001/*
002 * (C) Copyright 2013 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     Florent Guillaume
018 */
019package org.nuxeo.ecm.core.api.impl;
020
021import java.util.ArrayList;
022import java.util.Iterator;
023import java.util.List;
024import java.util.NoSuchElementException;
025
026import org.apache.commons.logging.Log;
027import org.apache.commons.logging.LogFactory;
028import org.nuxeo.ecm.core.api.CoreSession;
029import org.nuxeo.ecm.core.api.DocumentModel;
030import org.nuxeo.ecm.core.api.DocumentModelIterator;
031import org.nuxeo.ecm.core.api.DocumentRef;
032import org.nuxeo.ecm.core.api.Filter;
033import org.nuxeo.ecm.core.api.IdRef;
034
035/**
036 * Iterator over the children of a folder.
037 */
038public class DocumentModelChildrenIterator implements DocumentModelIterator {
039
040    private static final Log log = LogFactory.getLog(DocumentModelChildrenIterator.class);
041
042    private CoreSession session;
043
044    private String type;
045
046    private Filter filter;
047
048    private Iterator<String> it;
049
050    private DocumentModel next;
051
052    public DocumentModelChildrenIterator(CoreSession session, DocumentRef parentRef, String type, Filter filter)
053            {
054        this.session = session;
055        this.type = type;
056        this.filter = filter;
057
058        // fetch all the children ids now
059        List<DocumentRef> refs = session.getChildrenRefs(parentRef, null);
060        List<String> ids = new ArrayList<>(refs.size());
061        for (DocumentRef ref : refs) {
062            ids.add(ref.toString()); // always an IdRef
063        }
064        it = ids.iterator();
065    }
066
067    @Override
068    public boolean hasNext() {
069        if (next != null) {
070            return true;
071        }
072        // this could be optimized to retrieve batches of documents instead of
073        // one at a time; this would need to call SQLSession.getDocumentsById
074        // through a new CoreSession API (or improve getDocuments)
075        for (;;) {
076            if (!it.hasNext()) {
077                return false;
078            }
079            String id = it.next();
080            IdRef idRef = new IdRef(id);
081            if (!session.exists(idRef)) {
082                continue;
083            }
084            DocumentModel doc;
085            doc = session.getDocument(idRef);
086            if (accept(doc)) {
087                next = doc;
088                return true;
089            }
090            // continue
091        }
092    }
093
094    private boolean accept(DocumentModel doc) {
095        if (type != null && !type.equals(doc.getType())) {
096            return false;
097        }
098        if (filter != null && !filter.accept(doc)) {
099            return false;
100        }
101        return true;
102    }
103
104    @Override
105    public DocumentModel next() {
106        if (!hasNext()) {
107            throw new NoSuchElementException();
108        }
109        DocumentModel res = next;
110        next = null;
111        return res;
112    }
113
114    @Override
115    public void remove() {
116        throw new UnsupportedOperationException();
117    }
118
119    @Override
120    public Iterator<DocumentModel> iterator() {
121        return this; // NOSONAR this iterable does not support multiple traversals
122    }
123
124    @Override
125    public long size() {
126        return UNKNOWN_SIZE;
127    }
128
129}