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gecko-dev/rdf/base/nsRDFXMLSerializer.cpp

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=4 sw=4 et tw=80:
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsRDFXMLSerializer.h"
#include "nsIAtom.h"
#include "nsIOutputStream.h"
#include "nsIRDFService.h"
#include "nsIRDFContainerUtils.h"
#include "nsIServiceManager.h"
#include "nsString.h"
#include "nsXPIDLString.h"
#include "nsTArray.h"
#include "rdf.h"
#include "rdfutil.h"
#include "mozilla/Attributes.h"
#include "rdfIDataSource.h"
int32_t nsRDFXMLSerializer::gRefCnt = 0;
nsIRDFContainerUtils* nsRDFXMLSerializer::gRDFC;
nsIRDFResource* nsRDFXMLSerializer::kRDF_instanceOf;
nsIRDFResource* nsRDFXMLSerializer::kRDF_type;
nsIRDFResource* nsRDFXMLSerializer::kRDF_nextVal;
nsIRDFResource* nsRDFXMLSerializer::kRDF_Bag;
nsIRDFResource* nsRDFXMLSerializer::kRDF_Seq;
nsIRDFResource* nsRDFXMLSerializer::kRDF_Alt;
static const char kRDFDescriptionOpen[] = " <RDF:Description";
static const char kIDAttr[] = " RDF:ID=\"";
static const char kAboutAttr[] = " RDF:about=\"";
static const char kRDFDescriptionClose[] = " </RDF:Description>\n";
static const char kRDFResource1[] = " RDF:resource=\"";
static const char kRDFResource2[] = "\"/>\n";
static const char kRDFParseTypeInteger[] = " NC:parseType=\"Integer\">";
static const char kRDFParseTypeDate[] = " NC:parseType=\"Date\">";
static const char kRDFUnknown[] = "><!-- unknown node type -->";
nsresult
nsRDFXMLSerializer::Create(nsISupports* aOuter, REFNSIID aIID, void** aResult)
{
if (aOuter)
return NS_ERROR_NO_AGGREGATION;
nsCOMPtr<nsIRDFXMLSerializer> result = new nsRDFXMLSerializer();
if (! result)
return NS_ERROR_OUT_OF_MEMORY;
// The serializer object is here, addref gRefCnt so that the
// destructor can safely release it.
gRefCnt++;
nsresult rv;
rv = result->QueryInterface(aIID, aResult);
if (NS_FAILED(rv)) return rv;
if (gRefCnt == 1) do {
nsCOMPtr<nsIRDFService> rdf = do_GetService("@mozilla.org/rdf/rdf-service;1", &rv);
if (NS_FAILED(rv)) break;
rv = rdf->GetResource(NS_LITERAL_CSTRING(RDF_NAMESPACE_URI "instanceOf"),
&kRDF_instanceOf);
if (NS_FAILED(rv)) break;
rv = rdf->GetResource(NS_LITERAL_CSTRING(RDF_NAMESPACE_URI "type"),
&kRDF_type);
if (NS_FAILED(rv)) break;
rv = rdf->GetResource(NS_LITERAL_CSTRING(RDF_NAMESPACE_URI "nextVal"),
&kRDF_nextVal);
if (NS_FAILED(rv)) break;
rv = rdf->GetResource(NS_LITERAL_CSTRING(RDF_NAMESPACE_URI "Bag"),
&kRDF_Bag);
if (NS_FAILED(rv)) break;
rv = rdf->GetResource(NS_LITERAL_CSTRING(RDF_NAMESPACE_URI "Seq"),
&kRDF_Seq);
if (NS_FAILED(rv)) break;
rv = rdf->GetResource(NS_LITERAL_CSTRING(RDF_NAMESPACE_URI "Alt"),
&kRDF_Alt);
if (NS_FAILED(rv)) break;
rv = CallGetService("@mozilla.org/rdf/container-utils;1", &gRDFC);
if (NS_FAILED(rv)) break;
} while (0);
return rv;
}
nsRDFXMLSerializer::nsRDFXMLSerializer()
{
}
nsRDFXMLSerializer::~nsRDFXMLSerializer()
{
if (--gRefCnt == 0) {
NS_IF_RELEASE(kRDF_Bag);
NS_IF_RELEASE(kRDF_Seq);
NS_IF_RELEASE(kRDF_Alt);
NS_IF_RELEASE(kRDF_instanceOf);
NS_IF_RELEASE(kRDF_type);
NS_IF_RELEASE(kRDF_nextVal);
NS_IF_RELEASE(gRDFC);
}
}
NS_IMPL_ISUPPORTS(nsRDFXMLSerializer, nsIRDFXMLSerializer, nsIRDFXMLSource)
NS_IMETHODIMP
nsRDFXMLSerializer::Init(nsIRDFDataSource* aDataSource)
{
if (! aDataSource)
return NS_ERROR_NULL_POINTER;
mDataSource = aDataSource;
mDataSource->GetURI(getter_Copies(mBaseURLSpec));
// Add the ``RDF'' prefix, by default.
