1from __future__ import absolute_import, print_function, unicode_literals
2
3import re
4from .render import renderValue
5from .shared import JSONTemplateError, DeleteMarker, TemplateError, fromNow
6from . import builtins
7
8_context_re = re.compile(r'[a-zA-Z_][a-zA-Z0-9_]*$')
9
10
11def render(template, context):
12    if not all(_context_re.match(c) for c in context):
13        raise TemplateError('top level keys of context must follow '
14                            '/[a-zA-Z_][a-zA-Z0-9_]*/')
15    full_context = {'now': fromNow('0 seconds', None)}
16    full_context.update(builtins.build(full_context))
17    full_context.update(context)
18    rv = renderValue(template, full_context)
19    if rv is DeleteMarker:
20        return None
21    return rv
22