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Apache2::RequestRec - Perl API for Apache request record accessors

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Table of Contents

Synopsis

  use Apache2::RequestRec ();
  
  # set supported by the handler HTTP methods
  $allowed = $r->allowed();
  
  # auth type
  $auth_type = $r->ap_auth_type();
  
  # QUERY_STRING
  $args = $r->args();
  
  # non-parsed-headers handler
  $status = $r->assbackwards();
  
  # how many bytes were sent
  $bytes_sent = $r->bytes_sent();
  
  # client connection record
  $c = $r->connection();
  
  # "Content-Encoding" HTTP response header
  $r->content_encoding("gzip");
  
  # the languages of the content
  $languages = $r->content_languages();
  
  # "Content-Encoding" HTTP response header
  $r->content_type('text/plain');
  
  # special response headers table
  $err_headers_out = $r->err_headers_out();
  
  # request mapped filename
  $filename = $r->filename();
  
  # request finfo
  $finfo = $r->finfo();
  
  # 'SetHandler perl-script' equivalent
  $r->handler('perl-script');
  
  # was it a HEAD request?
  $status = $r->header_only();
  
  # request input headers table
  $headers_in = $r->headers_in();
  
  # request output headers table
  $headers_out = $r->headers_out();
  
  # hostname
  $hostname = $r->hostname();
  
  # input filters stack
  $input_filters = $r->input_filters();
  
  # get the main request obj in a sub-request
  $main_r = $r->main();
  
  # what's the current request (GET/POST/etc)?
  $method = $r->method();
  
  # what's the current method number?
  $methnum = $r->method_number();
  
  # current resource last modified time
  $mtime = $r->mtime();
  
  # next request object (in redirect)
  $next_r = $r->next();
  
  # there is no local copy
  $r->no_local_copy();
  
  # Apache ascii notes table
  $notes = $r->notes();
  
  # output filters stack
  $output_filters = $r->output_filters();
  
  # PATH_INFO
  $path_info = $r->path_info();
  
  # used in configuration directives modules
  $per_dir_config = $r->per_dir_config();
  
  # pool with life span of the current request
  $p = $r->pool();
  
  # previous request object in the internal redirect
  $prev_r = $r->prev();
  
  # connection level input filters stack
  $proto_input_filters = $r->proto_input_filters();
  
  # HTTP protocol version number
  $proto_num = $r->proto_num();
  
  # connection level output filters stack
  $proto_output_filters = $r->proto_output_filters();
  
  # the protocol, the client speaks: "HTTP/1.0", "HTTP/1.1", etc.
  $protocol = $r->protocol();
  
  # is it a proxy request
  $status = $r->proxyreq($val);
  
  # Time when the request started
  $request_time = $r->request_time();
  
  # server object
  $s = $r->server();
  
  # response status
  $status = $r->status();
  
  # response status line
  $status_line = $r->status_line();
  
  # manipulate %ENV of the subprocess
  $r->subprocess_env;
  $r->subprocess_env($key => $val);
  
  # first HTTP request header
  $request = $r->the_request();
  
  # the URI without any parsing performed
  $unparsed_uri = $r->unparsed_uri();
  
  # The path portion of the URI
  $uri = $r->uri();
  
  # auth username
  $user = $r->user();


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Description

Apache2::RequestRec provides the Perl API for Apache request_rec object.

The following packages extend the Apache2::RequestRec functionality: Apache2::Access, Apache2::Log, Apache2::RequestIO, Apache2::RequestUtil, Apache2::Response, Apache2::SubRequest and Apache2::URI.



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API

Apache2::RequestRec provides the following functions and/or methods:



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allowed

Get/set the allowed methods bitmask.

  $allowed      = $r->allowed();
  $prev_allowed = $r->allowed($new_allowed);

A handler must ensure that the request method is one that it is capable of handling. Generally modules should Apache2::DECLINE any request methods they do not handle. Prior to aborting the handler like this the handler should set $r->allowed to the list of methods that it is willing to handle. This bitvector is used to construct the "Allow:" header required for OPTIONS requests, and Apache2::Const::HTTP_METHOD_NOT_ALLOWED (405) and Apache2::Const::HTTP_NOT_IMPLEMENTED (501) status codes.