nsCOMPtr<nsIAtom> prefix;
prefix = NS_Atomize("RDF");
AddNameSpace(prefix, NS_LITERAL_STRING("http://www.w3.org/1999/02/22-rdf-syntax-ns#"));
prefix = NS_Atomize("NC");
AddNameSpace(prefix, NS_LITERAL_STRING("http://home.netscape.com/NC-rdf#"));
mPrefixID = 0;
return NS_OK;
}
NS_IMETHODIMP
nsRDFXMLSerializer::AddNameSpace(nsIAtom* aPrefix, const nsAString& aURI)
{
nsCOMPtr<nsIAtom> prefix = aPrefix;
if (!prefix) {
// Make up a prefix, we don't want default namespaces, so
// that we can use QNames for elements and attributes alike.
prefix = EnsureNewPrefix();
}
mNameSpaces.Put(aURI, prefix);
return NS_OK;
}
static nsresult
rdf_BlockingWrite(nsIOutputStream* stream, const char* buf, uint32_t size)
{
uint32_t written = 0;
uint32_t remaining = size;
while (remaining > 0) {
nsresult rv;
uint32_t cb;
if (NS_FAILED(rv = stream->Write(buf + written, remaining, &cb)))
return rv;
written += cb;
remaining -= cb;
}
return NS_OK;
}
static nsresult
rdf_BlockingWrite(nsIOutputStream* stream, const nsCSubstring& s)
{
return rdf_BlockingWrite(stream, s.BeginReading(), s.Length());
}
static nsresult
rdf_BlockingWrite(nsIOutputStream* stream, const nsAString& s)
{
NS_ConvertUTF16toUTF8 utf8(s);
return rdf_BlockingWrite(stream, utf8.get(), utf8.Length());
}
already_AddRefed<nsIAtom>
nsRDFXMLSerializer::EnsureNewPrefix()
{
nsAutoString qname;
nsCOMPtr<nsIAtom> prefix;
bool isNewPrefix;
do {
isNewPrefix = true;
qname.AssignLiteral("NS");
qname.AppendInt(++mPrefixID, 10);
prefix = NS_Atomize(qname);
nsNameSpaceMap::const_iterator iter = mNameSpaces.first();
while (iter != mNameSpaces.last() && isNewPrefix) {
isNewPrefix = (iter->mPrefix != prefix);
++iter;
}
} while (!isNewPrefix);
return prefix.forget();
}
// This converts a property resource (like
// "http://www.w3.org/TR/WD-rdf-syntax#Description") into a QName
// ("RDF:Description"), and registers the namespace, if it's made up.
nsresult
nsRDFXMLSerializer::RegisterQName(nsIRDFResource* aResource)
{
nsAutoCString uri, qname;
aResource->GetValueUTF8(uri);
nsNameSpaceMap::const_iterator iter = mNameSpaces.GetNameSpaceOf(uri);
if (iter != mNameSpaces.last()) {
NS_ENSURE_TRUE(iter->mPrefix, NS_ERROR_UNEXPECTED);
iter->mPrefix->ToUTF8String(qname);
qname.Append(':');
qname += StringTail(uri, uri.Length() - iter->mURI.Length());
mQNames.Put(aResource, qname);
return NS_OK;
}
// Okay, so we don't have it in our map. Try to make one up. This
// is very bogus.
int32_t i = uri.RFindChar('#'); // first try a '#'
if (i == -1) {
i = uri.RFindChar('/');
if (i == -1) {
// Okay, just punt and assume there is _no_ namespace on
// this thing...
mQNames.Put(aResource, uri);
return NS_OK;
}
}
// Take whatever is to the right of the '#' or '/' and call it the
// local name, make up a prefix.
nsCOMPtr<nsIAtom> prefix = EnsureNewPrefix();
mNameSpaces.Put(StringHead(uri, i+1), prefix);
prefix->ToUTF8String(qname);
qname.Append(':');
qname += StringTail(uri, uri.Length() - (i + 1));
mQNames.Put(aResource, qname);
return NS_OK;
}
nsresult
nsRDFXMLSerializer::GetQName(nsIRDFResource* aResource, nsCString& aQName)
{
return mQNames.Get(aResource, &aQName) ? NS_OK : NS_ERROR_UNEXPECTED;
}
bool
nsRDFXMLSerializer::IsContainerProperty(nsIRDFResource* aProperty)
{
// Return `true' if the property is an internal property related
// to being a container.
