name.martingeisse.wicket.autoform.annotation.validation.palette.StringLengthValidator.java Source code

Introduction

Here is the source code for name.martingeisse.wicket.autoform.annotation.validation.palette.StringLengthValidator.java

Source

/**
 * Copyright (c) 2011 Martin Geisse
 *
 * This file is distributed under the terms of the MIT license.
 */

package name.martingeisse.wicket.autoform.annotation.validation.palette;

import org.apache.wicket.behavior.Behavior;
import org.apache.wicket.util.io.IClusterable;
import org.apache.wicket.validation.IValidatable;
import org.apache.wicket.validation.IValidator;
import org.apache.wicket.validation.ValidationError;

/**
 * Common implementation for {@link ExactStringLength}, {@link MinStringLength}
 * and {@link MaxStringLength} validation.
 */
public class StringLengthValidator extends Behavior implements IValidator<String>, IClusterable {

    /**
     * the minLength
     */
    private final int minLength;

    /**
     * the maxLength
     */
    private final int maxLength;

    /**
     * Constructor.
     * @param annotation the annotation
     */
    public StringLengthValidator(final MinStringLength annotation) {
        minLength = checkNonNegative("minimum string length", annotation.value());
        maxLength = -1;
    }

    /**
     * Constructor.
     * @param annotation the annotation
     */
    public StringLengthValidator(final MaxStringLength annotation) {
        minLength = -1;
        maxLength = checkNonNegative("maximum string length", annotation.value());
    }

    /**
     * Constructor.
     * @param annotation the annotation
     */
    public StringLengthValidator(final ExactStringLength annotation) {
        minLength = maxLength = checkNonNegative("exact string length", annotation.value());
    }

    /**
     * 
     */
    private static int checkNonNegative(final String name, final int value) {
        if (value < 0) {
            throw new IllegalArgumentException(name + " must not be negative");
        }
        return value;
    }

    /* (non-Javadoc)
     * @see org.apache.wicket.validation.IValidator#validate(org.apache.wicket.validation.IValidatable)
     */
    @Override
    public void validate(IValidatable<String> validatable) {
        int length = validatable.getValue().length();
        if ((minLength >= 0 && length < minLength) || (maxLength >= 0 && length > maxLength)) {
            ValidationError error = new ValidationError(this, getVariation());
            error.setVariable("length", validatable.getValue().length());
            if (minLength >= 0 && maxLength >= 0 && minLength == maxLength) {
                error.setVariable("exact", minLength);
            } else {
                if (minLength >= 0) {
                    error.setVariable("minimum", minLength);
                }
                if (maxLength >= 0) {
                    error.setVariable("maximum", maxLength);
                }
            }
            validatable.error(error);
        }
    }

    /**
     * Returns the variation for the error message.
     */
    private String getVariation() {
        if (minLength >= 0) {
            if (maxLength >= 0) {
                if (minLength == maxLength) {
                    return "exact";
                } else {
                    return "range";
                }
            } else {
                return "minimum";
            }
        } else {
            if (maxLength >= 0) {
                return "maximum";
            } else {
                throw new IllegalStateException(
                        "validation error occured although neither a minimum nor a maximum string length are defined");
            }
        }
    }

}