NAME¶
ns_adp_argc, ns_adp_argv, ns_adp_bind_args, ns_adp_dir, ns_adp_eval,
ns_adp_ident, ns_adp_include, ns_adp_parse, ns_adp_safeeval - ADP execution
commands
SYNOPSIS¶
ns_adp_argc
ns_adp_argv ?index?
ns_adp_bind_args var1 ?var2...?
ns_adp_dir
ns_adp_eval page ?arg ...?
ns_adp_ident ?string?
ns_adp_include ?-cache seconds? ?-nocache? file ?arg ...?
ns_adp_parse ?-file file? ?-string string? ?-savedresult varName? ?-cwd path? ?args ... ?
ns_adp_safeeval page ?arg ...?
DESCRIPTION¶
These commands enable execution of ADP files or strings. Each call to
ns_adp_include results in a new ADP "call frame" similar to a
Tcl procedure with local variable scope. Variables may be passed to these call
frames as optional arguements and then accessed via the
ns_adp_argc,
ns_adp_argv, and
ns_adp_bind_args commands. The
ns_adp_eval,
ns_adp_safeeval, or ns_adp_parse can also accept
arguments via the same mechanism but execute in the same ADP call frame as
their parent, i.e., with the same local variables. See the
ns_adp page
for details on ADP syntax and control flow.
- ns_adp_argc
- This command returns the number of optional arguments passed to the ADP.
The count includes the argument for the ADP file or string.
- ns_adp_argv ?index ?default??
- This command returns the list of arguments passed to the ADP. If the
optional index argument is specified, only the given argument is
returned instead of the full list. If the optional default argument
is specified along with an index argument, it serves as the value
to return if the cooresponding index was not passed to the call frame.
- ns_adp_bind_args var1 ?var2...?
- This command can be used to set multiple optional ADP arguments to a list
of local variables. Argument binding begins with argument number 1, i.e.,
the first argument beyond the ADP file or script.
- ns_adp_dir
- This command returns the directory in which the ADP currently being
processed resides and which relative ADP files will be found.
- ns_adp_eval page ?arg ...?
- This command evaluates the ADP specified by page and returns the
output as the result. If any arguments are specified, they will be passed
to the ADP.
- ns_adp_ident ?string?
- This command returns and/or sets an arbitrary version management string
for the given ADP file. It could be used to specify a header replaced via
a CVS/RCS checkin:
<% ns_adp_ident {$Header: /cvsroot/aolserver/aolserver/doc/ns_adp_include.n,v 1.1 2006/04/13 19:07:12 jgdavidson Exp $} %>
- ns_adp_include ?-cache seconds? ?-nocache? file
? arg ...?
- This command parses the specified file as an ADP, including the text
blocks and any output generated by script blocks in the current output
buffer. The execution occurs in a new call frame with private local
variables similar to a Tcl procedure. The filename is the file
containing the ADP to be parsed. If the file is not an absolute filename,
the file is considered relative to the current ADP working directory which
is the directory of the previously included file. Optional arguments (
arg...) can be passed to the included ADP; see the
ns_adp_argv command above for details on accessing the values of
these variables. The optional -cache seconds argument
specifies the time to cache the results of execution. All output generated
by any scripts and included ADP's are saved for subsequent requests unless
an included ADP has a -nocache option. The use of -cache and
-nocache can be used to increase performance of ADP used to
generated a mix of personalized, non-cacheable, content and shared content
which changes more slowly. Under high load, the performance improvement
can be substaintial, especially in cases where the cached content is the
result of accessing a slow databases or web services. See the
EXAMPLES section for an example of using cached output.
- ns_adp_parse ?-file file? ?-string string?
?-savedresult varName? ? -cwd path? ?args ... ?
- This function processes the specified ADP file or string and returns the
result as a string. Processing a second ADP from inside an ADP is normally
best done with ns_adp_include as that command resolves relative
pathnames passed to it. Also note that ns_adp_parse will ignore any
directives to turn on streaming. Tcl_Eval is used to evaluate the Tcl
commands in the ADP.
The -string adp option can be used to parse a string of ADP text.
Although the <% ... %> syntax is allowed in the string, if
you have this embedded in an ADP, you have to be careful in constructing
the string that you do not prematurely terminate an enclosing script.
The -file file option can be used to parse ADP contained in the given
file. This use is similar to that of ns_adp_include except the
result is returned by the command instead of automatically being appended
to the output stream.
The -global and -local options are deprecated. All calls are
now local to the current ADP call frame such that the -local option
is ignored and the -global option generates an error.
Additional arguments are passed to the ADP execution and can be accessed via
the ns_adp_argc, ns_adp_argv, and ns_adp_bind_args
commands.
- ns_adp_safeeval string ?arg ...?
- The command evaluates the given ADP string in a safe environment which
ignores all cases of <% ... %> and <%= ... %>
commands, only allowing execution of per-defined registered tags. This
usage can be helpful to expose a limited set of dynamic functionality to
publishing staff without exposing the full command set.
EXAMPLE¶
The following example demonstrates passing an argument to an included ADP file:
<% ns_adp_include included.adp arg1 arg2 arg3 %>
The variables could be accessed within
included.adp with:
ns_adp_argc
--> return 4
ns_adp_argv 1
--> returns "arg1"
ns_adp_argv 10 MyDefault
--> returns "MyDefault" as there is no 10th argument
The followiong example demonstrates using the
-cache and
-nocache
options to the
ns_adp_include command to enhance performance through
caching execution output. Given the following files:
top.adp:
<% ns_adp_include -cache 60 cached.adp %>
cached.adp:
<%
ns_adp_puts "Time at cache: [ns_time]"
ns_adp_include -nocache nocache.adp
%>
nocache.adp:
<% ns_adp_puts "Time now: [ns_time]" %>
the results of
cached.adp will only update once every 60 seconds while
the results of
nocache.adp will be executed on each request, even
though it's included withing
cached.adp.
SEE ALSO¶
ns_adp_ctl(1), ns_adp_puts(n), ns_adp_flush(n), ns_adp_close(n)
KEYWORDS¶
ADP, dynamic pages, execution