if (aProperty == kRDF_instanceOf)
return true;
if (aProperty == kRDF_nextVal)
return true;
bool isOrdinal = false;
gRDFC->IsOrdinalProperty(aProperty, &isOrdinal);
if (isOrdinal)
return true;
return false;
}
// convert '&', '<', and '>' into "&amp;", "&lt;", and "&gt", respectively.
static const char amp[] = "&amp;";
static const char lt[] = "&lt;";
static const char gt[] = "&gt;";
static const char quot[] = "&quot;";
static void
rdf_EscapeAmpersandsAndAngleBrackets(nsCString& s)
{
uint32_t newLength, origLength;
newLength = origLength = s.Length();
// Compute the length of the result string.
const char* start = s.BeginReading();
const char* end = s.EndReading();
const char* c = start;
while (c != end) {
switch (*c) {
case '&' :
newLength += sizeof(amp) - 2;
break;
case '<':
case '>':
newLength += sizeof(gt) - 2;
break;
default:
break;
}
++c;
}
if (newLength == origLength) {
// nothing to escape
return;
}
// escape the chars from the end back to the front.
s.SetLength(newLength);
// Buffer might have changed, get the pointers again
start = s.BeginReading(); // begin of string
c = start + origLength - 1; // last char in original string
char* w = s.EndWriting() - 1; // last char in grown buffer
while (c >= start) {
switch (*c) {
case '&' :
w -= 4;
nsCharTraits<char>::copy(w, amp, sizeof(amp) - 1);
break;
case '<':
w -= 3;
nsCharTraits<char>::copy(w, lt, sizeof(lt) - 1);
break;
case '>':
w -= 3;
nsCharTraits<char>::copy(w, gt, sizeof(gt) - 1);
break;
default:
*w = *c;
}
--w;
--c;
}
}
// convert '"' to "&quot;"
static void
rdf_EscapeQuotes(nsCString& s)
{
int32_t i = 0;
while ((i = s.FindChar('"', i)) != -1) {
s.Replace(i, 1, quot, sizeof(quot) - 1);
i += sizeof(quot) - 2;
}
}
static void
rdf_EscapeAttributeValue(nsCString& s)
{
rdf_EscapeAmpersandsAndAngleBrackets(s);
rdf_EscapeQuotes(s);
}
nsresult
nsRDFXMLSerializer::SerializeInlineAssertion(nsIOutputStream* aStream,
nsIRDFResource* aResource,
nsIRDFResource* aProperty,
nsIRDFLiteral* aValue)
{
nsresult rv;
nsCString qname;
rv = GetQName(aProperty, qname);
NS_ENSURE_SUCCESS(rv, rv);
rv = rdf_BlockingWrite(aStream,
NS_LITERAL_CSTRING("\n "));
if (NS_FAILED(rv)) return rv;
const char16_t* value;
aValue->GetValueConst(&value);
NS_ConvertUTF16toUTF8 s(value);
rdf_EscapeAttributeValue(s);
rv = rdf_BlockingWrite(aStream, qname);
if (NS_FAILED(rv)) return rv;
rv = rdf_BlockingWrite(aStream, "=\"", 2);
if (NS_FAILED(rv)) return rv;
s.Append('"');
return rdf_BlockingWrite(aStream, s);
}
nsresult
nsRDFXMLSerializer::SerializeChildAssertion(nsIOutputStream* aStream,
nsIRDFResource* aResource,
nsIRDFResource* aProperty,
nsIRDFNode* aValue)
{
nsCString qname;
nsresult rv = GetQName(aProperty, qname);
NS_ENSURE_SUCCESS(rv, rv);
rv = rdf_BlockingWrite(aStream, " <", 5);
if (NS_FAILED(rv)) return rv;
rv = rdf_BlockingWrite(aStream, qname);
if (NS_FAILED(rv)) return rv;
nsCOMPtr<nsIRDFResource> resource;
nsCOMPtr<nsIRDFLiteral> literal;
nsCOMPtr<nsIRDFInt> number;
nsCOMPtr<nsIRDFDate> date;
if ((resource = do_QueryInterface(aValue)) != nullptr) {
nsAutoCString uri;
resource->GetValueUTF8(uri);
rdf_MakeRelativeRef(mBaseURLSpec, uri);
rdf_EscapeAttributeValue(uri);
rv = rdf_BlockingWrite(aStream, kRDFResource1,
sizeof(kRDFResource1) - 1);
if (NS_FAILED(rv)) return rv;
rv = rdf_BlockingWrite(aStream, uri);
if (NS_FAILED(rv)) return rv;
rv = rdf_BlockingWrite(aStream, kRDFResource2,
sizeof(kRDFResource2) - 1);
if (NS_FAILED(rv)) return rv;
goto no_close_tag;
}
else if ((literal = do_QueryInterface(aValue)) != nullptr) {