Since the default Apache handler deals with the OPTIONS method, all response handlers can usually decline to deal with OPTIONS. For example if the response handler handles only GET and POST methods, and not OPTIONS, it may want to say:

   use Apache2::Const -compile => qw(OK DECLINED M_GET M_POST M_OPTIONS);
   if ($r->method_number == Apache2::Const::M_OPTIONS) {
       $r->allowed($r->allowed | (1<<Apache2::Const::M_GET) | (1<<Apache2::Const::M_POST));
       return Apache2::Const::DECLINED;
   }

TRACE is always allowed, modules don't need to set it explicitly.

Since the default_handler will always handle a GET, a module which does *not* implement GET should probably return Apache2::Const::HTTP_METHOD_NOT_ALLOWED. Unfortunately this means that a script GET handler can't be installed by mod_actions.

For example, if the module can handle only POST method it could start with:

   use Apache2::Const -compile => qw(M_POST HTTP_METHOD_NOT_ALLOWED);
   unless ($r->method_number == Apache2::Const::M_POST) {
       $r->allowed($r->allowed | (1<<Apache2::Const::M_POST));
       return Apache2::Const::HTTP_METHOD_NOT_ALLOWED;
   }


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ap_auth_type

If an authentication check was made, get or set the ap_auth_type slot in the request record

  $auth_type = $r->ap_auth_type();
  $r->ap_auth_type($newval);

ap_auth_type holds the authentication type that has been negotiated between the client and server during the actual request. Generally, ap_auth_type is populated automatically when you call $r->get_basic_auth_pw so you don't really need to worry too much about it, but if you want to roll your own authentication mechanism then you will have to populate ap_auth_type yourself.

Note that $r->ap_auth_type was $r->connection->auth_type in the mod_perl 1.0 API.



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args

Get/set the request QUERY string

  $args      = $r->args();
  $prev_args = $r->args($new_args);


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assbackwards

When set to a true value, Apache won't send any HTTP response headers allowing you to send any headers.

  $status      = $r->assbackwards();
  $prev_status = $r->assbackwards($newval);

If you send your own set of headers, which includes the Keep-Alive HTTP response header, you must make sure to increment the number of requests served over this connection (which is normally done by the core connection output filter ap_http_header_filter, but skipped when assbackwards is enabled).

  $r->connection->keepalives($r->connection->keepalives + 1);

otherwise code relying on the value of $r->connection->keepalives may malfunction. For example, this counter is used to tell when a new request is coming in over the same connection to a filter that wants to parse only HTTP headers (like Apache2::Filter::HTTPHeadersFixup). Of course you will need to set $r->connection->keepalive(1) ) as well.



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bytes_sent

The number of bytes sent to the client, handy for logging, etc.

  $bytes_sent = $r->bytes_sent();

Though as of this writing in Apache 2.0 it doesn't really do what it did in Apache 1.3. It's just set to the size of the response body. The issue is that buckets from one request may get buffered and not sent during the lifetime of the request, so it's not easy to give a truly accurate count of "bytes sent to the network for this response".



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connection

Get the client connection record

  $c = $r->connection();


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content_encoding

Get/set content encoding (the "Content-Encoding" HTTP header). Content encodings are string like "gzip" or "compress".

  $ce      = $r->content_encoding();
  $prev_ce = $r->content_encoding($new_ce);

For example, here is how to send a gzip'ed response:

  require Compress::Zlib;
  $r->content_type("text/plain");
  $r->content_encoding("gzip");
  $r->print(Compress::Zlib::memGzip("some text to be gzipped));


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content_languages

Get/set content languages (the "Content-Language" HTTP header). Content languages are string like "en" or "fr".

  $languages = $r->content_languages();
  $prev_lang = $r->content_languages($nev_lang);


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content_type

Get/set the HTTP response Content-type header value.

  my $content_type      = $r->content_type();
  my $prev_content_type = $r->content_type($new_content_type);

For example, set the Content-type header to text/plain.

  $r->content_type('text/plain');

If you set this header via the headers_out table directly, it will be ignored by Apache. So do not do that.



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err_headers_out

Get/set MIME response headers, printed even on errors and persist across internal redirects.

  $err_headers_out = $r->err_headers_out();

The difference between headers_out and err_headers_out, is that the latter are printed even on error, and persist across internal redirects (so the headers printed for ErrorDocument handlers will have them).

For example, if a handler wants to return a 404 response, but nevertheless to set a cookie, it has to be:

  $r->err_headers_out->add('Set-Cookie' => $cookie);
  return Apache2::Const::NOT_FOUND;

If the handler does:

  $r->headers_out->add('Set-Cookie' => $cookie);
  return Apache2::Const::NOT_FOUND;

the Set-Cookie header won't be sent.



