1.12.1 Cheetah Template

Cheetah is a powerful, stable and well documented templating system. It works by parsing the template into a Python script and then executing that script with the dictionary to produce output. The performance of Cheetah can be improved by writing this script to a file and executing it each time Cheetah is run rather than re-generating it every time.

The useCompiled parameter of the parse() function can be used to determine the behaviour of this compilation. If useCompiled is False the template is parsed every time. This is the slowest but simplest option. If useCompiled is True the compiled template is used even if the original template has changed. This is the fastest option but you must manually tell Cheetah to recompile the template if it changes. If useCompiled is 'auto' then Cheetah will use the compiled file as long as the template has not been modified. If it has it will automatically recompile the template.

Warning: This is the best comprimise. If useCompiled is True or 'auto' then Cheetah must have write access to the directory containing the templates. If it doesn't you may get Internal Server Errors, particularly if you are using web.error with Cheetah templates to catch errors as an error will be thrown in the error catching code and this will lead to an error that is hard to track down.

import web
import Cheetah

<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>$title</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
</head>
<body>
<h1>$title</h1>
$welcomeMessage
#if $testVar == True
The test variable is True
#else
The test variable is not True
#end if
</body>
</html>

#!/usr/bin/env python

import sys; sys.path.append('../../../') # show python where the web modules are
import web.template

dict =  {
    'welcomeMessage':'Welcome to the test page!',
    'testVar':True,
    'title':'Cheetah Example',
}

print web.template.parse(
    type='cheetah', 
    file='file-web-template-cheetah.tmpl', 
    dict=dict
)

<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Cheetah Example</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
</head>
<body>
<h1>Cheetah Example</h1>
Welcome to the test page!
The test variable is True
</body>
</html>