const char16_t *value;
literal->GetValueConst(&value);
NS_ConvertUTF16toUTF8 s(value);
rdf_EscapeAmpersandsAndAngleBrackets(s);
rv = rdf_BlockingWrite(aStream, ">", 1);
if (NS_FAILED(rv)) return rv;
rv = rdf_BlockingWrite(aStream, s);
if (NS_FAILED(rv)) return rv;
}
else if ((number = do_QueryInterface(aValue)) != nullptr) {
int32_t value;
number->GetValue(&value);
nsAutoCString n;
n.AppendInt(value);
rv = rdf_BlockingWrite(aStream, kRDFParseTypeInteger,
sizeof(kRDFParseTypeInteger) - 1);
if (NS_FAILED(rv)) return rv;
rv = rdf_BlockingWrite(aStream, n);
if (NS_FAILED(rv)) return rv;
}
else if ((date = do_QueryInterface(aValue)) != nullptr) {
PRTime value;
date->GetValue(&value);
nsAutoCString s;
rdf_FormatDate(value, s);
rv = rdf_BlockingWrite(aStream, kRDFParseTypeDate,
sizeof(kRDFParseTypeDate) - 1);
if (NS_FAILED(rv)) return rv;
rv = rdf_BlockingWrite(aStream, s);
if (NS_FAILED(rv)) return rv;
}
else {
// XXX it doesn't support nsIRDFResource _or_ nsIRDFLiteral???
// We should serialize nsIRDFInt, nsIRDFDate, etc...
NS_WARNING("unknown RDF node type");
rv = rdf_BlockingWrite(aStream, kRDFUnknown, sizeof(kRDFUnknown) - 1);
if (NS_FAILED(rv)) return rv;
}
rv = rdf_BlockingWrite(aStream, "</", 2);
if (NS_FAILED(rv)) return rv;
rv = rdf_BlockingWrite(aStream, qname);
if (NS_FAILED(rv)) return rv;
return rdf_BlockingWrite(aStream, ">\n", 2);
no_close_tag:
return NS_OK;
}
nsresult
nsRDFXMLSerializer::SerializeProperty(nsIOutputStream* aStream,
nsIRDFResource* aResource,
nsIRDFResource* aProperty,
bool aInline,
int32_t* aSkipped)
{
nsresult rv = NS_OK;
int32_t skipped = 0;
nsCOMPtr<nsISimpleEnumerator> assertions;
mDataSource->GetTargets(aResource, aProperty, true, getter_AddRefs(assertions));
if (! assertions)
return NS_ERROR_FAILURE;
// Serializing the assertion inline is ok as long as the property has
// only one target value, and it is a literal that doesn't include line
// breaks.
bool needsChild = false;
while (1) {
bool hasMore = false;
assertions->HasMoreElements(&hasMore);
if (! hasMore)
break;
nsCOMPtr<nsISupports> isupports;
assertions->GetNext(getter_AddRefs(isupports));
nsCOMPtr<nsIRDFLiteral> literal = do_QueryInterface(isupports);
needsChild |= (!literal);
if (!needsChild) {
assertions->HasMoreElements(&needsChild);
if (!needsChild) {
const char16_t* literalVal = nullptr;
literal->GetValueConst(&literalVal);
if (literalVal) {
for (; *literalVal; literalVal++) {
if (*literalVal == char16_t('\n') ||
*literalVal == char16_t('\r')) {
needsChild = true;
break;
}
}
}
}
}
if (aInline && !needsChild) {
rv = SerializeInlineAssertion(aStream, aResource, aProperty, literal);
}
else if (!aInline && needsChild) {
nsCOMPtr<nsIRDFNode> value = do_QueryInterface(isupports);
rv = SerializeChildAssertion(aStream, aResource, aProperty, value);
}
else {
++skipped;
rv = NS_OK;
}
if (NS_FAILED(rv))
break;
}
*aSkipped += skipped;
return rv;
}
nsresult
nsRDFXMLSerializer::SerializeDescription(nsIOutputStream* aStream,
nsIRDFResource* aResource)
{
nsresult rv;
bool isTypedNode = false;
nsCString typeQName;
nsCOMPtr<nsIRDFNode> typeNode;
mDataSource->GetTarget(aResource, kRDF_type, true, getter_AddRefs(typeNode));
if (typeNode) {
nsCOMPtr<nsIRDFResource> type = do_QueryInterface(typeNode, &rv);
if (type) {
// Try to get a namespace prefix. If none is available,
// just treat the description as if it weren't a typed node
// after all and emit rdf:type as a normal property. This
// seems preferable to using a bogus (invented) prefix.
