intl/chardet/src/nsXMLEncodingObserver.cpp

   1 /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
   7  * the License. You may obtain a copy of the License at
   8  * http://www.mozilla.org/MPL/
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  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
  13  * License.
  14  *
  15  * The Original Code is mozilla.org code.
  16  *
  17  * The Initial Developer of the Original Code is
  18  * Netscape Communications Corporation.
  19  * Portions created by the Initial Developer are Copyright (C) 1999
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *   Pierre Phaneuf <pp@ludusdesign.com>
  24  *
  25  * Alternatively, the contents of this file may be used under the terms of
  26  * either of the GNU General Public License Version 2 or later (the "GPL"),
  27  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  28  * in which case the provisions of the GPL or the LGPL are applicable instead
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  37  * ***** END LICENSE BLOCK ***** */
  38 #include "nsICharsetAlias.h"
  39 #include "nsXMLEncodingObserver.h"
  40 #include "nsIXMLEncodingService.h"
  41 #include "nsIElementObserver.h"
  42 #include "nsIObserver.h"
  43 #include "nsIObserverService.h"
  44 #include "nsISupports.h"
  45 #include "nsCRT.h"
  46 #include "nsIParser.h"
  47 #include "pratom.h"
  48 #include "nsCharDetDll.h"
  49 #include "nsIServiceManager.h"
  50 #include "nsObserverBase.h"
  51 #include "nsWeakReference.h"
  52 #include "nsReadableUtils.h"
  53 #include "nsUnicharUtils.h"
  54
  55 static NS_DEFINE_CID(kCharsetAliasCID, NS_CHARSETALIAS_CID);
  56
  57 static const eHTMLTags gTags[] =
  58 { eHTMLTag_instruction,
  59   eHTMLTag_unknown
  60 };
  61
  62 //-------------------------------------------------------------------------
  63 nsXMLEncodingObserver::nsXMLEncodingObserver()
  64 {
  65   bXMLEncodingObserverStarted = PR_FALSE;
  66 }
  67 //-------------------------------------------------------------------------
  68 nsXMLEncodingObserver::~nsXMLEncodingObserver()
  69 {
  70   // call to end the ObserverService
  71   if (bXMLEncodingObserverStarted == PR_TRUE) {
  72     End();
  73   }
  74 }
  75
  76 //-------------------------------------------------------------------------
  77 NS_IMPL_ADDREF ( nsXMLEncodingObserver )
  78 NS_IMPL_RELEASE ( nsXMLEncodingObserver )
  79
  80 // Use the new scheme
  81 NS_IMPL_QUERY_INTERFACE4(nsXMLEncodingObserver,
  82                          nsIElementObserver,
  83                          nsIObserver,
  84                          nsIXMLEncodingService,
  85                          nsISupportsWeakReference)
  86
  87 //-------------------------------------------------------------------------
  88 NS_IMETHODIMP nsXMLEncodingObserver::Notify(
  89                      PRUint32 aDocumentID,
  90                      const PRUnichar* aTag,
  91                      PRUint32 numOfAttributes,
  92                      const PRUnichar* nameArray[],
  93                      const PRUnichar* valueArray[])
  94 {
  95     if(!nsDependentString(aTag).LowerCaseEqualsLiteral("?xml"))
  96         return NS_ERROR_ILLEGAL_VALUE;
  97     else
  98         return Notify(aDocumentID, numOfAttributes, nameArray, valueArray);
  99 }
 100 //-------------------------------------------------------------------------
 101 NS_IMETHODIMP nsXMLEncodingObserver::Notify(
 102                      PRUint32 aDocumentID,
 103                      eHTMLTags aTag,
 104                      PRUint32 numOfAttributes,
 105                      const PRUnichar* nameArray[],
 106                      const PRUnichar* valueArray[])
 107 {
 108     if(eHTMLTag_meta != aTag)
 109         return NS_ERROR_ILLEGAL_VALUE;
 110     else
 111         return Notify(aDocumentID, numOfAttributes, nameArray, valueArray);
 112 }
 113 //-------------------------------------------------------------------------
 114 NS_IMETHODIMP nsXMLEncodingObserver::Notify(
 115                      PRUint32 aDocumentID,
 116                      PRUint32 numOfAttributes,
 117                      const PRUnichar* nameArray[],
 118                      const PRUnichar* valueArray[])
 119 {
 120
 121     nsresult res = NS_OK;
 122     PRUint32 i;
 123
 124     if(numOfAttributes >= 3)
 125     {
 126       PRBool bGotCurrentCharset=PR_FALSE;
 127       PRBool bGotCurrentCharsetSource = PR_FALSE;
 128       PRBool bGotEncoding = PR_FALSE;
 129
 130       nsCAutoString currentCharset(NS_LITERAL_CSTRING("unknown"));
 131       nsAutoString charsetSourceStr(NS_LITERAL_STRING("unknown"));
 132       nsCAutoString encoding(NS_LITERAL_CSTRING("unknown"));
 133
 134       for(i=0; i < numOfAttributes; i++)
 135       {
 136          if(0==nsCRT::strcmp(nameArray[i], NS_LITERAL_STRING("charset").get()))
 137          {
 138            bGotCurrentCharset = PR_TRUE;
 139            LossyCopyUTF16toASCII(nsDependentString(valueArray[i]), currentCharset);
 140          } else if(0==nsCRT::strcmp(nameArray[i], NS_LITERAL_STRING("charsetSource").get())) {
 141            bGotCurrentCharsetSource = PR_TRUE;
 142            charsetSourceStr = valueArray[i];
 143          } else if(nsDependentString(nameArray[i]).LowerCaseEqualsLiteral("encoding")) {
 144            bGotEncoding = PR_TRUE;
 145            LossyCopyUTF16toASCII(nsDependentString(valueArray[i]), encoding);
 146          }
 147       }
 148
 149       // if we cannot find currentCharset or currentCharsetSource
 150       // return error.