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filename

Get/set the filename on disk corresponding to this response (the result of the URI --> filename translation).

  $filename      = $r->filename();
  $prev_filename = $r->filename($new_filename);

Note that if you change the filename after the PerlMapToStorageHandler phase was run and expect Apache to serve it, you need to update its stat record, like so:

  use Apache2::RequestRec ();
  use APR::Finfo ();
  use APR::Const -compile => qw(FINFO_NORM);
  $r->filename($newfile);
  $r->finfo(APR::Finfo::stat($newfile, APR::Const::FINFO_NORM, $r->pool));

if you don't, Apache will still try to use the previously cached information about the previously set value of the filename.



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finfo

Get and set the finfo request record member:

  $finfo = $r->finfo();
  $r->finfo($finfo);

Most of the time, this method is used to get the finfo member. The only reason you may want to set it is you need to use it before the Apache's default map_to_storage phase is called.

Examples:



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handler

Get/set the equivalent of the SetHandler directive.

  $handler      = $r->handler();
  $prev_handler = $r->handler($new_handler);


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header_only

Did the client has asked for headers only? e.g. if the request method was HEAD.

  $status = $r->header_only();


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headers_in

Get/set the request MIME headers:

  $headers_in = $r->headers_in();

This table is available starting from the PerlHeaderParserHandler phase.

For example you can use it to retrieve the cookie value sent by the client, in the Cookie: header:

    my $cookie = $r->headers_in->{Cookie} || '';


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headers_out

Get/set MIME response headers, printed only on 2xx responses.

  $headers_out = $r->headers_out();

See also err_headers_out, which allows to set headers for non-2xx responses and persist across internal redirects.



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hostname

Host, as set by full URI or Host:

  $hostname = $r->hostname();
  $prev_hostname = $r->hostname($new_hostname);


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input_filters

Get/set the first filter in a linked list of request level input filters:

  $input_filters      = $r->input_filters();
  $prev_input_filters = $r->input_filters($new_input_filters);

For example instead of using $r->read() to read the POST data, one could use an explicit walk through incoming bucket brigades to get that data. The following function read_post() does just that (in fact that's what $r->read() does behind the scenes):

  use APR::Brigade ();
  use APR::Bucket ();
  use Apache2::Filter ();
  
  use Apache2::Const -compile => qw(MODE_READBYTES);
  use APR::Const    -compile => qw(SUCCESS BLOCK_READ);
  
  use constant IOBUFSIZE => 8192;
  
  sub read_post {
      my $r = shift;
  
      my $bb = APR::Brigade->new($r->pool,
                                 $r->connection->bucket_alloc);
  
      my $data = '';
      my $seen_eos = 0;
      do {
          $r->input_filters->get_brigade($bb, Apache2::Const::MODE_READBYTES,
                                         APR::Const::BLOCK_READ, IOBUFSIZE);
  
          for (my $b = $bb->first; $b; $b = $bb->next($b)) {
              if ($b->is_eos) {
                  $seen_eos++;
                  last;
              }
  
              if ($b->read(my $buf)) {
                  $data .= $buf;
              }
  
              $b->remove; # optimization to reuse memory
          }
  
      } while (!$seen_eos);
  
      $bb->destroy;
  
      return $data;
  }

As you can see $r->input_filters gives us a pointer to the last of the top of the incoming filters stack.



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main

Get the main request record

  $main_r = $r->main();


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method

Get/set the current request method (e.g. GET, HEAD, POST, etc.):

  $method     = $r->method();
  $pre_method = $r->method($new_method);


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method_number

Get/set the HTTP method, issued by the client (Apache2::Const::M_GET, Apache2::Const::M_POST, etc.)

  $methnum      = $r->method_number();
  $prev_methnum = $r->method_number($new_methnum);

See the $r->allowed entry for examples.



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mtime

Last modified time of the requested resource

  $mtime      = $r->mtime();
  $prev_mtime = $r->mtime($new_mtime);


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next

Pointer to the redirected request if this is an external redirect

  $next_r = $r->next();


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no_local_copy

There is no local copy of this response

  $status = $r->no_local_copy();

Used internally in certain sub-requests to prevent sending Apache2::Const::HTTP_NOT_MODIFIED for a fragment or error documents. For example see the implementation in modules/filters/mod_include.c.

Also used internally in $r->meets_conditions -- if set to a true value, the conditions are always met.



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notes

Get/set text notes for the duration of this request. These notes can be passed from one module to another (not only mod_perl, but modules in any other language):

  $notes      = $r->notes();
  $prev_notes = $r->notes($new_notes);

If you want to pass Perl structures, you can use $r->pnotes.

