tapestry/tapestry-framework/src/java/org/apache/tapestry/valid/EmailValidator.java

// Copyright 2004, 2005 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.tapestry.valid;

import java.util.HashMap;
import java.util.Locale;
import java.util.Map;

import org.apache.tapestry.IMarkupWriter;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.form.IFormComponent;

/**
 * Simple validation of email strings, to enforce required, and minimum length
 * (maximum length is enforced in the client browser, by setting a maximum input
 * length on the text field).
 * 
 * @author Malcolm Edgar
 * @since 2.3
 */

public class EmailValidator extends BaseValidator
{

    private int _minimumLength;

    private String _minimumLengthMessage;

    private String _invalidEmailFormatMessage;

    private String _scriptPath = "/org/apache/tapestry/valid/EmailValidator.script";

    public EmailValidator()
    {
    }

    /**
     * Initializes the EmailValidator with properties defined by the
     * initializer.
     * 
     * @since 4.0
     */

    public EmailValidator(String initializer)
    {
        super(initializer);
    }

    public String toString(IFormComponent field, Object value)
    {
        if (value == null) return null;

        return value.toString();
    }

    public Object toObject(IFormComponent field, String input)
        throws ValidatorException
    {
        if (checkRequired(field, input)) return null;

        if (_minimumLength > 0 && input.length() < _minimumLength)
            throw new ValidatorException(buildMinimumLengthMessage(field),
                    ValidationConstraint.MINIMUM_WIDTH);

        if (!isValidEmail(input))
            throw new ValidatorException(buildInvalidEmailFormatMessage(field),
                    ValidationConstraint.EMAIL_FORMAT);

        return input;
    }

    public int getMinimumLength()
    {
        return _minimumLength;
    }

    public void setMinimumLength(int minimumLength)
    {
        _minimumLength = minimumLength;
    }

    public void renderValidatorContribution(IFormComponent field,
            IMarkupWriter writer, IRequestCycle cycle)
    {
        if (!isClientScriptingEnabled()) return;

        Map symbols = new HashMap();

        Locale locale = field.getPage().getLocale();
        String displayName = field.getDisplayName();

        if (isRequired())
            symbols.put("requiredMessage", buildRequiredMessage(field));

        if (_minimumLength > 0)
            symbols.put("minimumLengthMessage",
                    buildMinimumLengthMessage(field));

        String pattern = getPattern(getInvalidEmailFormatMessage(),
                "invalid-email-format", locale);

        symbols.put("emailFormatMessage", formatString(pattern, displayName));

        processValidatorScript(_scriptPath, cycle, field, symbols);
    }

    public String getScriptPath()
    {
        return _scriptPath;
    }

    /**
     * Allows a developer to use the existing validation logic with a different
     * client-side script. This is often sufficient to allow
     * application-specific error presentation (perhaps by using DHTML to update
     * the content of a &lt;span&gt; tag, or to use a more sophisticated pop-up
     * window than <code>window.alert()</code>).
     */

    public void setScriptPath(String scriptPath)
    {
        _scriptPath = scriptPath;
    }

    /**
     * Return true if the email format is valid.
     * 
     * @param email
     *            the email string to validate
     * @return true if the email format is valid
     */

    protected boolean isValidEmail(String email)
    {
        int atIndex = email.indexOf('@');

        return !((atIndex <= 0) || (atIndex == email.length() - 1));
    }

    /** @since 3.0 */

    public String getInvalidEmailFormatMessage()
    {
        return _invalidEmailFormatMessage;
    }

    /** @since 3.0 */

    public String getMinimumLengthMessage()
    {
        return _minimumLengthMessage;
    }

    /**
     * Overrides the <code>invalid-email-format</code> bundle key. Parameter
     * {0} is the display name of the field.
     * 
     * @since 3.0
     */

    public void setInvalidEmailFormatMessage(String string)
    {
        _invalidEmailFormatMessage = string;
    }

    /**
     * Overrides the <code>field-too-short</code> bundle key. Parameter {0} is
     * the minimum length. Parameter {1} is the display name of the field.
     * 
     * @since 3.0
     */
    public void setMinimumLengthMessage(String string)
    {
        _minimumLengthMessage = string;
    }

    /** @since 3.0 */

    protected String buildMinimumLengthMessage(IFormComponent field)
    {
        String pattern = getPattern(_minimumLengthMessage, "field-too-short",
                field.getPage().getLocale());

        return formatString(pattern, Integer.toString(_minimumLength), field
                .getDisplayName());
    }

    /** @since 3.0 */

    protected String buildInvalidEmailFormatMessage(IFormComponent field)
    {
        String pattern = getPattern(_invalidEmailFormatMessage,
                "invalid-email-format", field.getPage().getLocale());

        return formatString(pattern, field.getDisplayName());
    }
}