Setting Content-Type in a custom response (mp2)

I have a mod_perl-2 handler that uses custom_response() to display error
messages if something goes wrong:

$r->custom_response(Apache2::Const::SERVER_ERROR, $error);
return Apache2::Const::SERVER_ERROR;

That almost works fine, but the trouble is that the Content-Type header
is always set to "text/html; charset=3Diso-8859-1", in which the =
charset,
at least, is potentially wrong: all the pages in my software produce
UTF-8 and are normally output with Content-Type "application/xhtml+xml;
charset=3Dutf-8".

How do I set the Content-Type when issuing a custom_reponse()? The usual
thing of calling

$r->content_type("application/xhtml+xml; charset=3Dutf-8");

doesn't seem to work in this case.

Re: Setting Content-Type in a custom response (mp2)

On Thursday 11 March 2010 15:18:08 Steve Hay wrote:
> I have a mod_perl-2 handler that uses custom_response() to display error
> messages if something goes wrong:
>=20
> $r->custom_response(Apache2::Const::SERVER_ERROR, $error);
> return Apache2::Const::SERVER_ERROR;
>=20
> That almost works fine, but the trouble is that the Content-Type header
> is always set to "text/html; charset=3Diso-8859-1", in which the charset,
> at least, is potentially wrong: all the pages in my software produce
> UTF-8 and are normally output with Content-Type "application/xhtml+xml;
> charset=3Dutf-8".
>=20
> How do I set the Content-Type when issuing a custom_reponse()? The usual
> thing of calling
>=20
> $r->content_type("application/xhtml+xml; charset=3Dutf-8");
>=20
> doesn't seem to work in this case.
>=20
I think that is impossible. ap_send_error_response() contains this code:

if (apr_table_get(r->subprocess_env,
"suppress-error-charset") !=3D NULL) {
core_request_config *request_conf =3D
ap_get_module_config(r->request_config, &core_modul=
e);
request_conf->suppress_charset =3D 1; /* avoid adding default
* charset later
*/
ap_set_content_type(r, "text/html");
}
else {
ap_set_content_type(r, "text/html; charset=3Diso-8859-1");
}

The resulting content-type is either "text/html; charset=3Diso-8859-1" or=20
"text/html".

But instead of passing the response text directly to $r->custom_response yo=
u=20
can specify an URL. ap_die() will then create an internal redirect to this=
=20
URL. Via $r->prev->pnotes you can then access the pnotes of the failed=20
request. Putting all together a solution could look like:

$r->pnotes->{estring}=3D$error;
$r->pnotes->{ect}=3D'my/special-content-type';
# use an otherwise not used URL here
$r->custom_response(Apache2::Const::SERVER_ERROR, '/-/error');


SetHandler modperl
# please insert a \ at the end of each of the following lines=20
# up to }"
PerlResponseHandler "sub {
my ($r)=3D@_;
return Apache2::Const::NOT_FOUND unless $r->prev;
$r->content_type($r->prev->pnotes->{ect});
$r->print($r->prev->pnotes->{estring});
return Apache2::Const::OK;
}"


Torsten Förtsch

=2D-=20
Need professional modperl support? Hire me! (http://foertsch.name)

Like fantasy? http://kabatinte.net

RE: Setting Content-Type in a custom response (mp2)

Torsten Förtsch wrote on 2010-03-11:
> On Thursday 11 March 2010 15:18:08 Steve Hay wrote:
>> I have a mod_perl-2 handler that uses custom_response() to display
>> error messages if something goes wrong:
>>=20
>> $r->custom_response(Apache2::Const::SERVER_ERROR, $error);
>> return Apache2::Const::SERVER_ERROR;
>>=20
>> That almost works fine, but the trouble is that the Content-Type =
header
>> is always set to "text/html; charset=3Diso-8859-1", in which the =
charset,
>> at least, is potentially wrong: all the pages in my software produce
>> UTF-8 and are normally output with Content-Type =
"application/xhtml+xml;
>> charset=3Dutf-8".
>>=20
>> How do I set the Content-Type when issuing a custom_reponse()? The
>> usual thing of calling
>>=20
>> $r->content_type("application/xhtml+xml; charset=3Dutf-8");
>>=20
>> doesn't seem to work in this case.
>>=20
> I think that is impossible. ap_send_error_response() contains this =
code:
>=20
> if (apr_table_get(r->subprocess_env,
> "suppress-error-charset") !=3D NULL) {
> core_request_config *request_conf =3D
> ap_get_module_config(r->request_config,
> &core_module);
> request_conf->suppress_charset =3D 1; /* avoid adding =
default
> * charset later
> */
> ap_set_content_type(r, "text/html");
> }
> else {
> ap_set_content_type(r, "text/html; charset=3Diso-8859-1");
> }
> The resulting content-type is either "text/html; =
charset=3Diso-8859-1" or
> "text/html".
>=20
> But instead of passing the response text directly to $r-
>> custom_response you
> can specify an URL. ap_die() will then create an internal redirect to
> this URL. Via $r->prev->pnotes you can then access the pnotes of the
> failed request. Putting all together a solution could look like:
>=20
> $r->pnotes->{estring}=3D$error;
> $r->pnotes->{ect}=3D'my/special-content-type'; # use an otherwise =
not
> used URL here $r->custom_response(Apache2::Const::SERVER_ERROR,
> '/-/error');
> =20
>
> SetHandler modperl
> # please insert a \ at the end of each of the following lines
> # up to }"
> PerlResponseHandler "sub {
> my ($r)=3D@_; return Apache2::Const::NOT_FOUND unless $r->prev;
> $r->content_type($r->prev->pnotes->{ect});
> $r->print($r->prev->pnotes->{estring}); return =
Apache2::Const::OK;
> }"
>
>=20