Also see $c->notes



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output_filters

Get the first filter in a linked list of request level output filters:

  $output_filters      = $r->output_filters();
  $prev_output_filters = $r->output_filters($new_output_filters);

For example instead of using $r->print() to send the response body, one could send the data directly to the first output filter. The following function send_response_body() does just that:

  use APR::Brigade ();
  use APR::Bucket ();
  use Apache2::Filter ();
  
  sub send_response_body {
      my ($r, $data) = @_;
  
      my $bb = APR::Brigade->new($r->pool,
                                 $r->connection->bucket_alloc);
  
      my $b = APR::Bucket->new($bb->bucket_alloc, $data);
      $bb->insert_tail($b);
      $r->output_filters->fflush($bb);
      $bb->destroy;
  }

In fact that's what $r->read() does behind the scenes. But it also knows to parse HTTP headers passed together with the data and it also implements buffering, which the above function does not.



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path_info

Get/set the PATH_INFO, what is left in the path after the URI --> filename translation:

  $path_info      = $r->path_info();
  $prev_path_info = $r->path_info($path_info);


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per_dir_config

Get the dir config vector:

  $per_dir_config = $r->per_dir_config();

For an indepth discussion, refer to the Apache Server Configuration Customization in Perl chapter.



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pool

The pool associated with the request

  $p = $r->pool();


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prev

Pointer to the previous request if this is an internal redirect

  $prev_r = $r->prev();


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proto_input_filters

Get the first filter in a linked list of protocol level input filters:

  $proto_input_filters      = $r->proto_input_filters();
  $prev_proto_input_filters = $r->proto_input_filters($new_proto_input_filters);

$r->proto_input_filters points to the same filter as $r->connection->input_filters.



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proto_num

Get current request's HTTP protocol version number

  $proto_num = $r->proto_num();


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proto_output_filters

Get the first filter in a linked list of protocol level output filters:

  $proto_output_filters      = $r->proto_output_filters();
  $prev_proto_output_filters = $r->proto_output_filters($new_proto_output_filters);

$r->proto_output_filters points to the same filter as $r->connection->output_filters.



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protocol

Get a string identifying the protocol that the client speaks.

  $protocol = $r->protocol();


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proxyreq

Get/set the proxyrec request record member and optionally adjust other related fields.

  $status = $r->proxyreq($val);

For example to turn a normal request into a proxy request to be handled on the same server in the PerlTransHandler phase run:

  my $real_url = $r->unparsed_uri;
  $r->proxyreq(Apache2::Const::PROXYREQ_PROXY);
  $r->uri($real_url);
  $r->filename("proxy:$real_url");
  $r->handler('proxy-server');

Also remember that if you want to turn a proxy request into a non-proxy request, it's not enough to call:

  $r->proxyreq(Apache2::Const::PROXYREQ_NONE);

You need to adjust $r->uri and $r->filename as well if you run that code in PerlPostReadRequestHandler phase, since if you don't -- mod_proxy's own post_read_request handler will override your settings (as it will run after the mod_perl handler).

And you may also want to add

  $r->set_handlers(PerlResponseHandler => []);

so that any response handlers which match apache directives will not run in addition to the mod_proxy content handler.



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request_time

Time when the request started

  $request_time = $r->request_time();


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server

Get the Apache2::Server object for the server the request $r is running under.

  $s = $r->server();


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status

Get/set the reply status for the client request.

  $status      = $r->status();
  $prev_status = $r->status($new_status);

Usually you will set this value indirectly by returning the status code as the handler's function result. However, there are rare instances when you want to trick Apache into thinking that the module returned an Apache2::Const::OK status code, but actually send the browser a non-OK status. This may come handy when implementing an HTTP proxy handler. The proxy handler needs to send to the client, whatever status code the proxied server has returned, while returning Apache2::Const::OK to Apache. e.g.:

  $r->status($some_code);
  return Apache2::Const::OK

See also $r->status_line, which. if set, overrides $r->status.



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status_line

Get/set the response status line. The status line is a string like "200 Document follows" and it will take precedence over the value specified using the $r->status() described above.

  $status_line      = $r->status_line();
  $prev_status_line = $r->status_line($new_status_line);

When discussing $r->status we have mentioned that sometimes a handler runs to a successful completion, but may need to return a different code, which is the case with the proxy server. Assuming that the proxy handler forwards to the client whatever response the proxied server has sent, it'll usually use status_line(), like so:

  $r->status_line($response->code() . ' ' . $response->message());
  return Apache2::Const::OK;

In this example $response could be for example an HTTP::Response object, if LWP::UserAgent was used to implement the proxy.

