Ns register trace - Revision history

Akhassin at 23:58, 28 October 2009

2009-10-28T23:58:01Z

Akhassin at 07:33, 28 October 2009

2009-10-28T07:33:58Z

Akhassin at 07:31, 28 October 2009

2009-10-28T07:31:24Z

Akhassin at 07:30, 28 October 2009

2009-10-28T07:30:09Z

Akhassin at 07:28, 28 October 2009

2009-10-28T07:28:58Z

Akhassin at 07:21, 28 October 2009

2009-10-28T07:21:29Z

Akhassin at 07:21, 28 October 2009

2009-10-28T07:21:09Z

Akhassin at 06:42, 28 October 2009

2009-10-28T06:42:14Z

Akhassin at 06:22, 28 October 2009

2009-10-28T06:22:06Z

Akhassin at 06:11, 28 October 2009

2009-10-28T06:11:32Z

@@ Line 27: / Line 27: @@
   proc mytrace {conn arg1 arg2 arg3} ;# context must be a list of exactly three arguments which will be received in arg1, arg2 and arg3 respectively, your first parameter must be the connid
   ...
 : Note ns_register_trace is similar to [[ns_register_proc]] except that the pattern-matching for the URL is performed differently. With ns_register_proc, the specified URL is used to match that URL and any URL below it in the hierarchy. Wildcards such as "*" are meaningful for ns_register_proc only for the final part of the URL, such as /scripts/*.tcl. With ns_register_trace, the URLpattern is used to match URLs as a string with standard string-matching characters. ns_register_proc results in a single match, whereas multiple ns_register_trace's can be matched and will be called.

@@ Line 17: / Line 17: @@
 : The procedure to be registered can recieve optional arguments specified in ''context''.  Unlike filters registered with ns_register_filter, traces registered with this command do not get passed the usual ''why'' (aka ''when'') argument, however, the why argument must still be present and must be optional (unless your procedure takes 3 or more arguments), i.e. your procedure call signature can be one of these variants:
   proc mytrace {} ;#will not receive any arguments
   proc mytrace {args) ;# will not receive any arguments!

@@ Line 23: / Line 23: @@
   proc mytrace {context {why "void"}} ;# will receive the context or "", which should not be a list of arguments
   proc mytrace {conn context {why "void"}} ;# same as above only first argument will contain the connid
-  proc mytrace {conn arg1 arg2} ;# context must be a list of exactly two arguments which will be received in arg1 and arg2 respectively
+  proc mytrace {conn arg1 arg2} ;# context must be a list of exactly two arguments which will be received in arg1 and arg2 respectively, your first parameter must be the connid
-  proc mytrace {conn arg1 arg2 arg3} ;# context must be a list of exactly three arguments which will be received in arg1, arg2 and arg3 respectively
+  proc mytrace {conn arg1 arg2 arg3} ;# context must be a list of exactly three arguments which will be received in arg1, arg2 and arg3 respectively, your first parameter must be the connid
   ...

@@ Line 15: / Line 15: @@
   /employees/*.tcl /accounts/*/out
-: The procedure to be registered can recieve optional arguments specified in ''context''.  Unlike filters registered with ns_register_filter, traces registered with this command do not get passed the usual ''why'' (aka ''when'') argument, however, the why argument must still be present and must be optional, i.e. your procedure call signature can be one of these variants:
+: The procedure to be registered can recieve optional arguments specified in ''context''.  Unlike filters registered with ns_register_filter, traces registered with this command do not get passed the usual ''why'' (aka ''when'') argument, however, the why argument must still be present and must be optional (unless your procedure takes 3 or more arguments), i.e. your procedure call signature can be one of these variants:
   proc mytrace {} ;#will not receive any arguments

@@ Line 23: / Line 23: @@
   proc mytrace {context {why "void"}} ;# will receive the context or "", which should not be a list of arguments
   proc mytrace {conn context {why "void"}} ;# same as above only first argument will contain the connid
 : Note ns_register_trace is similar to [[ns_register_proc]] except that the pattern-matching for the URL is performed differently. With ns_register_proc, the specified URL is used to match that URL and any URL below it in the hierarchy. Wildcards such as "*" are meaningful for ns_register_proc only for the final part of the URL, such as /scripts/*.tcl. With ns_register_trace, the URLpattern is used to match URLs as a string with standard string-matching characters. ns_register_proc results in a single match, whereas multiple ns_register_trace's can be matched and will be called.

@@ Line 7: / Line 7: @@
 '''SYNOPSIS'''
-: '''ns_register_trace''' ''method urlPattern procName ?args?''
+: '''ns_register_trace''' ''method urlPattern procName ?context?''
 '''DESCRIPTION'''
@@ Line 15: / Line 15: @@
   /employees/*.tcl /accounts/*/out
-: The procedure to be registered
+: The procedure to be registered can recieve optional arguments specified in ''context''.  Unlike filters registered with ns_register_filter, traces registered with this command do not get passed the usual ''why'' (aka 'when'') argument, however, the why argument must still be present and must be optional, i.e. your procedure call signature can be one of these variants:
 : Note ns_register_trace is similar to [[ns_register_proc]] except that the pattern-matching for the URL is performed differently. With ns_register_proc, the specified URL is used to match that URL and any URL below it in the hierarchy. Wildcards such as "*" are meaningful for ns_register_proc only for the final part of the URL, such as /scripts/*.tcl. With ns_register_trace, the URLpattern is used to match URLs as a string with standard string-matching characters. ns_register_proc results in a single match, whereas multiple ns_register_trace's can be matched and will be called.

@@ Line 17: / Line 17: @@
 : Note ns_register_trace is similar to [[ns_register_proc]] except that the pattern-matching for the URL is performed differently. With ns_register_proc, the specified URL is used to match that URL and any URL below it in the hierarchy. Wildcards such as "*" are meaningful only for the final part of the URL, such as /scripts/*.tcl. With ns_register_trace, the URLpattern is used to match URLs as a string with standard string-matching characters. ns_register_proc results in a single match, whereas multiple ns_register_trace’s can be matched and will be called.
-: This command differs from [[ns_register_filter]] trace in that traces registered with this command only run if the request (or a trace filter registered with ns_register_filter trace) did not result in an error. In, addition, the return value of the last trace registered with this command is ignored, hence the name ''void trace filter''.
+: This command differs from [[ns_register_filter]] trace in that traces registered with this command only run if the request (or a trace filter registered with ns_register_filter trace) did not result in an error. In addition, the return value (including a thrown error) of any trace registered with this command is ignored, hence the name ''void trace filter''.  Because the return value is ignored it is not possible for a trace registered with this command to prevent execution of the next trace or the subsequent C-level ServerTraces (i.e. access logging).
 '''SEE ALSO'''