/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed 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.cocoon.woody.datatype.validationruleimpl;
import org.apache.cocoon.woody.datatype.ValidationRule;
import org.apache.cocoon.woody.datatype.ValidationError;
import org.apache.cocoon.woody.formmodel.CannotYetResolveWarning;
import org.apache.excalibur.xml.sax.XMLizable;
import org.outerj.expression.Expression;
import org.outerj.expression.ExpressionContext;
import org.outerj.expression.ExpressionException;
import java.math.BigDecimal;
/**
* Abstract base class providing common functionality for many {@link ValidationRule}
* implementations.
*
* @version $Id: AbstractValidationRule.java 30932 2004-07-29 17:35:38Z vgritsenko $
*/
public abstract class AbstractValidationRule implements ValidationRule {
private XMLizable failMessage;
/**
* Sets the failmessage to use for this validation rule, this will be used
* instead of the validation rules' built-in message. The message itself should
* be an object impementing XMLizable, such as a SaxBuffer instance. This
* allows fail messages to contain mixed content (instead of just
* being a string).
*/
public void setFailMessage(XMLizable object) {
this.failMessage = object;
}
/**
* Returns the failMessage wrapped in a ValidationError object.
*/
public ValidationError getFailMessage() {
return new ValidationError(failMessage);
}
/**
* Returns true if this validation rule has a user-defined fail message.
*/
public boolean hasFailMessage() {
return failMessage != null;
}
/**
* Helper method for evaluating expressions whose result is numeric.
*
* @param exprName a name for the expression that's descriptive for the user, e.g. the name of the attribute in which it was defined
* @param ruleName a descriptive name for the validation rule, usually the rule's element name
* @return either a ValidationError (because expression evaluation failed) or a CannotYetResolveWarning
* (because another, required field referenced in the expression has not yet a value), or a BigDecimal.
*/
protected Object evaluateNumeric(Expression expression, ExpressionContext expressionContext, String exprName, String ruleName) {
Object expressionResult;
try {
expressionResult = expression.evaluate(expressionContext);
} catch (CannotYetResolveWarning w) {
return w;
} catch (ExpressionException e) {
return new ValidationError("Error evaluating \"" + exprName + "\" expression on \"" +
ruleName + "\" validation rule", false);
}
if (!(expressionResult instanceof BigDecimal)) {
return new ValidationError("Got non-numeric result from \"" + exprName + "\" expression on \"" +
ruleName + "\" validation rule", false);
}
return expressionResult;
}
/**
* Helper method for evaluating expressions whose result is comparable.
*
* @param exprName a name for the expression that's descriptive for the user, e.g. the name of the attribute in which it was defined
* @param ruleName a descriptive name for the validation rule, usually the rule's element name
* @return either a ValidationError (because expression evaluation failed) or a CannotYetResolveWarning
* (because another, required field referenced in the expression has not yet a value), or a BigDecimal.
*/
protected Object evaluateComparable(Expression expression, ExpressionContext expressionContext, String exprName, String ruleName) {
Object expressionResult;
try {
expressionResult = expression.evaluate(expressionContext);
} catch (CannotYetResolveWarning w) {
return w;
} catch (ExpressionException e) {
return new ValidationError("Error evaluating \"" + exprName + "\" expression on \"" +
ruleName + "\" validation rule", false);
}
if (!(expressionResult instanceof Comparable)) {
return new ValidationError("Got non-comparable result from \"" + exprName + "\" expression on \"" +
ruleName + "\" validation rule", false);
}
return expressionResult;
}
}