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

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NAME

       ns_adp_registeradp, ns_adp_registerproc, ns_adp_registerscript, ns_adp_registertag, ns_register_adptag - ADP registered tags

SYNOPSIS

       ns_adp_registeradp tag ?endtag? adp
       ns_adp_registerproc tag ?endtag? proc
       ns_adp_registerscript tag ?endtag? script
       ns_adp_registertag tag ?endtag? adp
       ns_register_adptag tag ?endtag? script
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DESCRIPTION

       These  commands enable definition of HTML tags within an ADP file which are expanded and evaluated by the server before returning output to
       the client.  Tags are defined as eitehr a single tag with options, e.g., <mytag a=b c=d> or as an opening/closing tag pair,  e.g.,  <mytag>
       text </mytag>.  This approach is an alternative to direct calls via the <% script %> syntax as described in the ns_adp man page.

       ns_adp_registeradp tag ?endtag? adp

       ns_adp_registertag tag ?endtag? adp
	      These  commands are identical and register an ADP code fragment to be invoked when the specified tag is encountered while parsing an
	      ADP.  The tag argument specifies the tag that will trigger invocation of the ADP fragment, which is specified by the adp argument.

	      If the endtag argument is specified, then the ADP fragment will be invoked with two arguments: The first will be the  enclosed  con-
	      tent,  and  the  second will be the name of an ns_set with any attributes specified in the tag.  If no endtag argument is specified,
	      the ADP fragment will only be passed the name of the ns_set.  The arguments may be retrieved using  ns_adp_bindargs  or  ns_adp_argc
	      and ns_adp_argv.

	      When the ADP fragment is invoked, its result is inserted in the output instead of the tag (or, if the endtag was specified, in place
	      of the tag, end tag, and the enclosed content).

	      Note: Care must be taken when using this function from inside an ADP, because the adpstring is likely to contain	script	delimiters
	      (<%  ...	%>)  which  will  prematurely  terminate script fragments.  It is probably easier to restrict use of this function to .tcl
	      files.

       ns_adp_registerproc tag ?endtag? proc
	      This commands register a Tcl procedure to be evaluated when the given tag is encountered.  The tag argument specifies the  tag  that
	      will trigger a call to the procedure specified by the proc argument.

	      The procedure will be called with a variable number of arguments, one for each of the attributes provided in the tag.  If the endtag
	      argument is specified, the procedure will also receive a final argument with the contents of the text enclosed between the tags.	No
	      evaluation of the content will be performed, it will be passed as a single text block.

	      When the procedure is invoked, its result is inserted in the output instead of the tag (or, if the endtag was specified, in place of
	      the tag, end tag, and the enclosed content).

       ns_adp_registerscript tag ?endtag? script

       ns_register_adptag tag ?endtag? script
	      These commands are identical and register a Tcl script to be evaluated when the given tag is encountered.  The tag  argument  speci-
	      fies the tag that will trigger evaluation of the script specified by the script argument.

	      If  the  endtag argument is specified, then the script will be modified with two arguments appended:  The first will be the enclosed
	      content, and the second will be the name of an ns_set with any attributes specified in the tag.  If no endtag argument is specified,
	      the script will be modified with just the name of the ns_set appended.

	      When  the script is evaluated, its result is inserted in the output instead of the tag (or, if the endtag was specified, in place of
	      the tag, end tag, and the enclosed content).

EXAMPLES

       The following is a simple way of handling conditional content in ADPs:

	      proc remember {input tagset} {
		global _adp_memory
		set tagname [ns_set iget $tagset name]
		if {[string match "" $tagname]} {
		   set _adp_memory($tagname) $input
		   return ""
		} else {
		   return $input
		}
	      }
	      proc recall {name} {
		global _adp_memory
		if {[info exists _adp_memory($name)]} {
		   set parsecommand [list ns_adp_parse -string]
		   lappend parsecommand $_adp_memory($name)
		   ns_puts -nonewline [uplevel $parsecommand]
		} else {
		   ns_log Error "[ns_adp_argv 0]: Unable to recall
		}
	      }

       If the preceding Tcl has been executed (perhaps during server startup), then the following ADP fragment displays the results of a  database
       query in a table, or shows "No rows in result." if there are no rows:

	      <%
		set rows {}
		set db [ns_db gethandle]
		ns_db exec "select somecolumn from sometable"
		set row [ns_db bindargs $db]
		while {[ns_db getrow $db $row] > 0} {
		   lappend rows [ns_set get $row "somecolumn"]
		}
		ns_db releasehandle $db
	      %>
	      <remember name="hasrows_header">
	      <table>
	      </remember>
	      <remember name="hasrows_rows">
	      <tr>
		<td><%=$column%></td>
	      </tr>
	      </remember>
	      <remember name="hasrows_footer">
	      </table>
	      </remember>
	      No rows in result.
	      <remember name="norows">
	      <%
		if {[llength $rows] > 0} {
		   recall "hasrows_header"
		   foreach row $rows {
		     set column $row
		     recall "hasrows_rows"
		   }
		   recall "hasrows_footer"
		} else {
		   recall "norows"
		}
	      %>

       The following example demonstrates the use of ns_adp_registertag:

	      ns_adp_registertag printdate {
		The current date is: <%=[ns_httptime [ns_time]]%>
	      }
       Once  defined,  typically in a startup script, you could simple include the "<printdate>" tag to append the text with current date into the
       output buffer.

SEE ALSO

       ns_adp(1), ns_adp_eval(n), ns_adp_safeeval(n), ns_adp_include(n)

KEYWORDS

       ADP, dynamic pages, registered tag

AOLserver								4.0					    ns_adp_registertag(3aolserver)