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