Waitman Gobble, San Jose California
Hello, I am experimenting with the "Database as a Program" methodology described by [http://wiki.tcl.tk/78%|%D. Richard Hipp%|%] in the article [http://www.tcl.tk/community/tcl2004/Papers/D.RichardHipp/drh.html%|%SQLite and Tcl%|%]
At the moment my application consists of a short and simple main.tcl which decides which code segment to load from an sqlite3 database, executes the code and outputs the result.
I'm using the [http://tcl.apache.org/websh/%|%websh wrapper%|%] via [http://tcl.apache.org/websh/quickref/apache_module_specific_commands.html%|%mod_websh%|%]
Here is some sample code:
The app will process a request URI like http://example.com/main.ws3/hello
Strategy: Create a directory on the machine to create all the snippet Tcl files, then package into SQLite database
package.tcl (package all tcl scripts in current directory into SQLite database)
===
load /usr/local/lib/sqlite3/libtclsqlite3.so Sqlite3
sqlite3 db task.db
db eval {CREATE TABLE hd(path TEXT,src TEXT)}
set files [glob *.tcl]
foreach x $files {
set fp [open $x r]
set src [read $fp]
close $fp
set path /$x
db eval {INSERT INTO hd VALUES ($path,$src)}
}
db close
===
hello.tcl (hello world example)
===
set content "Hello, World"
===
main.ws3 (process request in URI and load corresponding tcl code)
===
set fp [open "layout.html" r]
set layout [read $fp]
close $fp
set path [web::request PATH_INFO].tcl
load /usr/local/lib/sqlite3/libtclsqlite3.so Sqlite3
sqlite3 db task.db
set process [db onecolumn {SELECT src FROM hd WHERE path=$path}]
eval $process
db close
set html [regsub "" $layout $content]
web::put $html
===
layout.html (a template)
===
boo
===
Experiments... Sample output (note, in development ;-)
#1 display CGI env info
http://creamy.mobi/test-series/testdt/main.ws3/testcmd
(ssl vars) https://creamy.mobi/test-series/testdt/main.ws3/testcmd
testcmd.tcl
===
set request [web::request -names]
set combine [join $request ", "]
set path [web::request PATH_INFO]
set content "Request Info
${combine}
${path}
"
===
#2 load and display static HTML file. The static page is specified in the query string (parameter pg).
For test purposes adds the page request at the top.
NOTE: You have to modify glob line in package.tcl, above, to also package html files in the current directory.
http://creamy.mobi/test-series/testdt/main.ws3/static?pg=contact
static.tcl (load html)
===
web::dispatch -postdata "" -cmd ""
set page /[web::param pg].html
set content "$page
"
append content [db onecolumn {SELECT src FROM hd WHERE path=$page}]
===
contact.html
===
Contact
Contact us page
(650) 396-7580
===
#3 test file_mtime and file_md5
http://creamy.mobi/test-series/testdt/main.ws3/checkfile
===
package require md5
set file_mtime [file mtime "layout.html"]
set file_md5 [md5::md5 -hex -filename "layout.html"]
set content "Layout File
File Modification Check
Last Modified: ${file_mtime}
MD5: ${file_md5}
"
===
#4 test time/ip
http://creamy.mobi/test-series/testdt/main.ws3/hash
===
set time [clock clicks]
set ip [web::request REMOTE_ADDR]
append content "time: $time $ip
"
===
Notes using websh/mod_websh
1. using mod_websh cwd is set to "/" (and not the directory in which the script is running)
2. when using mod_websh pkg download from site, also in freebsd /usr/ports/www/websh/ does not appear to log errors. download from svn and build seems to fix this problem (?)
sample build on freebsd
===
svn co http://svn.apache.org/repos/asf/tcl/websh/trunk websh
cd websh/src/unix
autoconf
./configure --with-tcl=/usr/local/lib/tcl8.5-threads \
--with-tclinclude=/usr/local/include/tcl8.5 \
--with-aprinclude=/usr/local/apache2/include/ \
--with-apuinclude=/usr/local/apache2/include/ \
--with-httpdinclude=/usr/local/apache2/include
gmake && gmake install
cp mod_websh* /usr/local/apache2/modules/
cp libwebsh85-threads.so.1 /usr/local/apache2/lib/
===
(vi httpd.conf)
===
LoadModule websh_module modules/mod_websh.so
AddType application/x-httpd-tcl .ws3
AddHandler websh .ws3
WebshConfig conf/websh.conf
===
(see files in src dist:)
===
doc/mod_websh/conf/httpd.conf
doc/mod_websh/conf/otherhandler.ws3
doc/mod_websh/conf/websh.conf
doc/mod_websh/conf/htmlhandler.ws3
===
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