com.haulmont.cuba.gui.xml.layout.ScreenXmlLoader.java Source code

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Here is the source code for com.haulmont.cuba.gui.xml.layout.ScreenXmlLoader.java

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/*
 * Copyright (c) 2008-2017 Haulmont.
 *
 * 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.haulmont.cuba.gui.xml.layout;

import com.haulmont.cuba.core.global.DevelopmentException;
import com.haulmont.cuba.core.global.Resources;
import com.haulmont.cuba.gui.logging.UIPerformanceLogger;
import com.haulmont.cuba.gui.xml.XmlInheritanceProcessor;
import org.apache.commons.io.IOUtils;
import org.dom4j.Document;
import org.dom4j.Element;
import org.perf4j.StopWatch;
import org.perf4j.slf4j.Slf4JStopWatch;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import javax.inject.Inject;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.util.Map;

/**
 * Loads screen XML descriptors.
 */
@Component(ScreenXmlLoader.NAME)
public class ScreenXmlLoader {

    public static final String NAME = "cuba_ScreenXmlLoader";

    @Inject
    protected Resources resources;

    @Inject
    protected ScreenXmlDocumentCache screenXmlCache;

    @Inject
    protected ScreenXmlParser screenXmlParser;

    /**
     * Loads a descriptor.
     * @param resourcePath  path to the resource containing the XML
     * @param id            screen ID
     * @param params        screen parameters
     * @return root XML element
     */
    public Element load(String resourcePath, String id, Map<String, Object> params) {
        StopWatch xmlLoadWatch = new Slf4JStopWatch(id + "#" + UIPerformanceLogger.LifeCycle.XML,
                LoggerFactory.getLogger(UIPerformanceLogger.class));

        String template = loadTemplate(resourcePath);
        Document document = getDocument(template, params);

        xmlLoadWatch.stop();
        return document.getRootElement();
    }

    protected String loadTemplate(String resourcePath) {
        InputStream stream = resources.getResourceAsStream(resourcePath);
        if (stream == null) {
            throw new DevelopmentException("Template is not found", "Path", resourcePath);
        }

        try {
            return IOUtils.toString(stream, StandardCharsets.UTF_8);
        } catch (IOException e) {
            throw new RuntimeException("Unable to read screen template");
        } finally {
            IOUtils.closeQuietly(stream);
        }
    }

    protected Document getDocument(String template, Map<String, Object> params) {
        Document document = screenXmlCache.get(template);
        if (document == null) {
            document = createDocument(template, params);
            screenXmlCache.put(template, document);
        }
        return document;
    }

    protected Document createDocument(String template, Map<String, Object> params) {
        Document originalDocument = screenXmlParser.parseDescriptor(template);

        XmlInheritanceProcessor processor = new XmlInheritanceProcessor(originalDocument, params);
        Element resultRoot = processor.getResultRoot();

        return resultRoot.getDocument();
    }
}