Scroll to navigation

ns_register_proc(3aolserver) AOLserver Built-In Commands ns_register_proc(3aolserver)


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


ns_register_adp ?-noinherit? method url file
ns_register_proc ?-noinherit? method url proc ?arg?
ns_unregister_adp ?-noinherit? method url
ns_unregister_proc ?-noinherit? method url


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.

The method is normally one of GET or POST 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 PUT, DELETE, or BROWSE.

The url parameter specifies the trailing, pathname portion of an url, for example, /myapp/search. 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 -noinherit flag in which case only exact match url's will be handled.

In addition, for the final pathname component, a "glob-style" pattern may also be specified to further restrict the match. For example, /myapp/*.adp would handle requests for all url which start with /myapp and have a final pathname component which ends with the .adp 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.

Calls to ns_register_proc and ns_register_adp are normally placed in server initialization scripts. The ns_unregister_proc and ns_unregister_adp commands are rarely used, normally only in the context of development or debugging.

This command maps the given method/url combination to a specific ADP file. The file 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 ns_adp_include command with the given file, returning the results of the output buffer to the client when the command returns.

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 ns_register_adp can provide more general mappings, not requiring actual ADP files to exist at the corresponding location in the filesystem.

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 Tcl_Eval 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 arg parameter to ns_register_proc, if given, is ignored. If it takes one argument, the procedure is passed the optional arg 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 ns_conn id 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 EXAMPLES section for details on how various arguments are handled for request procedures.

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 Ns_RegisterRequest routine. The optional -noinherit flag, if specified, requests removal of mappings previously made with the -noinherit flag with the commands above or via the NS_OP_NOINHERIT bit set in a call to the Ns_RegisterRequest routine.


The following example demonstrates the use of the -noinherit flag. Assume the following startup initializations code:

ns_register_proc -noinherit GET /foo/bar Aproc
ns_register_proc GET /foo/bar Bproc
ns_register_proc GET /foo/bar/hmm Cproc

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

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

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
When a request for the /twoargs URL is received, the 2args procedure will be called with the value of the connection id as the conn variable and "myarg" as the value of the arg variable.

When the server receives a request for /onearg, the server will invoke the 1arg procedure with just "myarg" as the value for the arg procedure variable. The connection id, if needed, can be obtained with ns_conn id.

Finally, when the server receives a request for /zeroargs, the 0args procedure will be called with no options. The "myarg" value passed to ns_register_proc is ignored and the connection id, if needed, can be obtained with ns_conn id.


ns_adp(n), Ns_RegisterRequest(3), Ns_UrlSpecificGet(n), Ns_UrlSpecificSet(n)


request callback, connection

4.5 AOLserver