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