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docs::api::Apache2::SubRequest(3pm) User Contributed Perl Documentation docs::api::Apache2::SubRequest(3pm)

NAME

Apache2::SubRequest - Perl API for Apache subrequests

Synopsis

  use Apache2::SubRequest ();
  
  # run internal redirects at once
  $r->internal_redirect($new_uri);
  $r->internal_redirect_handler($new_uri);
  
  # create internal redirect objects
  $subr = $r->lookup_uri("/foo");
  $subr = $r->lookup_method_uri("GET", "/tmp/bar")
  $subr = $r->lookup_file("/tmp/bar");
  # optionally manipulate the output through main request filters
  $subr = $r->lookup_uri("/foo", $r->output_filters);
  # now run them
  my $rc = $subr->run;

Description

"Apache2::SubRequest" contains API for creating and running of Apache sub-requests.

"Apache2::SubRequest" is a sub-class of "Apache2::RequestRec object".

API

"Apache2::SubRequest" provides the following functions and/or methods:

"DESTROY"

Free the memory associated with a sub request:

  undef $subr; # but normally don't do that
The sub request to finish

"DESTROY" is called automatically when $subr goes out of scope.

If you want to free the memory earlier than that (for example if you run several subrequests), you can "undef" the object as:

  undef $subr;

but never call "DESTROY" explicitly, since it'll result in "ap_destroy_sub_req" being called more than once, resulting in multiple brain injuries and certain hair loss.

"internal_redirect"

Redirect the current request to some other uri internally

  $r->internal_redirect($new_uri);
The current request
The URI to replace the current request with

In case that you want some other request to be served as the top-level request instead of what the client requested directly, call this method from a handler, and then immediately return "Apache2::Const::OK". The client will be unaware the a different request was served to her behind the scenes.

"internal_redirect_handler"

Identical to "internal_redirect", plus automatically sets "$r->content_type" is of the sub-request to be the same as of the main request, if "$r->handler" is true.

  $r->internal_redirect_handler($new_uri);
The current request
The URI to replace the current request with.

This function is designed for things like actions or CGI scripts, when using "AddHandler", and you want to preserve the content type across an internal redirect.

"lookup_file"

Create a subrequest for the given file. This sub request can be inspected to find information about the requested file

  $ret = $r->lookup_file($new_file);
  $ret = $r->lookup_file($new_file, $next_filter);
The current request
The file to lookup
See "$r->lookup_uri" for details.
The sub request record.

See "$r->lookup_uri" for further discussion.

"lookup_method_uri"

Create a sub request for the given URI using a specific method. This sub request can be inspected to find information about the requested URI

  $ret = $r->lookup_method_uri($method, $new_uri);
  $ret = $r->lookup_method_uri($method, $new_uri, $next_filter);
The current request
The method to use in the new sub request (e.g. "GET")
The URI to lookup
See "$r->lookup_uri" for details.
The sub request record.

See "$r->lookup_uri" for further discussion.

"lookup_uri"

Create a sub request from the given URI. This sub request can be inspected to find information about the requested URI.

  $ret = $r->lookup_uri($new_uri);
  $ret = $r->lookup_uri($new_uri, $next_filter);
The current request
The URI to lookup
The first filter the subrequest should pass the data through. If not specified it defaults to the first connection output filter for the main request "$r->proto_output_filters". So if the subrequest sends any output it will be filtered only once. If for example you desire to apply the main request's output filters to the sub-request output as well pass "$r->output_filters" as an argument.
The sub request record

Here is an example of a simple subrequest which serves uri /new_uri:

  sub handler {
      my $r = shift;
  
      my $subr = $r->lookup_uri("/new_uri");
      $subr->run;
  
      return Apache2::Const::OK;
  }

If let's say you have three request output filters registered to run for the main request:

  PerlOutputFilterHandler MyApache2::SubReqExample::filterA
  PerlOutputFilterHandler MyApache2::SubReqExample::filterB
  PerlOutputFilterHandler MyApache2::SubReqExample::filterC

and you wish to run them all, the code needs to become:

      my $subr = $r->lookup_uri("/new_uri", $r->output_filters);

and if you wish to run them all, but the first one ("filterA"), the code needs to be adjusted to be:

      my $subr = $r->lookup_uri("/new_uri", $r->output_filters->next);

"run"

Run a sub-request

  $rc = $subr->run();
The sub-request (e.g. returned by "lookup_uri")
The return code of the handler ("Apache2::Const::OK", "Apache2::Const::DECLINED", etc.)

Unsupported API

"Apache2::SubRequest" 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.

"internal_fast_redirect"

META: Autogenerated - needs to be reviewed/completed

Redirect the current request to a sub_req, merging the pools

  $r->internal_fast_redirect($sub_req);
The current request
A subrequest created from this request

META: httpd-2.0/modules/http/http_request.c declares this function as:

  /* XXX: Is this function is so bogus and fragile that we deep-6 it? */

do we really want to expose it to mod_perl users?

"lookup_dirent"

META: Autogenerated - needs to be reviewed/completed

Create a sub request for the given apr_dir_read result. This sub request can be inspected to find information about the requested file

  $lr = $r->lookup_dirent($finfo);
  $lr = $r->lookup_dirent($finfo, $subtype);
  $lr = $r->lookup_dirent($finfo, $subtype, $next_filter);
The current request
The apr_dir_read result to lookup
What type of subrequest to perform, one of;

  Apache2::SUBREQ_NO_ARGS     ignore r->args and r->path_info
  Apache2::SUBREQ_MERGE_ARGS  merge  r->args and r->path_info
    
The first filter the sub_request should use. If this is NULL, it defaults to the first filter for the main request
The new request record

META: where do we take the apr_dir_read result from?

See Also

mod_perl 2.0 documentation.

Copyright

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

Authors

The mod_perl development team and numerous contributors.

2024-03-07 perl v5.38.2