com.cgxlib.xq.rebind.SelectorGeneratorCssToXPath.java Source code

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Here is the source code for com.cgxlib.xq.rebind.SelectorGeneratorCssToXPath.java

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/*
 * Copyright 2011, The gwtquery team.
 *
 * 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.cgxlib.xq.rebind;

/*
 * #%L
 * CGXlib
 * %%
 * Copyright (C) 2016 CGXlib (http://www.cgxlib.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.
 * #L%
  Code is originally from gwtquery, and modified by CGXlib team.
 */

import com.cgxlib.xq.client.Selector;
import com.cgxlib.xq.client.impl.SelectorEngineCssToXPath;
import com.cgxlib.xq.client.impl.SelectorEngineCssToXPath.ReplaceCallback;
import com.cgxlib.xq.client.impl.SelectorEngineCssToXPath.Replacer;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.core.ext.UnableToCompleteException;
import com.google.gwt.core.ext.typeinfo.JMethod;
import com.google.gwt.user.rebind.SourceWriter;

import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
import java.util.ArrayList;
import java.util.regex.MatchResult;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Compile time selector generator which translates selector into XPath at
 * compile time. It Uses the SelectorEngineCssToXpath to produce the xpath
 * selectors
 */
public class SelectorGeneratorCssToXPath extends SelectorGeneratorBase {

    /**
     * The replacer implementation for the JVM.
     */
    public static final Replacer replacer = new Replacer() {
        public String replaceAll(String s, String r, Object o) {
            Pattern p = Pattern.compile(r);
            if (o instanceof ReplaceCallback) {
                final Matcher matcher = p.matcher(s);
                ReplaceCallback callback = (ReplaceCallback) o;
                while (matcher.find()) {
                    final MatchResult matchResult = matcher.toMatchResult();
                    ArrayList<String> argss = new ArrayList<String>();
                    for (int i = 0; i < matchResult.groupCount() + 1; i++) {
                        argss.add(matchResult.group(i));
                    }
                    final String replacement = callback.foundMatch(argss);
                    s = s.substring(0, matchResult.start()) + replacement + s.substring(matchResult.end());
                    matcher.reset(s);
                }
                return s;
            } else {
                return p.matcher(s).replaceAll(o.toString());
            }
        }
    };

    private SelectorEngineCssToXPath engine = new SelectorEngineCssToXPath(replacer);
    private XPathFactory factory = XPathFactory.newInstance();
    private XPath xpath = factory.newXPath();

    protected String css2Xpath(String s) {
        return engine.css2Xpath(s);
    }

    protected void generateMethodBody(SourceWriter sw, JMethod method, TreeLogger treeLogger, boolean hasContext)
            throws UnableToCompleteException {

        String selector = method.getAnnotation(Selector.class).value();
        String xselector = css2Xpath(selector);

        // Validate the generated xpath selector.
        try {
            validateXpath(xselector);
        } catch (XPathExpressionException e1) {
            System.err.println("Invalid XPath generated selector, please revise it: " + xselector);
            if (!selector.equals(xselector)) {
                System.err.println(
                        "If your css2 selector syntax is correct, open an issue in the gwtquery project. cssselector:"
                                + selector + " xpath: " + xselector);
            }
            throw new UnableToCompleteException();
        }

        sw.println("return " + wrap(method, "xpathEvaluate(\"" + xselector + "\", root)") + ";");
    }

    public void validateXpath(String xselector) throws XPathExpressionException {
        xpath.compile(xselector);
    }

    protected String getImplSuffix() {
        return "CssToXPath" + super.getImplSuffix();
    }
}