bundles/org.eclipse.capra.core/src/org/eclipse/capra/core/helpers/EMFHelper.java - capra/org.eclipse.capra - Git at Google

 /*******************************************************************************
  * Copyright (c) 2016, 2021 Chalmers | University of Gothenburg, rt-labs and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v20.html
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  * Contributors:
  *      Chalmers | University of Gothenburg and rt-labs - initial API and implementation and/or initial documentation
  *      Chalmers | University of Gothenburg - additional features, updated API
  *******************************************************************************/
 package org.eclipse.capra.core.helpers;

 import java.util.ArrayList;
 import java.util.List;

 import org.eclipse.emf.ecore.EAttribute;
 import org.eclipse.emf.ecore.EObject;

 /**
  * Contains methods to work with {@link EObject} instances encountered when
  * handling EMF models.
  */
 public class EMFHelper {

 	private EMFHelper() {
 		super();
 	}

 	/**
 	 * Builds an identifier String for the given EObject. This identifier starts
 	 * with
 	 * <ul>
 	 * <li>the attribute of the EObject as a String, if the EObject does only have
 	 * one attribute.</li>
 	 * <li>the attribute called 'name' of the EObject, if it has such an
 	 * attribute</li>
 	 * <li>any attribute of the EObject, but String attributes are preferred</li>
 	 * </ul>
 	 * The identifier ends with " : " followed by the type of the EObject. <br>
 	 * Example: A Node with the name "foo" will result in "foo : Node" <br>
 	 * If the EObject does not have any attributes or all attributes have the value
 	 * null, this function will only return the type of the EObject.
 	 */
 	public static String getIdentifier(final EObject eObject) {
 		if (eObject == null) {
 			return "<null>";
 		}
 		if (eObject.eClass() == null) {
 			return eObject.toString();
 		}

 		boolean success = false;

 		List<EAttribute> attributes = eObject.eClass().getEAllAttributes();
 		StringBuilder identifier = new StringBuilder();

 		success = tryGetNameAttribute(eObject, identifier);

 		// We didn't find a name. Try finding something else that we can use.
 		if (!success) {
 			success = tryGetAnyAttribute(eObject, attributes, identifier);
 		}

 		if (success) {
 			identifier.append(" : ");
 		}

 		identifier.append(eObject.eClass().getName());

 		return identifier.toString();
 	}

 	/**
 	 * Tries to retrieve a {@code String} representation of the provided
 	 * {@code EAttribute} for the provided {@code EObject}. If the attribute is
 	 * {@code null}, it is not a valid attribute of the given {@code EObject} or the
 	 * value of the attribute is {@code} null, this method will return {@code false}
 	 * and the provided {@code StringBuilder} will not be altered.
 	 *
 	 * @param builder {@code StringBuilder} to construct the String representation
 	 *                of the provided {@code EAttribute}. If this method returns
 	 *                {@code true}, this parameter has been changed, if it returns
 	 *                {@code false}, the {@code StringBuilder} is unaltered.
 	 * @return indicates the success of this function and if the
 	 *         {@code StringBuilder} contains output.
 	 */
 	public static boolean tryGetAttribute(final EObject eObject, final EAttribute attribute, final StringBuilder name) {
 		boolean success = false;
 		if (attribute != null) {
 			try {
 				Object obj = eObject.eGet(attribute);
 				if (obj != null) {
 					name.append(obj.toString());
 					success = true;
 				}
 			} catch (IllegalArgumentException ex) {
 				// Deliberately do nothing.
 				// This can happen if the provided attribute is not an attribute of the eObject.
 				// In this case, we just want the method to return false, which it does if we
 				// just hold our feet still.
 			}
 		}
 		return success;
 	}

 	/**
 	 * Tries to retrieve a String representation of the attribute "name" from the
 	 * provided {@code EObject}.
 	 *
 	 * @param builder {@code StringBuilder} to construct the String representation
 	 *                of the {@code EObject}'s "name" attribute. If this function
 	 *                returns {@code true}, this parameter has been filled, if it
 	 *                returns {@code false}, the {@code StringBuilder} is unaltered.
 	 * @return indicates the success of this function and if the
 	 *         {@code StringBuilder} contains output.
 	 * @see #tryGetAttribute(EObject, EAttribute, StringBuilder)
 	 */
 	public static boolean tryGetNameAttribute(final EObject eObject, final StringBuilder builder) {
 		boolean success = false;
 		for (EAttribute attribute : eObject.eClass().getEAllAttributes()) {
 			if (attribute.getName().equals("name")) {
 				success = tryGetAttribute(eObject, attribute, builder);
 			}
 		}
 		return success;
 	}

