dom/serializers/nsDOMSerializer.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "nsDOMSerializer.h"
   8
   9 #include "mozilla/Encoding.h"
  10 #include "mozilla/dom/Document.h"
  11 #include "nsIDocumentEncoder.h"
  12 #include "nsComponentManagerUtils.h"
  13 #include "nsContentUtils.h"
  14 #include "nsError.h"
  15 #include "nsINode.h"
  16
  17 using namespace mozilla;
  18
  19 nsDOMSerializer::nsDOMSerializer() = default;
  20
  21 static already_AddRefed<nsIDocumentEncoder> SetUpEncoder(
  22     nsINode& aRoot, const nsAString& aCharset, ErrorResult& aRv) {
  23   nsCOMPtr<nsIDocumentEncoder> encoder =
  24       do_createDocumentEncoder("application/xhtml+xml");
  25   if (!encoder) {
  26     aRv.Throw(NS_ERROR_FAILURE);
  27     return nullptr;
  28   }
  29
  30   dom::Document* doc = aRoot.OwnerDoc();
  31   bool entireDocument = (doc == &aRoot);
  32
  33   // This method will fail if no document
  34   nsresult rv = encoder->NativeInit(
  35       doc, u"application/xhtml+xml"_ns,
  36       nsIDocumentEncoder::OutputRaw |
  37           nsIDocumentEncoder::OutputDontRewriteEncodingDeclaration);
  38
  39   if (NS_FAILED(rv)) {
  40     aRv.Throw(rv);
  41     return nullptr;
  42   }
  43
  44   NS_ConvertUTF16toUTF8 charset(aCharset);
  45   if (charset.IsEmpty()) {
  46     doc->GetDocumentCharacterSet()->Name(charset);
  47   }
  48   rv = encoder->SetCharset(charset);
  49   if (NS_FAILED(rv)) {
  50     aRv.Throw(rv);
  51     return nullptr;
  52   }
  53
  54   // If we are working on the entire document we do not need to
  55   // specify which part to serialize
  56   if (!entireDocument) {
  57     rv = encoder->SetNode(&aRoot);
  58   }
  59
  60   if (NS_FAILED(rv)) {
  61     aRv.Throw(rv);
  62     return nullptr;
  63   }
  64
  65   return encoder.forget();
  66 }
  67
  68 void nsDOMSerializer::SerializeToString(nsINode& aRoot, nsAString& aStr,
  69                                         ErrorResult& aRv) {
  70   aStr.Truncate();
  71
  72   if (!nsContentUtils::CanCallerAccess(&aRoot)) {
  73     aRv.Throw(NS_ERROR_DOM_SECURITY_ERR);
  74     return;
  75   }
  76
  77   nsCOMPtr<nsIDocumentEncoder> encoder = SetUpEncoder(aRoot, u""_ns, aRv);
  78   if (aRv.Failed()) {
  79     return;
  80   }
  81
  82   nsresult rv = encoder->EncodeToString(aStr);
  83   if (NS_FAILED(rv)) {
  84     aRv.Throw(rv);
  85   }
  86 }
  87
  88 void nsDOMSerializer::SerializeToStream(nsINode& aRoot,
  89                                         nsIOutputStream* aStream,
  90                                         const nsAString& aCharset,
  91                                         ErrorResult& aRv) {
  92   if (NS_WARN_IF(!aStream)) {
  93     aRv.Throw(NS_ERROR_INVALID_ARG);
  94     return;
  95   }
  96
  97   // The charset arg can be empty, in which case we get the document's
  98   // charset and use that when serializing.
  99
 100   // No point doing a CanCallerAccess check, because we can only be
 101   // called by system JS or C++.
 102   nsCOMPtr<nsIDocumentEncoder> encoder = SetUpEncoder(aRoot, aCharset, aRv);
 103   if (aRv.Failed()) {
 104     return;
 105   }
 106
 107   nsresult rv = encoder->EncodeToStream(aStream);
 108   if (NS_FAILED(rv)) {
 109     aRv.Throw(rv);
 110   }
 111 }