BeanMetadataUtils.java

/*******************************************************************************
 * Copyright (c) 2008 - 2012 Spring IDE Developers
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Spring IDE Developers - initial API and implementation
 *******************************************************************************/
package org.springframework.ide.eclipse.beans.ui.model.metadata;

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.IExtensionPoint;
import org.eclipse.core.runtime.Platform;
import org.springframework.ide.eclipse.beans.core.internal.model.BeansModelUtils;
import org.springframework.ide.eclipse.beans.core.metadata.BeansMetadataPlugin;
import org.springframework.ide.eclipse.beans.core.metadata.model.IBeanMetadata;
import org.springframework.ide.eclipse.beans.core.model.IBean;
import org.springframework.ide.eclipse.beans.core.model.IBeansComponent;
import org.springframework.ide.eclipse.beans.core.model.IBeansConfig;
import org.springframework.ide.eclipse.beans.core.model.IBeansProject;
import org.springframework.ide.eclipse.beans.ui.BeansUIPlugin;

/**
 * Helper methods to load external contributed {@link IBeanMetadataContentProvider} and
 * {@link IBeanMetadataLabelProvider} for linking in third-party contributed bean meta data.
 * @author Christian Dupuis
 * @since 2.0.5
 */
public class BeanMetadataUtils {

	private static final String LABEL_PROVIDER_ATTRIBUTE = "labelProvider";

	private static final String CONTENT_PROVIDER_ATTRIBUTE = "contentProvider";

	private static final String METADATA_PROVIDERS_ELEMENT = "metadataProviders";

	private static final String PRIORITY_ATTRIBUTE = "priority";

	public static final String META_DATA_PROVIDERS_EXTENSION_POINT = BeansUIPlugin.PLUGIN_ID + ".metadataproviders";

	public static IBeanMetadataContentProvider getContenProvider(IBeanMetadata metaDataReference) {
		IBeanMetadataContentProvider contentProvider = null;
		int priority = -1;

		IExtensionPoint point = Platform.getExtensionRegistry().getExtensionPoint(META_DATA_PROVIDERS_EXTENSION_POINT);
		if (point != null) {
			for (IExtension extension : point.getExtensions()) {
				for (IConfigurationElement config : extension.getConfigurationElements()) {
					if (METADATA_PROVIDERS_ELEMENT.equals(config.getName())
							&& config.getAttribute(CONTENT_PROVIDER_ATTRIBUTE) != null) {
						try {
							int handlerPriority = getPriority(config);
							if (handlerPriority > priority) {
								
								Object handler = config.createExecutableExtension(CONTENT_PROVIDER_ATTRIBUTE);
								if (handler instanceof IBeanMetadataContentProvider) {
									IBeanMetadataContentProvider provider = (IBeanMetadataContentProvider) handler;
									if (provider.supports(metaDataReference)) {
										contentProvider = provider;
										priority = handlerPriority;
									}
								}
							}
						}
						catch (CoreException e) {
							BeansUIPlugin.log(e);
						}
					}
				}
			}
		}
		return contentProvider;
	}

	public static IBeanMetadataLabelProvider getLabelProvider(BeanMetadataReference metaDataReference) {
		IBeanMetadataLabelProvider labelProvider = null;
		int priority = -1;

		IExtensionPoint point = Platform.getExtensionRegistry().getExtensionPoint(META_DATA_PROVIDERS_EXTENSION_POINT);
		if (point != null) {
			for (IExtension extension : point.getExtensions()) {
				for (IConfigurationElement config : extension.getConfigurationElements()) {
					if (METADATA_PROVIDERS_ELEMENT.equals(config.getName())
							&& config.getAttribute(LABEL_PROVIDER_ATTRIBUTE) != null) {
						try {
							int handlerPriority = getPriority(config);
							if (handlerPriority > priority) {

								Object handler = config.createExecutableExtension(LABEL_PROVIDER_ATTRIBUTE);
								if (handler instanceof IBeanMetadataLabelProvider) {
									IBeanMetadataLabelProvider provider = (IBeanMetadataLabelProvider) handler;
									if (provider.supports(metaDataReference)) {
										labelProvider = provider;
										priority = handlerPriority;
									}
								}
							}
						}
						catch (CoreException e) {
							BeansUIPlugin.log(e);
						}
					}
				}
			}
		}
		return labelProvider;
	}

	public static IBeanMetadataLabelProvider getLabelProvider(IBeanMetadata metaData) {
		IBeanMetadataLabelProvider labelProvider = null;
		int priority = -1;

		IExtensionPoint point = Platform.getExtensionRegistry().getExtensionPoint(META_DATA_PROVIDERS_EXTENSION_POINT);
		if (point != null) {
			for (IExtension extension : point.getExtensions()) {
				for (IConfigurationElement config : extension.getConfigurationElements()) {
					if (METADATA_PROVIDERS_ELEMENT.equals(config.getName())
							&& config.getAttribute(LABEL_PROVIDER_ATTRIBUTE) != null) {
						try {
							int handlerPriority = getPriority(config);
							if (handlerPriority > priority) {

								Object handler = config.createExecutableExtension(LABEL_PROVIDER_ATTRIBUTE);
								if (handler instanceof IBeanMetadataLabelProvider) {
									IBeanMetadataLabelProvider provider = (IBeanMetadataLabelProvider) handler;
									if (provider.supports(metaData)) {
										labelProvider = provider;
										priority = handlerPriority;
									}
								}
							}
						}
						catch (CoreException e) {
							BeansUIPlugin.log(e);
						}
					}
				}
			}
		}
		return labelProvider;
	}

	public static Collection<? extends Object> getProjectChildren(IBeansProject project) {
		Map<String, BeanMetadataReference> metaDataMapping = new HashMap<String, BeanMetadataReference>();
		// add meta data grouping
		for (IBeansConfig beansConfig : project.getConfigs()) {
			// add beans from config
			for (IBean bean : BeansModelUtils.getBeans(beansConfig)) {
				addMetaDataForBean(project, metaDataMapping, bean);
			}

			// add nested component beans; required for component scan
			for (IBeansComponent beansComponent : beansConfig.getComponents()) {
				for (IBean bean : BeansModelUtils.getBeans(beansComponent)) {
					addMetaDataForBean(project, metaDataMapping, bean);
				}
			}
		}
		return metaDataMapping.values();
	}

	private static void addMetaDataForBean(IBeansProject project, Map<String, BeanMetadataReference> metaDataMapping,
			IBean bean) {
		for (IBeanMetadata metaData : BeansMetadataPlugin.getMetadataModel().getBeanMetadata(bean)) {
			if (!metaDataMapping.containsKey(metaData.getKey())) {
				metaDataMapping.put(metaData.getKey(),
						getContenProvider(metaData).getBeanMetadataReference(metaData, project));
			}
			metaDataMapping.get(metaData.getKey()).addChild(metaData);
		}
	}
	
	private static int getPriority(IConfigurationElement config) {
		int handlerPriority = 10; // DEFAULT_PRIORITY = 10
		if (config.getAttribute(PRIORITY_ATTRIBUTE) != null) {
			handlerPriority = Integer.valueOf(config.getAttribute(PRIORITY_ATTRIBUTE));
		}
		return handlerPriority;
	}

}