Error parsing UTF8 XML using TXMLDocument
lazarus / 5-Lazarus Extra Components

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dago71 · 2012-12-27 00:57

I were having trouble reading some XML files that where encoded in
UTF-8.

I sometimes get 'XML declaration is not allowed here', and after a
thorough investigation and much search in the forums, i had arrived to
the conclusion that the problem was the BOM.

I'm using 1.0.4, but tried with latest SVN and the error persisted.

Finally, today i noted that on line 1186 of laz2_XMLRead.pas it says

Code: [Select]  FBufSize := 6;             //  possible BOM and
'<?xml'
  Reload;

but UTF8 BOM is 3 bytes length, and '<?xml' are 5 

So i changed line 1186 to read
Code: [Select]  FBufSize := 8;             //  possible BOM and
'<?xml'
  Reload;

And the error was gone for me! 
Please some dev confirm that it's a valid fix for that problem.
Sorry if this is not the place to post this.

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esvignolo · 2013-03-20 22:18

Thanks mate! work for me too!!!!

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BigChimp · 2013-03-21 04:35

If dago's fix fixed the problem:
Best way to get the fix into official Lazarus/FPC is to add an issue
in the bug tracker, with the fix and preferably a sample
program+sample xml file.

No idea if this has been fixed in newer Lazarus/FPC, but if you're
interested in getting a fix in, please submit a bug

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vrull · 2013-03-21 18:29

I had same problem - some XML files, created by MS .NET applications,
caused the error on opening. This fix solved the problem, great!

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BigChimp · 2013-04-03 05:36

So did anybody file a bug report with the fix? Shame if this is kept
from users...

(And no, I'm not going to file the bug, because I'm not using the unit
and I'm busy improving FPC dbf support. Other FPC/Laz developers will
have similar use of their time. If somebody provides a bug report with
a ready made patch and demo program, that really cuts down on the time
devs need to look at improvements and makes it much more likely these
volunteers will incorporate the fix for everybody to use)