C++ nsCOMPtr::Assert方法代码示例

nsresult
RDFContentSinkImpl::ReinitContainer(nsIRDFResource* aContainerType, nsIRDFResource* aContainer)
{
    // Mega-kludge to deal with the fact that Make[Seq|Alt|Bag] is
    // idempotent, and as such, containers will have state (e.g.,
    // RDF:nextVal) maintained in the graph across loads. This
    // re-initializes each container's RDF:nextVal to '1', and 'marks'
    // the container as such.
    nsresult rv;

    nsCOMPtr<nsIRDFLiteral> one;
    rv = gRDFService->GetLiteral(NS_LITERAL_STRING("1").get(), getter_AddRefs(one));
    if (NS_FAILED(rv)) return rv;

    // Re-initialize the 'nextval' property
    nsCOMPtr<nsIRDFNode> nextval;
    rv = mDataSource->GetTarget(aContainer, kRDF_nextVal, true, getter_AddRefs(nextval));
    if (NS_FAILED(rv)) return rv;

    rv = mDataSource->Change(aContainer, kRDF_nextVal, nextval, one);
    if (NS_FAILED(rv)) return rv;

    // Re-mark as a container. XXX should be kRDF_type
    rv = mDataSource->Assert(aContainer, kRDF_instanceOf, aContainerType, true);
    NS_ASSERTION(NS_SUCCEEDED(rv), "unable to mark container as such");
    if (NS_FAILED(rv)) return rv;

    return NS_OK;
}

nsresult
RDFContentSinkImpl::AddProperties(const PRUnichar** aAttributes,
                                  nsIRDFResource* aSubject,
                                  PRInt32* aCount)
{
  if (aCount)
      *aCount = 0;

  nsCOMPtr<nsIAtom> localName;
  for (; *aAttributes; aAttributes += 2) {
      const nsDependentSubstring& nameSpaceURI =
          SplitExpatName(aAttributes[0], getter_AddRefs(localName));

      // skip 'xmlns' directives, these are "meta" information
      if (nameSpaceURI.EqualsLiteral("http://www.w3.org/2000/xmlns/")) {
        continue;
      }

      // skip `about', `ID', `resource', and 'nodeID' attributes (either with or
      // without the `rdf:' prefix); these are all "special" and
      // should've been dealt with by the caller.
      if (localName == kAboutAtom || localName == kIdAtom ||
          localName == kResourceAtom || localName == kNodeIdAtom) {
          if (nameSpaceURI.IsEmpty() ||
              nameSpaceURI.EqualsLiteral(RDF_NAMESPACE_URI))
              continue;
      }

      // Skip `parseType', `RDF:parseType', and `NC:parseType'. This
      // is meta-information that will be handled in SetParseMode.
      if (localName == kParseTypeAtom) {
          if (nameSpaceURI.IsEmpty() ||
              nameSpaceURI.EqualsLiteral(RDF_NAMESPACE_URI) ||
              nameSpaceURI.EqualsLiteral(NC_NAMESPACE_URI)) {
              continue;
          }
      }

      const char* attrName;
      localName->GetUTF8String(&attrName);

      NS_ConvertUTF16toUTF8 propertyStr(nameSpaceURI);    
      propertyStr.Append(attrName);

      // Add the assertion to RDF
      nsCOMPtr<nsIRDFResource> property;
      gRDFService->GetResource(propertyStr, getter_AddRefs(property));

      nsCOMPtr<nsIRDFLiteral> target;
      gRDFService->GetLiteral(aAttributes[1], 
                              getter_AddRefs(target));

      mDataSource->Assert(aSubject, property, target, PR_TRUE);
  }
  return NS_OK;
}

NS_IMETHODIMP 
RDFContentSinkImpl::HandleEndElement(const PRUnichar *aName)
{
  FlushText();

  nsIRDFResource* resource;
  if (NS_FAILED(PopContext(resource, mState, mParseMode))) {
      // XXX parser didn't catch unmatched tags?
#ifdef PR_LOGGING
      if (PR_LOG_TEST(gLog, PR_LOG_WARNING)) {
          nsAutoString tagStr(aName);
          char* tagCStr = ToNewCString(tagStr);

          PR_LogPrint
                 ("rdfxml: extra close tag '%s' at line %d",
                  tagCStr, 0/*XXX fix me */);

          NS_Free(tagCStr);
      }
#endif

      return NS_ERROR_UNEXPECTED; // XXX
  }

  // If we've just popped a member or property element, _now_ is the
  // time to add that element to the graph.
  switch (mState) {
    case eRDFContentSinkState_InMemberElement: 
      {
        nsCOMPtr<nsIRDFContainer> container;
        NS_NewRDFContainer(getter_AddRefs(container));
        container->Init(mDataSource, GetContextElement(1));
        container->AppendElement(resource);
      } 
      break;

    case eRDFContentSinkState_InPropertyElement: 
      {
        mDataSource->Assert(GetContextElement(1), GetContextElement(0), resource, true);                                          
      } break;
    default:
      break;
  }
  
  if (mContextStack->IsEmpty())
      mState = eRDFContentSinkState_InEpilog;

  NS_IF_RELEASE(resource);
  return NS_OK;
}

nsresult
RDFContentSinkImpl::FlushText()
{
    nsresult rv = NS_OK;
    if (0 != mTextLength) {
        if (rdf_IsDataInBuffer(mText, mTextLength)) {
            // XXX if there's anything but whitespace, then we'll
            // create a text node.

