Ns startcontent

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ns_startcontent - Configures connection for encoding non-binary content to be returned with ns_write


ns_startcontent ?-type content-type_and_charset | -charset charset?


This command is used to set the appropriate encoding prior to returning the content part of the response via ns_write.
If you write the headers to the client with ns_write instead of letting AOLserver do it (via ns_return or ns_respond), then AOLserver does not parse the content-type. You must explicitly tell it what charset to use immediately after you write the headers, by calling ns_startcontent in one of these forms:
  • ns_startcontent
Tells AOLserver that you have written the headers and do not wish the content to be translated.
  • ns_startcontent -charset charset
Tells AOLserver that you have written the headers and wish the following content to be translated to the specified charset.
  • ns_startcontent -type content-type_and_charset
Tells AOLserver that you have written the headers and wish the following content to be translated to the charset specified by content-type, which should be the same value you sent to the client in the Content-Type header. If content-type starts with text/ and does not contain a charset parameter, AOLserver 4.0 uses the server default as configured in ns/parameters OutputCharset. AOLserver 4.5 will actually throw an error if charset is not specified, so you may wish to redefine ns_startcontent in Tcl as listed in the notes below.


From Character Encoding in AOLserver:
# Assume japanesetext.html_sj is stored in Shift-JIS encoding.
set fd [open japanesetext.html_sj r]
fconfigure $fd -encoding shiftjis
set html [read $fd [file size japanesetext.html_sj]]
close $fd
set charset [ns_choosecharset -preference {utf-8 shift-jis euc-jp iso-2022-jp}]
set type "text/html; charset=$charset"
ns_write "HTTP/1.0 200 OK
Content-Type: $type
ns_startcontent -type $type
ns_write $html


In AOLserver 4.5, ns_startcontent's behavior has changed, so it may be convenient to reimplement ns_startcontent to be backward compatible as follows:
 if {[ns_info version] >= 4.5} {
   catch {rename ns_startcontent {}}
   proc ns_startcontent {args} {
   # Re-implement ns_startcontent in Tcl in AOLserver 4.5
   # because the -type option no longer falls back to
   # server's default encoding like it did in 4.0.
   # Luckily, in 4.5, ns_adp_mimetype now just
   # calls Ns_ConnSetType() which still does
   # and works outside of adps
       if {[llength $args]} {
           switch [string range [lindex $args 0] 1 end] {
               charset {
                   ns_conn encoding [ns_encodingforcharset [lindex $args 1]]
               type {
                   ns_adp_mimetype [lindex $args 1]
       # NaviServer removed write_encoded
       catch {ns_conn write_encoded 1}
       return ""


ns_write, ns_choosecharset, ns_config