Description:
the engine works by converting a template (which is a string, or a file) into a Tcl script, and then running it.Each line of text encountered will be returned as is. Exception is text between <% ... %> which is treated as Tcl code (the eval happens into regular interp)
Why not expand?
expand is a simple and snugly for Tcl language, be mounted in tcllib. You can use it as quick as flash.
But, that library has a problem, when to really use. we cannot write easily following signs { }.
Why not TemplaTcl?
TemplaTcl is a powerful and cool template engine.
But now, we cannot use it on Tcl8.4 :(
tmpl_parser is
a simple and fast template engine. That still not have function to read a file, create a parser object.
But we can use it instant, only write a command require or source.
Usage:
first, let's create a template file (templtest.tmpl):
<table><%
for {set i 0} {$i < 4} {incr i} { %>
<tr>
<td><%= $i %></td>
</tr><%
} %>
</table>
<ul>
<% foreach item $cityList {
%><li><%= $item %>
<% } %>
</ul>the above template (in HTML language) generates a 4-row table, and an unordered list, taking values from a $cityList variable, that we're going to define. First let's load the code:
source tmpl_parser.tcl
reading template file.
set fd [open templtest.tmpl r] set tmpl [read $fd] close $fd
now create a parser instance:
set parser [::tmpl_parser::tmpl_parser $tmpl]
set the variables used in our template:
set cityList {Ragusa Ravenna Rieti Rimini Rome Rovigo}and render the template:
puts [eval $parser]
Here's the output that gets produced:
<table>
<tr>
<td>1</td>
</tr>
<tr>
<td>2</td>
</tr>
<tr>
<td>3</td>
</tr>
<tr>
<td>4</td>
</tr>
</table>
<ul>
<li>Ragusa
<li>Ravenna
<li>Rieti
<li>Rimini
<li>Rome
<li>Rovigo
</ul># tmpl_parser.tcl # # Tcl embeddedd script parser(a template engine) # # This module comverts Tcl embeddedd scripts into a Tcl normal script(parser), # after you just have to do eval command for the generated parser. # # Copyright (c) 2007 by Kanryu KATO<[email protected]> # licensed on Tcl License.
package require Tcl 8.3 package provide tmpl_parser 0.1
namespace eval ::tmpl_parser {
namespace export tmpl_parser
}
proc ::tmpl_parser::tmpl_parser {tmpl} {
# Tcl enbedded tags
# [[outer <%...inner...%> outer]] <-$tmpl
# [ = ] <-$token
# cd ef hi j <-indexes
set parser { {set _o {}} }
while {[set i [string first %> $tmpl]] != -1} {
set h [expr $i-1]
set j [expr $i+2]
set token [string range $tmpl 0 $h]
set d [string first <% $token]
set c [expr $d-1]
set e [expr $d+2]
set f [expr $d+3]
# outer
lappend parser [escaped_parse [string range $token 0 $c]]
switch [string index $token $e] {
"=" {
# normal expression (e.g. Thanks <%=$count%> accesses!)
lappend parser [normal_parse [string range $token $f end]]
}
":" {
# numeric expression (e.g. <%:$i+2000%>)
lappend parser [numeric_parse [string range $token $f end]]
}
default {
# enbedded Tcl command is passed through listing
lappend parser [string range $token $e end]
}
}
# after "%>"
set tmpl [string range $tmpl $j end]
}
#last outer
lappend parser [escaped_parse $tmpl]
lappend parser {join $_o ""}
return [join $parser "\n"]}
proc ::tmpl_parser::escaped_parse {str} {
set str [string map {\" \\\" \{ \\\{ \} \\\} \\ \\\\} $str]
return "lappend _o \"$str\""}
proc ::tmpl_parser::normal_parse {str} {
return "lappend _o $str"
}
proc ::tmpl_parser::numeric_parse {str} {
return "lappend _o [expr $str]"
}
[ Category Application | Category Template Category Template and Macro processing ]