            switch (mState) {
            case eRDFContentSinkState_InMemberElement: {
                nsCOMPtr<nsIRDFNode> node;
                ParseText(getter_AddRefs(node));

                nsCOMPtr<nsIRDFContainer> container;
                NS_NewRDFContainer(getter_AddRefs(container));
                container->Init(mDataSource, GetContextElement(1));

                container->AppendElement(node);
            }
            break;

            case eRDFContentSinkState_InPropertyElement: {
                nsCOMPtr<nsIRDFNode> node;
                ParseText(getter_AddRefs(node));

                mDataSource->Assert(GetContextElement(1), GetContextElement(0), node, true);
            }
            break;

            default:
                // just ignore it
                break;
            }
        }
        mTextLength = 0;
    }
    return rv;
}

nsresult
RDFContentSinkImpl::OpenProperty(const PRUnichar* aName, const PRUnichar** aAttributes)
{
    nsresult rv;

    // an "object" non-terminal is either a "description", a "typed
    // node", or a "container", so this change the content sink's
    // state appropriately.
    nsCOMPtr<nsIAtom> localName;
    const nsDependentSubstring& nameSpaceURI =
        SplitExpatName(aName, getter_AddRefs(localName));

    NS_ConvertUTF16toUTF8 propertyStr(nameSpaceURI);
    propertyStr.Append(nsAtomCString(localName));

    nsCOMPtr<nsIRDFResource> property;
    rv = gRDFService->GetResource(propertyStr, getter_AddRefs(property));
    if (NS_FAILED(rv)) return rv;

    // See if they've specified a 'resource' attribute, in which case
    // they mean *that* to be the object of this property.
    nsCOMPtr<nsIRDFResource> target;
    GetResourceAttribute(aAttributes, getter_AddRefs(target));

    bool isAnonymous = false;

    if (! target) {
        // See if an 'ID' attribute has been specified, in which case
        // this corresponds to the fourth form of [6.12].

        // XXX strictly speaking, we should reject the RDF/XML as
        // invalid if they've specified both an 'ID' and a 'resource'
        // attribute. Bah.

        // XXX strictly speaking, 'about=' isn't allowed here, but
        // what the hell.
        GetIdAboutAttribute(aAttributes, getter_AddRefs(target), &isAnonymous);
    }

    if (target) {
        // They specified an inline resource for the value of this
        // property. Create an RDF resource for the inline resource
        // URI, add the properties to it, and attach the inline
        // resource to its parent.
        PRInt32 count;
        rv = AddProperties(aAttributes, target, &count);
        NS_ASSERTION(NS_SUCCEEDED(rv), "problem adding properties");
        if (NS_FAILED(rv)) return rv;

        if (count || !isAnonymous) {
            // If the resource was "anonymous" (i.e., they hadn't
            // explicitly set an ID or resource attribute), then we'll
            // only assert this property from the context element *if*
            // there were properties specified on the anonymous
            // resource.
            rv = mDataSource->Assert(GetContextElement(0), property, target, true);
            if (NS_FAILED(rv)) return rv;
        }

        // XXX Technically, we should _not_ fall through here and push
        // the element onto the stack: this is supposed to be a closed
        // node. But right now I'm lazy and the code will just Do The
        // Right Thing so long as the RDF is well-formed.
    }

    // Push the element onto the context stack and change state.
    PushContext(property, mState, mParseMode);
    mState = eRDFContentSinkState_InPropertyElement;
    SetParseMode(aAttributes);

    return NS_OK;
}

nsresult
RDFContentSinkImpl::OpenObject(const PRUnichar* aName, 
                               const PRUnichar** aAttributes)
{
    // an "object" non-terminal is either a "description", a "typed
    // node", or a "container", so this change the content sink's
    // state appropriately.
    nsCOMPtr<nsIAtom> localName;
    const nsDependentSubstring& nameSpaceURI =
        SplitExpatName(aName, getter_AddRefs(localName));

    // Figure out the URI of this object, and create an RDF node for it.
    nsCOMPtr<nsIRDFResource> source;
    GetIdAboutAttribute(aAttributes, getter_AddRefs(source));

    // If there is no `ID' or `about', then there's not much we can do.
    if (! source)
        return NS_ERROR_FAILURE;

    // Push the element onto the context stack
    PushContext(source, mState, mParseMode);

    // Now figure out what kind of state transition we need to
    // make. We'll either be going into a mode where we parse a
    // description or a container.
    bool isaTypedNode = true;

    if (nameSpaceURI.EqualsLiteral(RDF_NAMESPACE_URI)) {
        isaTypedNode = false;

        if (localName == kDescriptionAtom) {
            // it's a description
            mState = eRDFContentSinkState_InDescriptionElement;
        }
        else if (localName == kBagAtom) {
            // it's a bag container
            InitContainer(kRDF_Bag, source);
            mState = eRDFContentSinkState_InContainerElement;
        }
        else if (localName == kSeqAtom) {
            // it's a seq container
            InitContainer(kRDF_Seq, source);
            mState = eRDFContentSinkState_InContainerElement;
        }
        else if (localName == kAltAtom) {
            // it's an alt container
            InitContainer(kRDF_Alt, source);
            mState = eRDFContentSinkState_InContainerElement;
        }
        else {
            // heh, that's not *in* the RDF namespace: just treat it
            // like a typed node
            isaTypedNode = true;
        }
    }

    if (isaTypedNode) {
        NS_ConvertUTF16toUTF8 typeStr(nameSpaceURI);
        typeStr.Append(nsAtomCString(localName));

        nsCOMPtr<nsIRDFResource> type;
        nsresult rv = gRDFService->GetResource(typeStr, getter_AddRefs(type));
        if (NS_FAILED(rv)) return rv;

        rv = mDataSource->Assert(source, kRDF_type, type, true);
        if (NS_FAILED(rv)) return rv;

        mState = eRDFContentSinkState_InDescriptionElement;
    }

    AddProperties(aAttributes, source);
    return NS_OK;
}