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Re: External subset processing by browsers

• From: George Cristian Bina <george@o...>
• To: Andrew Welch <andrew.j.welch@g...>
• Date: Mon, 08 Dec 2008 13:21:00 +0200

Hi Andrew,

Try setting http://xml.org/sax/features/external-general-entities to 
false. See also:
http://xerces.apache.org/xerces2-j/features.html#external-general-entities

Best Regards,
George
-- 
George Cristian Bina
<oXygen/> XML Editor, Schema Editor and XSLT Editor/Debugger
http://www.oxygenxml.com

Andrew Welch wrote:
> Hi Elliotte,
> 
> 2008/12/5 Elliotte Rusty Harold <elharo@m...>:
>> Firefox. There are two separate issues here:
>>
>> 1. Whether Firefox should read the external DTD subset.
>> 2. How it should treat unrecognized entities when it doesn't read the
>> external subset.
>>
>> Let me check the spec, but my recollection is that if the external DTD
>> subset is not read, unrecognized entities are not a fatal error.
> 
> I have a similar issue, for example there are some RSS feeds which
> contain entity references but no doctype:
> 
> <foo>foo &euro; bar</foo>
> 
> I was trying the handle them by supplying a LexicalHandler (to trap
> and convert them to numeric refs), and setting a few Xerces features,
> but it always throws an exception for it before the startEntity event.
> 
> Sample code (using Xerces 2.9.0):
> 
> public class Test extends XMLFilterImpl implements LexicalHandler {
> 
>     public static void main(String... args) throws Exception {
>         new Test();
>     }
> 
>     public Test() throws Exception {
> 
>         String xml = "<foo>foo &euro; bar</foo>";
> 
>         XMLReader xmlReader =
> XMLReaderFactory.createXMLReader("org.apache.xerces.parsers.SAXParser");
>         xmlReader.setProperty("http://xml.org/sax/properties/lexical-handler",
> this);
>         xmlReader.setFeature("http://apache.org/xml/features/scanner/notify-char-refs",
> true);
>         xmlReader.setFeature("http://apache.org/xml/features/validation/unparsed-entity-checking",
> false);
>         xmlReader.setFeature("http://xml.org/sax/features/external-parameter-entities",
> false);
>         xmlReader.setEntityResolver(this);
>         xmlReader.parse(new InputSource(new StringReader(xml)));
>     }
> 
>     @Override
>     public void startDocument() throws SAXException {
>         super.startDocument();
>     }
> 
>    public void startEntity(String name) throws SAXException {
>        System.out.println("Start ent: " + name);
>     }
> 
>     public void endEntity(String name) throws SAXException { }
>     public void startCDATA() throws SAXException { }
>     public void endCDATA() throws SAXException {  }
>     public void startDTD(String name, String publicId, String
> systemId) throws SAXException { }
>     public void endDTD() throws SAXException { }
>     public void comment(char[] ch, int start, int length) throws
> SAXException { }
> }
> 
> The output when running this is:
> 
> [Fatal Error] :1:16: The entity "euro" was referenced, but not declared.
> Exception in thread "main" org.xml.sax.SAXParseException: The entity
> "euro" was referenced, but not declared.
>         at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
>         at Test.<init>(Test.java:37)
> 
> 
> It would be really nice to handle this non-well-formed input using XML
> tools without resorting to a regex replace across every feed... I'm
> not sure it's possible but the features make it seem like it should be
> - any ideas?
> 
> 
> thanks

• Follow-Ups:
  • Re: External subset processing by browsers
    • From: "Andrew Welch" <andrew.j.welch@g...>

• References:
  • External subset processing by browsers
    • From: ht@i... (Henry S. Thompson)
  • Re: External subset processing by browsers
    • From: Elliotte Rusty Harold <elharo@m...>
  • Re: External subset processing by browsers
    • From: "Andrew Welch" <andrew.j.welch@g...>