org.argeo.cms/src/org/argeo/cms/acr/xml/DomContentProvider.java

   1 package org.argeo.cms.acr.xml;
   2
   3 import java.io.IOException;
   4 import java.io.OutputStream;
   5 import java.util.ArrayList;
   6 import java.util.Collections;
   7 import java.util.Iterator;
   8 import java.util.List;
   9
  10 import javax.xml.namespace.NamespaceContext;
  11 import javax.xml.transform.TransformerFactory;
  12 import javax.xml.xpath.XPath;
  13 import javax.xml.xpath.XPathConstants;
  14 import javax.xml.xpath.XPathExpressionException;
  15 import javax.xml.xpath.XPathFactory;
  16
  17 import org.argeo.api.acr.Content;
  18 import org.argeo.api.acr.ContentNotFoundException;
  19 import org.argeo.api.acr.CrName;
  20 import org.argeo.api.acr.NamespaceUtils;
  21 import org.argeo.api.acr.spi.ContentProvider;
  22 import org.argeo.api.acr.spi.ProvidedContent;
  23 import org.argeo.api.acr.spi.ProvidedSession;
  24 import org.argeo.cms.acr.CmsContentRepository;
  25 import org.w3c.dom.Document;
  26 import org.w3c.dom.Element;
  27 import org.w3c.dom.NodeList;
  28
  29 public class DomContentProvider implements ContentProvider, NamespaceContext {
  30         private final Document document;
  31
  32         // XPath
  33         // TODO centralise in some executor?
  34         private final ThreadLocal<XPath> xPath;
  35
  36         private TransformerFactory transformerFactory;
  37
  38         private String mountPath;
  39
  40         public DomContentProvider(String mountPath, Document document) {
  41                 this.mountPath = mountPath;
  42                 this.document = document;
  43                 this.document.normalizeDocument();
  44
  45                 transformerFactory = TransformerFactory.newInstance();
  46
  47                 XPathFactory xPathFactory = XPathFactory.newInstance();
  48                 xPath = new ThreadLocal<>() {
  49
  50                         @Override
  51                         protected XPath initialValue() {
  52                                 // TODO set the document as namespace context?
  53                                 XPath res = xPathFactory.newXPath();
  54                                 res.setNamespaceContext(DomContentProvider.this);
  55                                 return res;
  56                         }
  57                 };
  58         }
  59
  60 //      @Override
  61 //      public Content get() {
  62 //              return new DomContent(this, document.getDocumentElement());
  63 //      }
  64
  65 //      public Element createElement(String name) {
  66 //              return document.createElementNS(null, name);
  67 //
  68 //      }
  69
  70         @Override
  71         public ProvidedContent get(ProvidedSession session, String relativePath) {
  72                 if ("".equals(relativePath))
  73                         return new DomContent(session, this, document.getDocumentElement());
  74
  75                 NodeList nodes = findContent(relativePath);
  76                 if (nodes.getLength() > 1)
  77                         throw new IllegalArgumentException("Multiple content found for " + relativePath + " under " + mountPath);
  78                 if (nodes.getLength() == 0)
  79                         throw new ContentNotFoundException(session, mountPath + "/" + relativePath,
  80                                         "Path " + relativePath + " under " + mountPath + " was not found");
  81                 Element element = (Element) nodes.item(0);
  82                 return new DomContent(session, this, element);
  83         }
  84
  85         protected NodeList findContent(String relativePath) {
  86                 if (relativePath.startsWith("/"))
  87                         throw new IllegalArgumentException("Relative path cannot start with /");
  88                 String xPathExpression = '/' + relativePath;
  89                 if ("/".equals(mountPath))
  90                         xPathExpression = "/" + CrName.root.qName() + xPathExpression;
  91                 try {
  92                         NodeList nodes = (NodeList) xPath.get().evaluate(xPathExpression, document, XPathConstants.NODESET);
  93                         return nodes;
  94                 } catch (XPathExpressionException e) {
  95                         throw new IllegalArgumentException("XPath expression " + xPathExpression + " cannot be evaluated", e);
  96                 }
  97
  98         }
  99
 100         @Override
 101         public boolean exists(ProvidedSession session, String relativePath) {
 102                 if ("".equals(relativePath))
 103                         return true;
 104                 NodeList nodes = findContent(relativePath);
 105                 return nodes.getLength() != 0;
 106         }
 107
 108         public void persist(ProvidedSession session) {
 109                 if (mountPath != null) {
 110                         Content mountPoint = session.getMountPoint(mountPath);
 111                         try (OutputStream out = mountPoint.open(OutputStream.class)) {
 112                                 CmsContentRepository contentRepository = (CmsContentRepository) session.getRepository();
 113                                 contentRepository.writeDom(document, out);
 114                         } catch (IOException e) {
 115                                 throw new IllegalStateException("Cannot persist " + mountPath, e);
 116                         }
 117                 }
 118         }
 119
 120         @Override
 121         public String getMountPath() {
 122                 return mountPath;
 123         }
 124
 125         public void registerPrefix(String prefix, String namespace) {
 126                 DomUtils.addNamespace(document.getDocumentElement(), prefix, namespace);
 127         }
 128
 129         /*
 130          * NAMESPACE CONTEXT
 131          */
 132         @Override
 133         public String getNamespaceURI(String prefix) {
 134                 String namespaceURI = NamespaceUtils.getStandardNamespaceURI(prefix);
 135                 if (namespaceURI != null)
 136                         return namespaceURI;
 137                 return document.lookupNamespaceURI(prefix);
 138         }
 139
 140         @Override
 141         public String getPrefix(String namespaceURI) {
 142                 String prefix = NamespaceUtils.getStandardPrefix(namespaceURI);
 143                 if (prefix != null)
 144                         return prefix;
 145                 return document.lookupPrefix(namespaceURI);
 146         }
 147
 148         @Override
 149         public Iterator<String> getPrefixes(String namespaceURI) {
 150                 List<String> res = new ArrayList<>();
 151                 res.add(getPrefix(namespaceURI));
 152                 return Collections.unmodifiableList(res).iterator();
 153         }
 154
 155         TransformerFactory getTransformerFactory() {
 156                 return transformerFactory;
 157         }
 158
 159 }