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 relativePath) {
  65                 if ("".equals(relativePath))
  66                         return new DomContent(session, this, document.getDocumentElement());
  67
  68                 NodeList nodes = findContent(relativePath);
  69                 if (nodes.getLength() > 1)
  70                         throw new IllegalArgumentException("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         }
  76
  77         protected NodeList findContent(String relativePath) {
  78                 if (relativePath.startsWith("/"))
  79                         throw new IllegalArgumentException("Relative path cannot start with /");
  80                 String xPathExpression = '/' + relativePath;
  81                 if ("/".equals(mountPath))
  82                         xPathExpression = "/cr:root" + xPathExpression;
  83                 try {
  84                         NodeList nodes = (NodeList) xPath.get().evaluate(xPathExpression, document, XPathConstants.NODESET);
  85                         return nodes;
  86                 } catch (XPathExpressionException e) {
  87                         throw new IllegalArgumentException("XPath expression " + xPathExpression + " cannot be evaluated", e);
  88                 }
  89
  90         }
  91
  92         @Override
  93         public boolean exists(ProvidedSession session, String relativePath) {
  94                 if ("".equals(relativePath))
  95                         return true;
  96                 NodeList nodes = findContent(relativePath);
  97                 return nodes.getLength() != 0;
  98         }
  99
 100         public void persist(ProvidedSession session) {
 101                 if (mountPath != null) {
 102                         Content mountPoint = session.getMountPoint(mountPath);
 103                         try (OutputStream out = mountPoint.open(OutputStream.class)) {
 104                                 CmsContentRepository contentRepository = (CmsContentRepository) session.getRepository();
 105                                 contentRepository.writeDom(document, out);
 106                         } catch (IOException e) {
 107                                 throw new IllegalStateException("Cannot persist " + mountPath, e);
 108                         }
 109                 }
 110         }
 111
 112         @Override
 113         public String getMountPath() {
 114                 return mountPath;
 115         }
 116
 117         public void registerPrefix(String prefix, String namespace) {
 118                 DomUtils.addNamespace(document.getDocumentElement(), prefix, namespace);
 119         }
 120
 121         /*
 122          * NAMESPACE CONTEXT
 123          */
 124         @Override
 125         public String getNamespaceURI(String prefix) {
 126                 String namespaceURI = NamespaceUtils.getStandardNamespaceURI(prefix);
 127                 if (namespaceURI != null)
 128                         return namespaceURI;
 129                 return document.lookupNamespaceURI(prefix);
 130         }
 131
 132         @Override
 133         public String getPrefix(String namespaceURI) {
 134                 String prefix = NamespaceUtils.getStandardPrefix(namespaceURI);
 135                 if (prefix != null)
 136                         return prefix;
 137                 return document.lookupPrefix(namespaceURI);
 138         }
 139
 140         @Override
 141         public Iterator<String> getPrefixes(String namespaceURI) {
 142                 List<String> res = new ArrayList<>();
 143                 res.add(getPrefix(namespaceURI));
 144                 return Collections.unmodifiableList(res).iterator();
 145         }
 146
 147 }