mitm.djigzo.web.components.RegExprFilter.java Source code

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Here is the source code for mitm.djigzo.web.components.RegExprFilter.java

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/*
 * Copyright (c) 2008-2011, Martijn Brinkers, Djigzo.
 * 
 * This file is part of Djigzo email encryption.
 *
 * Djigzo is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License 
 * version 3, 19 November 2007 as published by the Free Software 
 * Foundation.
 *
 * Djigzo is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public 
 * License along with Djigzo. If not, see <http://www.gnu.org/licenses/>
 *
 * Additional permission under GNU AGPL version 3 section 7
 * 
 * If you modify this Program, or any covered work, by linking or 
 * combining it with saaj-api-1.3.jar, saaj-impl-1.3.jar, 
 * wsdl4j-1.6.1.jar (or modified versions of these libraries), 
 * containing parts covered by the terms of Common Development and 
 * Distribution License (CDDL), Common Public License (CPL) the 
 * licensors of this Program grant you additional permission to 
 * convey the resulting work.
 */
package mitm.djigzo.web.components;

import java.util.regex.Pattern;

import mitm.common.util.RegExprUtils;
import mitm.common.ws.WebServiceCheckedException;

import org.apache.commons.lang.StringEscapeUtils;
import org.apache.tapestry5.annotations.Component;
import org.apache.tapestry5.annotations.IncludeStylesheet;
import org.apache.tapestry5.annotations.Persist;
import org.apache.tapestry5.corelib.components.Form;
import org.apache.tapestry5.corelib.components.TextField;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@IncludeStylesheet("context:styles/components/regExprFilter.css")
public class RegExprFilter {
    private final static Logger logger = LoggerFactory.getLogger(RegExprFilter.class);

    /*
     * The value to filter on. Can be a regular expression if filter is true.
     */
    @Persist
    private String filter;

    /*
     * True if the filter is a regular expression
     */
    @Persist
    private boolean regExpr;

    @Component
    private Form filterForm;

    @Component(id = "filter")
    private TextField filterTextField;

    public boolean isFilterDisabled() {
        return filter == null || filter.length() == 0;
    }

    public boolean isRegExpr() {
        return regExpr;
    }

    public void setRegExpr(boolean regExpr) {
        this.regExpr = regExpr;
    }

    public String getFilter() {
        return filter;
    }

    public void setFilter(String filter) {
        this.filter = filter;
    }

    /**
     * Returns the regular expression pattern. If the user did not select the regular expression checkbox the regular
     * expression that's being returned is prepended with (?i) (ie. case insensitive) search. If escapeHTML is true
     * the search expression is HTML escaped before a pattern is build. This is needed when you want to match
     * the pattern against a HTML file but you want the user to be able to search for HTML special characters (like <)
     * without the user having to change it into the HTML entity.
     */
    public Pattern getPattern(boolean escapeHTML) {
        /*
         * We will always return a Pattern but if the user did not select the regular expression 
         * checkbox we will create a pattern from the filter 
         */
        String expression = filter;

        Pattern pattern = null;

        if (expression != null && expression.length() > 0) {
            if (escapeHTML) {
                expression = StringEscapeUtils.escapeHtml(expression);
            }

            if (!regExpr) {
                /*
                 * We need to escape all characters that have a special meaning for regular expressions 
                 */
                expression = "(?i)" + RegExprUtils.escape(expression);
            }

            try {
                pattern = Pattern.compile(expression);
            } catch (IllegalArgumentException e) {
                /*
                 * Even though the for does not validate getPattern is still called so we should
                 * catch any compile errors.
                 */
                logger.error("Error in regular expression.");
            }
        }

        return pattern;
    }

    public void onValidateForm() throws WebServiceCheckedException {
        /*
         * Skip checks if the filter is empty
         */
        if (filter == null || filter.length() == 0) {
            return;
        }

        /*
         * Check that the filter is a valid regular expression
         */
        if (isRegExpr()) {
            try {
                Pattern.compile(filter);
            } catch (IllegalArgumentException e) {
                filterForm.recordError(filterTextField, "The filter is not a valid regular expression.");
            }
        }
    }
}