 	/**
 	 * Attempts to retrieve a {@code String} representation of any of the given
 	 * attributes. For that purpose, it iterates over all attributes until it finds
 	 * one which is not null and non-empty. It then adds the String representation
 	 * of that attribute's value to the provided {@code StringBuilder} and returns
 	 * {@code true}.
 	 *
 	 * @param builder {@code StringBuilder} to construct the String representation
 	 *                of the first non-null, non-empty attribute. If this function
 	 *                returns {@code true}, this parameter has been filled, if it
 	 *                returns {@code false}, the {@code StringBuilder} is unaltered.
 	 * @return indicates the success of this function and if the
 	 *         {@code StringBuilder} contains output.
 	 */
 	public static boolean tryGetAnyAttribute(final EObject eObject, final List<EAttribute> attributes,
 			final StringBuilder name) {
 		boolean success = false;
 		String stringName = "";
 		for (EAttribute feature : attributes) {
 			Object obj = eObject.eGet(feature);
 			if (obj instanceof String) {
 				stringName = (String) obj;
 			} else if (obj != null) {
 				stringName = obj.toString();
 			}
 			if (stringName != null && !stringName.equals("null")) {
 				name.append(stringName);
 				success = true;
 				break;
 			}
 		}
 		return success;
 	}

 	/**
 	 * Linearizes a tree to a list. The function checks if the provided parameter is
 	 * of type {@link EObject} and linearizes only if that is the case. The root of
 	 * the tree will always be the first element in the list.
 	 *
 	 * @param object the object to linearize
 	 * @return a list of {@link EObject}s originally contained in the tree structure
 	 *         of the parameter or an empty list if the paramter was not an
 	 *         {@link EObject}
 	 */
 	public static List<EObject> linearize(Object object) {
 		ArrayList<EObject> elementList = new ArrayList<>();
 		if (object instanceof EObject) {
 			EObject root = (EObject) object;
 			elementList.add(root);
 			root.eAllContents().forEachRemaining(elementList::add);
 		}
 		return elementList;
 	}

 	/**
 	 * Public API access for other classes to get the name attribute of an EObject
 	 *
 	 * @param eObject
 	 * @return String
 	 */
 	public static String getNameAttribute(final EObject eObject) {
 		StringBuilder name = new StringBuilder();
 		tryGetNameAttribute(eObject, name);
 		return name.toString();
 	}

 	/**
 	 * Compares to {@link EObject} instances based on their identifier using
 	 * {@link EMFHelper#getIdentifier(EObject)}.
 	 *
 	 * @param first  the first {@code EObject} to compare
 	 * @param second the second {@code EObject} to compare
 	 * @return {@code true} if the identifiers of the two instances are equal,
 	 *         {@code false} otherwise
 	 */
 	public static boolean hasSameIdentifier(EObject first, EObject second) {
 		return EMFHelper.getIdentifier(first).equals(EMFHelper.getIdentifier(second));
 	}

 	/**
 	 * Checks if the given {@link EObject} is in the list of {@code EObject}s using
 	 * {@link #hasSameIdentifier(EObject, EObject)}.
 	 *
 	 * @param list the list to check
 	 * @param obj  the object to check for
 	 * @return {@code true} if {@code obj} is in {@code list}, {@code false}
 	 *         otherwise
 	 */
 	public static boolean isElementInList(List<EObject> list, EObject obj) {
 		for (EObject next : list) {
 			if (EMFHelper.hasSameIdentifier(obj, next)) {
 				return true;
 			}
 		}
 		return false;
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2016, 2021 Chalmers \| University of Gothenburg, rt-labs and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v2.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v20.html
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* Chalmers \| University of Gothenburg and rt-labs - initial API and implementation and/or initial documentation
	* Chalmers \| University of Gothenburg - additional features, updated API
	*******************************************************************************/
	package org.eclipse.capra.core.helpers;

	import java.util.ArrayList;
	import java.util.List;

	import org.eclipse.emf.ecore.EAttribute;
	import org.eclipse.emf.ecore.EObject;

	/**
	* Contains methods to work with {@link EObject} instances encountered when
	* handling EMF models.
	*/
	public class EMFHelper {

	private EMFHelper() {
	super();
	}

	/**
	* Builds an identifier String for the given EObject. This identifier starts
	* with
	* <ul>
	* <li>the attribute of the EObject as a String, if the EObject does only have
	* one attribute.</li>
	* <li>the attribute called 'name' of the EObject, if it has such an
	* attribute</li>
	* <li>any attribute of the EObject, but String attributes are preferred</li>
	* </ul>
	* The identifier ends with " : " followed by the type of the EObject. <br>
	* Example: A Node with the name "foo" will result in "foo : Node" <br>
	* If the EObject does not have any attributes or all attributes have the value
	* null, this function will only return the type of the EObject.
	*/
	public static String getIdentifier(final EObject eObject) {
	if (eObject == null) {
	return "<null>";
	}
	if (eObject.eClass() == null) {
	return eObject.toString();
	}

	boolean success = false;

	List<EAttribute> attributes = eObject.eClass().getEAllAttributes();
	StringBuilder identifier = new StringBuilder();

	success = tryGetNameAttribute(eObject, identifier);

