/
templating.py
206 lines (156 loc) · 6.24 KB
/
templating.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
import os
import core
from util import memoize, relpath
from markupsafe import Markup
# Just shorthand
SEP, ALTSEP, EXTSEP = os.path.sep, os.path.altsep, os.path.extsep
engine_name_cache = {}
_default_rendering_extension_lookup = {
'mako': ['mak', 'mako'],
'genshi': ['genshi', 'html'],
# just for backwards compatibility with tw2 2.0.0
'genshi_abs': ['genshi', 'html'],
'jinja': ['jinja', 'html'],
'kajiki': ['kajiki', 'html'],
'chameleon': ['pt']
}
def get_rendering_extensions_lookup(mw):
if mw is None:
rl = core.request_local()
mw = rl.get('middleware')
if mw is None:
return _default_rendering_extension_lookup
return mw.config.rendering_extension_lookup
@memoize
def get_engine_name(template_name, mw=None):
if template_name in engine_name_cache:
return engine_name_cache[template_name]
if ':' in template_name:
engine_name = template_name.split(':', 1)[0]
engine_name_cache[template_name] = engine_name
return engine_name
try:
if mw is None:
rl = core.request_local()
mw = rl['middleware']
pref_rend_eng = mw.config.preferred_rendering_engines
except (KeyError, AttributeError):
pref_rend_eng = ['mako', 'genshi', 'jinja', 'kajiki', 'chameleon']
# find the first file in the preffered engines available for templating
for engine_name in pref_rend_eng:
try:
get_source(engine_name, template_name, mw=mw)
engine_name_cache[template_name] = engine_name
return engine_name
except IOError:
pass
if not mw.config.strict_engine_selection:
pref_rend_eng = ['mako', 'genshi', 'jinja', 'kajiki', 'chameleon']
for engine_name in pref_rend_eng:
try:
get_source(engine_name, template_name, mw=mw)
engine_name_cache[template_name] = engine_name
return engine_name
except IOError:
pass
raise ValueError("Could not find engine name for %s" % template_name)
@memoize
def _get_dotted_filename(engine_name, template, mw=None):
rendering_extension_lookup = get_rendering_extensions_lookup(mw)
template = _strip_engine_name(template, mw)
location, filename = template.rsplit('.', 1)
module = __import__(location, globals(), locals(), ['*'])
parent_dir = SEP.join(module.__file__.split(SEP)[:-1])
for extension in rendering_extension_lookup[engine_name]:
abs_filename = parent_dir + SEP + filename + EXTSEP + extension
if os.path.exists(abs_filename):
return abs_filename
raise IOError("Couldn't find source for %r" % template)
def _strip_engine_name(template, mw=None):
""" Strip off the leading engine name from the template if it exists. """
rendering_extension_lookup = get_rendering_extensions_lookup(mw)
if any(map(template.lstrip().startswith, rendering_extension_lookup)):
return template.split(':', 1)[1]
return template
@memoize
def get_source(engine_name, template, inline=False, mw=None):
if inline:
return template
if SEP in template or (ALTSEP and ALTSEP in template):
filename = _strip_engine_name(template, mw=mw)
else:
filename = _get_dotted_filename(engine_name, template, mw=mw)
# TODO -- use a context manager here once we drop support for py2.5.
f = open(filename, 'r')
try:
source = f.read()
finally:
f.close()
return source
@memoize
def get_render_callable(engine_name, displays_on, src, filename=None):
""" Returns a function that takes a template source and kwargs. """
# See the discussion here re: `displays_on` -- http://bit.ly/JRqbRw
directory = None
if filename:
if SEP not in filename and (not ALTSEP or ALTSEP not in filename):
filename = _get_dotted_filename(engine_name, filename)
directory = os.path.dirname(filename)
if engine_name == 'mako':
import mako.template
args = dict(text=src)
if filename:
args['filename'] = relpath(filename, directory)
from mako.lookup import TemplateLookup
args['lookup'] = TemplateLookup(
directories=[directory])
tmpl = mako.template.Template(**args)
return lambda kwargs: Markup(tmpl.render(**kwargs))
elif engine_name in ('genshi', 'genshi_abs'):
import genshi.template
args = dict(
source=src,
)
if filename:
args['loader'] = genshi.template.TemplateLoader([
genshi.template.loader.directory(directory),
])
tmpl = genshi.template.MarkupTemplate(**args)
return lambda kwargs: Markup(
''.join(tmpl.generate(**kwargs).serialize('xhtml'))
)
elif engine_name == 'jinja':
import jinja2
from jinja_util import htmlbools
env = jinja2.environment.get_spontaneous_environment()
env.filters['htmlbools'] = htmlbools
tmpl = env.from_string(src, template_class=jinja2.Template)
#tmpl = jinja2.Template(src)
#tmpl.environment.filters['htmlbools'] = htmlbools
tmpl.filename = filename
return lambda kwargs: Markup(tmpl.render(**kwargs))
elif engine_name == 'kajiki':
import kajiki
tmpl = kajiki.XMLTemplate(src, filename=filename)
return lambda kwargs: Markup(tmpl(kwargs).render())
elif engine_name == 'chameleon':
import chameleon
tmpl = chameleon.PageTemplate(src, filename=filename)
return lambda kwargs: Markup(tmpl.render(**kwargs).strip())
raise NotImplementedError("Unhandled engine")
def render(template_name, displays_on, kwargs, inline=False, mw=None):
""" Highest level function, here for convenience.
Makes use of *all* other functions in this module.
"""
# Determine the engine name
if not inline:
engine_name = get_engine_name(template_name, mw)
else:
engine_name = inline
# Load the template source
source = get_source(engine_name, template_name, inline, mw)
# Establish the render function
callback = get_render_callable(
engine_name, displays_on, source, template_name)
# Do it
return callback(kwargs)