isTypedNode = NS_SUCCEEDED(GetQName(type, typeQName));
}
}
nsAutoCString uri;
rv = aResource->GetValueUTF8(uri);
if (NS_FAILED(rv)) return rv;
rdf_MakeRelativeRef(mBaseURLSpec, uri);
rdf_EscapeAttributeValue(uri);
// Emit an open tag and the subject
if (isTypedNode) {
rv = rdf_BlockingWrite(aStream, NS_LITERAL_STRING(" <"));
if (NS_FAILED(rv)) return rv;
// Watch out for the default namespace!
rv = rdf_BlockingWrite(aStream, typeQName);
if (NS_FAILED(rv)) return rv;
}
else {
rv = rdf_BlockingWrite(aStream, kRDFDescriptionOpen,
sizeof(kRDFDescriptionOpen) - 1);
if (NS_FAILED(rv)) return rv;
}
if (uri[0] == char16_t('#')) {
uri.Cut(0, 1);
rv = rdf_BlockingWrite(aStream, kIDAttr, sizeof(kIDAttr) - 1);
}
else {
rv = rdf_BlockingWrite(aStream, kAboutAttr, sizeof(kAboutAttr) - 1);
}
if (NS_FAILED(rv)) return rv;
uri.Append('"');
rv = rdf_BlockingWrite(aStream, uri);
if (NS_FAILED(rv)) return rv;
// Any value that's a literal we can write out as an inline
// attribute on the RDF:Description
AutoTArray<nsIRDFResource*, 8> visited;
int32_t skipped = 0;
nsCOMPtr<nsISimpleEnumerator> arcs;
mDataSource->ArcLabelsOut(aResource, getter_AddRefs(arcs));
if (arcs) {
// Don't re-serialize rdf:type later on
if (isTypedNode)
visited.AppendElement(kRDF_type);
while (1) {
bool hasMore = false;
arcs->HasMoreElements(&hasMore);
if (! hasMore)
break;
nsCOMPtr<nsISupports> isupports;
arcs->GetNext(getter_AddRefs(isupports));
nsCOMPtr<nsIRDFResource> property = do_QueryInterface(isupports);
if (! property)
continue;
// Ignore properties that pertain to containers; we may be
// called from SerializeContainer() if the container resource
// has been assigned non-container properties.
if (IsContainerProperty(property))
continue;
// Only serialize values for the property once.
if (visited.Contains(property.get()))
continue;
visited.AppendElement(property.get());
SerializeProperty(aStream, aResource, property, true, &skipped);
}
}
if (skipped) {
// Close the RDF:Description tag.
rv = rdf_BlockingWrite(aStream, NS_LITERAL_CSTRING(">\n"));
if (NS_FAILED(rv)) return rv;
// Now write out resources (which might have their own
// substructure) as children.
mDataSource->ArcLabelsOut(aResource, getter_AddRefs(arcs));
if (arcs) {
// Forget that we've visited anything
visited.Clear();
// ... except for rdf:type
if (isTypedNode)
visited.AppendElement(kRDF_type);
while (1) {
bool hasMore = false;
arcs->HasMoreElements(&hasMore);
if (! hasMore)
break;
nsCOMPtr<nsISupports> isupports;
arcs->GetNext(getter_AddRefs(isupports));
nsCOMPtr<nsIRDFResource> property = do_QueryInterface(isupports);
if (! property)
continue;
// Ignore properties that pertain to containers; we may be
// called from SerializeContainer() if the container
// resource has been assigned non-container properties.
if (IsContainerProperty(property))
continue;
// have we already seen this property? If so, don't write it
// out again; serialize property will write each instance.
if (visited.Contains(property.get()))
continue;
visited.AppendElement(property.get());
SerializeProperty(aStream, aResource, property, false, &skipped);
}
}
// Emit a proper close-tag.
if (isTypedNode) {
rv = rdf_BlockingWrite(aStream, NS_LITERAL_CSTRING(" </"));
if (NS_FAILED(rv)) return rv;
// Watch out for the default namespace!
rdf_BlockingWrite(aStream, typeQName);
if (NS_FAILED(rv)) return rv;
rdf_BlockingWrite(aStream, ">\n", 2);
if (NS_FAILED(rv)) return rv;
}
else {
rv = rdf_BlockingWrite(aStream, kRDFDescriptionClose,
sizeof(kRDFDescriptionClose) - 1);
if (NS_FAILED(rv)) return rv;
}
}
else {
// If we saw _no_ child properties, then we can don't need a
// close-tag.
