Re: [xml] Making Sure Output is XML safe

["Elvis Stansvik" <elvstone gmail com>]

Hi,

2008/11/25 Danie van der Walt <dvdwalt foneworx co za>:
> Hi Elvis
>
> I seem to have run into another problem :(.
> I have a mysql database, storing messages in UTF-8, when I select from it
> using c/c++ and libmysql.
>
> I get a warning from libxml saying:
>     error : xmlEncodeEntitiesReentrant : input not UTF-8
>
> Im not sure if it is the data that is getting returned by mysql, or the
> format of the string.

You have to explain a bit better here, or better yet show the code. In
any case, xmlEncodeEntitiesReentrant() is not lying, if it says the
input is not UTF-8, it is not UTF-8. There's nothing libxml2 can do to
help you with that. You need to pass a sequence of NULL-terminated
UTF-8 bytes to the libxml2 library. Period.

> When I store the data plain(latin1)  is seems to work. Only problem is I
> need to store the
> information in UTF-8.

What storage are you talking about here? Your MySQL database? In any
case, no matter if your data is in UTF-8 in your database or not, it
must be UTF-8 when it is passed to libxml2.

> Have you come across a similar problem?

No, I have never parsed XML coming from a MySQL database with libxml2,
and it was a long time since I used the MySQL C client library. But I
think that is besides the point. The only thing that matters here is
that you are passing invalid UTF-8 to libxml2, and that will never
work. I really don't think this is a libxml2 question. Just debug your
code and make sure that at the call to xmlEncodeEntitiesReentrant(),
the string you pass is valid UTF-8 bytes, and NULL-terminated.

Good luck,
Elvis

> *********************************************************
> Danie van der Walt
> FoneWorx
> Senior Programmer
> Tel : +27112930000
> MSN : predetor_me hotmail com
> GoogleTalk : predetorlinux gmail com
> *********************************************************
>
>
> Elvis Stansvik wrote:
>
> I forgot the footnote:
>
> [1] http://xmlsoft.org/html/libxml-entities.html#xmlEncodeEntitiesReentrant
>
> Elvis
>
> 2008/11/14 Elvis Stansvik <elvstone gmail com>:
>
>
> Hi Danie,
>
> 2008/11/5 Danie van der Walt <dvdwalt foneworx co za>:
>
>
> HI Guys
>
> I hope you can help me.
> I'm currently using libxml to parse incomming xml, but simply using printf
> to generate my reply xml.
>
> I have one variable that may contain characters that are not xml
> safe/friendly like '<' as an example.
> Is there anyway that I can parse some text to a function and get a xml
> "safe/friendly" output that I can use
> in my app.
>
>
> Use xmlEncodeEntitiesReentrant() [1] to encode entities in a string. Like
> this:
>
> #include <stdio.h>
>
> #include <libxml/parser.h>
> #include <libxml/entities.h>
>
> int main (int argc, char *argv[])
> {
>    LIBXML_TEST_VERSION
>
>    const xmlChar *str = "string with < and > in it";
>    const xmlChar *xml = "<foo />";
>
>    xmlDoc *doc = xmlReadMemory(xml, 8, "xml", "UTF-8", 0);
>    xmlChar *safe_str = xmlEncodeEntitiesReentrant(doc, str);
>
>    printf("%s\n", safe_str);
>
>    xmlFree(safe_str);
>    xmlFreeDoc(doc);
>    xmlCleanupParser();
>
>    return(0);
> }
>
> Note that you need to pass it your document pointer as argument too,
> so that it will know about all entities and not just &lt;, &gt; et.c.
>
> Regards,
> Elvis
>
>
>
> Regards
> Danie
>
>
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