com.ufukuzun.myth.dialect.util.ExpressionUtils.java Source code

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Here is the source code for com.ufukuzun.myth.dialect.util.ExpressionUtils.java

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/*
 * Copyright 2012, Ufuk Uzun (http://www.ufukuzun.com/)
 *
 * 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 com.ufukuzun.myth.dialect.util;

import org.apache.commons.lang3.StringUtils;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public final class ExpressionUtils {

    private static final Pattern DOLLAR_EXPRESSION_PATTERN = Pattern.compile("\\$\\{.+?\\}");

    private static final Pattern RENDER_EXPRESSION_PATTERN = Pattern.compile("\\[\\[(.+?)>>(.+?)\\]\\]");

    private ExpressionUtils() {
    }

    public static List<String> splitIdFragments(String value) {
        List<String> idFragments = new ArrayList<String>();

        if (StringUtils.isNotBlank(value)) {
            value = StringUtils.remove(value, "${}");
            Matcher matcher = DOLLAR_EXPRESSION_PATTERN.matcher(value);
            while (matcher.find()) {
                idFragments.add(matcher.group());
                value = StringUtils.remove(value, matcher.group());
            }

            idFragments.addAll(Arrays.asList(StringUtils.split(value)));
        }

        return idFragments;
    }

    public static boolean isDollarExpression(String value) {
        List<String> idFragments = splitIdFragments(value);
        return !idFragments.isEmpty() && idFragments.size() == 1
                && idFragments.get(0).matches(DOLLAR_EXPRESSION_PATTERN.pattern());
    }

    public static String[] splitRenderFragmentAndUpdates(String value) {
        String renderFragment = "";
        String updates = "";

        if (StringUtils.isNotBlank(value)) {
            Matcher matcher = RENDER_EXPRESSION_PATTERN.matcher(value);
            if (matcher.matches()) {
                renderFragment = matcher.group(1).trim();
                updates = matcher.group(2).trim();
            }
        }

        return new String[] { renderFragment, updates };
    }

    public static boolean isRenderExpression(String value) {
        String[] result = splitRenderFragmentAndUpdates(value);
        return StringUtils.isNotBlank(result[0]) && StringUtils.isNotBlank(result[1]);
    }

    public static List<String> extractRenderExpressions(String value) {
        List<String> renderExpressions = new ArrayList<String>();

        if (StringUtils.isNotBlank(value)) {
            Matcher matcher = RENDER_EXPRESSION_PATTERN.matcher(value);
            while (matcher.find()) {
                renderExpressions.add(matcher.group());
            }
        }

        return renderExpressions;
    }

    public static String removeRenderExpressions(String value) {
        if (StringUtils.isNotBlank(value)) {
            List<String> renderExpressions = extractRenderExpressions(value);
            for (String each : renderExpressions) {
                value = StringUtils.remove(value, each);
            }
        }

        return value;
    }

}