/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.synapse.config.xml;
import org.apache.axiom.om.OMAttribute;
import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.impl.builder.StAXOMBuilder;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.synapse.SynapseException;
import org.apache.synapse.config.SynapseConfigUtils;
import org.apache.synapse.mediators.Value;
import org.apache.synapse.util.xpath.SynapseJsonPath;
import org.apache.synapse.util.xpath.SynapseXPath;
import org.jaxen.JaxenException;
import javax.xml.namespace.QName;
/**
* Factory for {@link org.apache.synapse.mediators.Value} instances.
*/
public class ValueFactory {
private static final Log log = LogFactory.getLog(ValueFactory.class);
private static final QName ATT_KEY = new QName("key");
/**
* Create a key instance
*
* @param elem OMElement
* @return Key
*/
public Value createValue(String name, OMElement elem) {
Value key = null;
OMAttribute attKey = elem.getAttribute(new QName(name));
if (attKey != null) {
String attributeValue = attKey.getAttributeValue();
boolean hasEscape = isEscapedExpression(attributeValue);
if (!hasEscape && isDynamicKey(attributeValue)) {
/** dynamic key */
// Filter json-eval expressions
if (attributeValue.startsWith("{json-eval(")) {
// Get the expression in-between "{}"
attributeValue = attributeValue.substring(1, attributeValue.length() - 1);
SynapseJsonPath synJsonPath = createSynJsonPath(attributeValue);
key = new Value(synJsonPath);
} else {
SynapseXPath synXpath = createSynXpath(elem, attributeValue);
key = new Value(synXpath);
}
} else if (hasEscape) {
/** escaped expr */
key = new Value(getEscapedExpression(attributeValue));
key.setNamespaces(elem);
} else {
/** static key */
key = new Value(attributeValue);
}
} else {
handleException("The 'key' attribute is required for the XSLT mediator");
}
return key;
}
/**
* Create a key instance
*
* @param elem OMElement
* @return Key
*/
public Value createTextValue(OMElement elem) {
Value key = null;
//OMAttribute attKey = elem.getAttribute(new QName(name));
String textValue = elem.getText();
if (textValue != null) {
boolean hasEscape = isEscapedExpression(textValue);
if (!hasEscape && isDynamicKey(textValue)) {
/** dynamic key */
// Filter json-eval expressions
if (textValue.startsWith("{json-eval(")) {
// Get the JSON expression in-between "{}"
textValue = textValue.substring(1, textValue.length() - 1);
SynapseJsonPath synJsonPath = createSynJsonPath(textValue);
key = new Value(synJsonPath);
} else {
SynapseXPath synXpath = createSynXpath(elem, textValue);
key = new Value(synXpath);
}
} else if (hasEscape) {
/** escaped expr */
key = new Value(getEscapedExpression(textValue));
key.setNamespaces(elem);
} else {
/** static key */
key = new Value(textValue);
}
} else {
handleException("The 'key' attribute is required for the XSLT mediator");
}
return key;
}
/**
* Validate the given key to identify whether it is static or dynamic key
* If the key is in the {} format then it is dynamic key(XPath)
* Otherwise just a static key
*
* @param keyValue string to validate as a key
* @return isDynamicKey representing key type
*/
public boolean isDynamicKey(String keyValue) {
boolean dynamicKey = false;
final char startExpression = '{';
final char endExpression = '}';
char firstChar = keyValue.charAt(0);
char lastChar = keyValue.charAt(keyValue.length() - 1);
if (startExpression == firstChar && endExpression == lastChar) {
dynamicKey = true;
}
return dynamicKey;
}
/**
* we'll focus on the trivial escape ie:- ones that have escape characters at start and end
*/
private boolean isEscapedExpression(String escapeExpr){
final char startEscapeChar = '{';
final char endEscapeChar = '}';
String expr = escapeExpr.trim();
if(expr.length() <= 3){
return false;
}
//check if this is a escape expression ie:- {{//m0:getQuote}}
char firstChar = expr.charAt(0);
char nextTofirstChar = expr.charAt(1);
char lastChar = expr.charAt(expr.length() - 1);
char prevTolastChar = expr.charAt(expr.length() - 2);
//if starting and ending chars have braces ;
if (startEscapeChar == firstChar && endEscapeChar == lastChar) {
return firstChar == nextTofirstChar && lastChar == prevTolastChar;
}
return false;
}
private String getEscapedExpression(String originalExpr){
return originalExpr.trim().substring(1, originalExpr.length() - 1);
}
/**
* Create synapse xpath expression
* {} type user input is used to create real xpath expression
*
* @param elem the element
* @param key xpath expression with {}
* @return SynapseXpath
*/
public SynapseXPath createSynXpath(OMElement elem, String key) {
//derive XPath Expression from key
String xpathExpr = key.trim().substring(1, key.length() - 1);
SynapseXPath synapseXPath = null;
try {
synapseXPath = SynapseXPathFactory.getSynapseXPath(elem, xpathExpr);
} catch (JaxenException e) {
handleException("Can not create Synapse Xpath from given key");
}
return synapseXPath;
}
/**
* Create synapse jsonpath expression
*
* @param key jsonpath expression eg: json-eval($.info)
* @return SynapseJsonPath
*/
public SynapseJsonPath createSynJsonPath(String key) {
// Derive JsonPath Expression from key removing "json-eval(" & ")"
String jsonPathExpr = key.trim().substring(10, key.length() - 1);
SynapseJsonPath synapseJsonPath = null;
try {
synapseJsonPath = SynapseJsonPathFactory.getSynapseJsonPath(jsonPathExpr);
} catch (JaxenException e) {
handleException("Can not create SynapseJsonPath from given: " + key);
}
return synapseJsonPath;
}
/**
* Handle exceptions
*
* @param msg error message
*/
private void handleException(String msg) {
log.error(msg);
throw new SynapseException(msg);
}
}