# myhttp.tcl - Playing HTTP
if 0 {[Richard Suchenwirth] 2004-02-14 - After being online at home, I
felt I had to learn some more about the Hypertext Transfer Protocol
(HTTP) that drives the Web. Tcl has good support with the [http]
package, so I didn't need to walk the last steps to the [socket]
invocation myself, but concentrate on what comes back after a HTTP GET,
especially the headers. So here's my HTTP plaything, the ugliest
browser I've seen in a long time, because it does not try to render
HTML, just displays the plain text that came. However, it is still
interesting, for looking behind the glittering facades of "real"
browsers...

You have an entry on top, in which to type an URL, and the
text at bottom displays what came back after you hit <Return>,
images being rendered via the great [Img] extension, everything else as
plain text.
}

 package require http
 package require Img
 package require base64

 pack [entry .e -textvar e] -fill x -expand 1
 bind .e <Return> {go .f.t $e}
 pack [frame .f] -fill both -expand 1
 pack [scrollbar .f.y -command ".f.t yscroll"] -fill y -side right
 pack [text .f.t -wrap word -yscrollc ".f.y set"] \
    -fill both -expand 1 -side right
 foreach i {red blue green3} {.f.t tag config $i -foreground $i}
 focus .e
 raise .

 proc go {w url} {
    set token [http::geturl $url]
    upvar #0 $token arr
    $w see end
    $w insert end \n$arr(url)   blue
    if [info exists arr(error)] {$w insert end \n$arr(error) red}
    $w insert end \n$arr(meta)  green3
    if [regexp {Content-Type image/([^ ]+)} $arr(meta) -> format] {
        set im [image create photo -data [base64::encode $arr(body)]]
        $w insert end \n
        $w image create end -image $im
    } else {
        $w insert end \n$arr(body)
    }
    http::cleanup $token
 }
 bind . <Escape> {exec wish $argv0 &; exit}


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[Arts and crafts of Tcl-Tk programming]