Thanks! That works a treat :-)

RE: Setting Content-Type in a custom response (mp2)

Hi all,

I searched for that solution for hours not finding any until
Torsten posted this one.

IMHO it's worth it to put Torsten's snippet to the documentation
pages of mod_perl.

Even the book 'mod_perl 2 user's guide' leaves a big hole
in that area.

Thank you Torsten!

Best regards
Andreas Mock



-----Ursprüngliche Nachricht-----
Von: Steve Hay=20
Gesendet: 12.03.2010 10:58:15
An: "Torsten Förtsch" ,modperl@perl.apache.o=
rg
Betreff: RE: Setting Content-Type in a custom response (mp2)

>Torsten Förtsch wrote on 2010-03-11:
>> On Thursday 11 March 2010 15:18:08 Steve Hay wrote:
>>> I have a mod_perl-2 handler that uses custom_response() to display
>>> error messages if something goes wrong:
>>>=20
>>> $r->custom_response(Apache2::Const::SERVER_ERROR, $error);
>>> return Apache2::Const::SERVER_ERROR;
>>>=20
>>> That almost works fine, but the trouble is that the Content-Type header
>>> is always set to "text/html; charset=3Diso-8859-1", in which the charse=
t,
>>> at least, is potentially wrong: all the pages in my software produce
>>> UTF-8 and are normally output with Content-Type "application/xhtml+xml;
>>> charset=3Dutf-8".
>>>=20
>>> How do I set the Content-Type when issuing a custom_reponse()? The
>>> usual thing of calling
>>>=20
>>> $r->content_type("application/xhtml+xml; charset=3Dutf-8");
>>>=20
>>> doesn't seem to work in this case.
>>>=20
>> I think that is impossible. ap_send_error_response() contains this code:
>>=20
>> if (apr_table_get(r->subprocess_env,
>> "suppress-error-charset") !=3D NULL) {
>> core_request_config *request_conf =3D
>> ap_get_module_config(r->request_config,
>> &core_module);
>> request_conf->suppress_charset =3D 1; /* avoid adding defaul=
t
>> * charset later
>> */
>> ap_set_content_type(r, "text/html");
>> }
>> else {
>> ap_set_content_type(r, "text/html; charset=3Diso-8859-1");
>> }
>> The resulting content-type is either "text/html; charset=3Diso-8859-1" =
or
>> "text/html".
>>=20
>> But instead of passing the response text directly to $r-
>>> custom_response you
>> can specify an URL. ap_die() will then create an internal redirect to
>> this URL. Via $r->prev->pnotes you can then access the pnotes of the
>> failed request. Putting all together a solution could look like:
>>=20
>> $r->pnotes->{estring}=3D$error;
>> $r->pnotes->{ect}=3D'my/special-content-type'; # use an otherwise not
>> used URL here $r->custom_response(Apache2::Const::SERVER_ERROR,
>> '/-/error');
>> =20
>>
>> SetHandler modperl
>> # please insert a \ at the end of each of the following lines
>> # up to }"
>> PerlResponseHandler "sub {
>> my ($r)=3D@_; return Apache2::Const::NOT_FOUND unless $r->prev;
>> $r->content_type($r->prev->pnotes->{ect});
>> $r->print($r->prev->pnotes->{estring}); return Apache2::Const::OK;
>> }"
>>
>>=20
>
>Thanks! That works a treat :-)