rv = rdf_BlockingWrite(aStream, NS_LITERAL_CSTRING(" />\n"));
if (NS_FAILED(rv)) return rv;
}
return NS_OK;
}
nsresult
nsRDFXMLSerializer::SerializeMember(nsIOutputStream* aStream,
nsIRDFResource* aContainer,
nsIRDFNode* aMember)
{
// If it's a resource, then output a "<RDF:li RDF:resource=... />"
// tag, because we'll be dumping the resource separately. (We
// iterate thru all the resources in the datasource,
// remember?) Otherwise, output the literal value.
nsCOMPtr<nsIRDFResource> resource;
nsCOMPtr<nsIRDFLiteral> literal;
nsCOMPtr<nsIRDFInt> number;
nsCOMPtr<nsIRDFDate> date;
static const char kRDFLIOpen[] = " <RDF:li";
nsresult rv = rdf_BlockingWrite(aStream, kRDFLIOpen,
sizeof(kRDFLIOpen) - 1);
if (NS_FAILED(rv)) return rv;
if ((resource = do_QueryInterface(aMember)) != nullptr) {
nsAutoCString uri;
resource->GetValueUTF8(uri);
rdf_MakeRelativeRef(mBaseURLSpec, uri);
rdf_EscapeAttributeValue(uri);
rv = rdf_BlockingWrite(aStream, kRDFResource1,
sizeof(kRDFResource1) - 1);
if (NS_FAILED(rv)) return rv;
rv = rdf_BlockingWrite(aStream, uri);
if (NS_FAILED(rv)) return rv;
rv = rdf_BlockingWrite(aStream, kRDFResource2,
sizeof(kRDFResource2) - 1);
if (NS_FAILED(rv)) return rv;
goto no_close_tag;
}
else if ((literal = do_QueryInterface(aMember)) != nullptr) {
const char16_t *value;
literal->GetValueConst(&value);
static const char kRDFLIOpenGT[] = ">";
// close the '<RDF:LI' before adding the literal
rv = rdf_BlockingWrite(aStream, kRDFLIOpenGT,
sizeof(kRDFLIOpenGT) - 1);
if (NS_FAILED(rv)) return rv;
NS_ConvertUTF16toUTF8 s(value);
rdf_EscapeAmpersandsAndAngleBrackets(s);
rv = rdf_BlockingWrite(aStream, s);
if (NS_FAILED(rv)) return rv;
}
else if ((number = do_QueryInterface(aMember)) != nullptr) {
int32_t value;
number->GetValue(&value);
nsAutoCString n;
n.AppendInt(value);
rv = rdf_BlockingWrite(aStream, kRDFParseTypeInteger,
sizeof(kRDFParseTypeInteger) - 1);
if (NS_FAILED(rv)) return rv;
rv = rdf_BlockingWrite(aStream, n);
if (NS_FAILED(rv)) return rv;
}
else if ((date = do_QueryInterface(aMember)) != nullptr) {
PRTime value;
date->GetValue(&value);
nsAutoCString s;
rdf_FormatDate(value, s);
rv = rdf_BlockingWrite(aStream, kRDFParseTypeDate,
sizeof(kRDFParseTypeDate) - 1);
if (NS_FAILED(rv)) return rv;
rv = rdf_BlockingWrite(aStream, s);
if (NS_FAILED(rv)) return rv;
}
else {
// XXX it doesn't support nsIRDFResource _or_ nsIRDFLiteral???
// We should serialize nsIRDFInt, nsIRDFDate, etc...
NS_WARNING("unknown RDF node type");
rv = rdf_BlockingWrite(aStream, kRDFUnknown, sizeof(kRDFUnknown) - 1);
if (NS_FAILED(rv)) return rv;
}
{
static const char kRDFLIClose[] = "</RDF:li>\n";
rv = rdf_BlockingWrite(aStream, kRDFLIClose, sizeof(kRDFLIClose) - 1);
if (NS_FAILED(rv)) return rv;
}
no_close_tag:
return NS_OK;
}
nsresult
nsRDFXMLSerializer::SerializeContainer(nsIOutputStream* aStream,
nsIRDFResource* aContainer)
{
nsresult rv;
nsAutoCString tag;
// Decide if it's a sequence, bag, or alternation, and print the
// appropriate tag-open sequence
if (IsA(mDataSource, aContainer, kRDF_Bag)) {
tag.AssignLiteral("RDF:Bag");
}
else if (IsA(mDataSource, aContainer, kRDF_Seq)) {
tag.AssignLiteral("RDF:Seq");
}
else if (IsA(mDataSource, aContainer, kRDF_Alt)) {
tag.AssignLiteral("RDF:Alt");
}
else {
NS_ASSERTION(false, "huh? this is _not_ a container.");
return NS_ERROR_UNEXPECTED;
}
rv = rdf_BlockingWrite(aStream, " <", 3);
if (NS_FAILED(rv)) return rv;
rv = rdf_BlockingWrite(aStream, tag);
if (NS_FAILED(rv)) return rv;
// Unfortunately, we always need to print out the identity of the
// resource, even if was constructed "anonymously". We need to do
// this because we never really know who else might be referring
// to it...