This method is also handy when you extend the HTTP protocol and add new response codes. For example you could invent a new error code and tell Apache to use that in the response like so:

  $r->status_line("499 We have been FooBared");
  return Apache2::Const::OK;

Here 499 is the new response code, and We have been FooBared is the custom response message.



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subprocess_env

Get/set the Apache subprocess_env table, or optionally set the value of a named entry.

               $r->subprocess_env;
  $env_table = $r->subprocess_env;
  
         $r->subprocess_env($key => $val);
  $val = $r->subprocess_env($key);

When called in VOID context with no arguments, it populate %ENV with special variables (e.g. $ENV{QUERY_STRING}) like mod_cgi does.

When called in a non-VOID context with no arguments, it returns an APR::Table object.

When the $key argument (string) is passed, it returns the corresponding value (if such exists, or undef. The following two lines are equivalent:

  $val = $r->subprocess_env($key);
  $val = $r->subprocess_env->get($key);

When the $key and the $val arguments (strings) are passed, the value is set. The following two lines are equivalent:

  $r->subprocess_env($key => $val);
  $r->subprocess_env->set($key => $val);

The subprocess_env table is used by Apache2::SubProcess, to pass environment variables to externally spawned processes. It's also used by various Apache modules, and you should use this table to pass the environment variables. For example if in PerlHeaderParserHandler you do:

   $r->subprocess_env(MyLanguage => "de");

you can then deploy mod_include and write in .shtml document:

   <!--#if expr="$MyLanguage = en" -->
   English
   <!--#elif expr="$MyLanguage = de" -->
   Deutsch
   <!--#else -->
   Sorry
   <!--#endif -->


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the_request

First HTTP request header

  $request = $r->the_request();
  $old_request = $r->uri($new_request);


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unparsed_uri

The URI without any parsing performed

  $unparsed_uri = $r->unparsed_uri();

If for example the request was:

  GET /foo/bar/my_path_info?args=3 HTTP/1.0

$r->uri returns:

  /foo/bar/my_path_info

whereas $r->unparsed_uri returns:

  /foo/bar/my_path_info?args=3


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uri

The path portion of the URI

  $uri         = $r->uri();
  my $prec_uri = $r->uri($new_uri);

See the example in the $r->unparsed_uri section.



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user

Get the user name, if an authentication process was successful. Or set it.

  $user      = $r->user();
  $prev_user = $r->user($new_user);

For example, let's print the username passed by the client:

  my ($res, $sent_pw) = $r->get_basic_auth_pw;
  return $res if $res != Apache2::Const::OK;
  print "User: ", $r->user;


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Unsupported API

Apache2::RequestRec also provides auto-generated Perl interface for a few other methods which aren't tested at the moment and therefore their API is a subject to change. These methods will be finalized later as a need arises. If you want to rely on any of the following methods please contact the the mod_perl development mailing list so we can help each other take the steps necessary to shift the method to an officially supported API.



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allowed_methods

META: Autogenerated - needs to be reviewed/completed

List of allowed methods

  $list = $r->allowed_methods();

META: Apache2::MethodList is not available at the moment



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allowed_xmethods

META: Autogenerated - needs to be reviewed/completed

Array of extension methods

  $array = $r->allowed_xmethods();

META: APR::ArrayHeader is not available at the moment



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request_config

Config vector containing pointers to request's per-server config structures

  $ret = $r->request_config($newval);


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used_path_info

META: Autogenerated - needs to be reviewed/completed

Flag for the handler to accept or reject path_info on the current request. All modules should respect the AP_REQ_ACCEPT_PATH_INFO and AP_REQ_REJECT_PATH_INFO values, while AP_REQ_DEFAULT_PATH_INFO indicates they may follow existing conventions. This is set to the user's preference upon HOOK_VERY_FIRST of the fixups.

  $ret = $r->used_path_info($newval);


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See Also

mod_perl 2.0 documentation.



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Copyright

mod_perl 2.0 and its core modules are copyrighted under The Apache Software License, Version 2.0.



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Authors

The mod_perl development team and numerous contributors.
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previous page: Apache2::RequestIO - Perl API for Apache request record IOpage up: mod_perl 2.0 APInext page: Apache2::RequestUtil - Perl API for Apache request record utils

Last modified Sat Feb 15 17:38:39 2014

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