#!/usr/bin/env python
#
# Templite+
# A light-weight, fully functional, general purpose templating engine
#
# Copyright (c) 2009 joonis new media
# Author: Thimo Kraemer <thimo.kraemer@joonis.de>
#
# Based on Templite - Tomer Filiba
# http://code.activestate.com/recipes/496702/
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
# MA 02110-1301, USA.
#
import sys, re
class Templite(object):
auto_emit = re.compile('(^[\'\"])|(^[a-zA-Z0-9_\[\]\'\"]+$)')
def __init__(self, template, start='${', end='}$'):
if len(start) != 2 or len(end) != 2:
raise ValueError('each delimiter must be two characters long')
delimiter = re.compile('%s(.*?)%s' % (re.escape(start), re.escape(end)), re.DOTALL)
offset = 0
tokens = []
for i, part in enumerate(delimiter.split(template)):
part = part.replace('\\'.join(list(start)), start)
part = part.replace('\\'.join(list(end)), end)
if i % 2 == 0:
if not part: continue
part = part.replace('\\', '\\\\').replace('"', '\\"')
part = '\t' * offset + 'emit("""%s""")' % part
else:
part = part.rstrip()
if not part: continue
if part.lstrip().startswith(':'):
if not offset:
raise SyntaxError('no block statement to terminate: ${%s}$' % part)
offset -= 1
part = part.lstrip()[1:]
if not part.endswith(':'): continue
elif self.auto_emit.match(part.lstrip()):
part = 'emit(%s)' % part.lstrip()
lines = part.splitlines()
margin = min(len(l) - len(l.lstrip()) for l in lines if l.strip())
part = '\n'.join('\t' * offset + l[margin:] for l in lines)
if part.endswith(':'):
offset += 1
tokens.append(part)
if offset:
raise SyntaxError('%i block statement(s) not terminated' % offset)
self.__code = compile('\n'.join(tokens), '<templite %r>' % template[:20], 'exec')
def render(self, __namespace=None, **kw):
"""
renders the template according to the given namespace.
__namespace - a dictionary serving as a namespace for evaluation
**kw - keyword arguments which are added to the namespace
"""
namespace = {}
if __namespace: namespace.update(__namespace)
if kw: namespace.update(kw)
namespace['emit'] = self.write
__stdout = sys.stdout
sys.stdout = self
self.__output = []
eval(self.__code, namespace)
sys.stdout = __stdout
return ''.join(self.__output)
def write(self, *args):
for a in args:
self.__output.append(str(a))
if __name__ == '__main__':
template = r"""
This we already know:
<html>
<body>
${
def say_hello(arg):
emit("hello ", arg, "<br>")
}$
<table>
${
for i in range(10):
emit("<tr><td> ")
say_hello(i)
emit(" </tr></td>\n")
}$
</table>
${emit("hi")}$
tralala ${if x > 7:
say_hello("big x")}$ lala
$\{this is escaped starting delimiter
${emit("this }\$ is an escaped ending delimiter")}$
${# this is a python comment }$
</body>
</html>
But this is completely new:
${if x > 7:}$
x is ${emit('greater')}$ than ${print x-1}$ Well, the print statement produces a newline.
${:else:}$
This terminates the previous code block and starts an else code block
Also this would work: $\{:end}\$$\{else:}\$, but not this: $\{:end}\$ $\{else:}\$
${:this terminates the else-block
only the starting colon is essential}$
So far you had to write:
${
if x > 3:
emit('''
After a condition you could not continue your template.
You had to write pure python code.
The only way was to use %%-based substitutions %s
''' % x)
}$
${if x > 6:}$
Now you do not need to break your template ${print x}$
${:elif x > 3:}$
This is great
${:endif}$
${for i in range(x-1):}$ Of course you can use any type of block statement ${i}$ ${"fmt: %s" % (i*2)}$
${:else:}$
Single variables and expressions starting with quotes are substituted automatically.
Instead $\{emit(x)}\$ you can write $\{x}\$ or $\{'%s' % x}\$ or $\{"", x}\$
Therefore standalone statements like break, continue or pass
must be enlosed by a semicolon: $\{continue;}\$
The end
${:end-for}$
"""
t = Templite(template)
print t.render(x=8)
# Output is:
"""
This we already know:
<html>
<body>
<table>
<tr><td> hello 0<br> </tr></td>
<tr><td> hello 1<br> </tr></td>
<tr><td> hello 2<br> </tr></td>
<tr><td> hello 3<br> </tr></td>
<tr><td> hello 4<br> </tr></td>
<tr><td> hello 5<br> </tr></td>
<tr><td> hello 6<br> </tr></td>
<tr><td> hello 7<br> </tr></td>
<tr><td> hello 8<br> </tr></td>
<tr><td> hello 9<br> </tr></td>
</table>
hi
tralala hello big x<br> lala
${this is escaped starting delimiter
this }$ is an escaped ending delimiter
</body>
</html>
But this is completely new:
x is greater than 7
Well, the print statement produces a newline.
So far you had to write:
After a condition you could not continue your template.
You had to write pure python code.
The only way was to use %-based substitutions 8
Now you do not need to break your template 8
Of course you can use any type of block statement 0 fmt: 0
Of course you can use any type of block statement 1 fmt: 2
Of course you can use any type of block statement 2 fmt: 4
Of course you can use any type of block statement 3 fmt: 6
Of course you can use any type of block statement 4 fmt: 8
Of course you can use any type of block statement 5 fmt: 10
Of course you can use any type of block statement 6 fmt: 12
Single variables and expressions starting with quotes are substituted automatically.
Instead ${emit(x)}$ you can write ${x}$ or ${'%s' % x}$ or ${"", x}$
Therefore standalone statements like break, continue or pass
must be enlosed by a semicolon: ${continue;}$
The end
"""
