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.so man.macros

.TH ns_register_proc n 4.5 AOLserver "AOLserver Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
ns_register_adp, ns_register_proc, ns_unregister_adp, ns_unregister_proc \- Facilities to manage mappings for HTTP requests to Tcl procedures or ADP files
.SH SYNOPSIS
.nf
\fBns_register_adp\fR ?\fI-noinherit\fR? \fImethod url file\fR
\fBns_register_proc\fR ?\fI-noinherit\fR? \fImethod url proc\fR ?\fIarg\fR?
\fBns_unregister_adp\fR ?\fI-noinherit\fR? \fImethod url\fR
\fBns_unregister_proc\fR ?\fI-noinherit\fR? \fImethod url\fR
.fi
.BE

.SH DESCRIPTION
These commands manage mappings of HTTP request to Tcl procedures
or ADP files.  The server will invoke the given procedure or ADP
file when the corresponding method/url combination is requested.

.PP
The \fImethod\fR is normally one of \fIGET\fR or \fIPOST\fR although
there is no restriction as internally method is always treated
simply as a string.  Specialized applications, for example, a WebDav
file server, could register additional methods such as \fIPUT\fR,
\fIDELETE\fR, or \fIBROWSE\fR.

.PP
The \fIurl\fR parameter specifies the trailing, pathname portion
of an url, for example, \fI/myapp/search\fR.  Requests for the
specified url or any url's with additional path elements which do
not have more specific mappings will be handled by the given procedure
or ADP file.  This behavior can be changed with the optional
\fI-noinherit\fR flag in which case only exact match url's will be
handled.

.PP
In addition, for the final pathname component, a "glob-style" pattern
may also be specified to further restrict the match.  For example,
\fI/myapp/*.adp\fR would handle requests for all url which start
with \fI/myapp\fR and have a final pathname component which ends
with the \fI.adp\fR extension.  Note that the method cannot be
specified as a glob pattern, i.e., attempting to map "*" will map
the single character string "*" as the method, it will not map all
possible methods.

.PP
Calls to \fBns_register_proc\fR and \fBns_register_adp\fR are
normally placed in server initialization scripts.  The
\fBns_unregister_proc\fR and \fBns_unregister_adp\fR commands are
rarely used, normally only in the context of development or debugging.

.TP
\fBns_register_adp\fR ?\fI-noinherit\fR? \fImethod url file\fR
This command maps the given method/url combination to a specific
ADP file.  The \fIfile\fR argument must be an absolute pathname and
a regular file.  When the server receives a matching request, it
will allocate a Tcl interpreter and invoke the \fBns_adp_include\fR
command with the given file, returning the results of the output
buffer to the client when the command returns.
.sp
Note it is also possible to provide mappings for ADP files in the
config file as well although those mappings are intended to support
mixing of ADP and static files in the server's basic page root.
Using \fBns_register_adp\fR can provide more general mappings, not
requiring actual ADP files to exist at the corresponding location
in the filesystem.

.TP
\fBns_register_proc\fR ?\fI-noinherit\fR? \fImethod url proc\fR ?\fIarg\fR?
This command maps the given method/url combination to a Tcl procedure.
When the server receives a matching request, it allocates a Tcl
interpreter and calls \fBTcl_Eval\fR with a script constructed of
the procedure with zero, one, or two arguments depending on the
arguments expected for the procedure.  If the procedure accepts no
arguments, none are passed and the \fIarg\fR parameter to
\fBns_register_proc\fR, if given, is ignored.  If it takes one
argument, the procedure is passed the optional \fIarg\fR parameter
or a null string if no argument was given.  If the procedure accepts
two arguments, the first argument will be the "connection id"
followed by the argument as described for the case of one argument.
The connection id is a small string of the form "cns#" where # is
a monotonically increasing integer value which will eventually wrap
after the server has been running for a long time.  This id is also
returned via the the \fBns_conn id\fR command.  This connection id
is for information purposes only and is is otherwise useless and
not required to be passed to any other AOLserver Tcl command.  See
the \fBEXAMPLES\fR section for details on how various arguments are
handled for request procedures.

.TP
\fBns_unregister_adp\fR ?\fI-noinherit\fR? \fImethod url\fR
.TP
\fBns_unregister_proc\fR ?\fI-noinherit\fR? \fImethod url\fR
These commands are identical and can be used to remove any mapping
for the given method/url.  Note that no check is made to confirm
the given mapping exists or was in fact a Tcl procedure, ADP file,
or some other C-level mapping created with the \fBNs_RegisterRequest\fR
routine.  The optional \fI-noinherit\fR flag, if specified, requests
removal of mappings previously made with the \fI-noinherit\fR flag
with the commands above or via the \fINS_OP_NOINHERIT\fR bit set
in a call to the \fBNs_RegisterRequest\fR routine.

.SH EXAMPLES
The following example demonstrates the use of the \fI-noinherit\fR
flag.  Assume the following startup initializations code:

.CS
ns_register_proc -noinherit GET /foo/bar Aproc
ns_register_proc GET /foo/bar Bproc
ns_register_proc GET /foo/bar/hmm Cproc
.CE

In this case, \fIAproc\fR will be called when the requested URL is
exactly \fI/foo/bar\fR while \fIBproc\fR will be called when the
requested URL is anything below \fI/foo/bar\fR, provided there is
not already another procedure registered to be called for that exact
URL or for an URL with a closer match. \fICproc\fR (not Bproc) will
be called when the requested URL is equal to or below /foo/bar/hmm.

.PP
The following example demonstrates the multiple forms of which a
Tcl procedure can be defined:

.CS
ns_register_proc GET /zeroargs 0args myarg
ns_register_proc GET /onearg 1arg myarg
ns_register_proc GET /twoargs 2args myarg
ns_register_proc GET /twoargs 2args myarg

proc 0args {} {
    ns_returnnotice 200 "no args"
} ;# noargs

proc 1arg {arg} {
    ns_returnnotice 200 "arg: $arg"
} ;# context

proc 2args {conn arg} {
    ns_returnnotice 200 "connid: $conn, arg: $arg"
} ;# conncontext
.CE
When a request for the /twoargs URL is received, the \fI2args\fR
procedure will be called with the value of the connection id as the
\fIconn\fR variable and "myarg" as the value of the \fIarg\fR
variable.
.sp
When the server receives a request for \fI/onearg\fR, the server
will invoke the \fI1arg\fR procedure with just "myarg" as the value
for the \fIarg\fR procedure variable.  The connection id, if needed,
can be obtained with \fBns_conn id\fR.
.sp
Finally, when the server receives a request for \fI/zeroargs\fR,
the \fI0args\fR procedure will be called with no options.  The
"myarg" value passed to \fBns_register_proc\fR is ignored and the
connection id, if needed, can be obtained with \fBns_conn id\fR.

.SH "SEE ALSO"
ns_adp(n), Ns_RegisterRequest(3), Ns_UrlSpecificGet(n), Ns_UrlSpecificSet(n)

.SH KEYWORDS
request callback, connection