nsAutoCString uri;
if (NS_SUCCEEDED(aContainer->GetValueUTF8(uri))) {
rdf_MakeRelativeRef(mBaseURLSpec, uri);
rdf_EscapeAttributeValue(uri);
if (uri.First() == '#') {
// Okay, it's actually identified as an element in the
// current document, not trying to decorate some absolute
// URI. We can use the 'ID=' attribute...
uri.Cut(0, 1); // chop the '#'
rv = rdf_BlockingWrite(aStream, kIDAttr, sizeof(kIDAttr) - 1);
if (NS_FAILED(rv)) return rv;
}
else {
// We need to cheat and spit out an illegal 'about=' on
// the sequence.
rv = rdf_BlockingWrite(aStream, kAboutAttr,
sizeof(kAboutAttr) - 1);
if (NS_FAILED(rv)) return rv;
}
rv = rdf_BlockingWrite(aStream, uri);
if (NS_FAILED(rv)) return rv;
rv = rdf_BlockingWrite(aStream, "\"", 1);
if (NS_FAILED(rv)) return rv;
}
rv = rdf_BlockingWrite(aStream, ">\n", 2);
if (NS_FAILED(rv)) return rv;
// First iterate through each of the ordinal elements (the RDF/XML
// syntax doesn't allow us to place properties on RDF container
// elements).
nsCOMPtr<nsISimpleEnumerator> elements;
rv = NS_NewContainerEnumerator(mDataSource, aContainer, getter_AddRefs(elements));
if (NS_SUCCEEDED(rv)) {
while (1) {
bool hasMore;
rv = elements->HasMoreElements(&hasMore);
if (NS_FAILED(rv)) break;
if (! hasMore)
break;
nsCOMPtr<nsISupports> isupports;
elements->GetNext(getter_AddRefs(isupports));
nsCOMPtr<nsIRDFNode> element = do_QueryInterface(isupports);
NS_ASSERTION(element != nullptr, "not an nsIRDFNode");
if (! element)
continue;
SerializeMember(aStream, aContainer, element);
}
}
// close the container tag
rv = rdf_BlockingWrite(aStream, " </", 4);
if (NS_FAILED(rv)) return rv;
tag.Append(">\n", 2);
rv = rdf_BlockingWrite(aStream, tag);
if (NS_FAILED(rv)) return rv;
// Now, we iterate through _all_ of the arcs, in case someone has
// applied properties to the bag itself. These'll be placed in a
// separate RDF:Description element.
nsCOMPtr<nsISimpleEnumerator> arcs;
mDataSource->ArcLabelsOut(aContainer, getter_AddRefs(arcs));
bool wroteDescription = false;
while (! wroteDescription) {
bool hasMore = false;
rv = arcs->HasMoreElements(&hasMore);
if (NS_FAILED(rv)) break;
if (! hasMore)
break;
nsIRDFResource* property;
rv = arcs->GetNext((nsISupports**) &property);
if (NS_FAILED(rv)) break;
// If it's a membership property, then output a "LI"
// tag. Otherwise, output a property.
if (! IsContainerProperty(property)) {
rv = SerializeDescription(aStream, aContainer);
wroteDescription = true;
}
NS_RELEASE(property);
if (NS_FAILED(rv))
break;
}
return NS_OK;
}
nsresult
nsRDFXMLSerializer::SerializePrologue(nsIOutputStream* aStream)
{
static const char kXMLVersion[] = "<?xml version=\"1.0\"?>\n";
nsresult rv;
rv = rdf_BlockingWrite(aStream, kXMLVersion, sizeof(kXMLVersion) - 1);
if (NS_FAILED(rv)) return rv;
// global name space declarations
rv = rdf_BlockingWrite(aStream, NS_LITERAL_CSTRING("<RDF:RDF "));
if (NS_FAILED(rv)) return rv;
nsNameSpaceMap::const_iterator first = mNameSpaces.first();
nsNameSpaceMap::const_iterator last = mNameSpaces.last();
for (nsNameSpaceMap::const_iterator entry = first; entry != last; ++entry) {
if (entry != first) {
rv = rdf_BlockingWrite(aStream, NS_LITERAL_CSTRING("\n "));
if (NS_FAILED(rv)) return rv;
}
rv = rdf_BlockingWrite(aStream, NS_LITERAL_CSTRING("xmlns"));
if (NS_FAILED(rv)) return rv;
if (entry->mPrefix) {
rv = rdf_BlockingWrite(aStream, NS_LITERAL_CSTRING(":"));
if (NS_FAILED(rv)) return rv;
nsAutoCString prefix;
