Re: [naviserver-devel] ADP without file name extensions

[Gustaf N. <ne...@wu...>]

Dear John,

I've prototyped something along these lines, which looks promising so far.

Premises:
- fit into urlspace mechanism
- not limited in applicability to .adp
- no full rewrite of urlspace (which is already complex enough)
- keep speed of existing implementation
- provide a mostly conservative extensions

Some of these premises overlap.
One option would be to switch from glob string matching to regexp,
but that would be significantly slower and would require a larger
changes to avoid frequent regexp compilations.

The implemented approach allows to specify in addition to a
(positive) match pattern (such as "foo*") optionally a negative match
pattern (such as ^*.*), which can be used to say "match which such
names except with some others". One can specify e.g. "foo*^*.*"
which means files starting with "foo" but which must not have
an extension (must not match with "*.*"). One can use as well
rules like "must not contain a dash", or "must not start with an upper
case character" or whatever. Both match pattern are applied with
Tcl's string match implementation, which is quite efficient.

To see this in action, look at the following test case, where
an urlspace entry s set with an extension (foo*.tcl), one other is
set with a wild card (/bar*) and one is set with a wild card and
a negative pattern. These urlspace entries are matched with
URLs with and without extension. Either
- only the URL with the extension is matched (first two cases), or
- both URLs are matched (second two cases), or
- just the entry without the extension is matched (last two cases)

=======================================================================
test ns_urlspace-5.1 {wild-card-filter with negative patterns} -setup {
     ns_urlspace set /foo*.tcl 1
     ns_urlspace set /bar*     2
     ns_urlspace set /baz*^*.* 3
} -body {
     foreach url {
	/foo1.tcl /foo1
	/bar1.tcl /bar1
	/baz1.tcl /baz1
     } {
	lappend _ [ns_urlspace get $url]
     }
     set _
} -cleanup {
     unset -nocomplain _
} -result {1 {} 2 2 {} 3}
=======================================================================

The path matching is untouched, as well as the features noinherit, 
exact, etc.

To apply this approach to the .adp case, one can now call ns_register_adp
(in addition to the standard cases) with a negative pattern, add optionally
in the ADP PageRequest() the .adp if the first match fails, and we are 
done.

In the test cases, there exists a /helloworld.adp file, which can be called
now via /helloworld, whereas /hellow returns a 404 like usual.

=======================================================================
test adp-2.1 {ADP page map} -setup {
     ns_register_adp GET /hello*^*.*
} -body {
     nstest::http -getbody 1 GET /helloworld
} -cleanup {
     ns_unregister_op GET /hello*^*.*
} -result {200 {Hello World!}}
=======================================================================

I have not looked at the consequences for subsumption of patterns, or
deletion/querying of patterns etc, but this seems doable.

Syntax-wise, we could consider as well the following candidates

    {/hello*^[*.*]}
    "/hello* ^*.*"
     /hello*^{*.*}
     /hello*{^}*.*
     /hello*{NOT}*.*
    "/hello* -not *.*"
    "/hello* -not *.* -noinherit"

However, i am not too happy about requiring quoting with double quotes 
or braces.
The single character "^" has advantages for escaping, when it should be 
taken literally
(and not as start character for a negative pattern).

The last syntax option has the advantage to specify also "-noinherit" in 
the string
provided to e.g. map in the config file, which is currently not possible 
(meaning:
do not apply this matching rule for the underlying directories).

OTOH, the -noinherit etc. is already supported by the API, so, why 
reinvent some
(redundant) syntax, we could as well use instead of "map" a "mapcmd" with a
generalized "ns_register" (setting per default the methods GET POST HEAD)

    ns_section ns/server/default/adp
    ns_param   mapcmd  {ns_register ... -pattern /*.adp -noinherit}
    ns_param   mapcmd  {ns_register ... -pattern /* -except *.*}

this way, we get standardized error messages, etc... The old "map" 
syntax can be supported as well for a while... The same can be made as 
well for other "maps" (e.g. connection pool mappings) Comments are 
always welcome. all the best -g