	// We didn't find a name. Try finding something else that we can use.
	if (!success) {
	success = tryGetAnyAttribute(eObject, attributes, identifier);
	}

	if (success) {
	identifier.append(" : ");
	}

	identifier.append(eObject.eClass().getName());

	return identifier.toString();
	}

	/**
	* Tries to retrieve a {@code String} representation of the provided
	* {@code EAttribute} for the provided {@code EObject}. If the attribute is
	* {@code null}, it is not a valid attribute of the given {@code EObject} or the
	* value of the attribute is {@code} null, this method will return {@code false}
	* and the provided {@code StringBuilder} will not be altered.
	*
	* @param builder {@code StringBuilder} to construct the String representation
	* of the provided {@code EAttribute}. If this method returns
	* {@code true}, this parameter has been changed, if it returns
	* {@code false}, the {@code StringBuilder} is unaltered.
	* @return indicates the success of this function and if the
	* {@code StringBuilder} contains output.
	*/
	public static boolean tryGetAttribute(final EObject eObject, final EAttribute attribute, final StringBuilder name) {
	boolean success = false;
	if (attribute != null) {
	try {
	Object obj = eObject.eGet(attribute);
	if (obj != null) {
	name.append(obj.toString());
	success = true;
	}
	} catch (IllegalArgumentException ex) {
	// Deliberately do nothing.
	// This can happen if the provided attribute is not an attribute of the eObject.
	// In this case, we just want the method to return false, which it does if we
	// just hold our feet still.
	}
	}
	return success;
	}

	/**
	* Tries to retrieve a String representation of the attribute "name" from the
	* provided {@code EObject}.
	*
	* @param builder {@code StringBuilder} to construct the String representation
	* of the {@code EObject}'s "name" attribute. If this function
	* returns {@code true}, this parameter has been filled, if it
	* returns {@code false}, the {@code StringBuilder} is unaltered.
	* @return indicates the success of this function and if the
	* {@code StringBuilder} contains output.
	* @see #tryGetAttribute(EObject, EAttribute, StringBuilder)
	*/
	public static boolean tryGetNameAttribute(final EObject eObject, final StringBuilder builder) {
	boolean success = false;
	for (EAttribute attribute : eObject.eClass().getEAllAttributes()) {
	if (attribute.getName().equals("name")) {
	success = tryGetAttribute(eObject, attribute, builder);
	}
	}
	return success;
	}

	/**
	* Attempts to retrieve a {@code String} representation of any of the given
	* attributes. For that purpose, it iterates over all attributes until it finds
	* one which is not null and non-empty. It then adds the String representation
	* of that attribute's value to the provided {@code StringBuilder} and returns
	* {@code true}.
	*
	* @param builder {@code StringBuilder} to construct the String representation
	* of the first non-null, non-empty attribute. If this function
	* returns {@code true}, this parameter has been filled, if it
	* returns {@code false}, the {@code StringBuilder} is unaltered.
	* @return indicates the success of this function and if the
	* {@code StringBuilder} contains output.
	*/
	public static boolean tryGetAnyAttribute(final EObject eObject, final List<EAttribute> attributes,
	final StringBuilder name) {
	boolean success = false;
	String stringName = "";
	for (EAttribute feature : attributes) {
	Object obj = eObject.eGet(feature);
	if (obj instanceof String) {
	stringName = (String) obj;
	} else if (obj != null) {
	stringName = obj.toString();
	}
	if (stringName != null && !stringName.equals("null")) {
	name.append(stringName);
	success = true;
	break;
	}
	}
	return success;
	}

	/**
	* Linearizes a tree to a list. The function checks if the provided parameter is
	* of type {@link EObject} and linearizes only if that is the case. The root of
	* the tree will always be the first element in the list.
	*
	* @param object the object to linearize
	* @return a list of {@link EObject}s originally contained in the tree structure
	* of the parameter or an empty list if the paramter was not an
	* {@link EObject}
	*/
	public static List<EObject> linearize(Object object) {
	ArrayList<EObject> elementList = new ArrayList<>();
	if (object instanceof EObject) {
	EObject root = (EObject) object;
	elementList.add(root);
	root.eAllContents().forEachRemaining(elementList::add);
	}
	return elementList;
	}

	/**
	* Public API access for other classes to get the name attribute of an EObject
	*
	* @param eObject
	* @return String
	*/
	public static String getNameAttribute(final EObject eObject) {
	StringBuilder name = new StringBuilder();
	tryGetNameAttribute(eObject, name);
	return name.toString();
	}

	/**
	* Compares to {@link EObject} instances based on their identifier using
	* {@link EMFHelper#getIdentifier(EObject)}.
	*
	* @param first the first {@code EObject} to compare
	* @param second the second {@code EObject} to compare
	* @return {@code true} if the identifiers of the two instances are equal,
	* {@code false} otherwise
	*/
	public static boolean hasSameIdentifier(EObject first, EObject second) {
	return EMFHelper.getIdentifier(first).equals(EMFHelper.getIdentifier(second));
	}

	/**
	* Checks if the given {@link EObject} is in the list of {@code EObject}s using
	* {@link #hasSameIdentifier(EObject, EObject)}.
	*
	* @param list the list to check
	* @param obj the object to check for
	* @return {@code true} if {@code obj} is in {@code list}, {@code false}
	* otherwise
	*/
	public static boolean isElementInList(List<EObject> list, EObject obj) {
	for (EObject next : list) {
	if (EMFHelper.hasSameIdentifier(obj, next)) {
	return true;
	}
	}
	return false;
	}
	}