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


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



 




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 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 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 specifies 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



  

    4.0
    AOLserver