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

   1 package org.argeo.cms.acr.xml;
   2
   3 import java.util.ArrayList;
   4 import java.util.Collections;
   5 import java.util.Iterator;
   6 import java.util.List;
   7
   8 import javax.xml.namespace.NamespaceContext;
   9 import javax.xml.xpath.XPath;
  10 import javax.xml.xpath.XPathConstants;
  11 import javax.xml.xpath.XPathExpressionException;
  12 import javax.xml.xpath.XPathFactory;
  13
  14 import org.argeo.api.acr.Content;
  15 import org.argeo.api.acr.ContentNotFoundException;
  16 import org.argeo.api.acr.NamespaceUtils;
  17 import org.argeo.api.acr.spi.ContentProvider;
  18 import org.argeo.api.acr.spi.ProvidedSession;
  19 import org.w3c.dom.Document;
  20 import org.w3c.dom.Element;
  21 import org.w3c.dom.NodeList;
  22
  23 public class DomContentProvider implements ContentProvider, NamespaceContext {
  24         private Document document;
  25
  26         // XPath
  27         // TODO centralise in some executor?
  28         private final ThreadLocal<XPath> xPath;
  29
  30         public DomContentProvider(Document document) {
  31                 this.document = document;
  32                 this.document.normalizeDocument();
  33                 XPathFactory xPathFactory = XPathFactory.newInstance();
  34                 xPath = new ThreadLocal<>() {
  35
  36                         @Override
  37                         protected XPath initialValue() {
  38                                 // TODO set the document as namespace context?
  39                                 XPath res = xPathFactory.newXPath();
  40                                 res.setNamespaceContext(DomContentProvider.this);
  41                                 return res;
  42                         }
  43                 };
  44         }
  45
  46 //      @Override
  47 //      public Content get() {
  48 //              return new DomContent(this, document.getDocumentElement());
  49 //      }
  50
  51 //      public Element createElement(String name) {
  52 //              return document.createElementNS(null, name);
  53 //
  54 //      }
  55
  56         @Override
  57         public Content get(ProvidedSession session, String mountPath, String relativePath) {
  58                 if ("".equals(relativePath))
  59                         return new DomContent(session, this, document.getDocumentElement());
  60                 if (relativePath.startsWith("/"))
  61                         throw new IllegalArgumentException("Relative path cannot start with /");
  62
  63                 String xPathExpression = '/' + relativePath;
  64                 if ("/".equals(mountPath))
  65                         xPathExpression = "/cr:root" + xPathExpression;
  66                 try {
  67                         NodeList nodes = (NodeList) xPath.get().evaluate(xPathExpression, document, XPathConstants.NODESET);
  68                         if (nodes.getLength() > 1)
  69                                 throw new IllegalArgumentException(
  70                                                 "Multiple content found for " + relativePath + " under " + mountPath);
  71                         if (nodes.getLength() == 0)
  72                                 throw new ContentNotFoundException("Path " + relativePath + " under " + mountPath + " was not found");
  73                         Element element = (Element) nodes.item(0);
  74                         return new DomContent(session, this, element);
  75                 } catch (XPathExpressionException e) {
  76                         throw new IllegalArgumentException("XPath expression " + xPathExpression + " cannot be evaluated", e);
  77                 }
  78         }
  79
  80         /*
  81          * NAMESPACE CONTEXT
  82          */
  83         @Override
  84         public String getNamespaceURI(String prefix) {
  85                 String namespaceURI = NamespaceUtils.getStandardNamespaceURI(prefix);
  86                 if (namespaceURI != null)
  87                         return namespaceURI;
  88                 return document.lookupNamespaceURI(prefix);
  89         }
  90
  91         @Override
  92         public String getPrefix(String namespaceURI) {
  93                 String prefix = NamespaceUtils.getStandardPrefix(namespaceURI);
  94                 if (prefix != null)
  95                         return prefix;
  96                 return document.lookupPrefix(namespaceURI);
  97         }
  98
  99         @Override
 100         public Iterator<String> getPrefixes(String namespaceURI) {
 101                 List<String> res = new ArrayList<>();
 102                 res.add(getPrefix(namespaceURI));
 103                 return Collections.unmodifiableList(res).iterator();
 104         }
 105
 106 }