src/java/org/apache/fulcrum/intake/validator/DefaultValidator.java

package org.apache.fulcrum.intake.validator;

/*
 * 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.
 */

import java.util.Map;

import org.apache.avalon.framework.logger.LogEnabled;
import org.apache.avalon.framework.logger.Logger;
import org.apache.commons.lang.StringUtils;
import org.apache.fulcrum.intake.model.Field;

/**
 * DefaultValidator that will compare a testValue against the following
 * constraints:
 *
 * <table>
 * <tr><th>Name</th><th>Valid Values</th><th>Default Value</th></tr>
 * <tr><td>required</td><td>true|false</td><td>false</td></tr>
 * <tr><td>mask</td><td>regexp</td><td>&nbsp;</td></tr>
 * <tr><td>minLength</td><td>integer</td><td>0</td></tr>
 * <tr><td>maxLength</td><td>integer</td><td>&nbsp;</td></tr>
 * </table>
 *
 * This validator can serve as the base class for more specific validators
 *
 * @author <a href="mailto:jmcnally@collab.net">John McNally</a>
 * @author <a href="mailto:quintonm@bellsouth.net">Quinton McCombs</a>
 * @author <a href="mailto:Colin.Chalmers@maxware.nl">Colin Chalmers</a>
 * @author <a href="mailto:tv@apache.org">Thomas Vandahl</a>
 * @version $Id$
 */
abstract public class DefaultValidator<T>
        implements Validator<T>, InitableByConstraintMap, LogEnabled
{
    /** A boolean value to signify if the field is definitely required or not */
    protected boolean required = false;

    /** The message to show if field fails required test */
    protected String requiredMessage = null;

    /** The minimum length of the field */
    protected int minLength = 0;

    /** The message to show if field fails min-length test */
    protected String minLengthMessage = null;

    /** The maximum length of the field */
    protected int maxLength = 0;

    /** The message to show if field fails max-length test */
    protected String maxLengthMessage = null;

    /** Error message pertaining to Rule that was broken */
    protected String errorMessage = null;

    /** Logging */
    protected Logger log;

    /**
     * Default constructor
     */
    public DefaultValidator()
    {
        //
    }

    /**
	 * Enable Avalon Logging
	 */
	@Override
	public void enableLogging(Logger logger)
	{
		this.log = logger.getChildLogger(getClass().getSimpleName());
	}

    /**
     * Extract the relevant parameters from the constraints listed
     * in <rule> tags within the intake.xml file.
     *
     * @param paramMap a <code>Map</code> of <code>Rule</code>'s
     * containing constraints on the input.
     * @exception InvalidMaskException An invalid mask was specified for one of the rules
     */
    @Override
	public void init(Map<String, ? extends Constraint> paramMap)
            throws InvalidMaskException
    {
        Constraint constraint = paramMap.get(REQUIRED_RULE_NAME);
        if (constraint != null)
        {
            String param = constraint.getValue();
            required = Boolean.valueOf(param).booleanValue();
            requiredMessage = constraint.getMessage();
        }

        constraint = paramMap.get(MIN_LENGTH_RULE_NAME);
        if (constraint != null)
        {
            String param = constraint.getValue();
            minLength = Integer.parseInt(param);
            minLengthMessage = constraint.getMessage();
        }

        constraint = paramMap.get(MAX_LENGTH_RULE_NAME);
        if (constraint != null)
        {
            String param = constraint.getValue();
            maxLength = Integer.parseInt(param);
            maxLengthMessage = constraint.getMessage();
        }
    }

    /**
     * Determine whether a field meets the criteria specified
     * in the constraints defined for this validator
     *
     * @param field a <code>Field</code> to be tested
     * @return true if valid, false otherwise
     */
    @Override
	public boolean isValid(Field<T> field)
    {
        boolean valid = false;
        try
        {
            assertValidity(field);
            valid = true;
        }
        catch (ValidationException ve)
        {
            valid = false;
        }
        return valid;
    }

    /**
     * Determine whether a field meets the criteria specified
     * in the constraints defined for this validator
     *
     * @param field a <code>Field</code> to be tested
     * @exception ValidationException containing an error message if the
     * testValue did not pass the validation tests.
     */
    @Override
	public void assertValidity(Field<T> field)
            throws ValidationException
    {
    	if (field.isMultiValued())
    	{
    		String[] stringValues = (String[])field.getTestValue();

    		for (int i = 0; i < stringValues.length; i++)
    		{
    			assertValidity(stringValues[i]);
    		}
    	}
    	else
    	{
    		assertValidity((String)field.getTestValue());
    	}
    }

