Re: [PHP-XML-DEV] xml error handling for 5.1

Hi

Looks good to me and it's more or less one of the ways I had in mind.

I think it's a plain and simple approach. Some people wanted exceptions 
for that, but IMHO it's not necessery and would force you to try/catch 
even for simple warnings.

I would have preferred the callback approach, but I see the problems you 
had with that. I can live very well with this implementation. And I 
prefer it anyway over memleak hunting ;)

I will do some tests (hopefully over the weekend) and report back

chregu

On 4.2.2005 13:43 Uhr, Rob Richards wrote:
> After trying many different approaches for better error handling 
> support, I ultimately went with something simple - at least to start with.
> At first, I thought about letting users set a dedicated error handler 
> for the errors, but ran into issues with memory leaks.
> Since they could exit or throw an exception in their handler, I couldnt 
> find any way to be able to clean up stuff since the error would occur in 
> the middle of libxml processing and never get a chance to return to the 
> extension's internal function call.
> 
>  From here I decided to go the route of not issuing any errors from 
> libxml directly and letting the user grab them after the function call 
> returned.
> This I have dumbed down quite alot to keep it simple and at least 
> hopefully a starting point. It works as follows:
> 
> 3 new functions in libxml extension as well as some constants:
> constants which map to the error level:
> LIBXML_ERR_NONE
> LIBXML_ERR_WARNING
> LIBXML_ERR_ERROR
> LIBXML_ERR_FATAL
> 
> void libxml_use_interal_errors(boolean use_errors)
>     - use interal error object. this will disable the php_error_docref 
> errors when an error occurs within libxml.
>    It will switch to libxml structured errors in order to populate the 
> error structure, but will not automatically throw the errors.
> 
> object libxml_get_last_error()
>    If a function fails (or the user just wants to check the last error 
> state), a call to this will return a LibXMLError object.
>    Went with the object as it was quick to implement
> 
> void libxml_clear_errors()
>    - Clears the last libxml error so a subsequent call to 
> libxml_get_last_error() (unless error) would return FALSE
> 
> Here's a few examples:
> libxml_use_interal_errors(TRUE);
> if ( ! ($t = DOMDocument::loadXML("<root>"))) {
> $err = libxml_get_last_error();
> var_dump($err);   }
> 
> -- Output --
> object(LibXMLError)#1 (5) {
>  ["level"]=>  int(3)
>  ["code"]=>  int(77)
>  ["message"]=>  string(41) "Premature end of data in tag root line 1"
>  ["file"]=>  string(0) ""
>  ["line"]=>  int(1)
> }
> 
> libxml_use_interal_errors(TRUE);
> $xml = '<books><book>Book 1</booka></books>';
> if (! ($xml = simplexml_load_string($xml))) {
>    $err = libxml_get_last_error();
>    var_dump($err);   }
> 
> -- Output --
> object(LibXMLError)#2 (5) {
>  ["level"]=>  int(3)
>  ["code"]=>  int(73)
>  ["message"]=>  string(13) "expected '>'"
>  ["file"]=>  string(0) ""
>  ["line"]=>  int(1)
> }
> 
> Not sure wether code is really needed or not as I'm not sure wether 
> every libxml error code should be defined as a constant - there's quite 
> a few of them. Also file is only populated if error from an xml file 
> rather than a string.
> 
> Error handling stuff requires libxml 2.6.0+ and patch can be found at:
> http://ctindustries.net/libxml/libxml_error.diff.txt
> 
> Any comments, suggestions or changes on this stuff? It's still in 
> testing and I would like some feedback since I kind of winged this stuff 
> - hard guessing how to implement from just the requests that the xml 
> stuff needs better error support with no specifics - :)
> 
> Rob
> 
> 
> 

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