entry->mPrefix->ToUTF8String(prefix);
rv = rdf_BlockingWrite(aStream, prefix);
if (NS_FAILED(rv)) return rv;
}
rv = rdf_BlockingWrite(aStream, NS_LITERAL_CSTRING("=\""));
if (NS_FAILED(rv)) return rv;
nsAutoCString uri(entry->mURI);
rdf_EscapeAttributeValue(uri);
rv = rdf_BlockingWrite(aStream, uri);
if (NS_FAILED(rv)) return rv;
rv = rdf_BlockingWrite(aStream, NS_LITERAL_CSTRING("\""));
if (NS_FAILED(rv)) return rv;
}
return rdf_BlockingWrite(aStream, NS_LITERAL_CSTRING(">\n"));
}
nsresult
nsRDFXMLSerializer::SerializeEpilogue(nsIOutputStream* aStream)
{
return rdf_BlockingWrite(aStream, NS_LITERAL_CSTRING("</RDF:RDF>\n"));
}
class QNameCollector final : public rdfITripleVisitor {
public:
NS_DECL_ISUPPORTS
NS_DECL_RDFITRIPLEVISITOR
explicit QNameCollector(nsRDFXMLSerializer* aParent)
: mParent(aParent){}
private:
~QNameCollector() {}
nsRDFXMLSerializer* mParent;
};
NS_IMPL_ISUPPORTS(QNameCollector, rdfITripleVisitor)
nsresult
QNameCollector::Visit(nsIRDFNode* aSubject, nsIRDFResource* aPredicate,
nsIRDFNode* aObject, bool aTruthValue)
{
if (aPredicate == mParent->kRDF_type) {
// try to get a type QName for aObject, should be a resource
nsCOMPtr<nsIRDFResource> resType = do_QueryInterface(aObject);
if (!resType) {
// ignore error
return NS_OK;
}
if (mParent->mQNames.Get(resType, nullptr)) {
return NS_OK;
}
mParent->RegisterQName(resType);
return NS_OK;
}
if (mParent->mQNames.Get(aPredicate, nullptr)) {
return NS_OK;
}
if (aPredicate == mParent->kRDF_instanceOf ||
aPredicate == mParent->kRDF_nextVal)
return NS_OK;
bool isOrdinal = false;
mParent->gRDFC->IsOrdinalProperty(aPredicate, &isOrdinal);
if (isOrdinal)
return NS_OK;
mParent->RegisterQName(aPredicate);
return NS_OK;
}
nsresult
nsRDFXMLSerializer::CollectNamespaces()
{
// Iterate over all Triples to get namespaces for subject resource types
// and Predicates and cache all the QNames we want to use.
nsCOMPtr<rdfITripleVisitor> collector =
new QNameCollector(this);
nsCOMPtr<rdfIDataSource> ds = do_QueryInterface(mDataSource); // XXX API
NS_ENSURE_TRUE(collector && ds, NS_ERROR_FAILURE);
return ds->VisitAllTriples(collector);
}
//----------------------------------------------------------------------
NS_IMETHODIMP
nsRDFXMLSerializer::Serialize(nsIOutputStream* aStream)
{
nsresult rv;
rv = CollectNamespaces();
if (NS_FAILED(rv)) return rv;
nsCOMPtr<nsISimpleEnumerator> resources;
rv = mDataSource->GetAllResources(getter_AddRefs(resources));
if (NS_FAILED(rv)) return rv;
rv = SerializePrologue(aStream);
if (NS_FAILED(rv))
return rv;
while (1) {
bool hasMore = false;
resources->HasMoreElements(&hasMore);
if (! hasMore)
break;
nsCOMPtr<nsISupports> isupports;
resources->GetNext(getter_AddRefs(isupports));
nsCOMPtr<nsIRDFResource> resource = do_QueryInterface(isupports);
if (! resource)
continue;
if (IsA(mDataSource, resource, kRDF_Bag) ||
IsA(mDataSource, resource, kRDF_Seq) ||
IsA(mDataSource, resource, kRDF_Alt)) {
rv = SerializeContainer(aStream, resource);
}
else {
rv = SerializeDescription(aStream, resource);
}
if (NS_FAILED(rv))
break;
}
rv = SerializeEpilogue(aStream);
return rv;
}
bool
nsRDFXMLSerializer::IsA(nsIRDFDataSource* aDataSource, nsIRDFResource* aResource, nsIRDFResource* aType)
{
nsresult rv;
bool result;
rv = aDataSource->HasAssertion(aResource, kRDF_instanceOf, aType, true, &result);
if (NS_FAILED(rv)) return false;
return result;
}
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