Java tutorial
/* * See the NOTICE file distributed with this work for additional * information regarding copyright ownership. * * This is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * This software is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this software; if not, write to the Free * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA, or see the FSF site: http://www.fsf.org. */ package org.xwiki.refactoring.internal.splitter; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.ListIterator; import java.util.Map; import javax.inject.Singleton; import org.apache.commons.lang3.StringUtils; import org.xwiki.component.annotation.Component; import org.xwiki.refactoring.WikiDocument; import org.xwiki.refactoring.splitter.DocumentSplitter; import org.xwiki.refactoring.splitter.criterion.SplittingCriterion; import org.xwiki.refactoring.splitter.criterion.naming.NamingCriterion; import org.xwiki.rendering.block.Block; import org.xwiki.rendering.block.Block.Axes; import org.xwiki.rendering.block.BlockFilter; import org.xwiki.rendering.block.HeaderBlock; import org.xwiki.rendering.block.IdBlock; import org.xwiki.rendering.block.LinkBlock; import org.xwiki.rendering.block.NewLineBlock; import org.xwiki.rendering.block.SectionBlock; import org.xwiki.rendering.block.SpaceBlock; import org.xwiki.rendering.block.SpecialSymbolBlock; import org.xwiki.rendering.block.WordBlock; import org.xwiki.rendering.block.XDOM; import org.xwiki.rendering.block.match.ClassBlockMatcher; import org.xwiki.rendering.listener.reference.DocumentResourceReference; import org.xwiki.rendering.listener.reference.ResourceReference; import org.xwiki.rendering.listener.reference.ResourceType; /** * Default implementation of {@link DocumentSplitter}. * * @version $Id: fc0fdd10dbe96c433b09736622c62de752a4bce5 $ * @since 1.9M1 */ @Component @Singleton public class DefaultDocumentSplitter implements DocumentSplitter { /** * The name of the anchor link parameter. */ private static final String ANCHOR_PARAMETER = "anchor"; @Override public List<WikiDocument> split(WikiDocument rootDoc, SplittingCriterion splittingCriterion, NamingCriterion namingCriterion) { List<WikiDocument> result = new ArrayList<WikiDocument>(); // Add the rootDoc into the result result.add(rootDoc); // Recursively split the root document. split(rootDoc, rootDoc.getXdom().getChildren(), 1, result, splittingCriterion, namingCriterion); updateAnchors(result); return result; } /** * A recursive method for traversing the xdom of the root document and splitting it into sub documents. * * @param parentDoc the parent {@link WikiDocument} under which the given list of children reside. * @param children current list of blocks being traversed. * @param depth the depth from the root xdom to current list of children. * @param result space for storing the resulting documents. * @param splittingCriterion the {@link SplittingCriterion}. * @param namingCriterion the {@link NamingCriterion}. */ private void split(WikiDocument parentDoc, List<Block> children, int depth, List<WikiDocument> result, SplittingCriterion splittingCriterion, NamingCriterion namingCriterion) { ListIterator<Block> it = children.listIterator(); while (it.hasNext()) { Block block = it.next(); if (splittingCriterion.shouldSplit(block, depth)) { // Split a new document and add it to the results list. XDOM xdom = new XDOM(block.getChildren()); String newDocumentName = namingCriterion.getDocumentName(xdom); WikiDocument newDoc = new WikiDocument(newDocumentName, xdom, parentDoc); result.add(newDoc); // Remove the original block from the parent document. it.remove(); // Place a link from the parent to child. it.add(new NewLineBlock()); it.add(createLink(block, newDocumentName)); // Check whether this node should be further traversed. if (splittingCriterion.shouldIterate(block, depth)) { split(newDoc, newDoc.getXdom().getChildren(), depth + 1, result, splittingCriterion, namingCriterion); } } else if (splittingCriterion.shouldIterate(block, depth)) { split(parentDoc, block.getChildren(), depth + 1, result, splittingCriterion, namingCriterion); } } } /** * Creates a {@link LinkBlock} suitable to be placed in the parent document. * * @param block the {@link Block} that has just been split into a separate document. * @param target name of the target wiki document. * @return a {@link LinkBlock} representing the link from the parent document to new document. */ private LinkBlock createLink(Block block, String target) { Block firstBlock = block.getChildren().get(0); if (firstBlock instanceof HeaderBlock) { DocumentResourceReference reference = new DocumentResourceReference(target); // Clone the header block and remove any unwanted stuff Block clonedHeaderBlock = firstBlock.clone(new BlockFilter() { @Override public List<Block> filter(Block block) { List<Block> blocks = new ArrayList<Block>(); if (block instanceof WordBlock || block instanceof SpaceBlock || block instanceof SpecialSymbolBlock) { blocks.add(block); } return blocks; } }); return new LinkBlock(clonedHeaderBlock.getChildren(), reference, false); } else if (firstBlock instanceof SectionBlock) { return createLink(firstBlock, target); } else { throw new IllegalArgumentException( "A SectionBlock should either begin with a HeaderBlock or another SectionBlock."); } } /** * Update the links to internal document fragments after those fragments have been moved as a result of the split. * For instance the "#Chapter1" anchor will be updated to "ChildDocument#Chapter1" if the document fragment * identified by "Chapter1" has been moved to "ChildDocument" as a result of the split. * * @param documents the list of documents whose anchors to update */ private void updateAnchors(List<WikiDocument> documents) { // First we need to collect all the document fragments and map them to their new location. Map<String, String> fragments = collectDocumentFragments(documents); // Update the anchors. for (WikiDocument document : documents) { updateAnchors(document, fragments); } } /** * @param document the document whose anchors to update * @param fragments see {@link #collectDocumentFragments(List)} */ private void updateAnchors(WikiDocument document, Map<String, String> fragments) { for (LinkBlock linkBlock : document.getXdom().<LinkBlock>getBlocks(new ClassBlockMatcher(LinkBlock.class), Axes.DESCENDANT)) { ResourceReference reference = linkBlock.getReference(); ResourceType resoureceType = reference.getType(); String fragment = null; if ((ResourceType.DOCUMENT.equals(resoureceType) || ResourceType.SPACE.equals(resoureceType)) && StringUtils.isEmpty(reference.getReference())) { fragment = reference.getParameter(ANCHOR_PARAMETER); } else if (StringUtils.startsWith(reference.getReference(), "#") && (ResourceType.PATH.equals(resoureceType) || ResourceType.URL.equals(resoureceType))) { fragment = reference.getReference().substring(1); } String targetDocument = fragments.get(fragment); if (targetDocument != null && !targetDocument.equals(document.getFullName())) { // The fragment has been moved so we need to update the link. reference.setType(ResourceType.DOCUMENT); reference.setReference(targetDocument); reference.setParameter(ANCHOR_PARAMETER, fragment); } } } /** * Looks for document fragments in the given documents. A document fragment is identified by an {@link IdBlock} for * instance. * * @param documents the list of documents whose fragments to collect * @return the collection of document fragments mapped to the document that contains them */ private Map<String, String> collectDocumentFragments(List<WikiDocument> documents) { Map<String, String> fragments = new HashMap<String, String>(); for (WikiDocument document : documents) { for (IdBlock idBlock : document.getXdom().<IdBlock>getBlocks(new ClassBlockMatcher(IdBlock.class), Axes.DESCENDANT)) { fragments.put(idBlock.getName(), document.getFullName()); } } return fragments; } }