supportedAttributes) {
for (Map.Entry attribute : XMLUtil.getAttributes(element).entrySet()) {
if (!supportedAttributes.contains(attribute.getKey()))
throw new ConfigurationError("Not a supported import attribute: " + attribute.getKey());
}
}
protected static void syntaxError(String message, Element element) {
throw new SyntaxError("Syntax error: " + message, XMLUtil.format(element));
}
protected static void syntaxWarning(String message, Element element) {
LOGGER.warn("Syntax warning: " + message + " in " + XMLUtil.format(element));
}
}