 151       if( ! (bGotCurrentCharset && bGotCurrentCharsetSource))
 152       {
 153          return NS_ERROR_ILLEGAL_VALUE;
 154       }
 155
 156       PRInt32 err;
 157       PRInt32 charsetSourceInt = charsetSourceStr.ToInteger(&err);
 158
 159       // if we cannot convert the string into PRInt32, return error
 160       if(NS_FAILED(err))
 161          return NS_ERROR_ILLEGAL_VALUE;
 162
 163       PRInt32 currentCharsetSource = charsetSourceInt;
 164
 165       if(kCharsetFromMetaTag > currentCharsetSource)
 166       {
 167            if(! encoding.Equals(currentCharset))
 168            {
 169               nsCOMPtr<nsICharsetAlias> calias = do_GetService(kCharsetAliasCID, &res);
 170                if(NS_SUCCEEDED(res) && (nsnull != calias) )
 171                {
 172                     PRBool same = PR_FALSE;
 173                     res = calias->Equals( encoding, currentCharset, &same);
 174                     if(NS_SUCCEEDED(res) && (! same))
 175                     {
 176                           nsCAutoString preferred;
 177                           res = calias->GetPreferred(encoding,
 178                                                      preferred);
 179                           if(NS_SUCCEEDED(res))
 180                           {
 181                             res = NotifyWebShell(0,0, preferred.get(), kCharsetFromMetaTag );
 182                             return res;
 183                           } // if check for GetPreferred
 184                     } // if check res for Equals
 185                 } // if check res for GetService
 186             } // if Equals
 187        } // if
 188     } // if
 189
 190     return NS_OK;
 191 }
 192
 193 //-------------------------------------------------------------------------
 194 NS_IMETHODIMP nsXMLEncodingObserver::Observe(nsISupports*, const char*, const PRUnichar*)
 195 {
 196     return NS_ERROR_NOT_IMPLEMENTED;
 197 }
 198 //-------------------------------------------------------------------------
 199 NS_IMETHODIMP nsXMLEncodingObserver::Start()
 200 {
 201     nsresult res = NS_OK;
 202
 203     if (bXMLEncodingObserverStarted == PR_TRUE)
 204       return res;
 205
 206     nsCOMPtr<nsIObserverService> anObserverService = do_GetService("@mozilla.org/observer-service;1", &res);
 207
 208     if (NS_SUCCEEDED(res)) {
 209       res = anObserverService->AddObserver(this, "xmlparser", PR_TRUE);
 210
 211       bXMLEncodingObserverStarted = PR_TRUE;
 212     }
 213
 214     return res;
 215 }
 216 //-------------------------------------------------------------------------
 217 NS_IMETHODIMP nsXMLEncodingObserver::End()
 218 {
 219     nsresult res = NS_OK;
 220
 221     if (bXMLEncodingObserverStarted == PR_FALSE)
 222       return res;
 223
 224     nsCOMPtr<nsIObserverService> anObserverService = do_GetService("@mozilla.org/observer-service;1", &res);
 225     if (NS_SUCCEEDED(res)) {
 226       res = anObserverService->RemoveObserver(this, "xmlparser");
 227
 228       bXMLEncodingObserverStarted = PR_FALSE;
 229     }
 230
 231     return res;
 232 }
 233