    /**
     * Determine whether a testValue meets the criteria specified
     * in the constraints defined for this validator
     *
     * @param testValue a <code>String</code> to be tested
     * @return true if valid, false otherwise
     *
     * @deprecated use isValid(Field) instead
     */
    @Override
	public boolean isValid(String testValue)
    {
        boolean valid = false;
        try
        {
            assertValidity(testValue);
            valid = true;
        }
        catch (ValidationException ve)
        {
            valid = false;
        }
        return valid;
    }

    /**
     * Determine whether a testValue meets the criteria specified
     * in the constraints defined for this validator
     *
     * @param testValue a <code>String</code> to be tested
     * @exception ValidationException containing an error message if the
     * testValue did not pass the validation tests.
     */
    @Override
	public void assertValidity(String testValue)
            throws ValidationException
    {
        if (!required && StringUtils.isEmpty(testValue))
        {
            return;
        }
        if (required && StringUtils.isEmpty(testValue))
        {
            errorMessage = requiredMessage;
            throw new ValidationException(requiredMessage);
        }

        if (minLength > 0 && testValue.length() < minLength)
        {
            errorMessage = minLengthMessage;
            throw new ValidationException(minLengthMessage);
        }
        if (maxLength > 0 && testValue.length() > maxLength)
        {
            errorMessage = maxLengthMessage;
            throw new ValidationException(maxLengthMessage);
        }
    }


    /**
     * Get the error message resulting from invalid input.
     *
     * @return a <code>String</code> message, or the empty String "".
     */
    @Override
	public String getMessage()
    {
        String retValue = "";

        if(errorMessage != null)
        {
            retValue = errorMessage;
        }

        return retValue;
    }

    // ************************************************************
    // **                Bean accessor methods                   **
    // ************************************************************

    /**
     * Get the value of required.
     *
     * @return value of required.
     */
    public boolean isRequired()
    {
        return required;
    }

    /**
     * Set the value of required.
     *
     * @param required  Value to assign to required.
     */
    public void setRequired(boolean required)
    {
        this.required = required;
    }

    /**
     * Get the value of requiredMessage.
     *
     * @return value of requiredMessage.
     */
    public String getRequiredMessage()
    {
        return requiredMessage;
    }

    /**
     * Set the value of requiredMessage.
     *
     * @param requiredMessage  Value to assign to requiredMessage.
     */
    public void setRequiredMessage(String requiredMessage)
    {
        this.requiredMessage = requiredMessage;
    }

    /**
     * Get the value of minLength.
     *
     * @return value of minLength.
     */
    public int getMinLength()
    {
        return minLength;
    }

    /**
     * Set the value of minLength.
     *
     * @param minLength  Value to assign to minLength.
     */
    public void setMinLength(int minLength)
    {
        this.minLength = minLength;
    }

    /**
     * Get the value of minLengthMessage.
     *
     * @return value of minLengthMessage.
     */
    public String getMinLengthMessage()
    {
        return minLengthMessage;
    }

    /**
     * Set the value of minLengthMessage.
     *
     * @param minLengthMessage  Value to assign to minLengthMessage.
     */
    public void setMinLengthMessage(String minLengthMessage)
    {
        this.minLengthMessage = minLengthMessage;
    }

    /**
     * Get the value of maxLength.
     *
     * @return value of maxLength.
     */
    public int getMaxLength()
    {
        return maxLength;
    }

    /**
     * Set the value of maxLength.
     *
     * @param maxLength  Value to assign to maxLength.
     */
    public void setMaxLength(int maxLength)
    {
        this.maxLength = maxLength;
    }

    /**
     * Get the value of maxLengthMessage.
     *
     * @return value of maxLengthMessage.
     */
    public String getMaxLengthMessage()
    {
        return maxLengthMessage;
    }

    /**
     * Set the value of maxLengthMessage.
     *
     * @param maxLengthMessage  Value to assign to maxLengthMessage.
     */
    public void setMaxLengthMessage(String maxLengthMessage)
    {
        this.maxLengthMessage = maxLengthMessage;
    }
}