You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
951 lines
35 KiB
951 lines
35 KiB
""" |
|
This is the Django template system. |
|
|
|
How it works: |
|
|
|
The Lexer.tokenize() function converts a template string (i.e., a string containing |
|
markup with custom template tags) to tokens, which can be either plain text |
|
(TOKEN_TEXT), variables (TOKEN_VAR) or block statements (TOKEN_BLOCK). |
|
|
|
The Parser() class takes a list of tokens in its constructor, and its parse() |
|
method returns a compiled template -- which is, under the hood, a list of |
|
Node objects. |
|
|
|
Each Node is responsible for creating some sort of output -- e.g. simple text |
|
(TextNode), variable values in a given context (VariableNode), results of basic |
|
logic (IfNode), results of looping (ForNode), or anything else. The core Node |
|
types are TextNode, VariableNode, IfNode and ForNode, but plugin modules can |
|
define their own custom node types. |
|
|
|
Each Node has a render() method, which takes a Context and returns a string of |
|
the rendered node. For example, the render() method of a Variable Node returns |
|
the variable's value as a string. The render() method of an IfNode returns the |
|
rendered output of whatever was inside the loop, recursively. |
|
|
|
The Template class is a convenient wrapper that takes care of template |
|
compilation and rendering. |
|
|
|
Usage: |
|
|
|
The only thing you should ever use directly in this file is the Template class. |
|
Create a compiled template object with a template_string, then call render() |
|
with a context. In the compilation stage, the TemplateSyntaxError exception |
|
will be raised if the template doesn't have proper syntax. |
|
|
|
Sample code: |
|
|
|
>>> from django import template |
|
>>> s = u'<html>{% if test %}<h1>{{ varvalue }}</h1>{% endif %}</html>' |
|
>>> t = template.Template(s) |
|
|
|
(t is now a compiled template, and its render() method can be called multiple |
|
times with multiple contexts) |
|
|
|
>>> c = template.Context({'test':True, 'varvalue': 'Hello'}) |
|
>>> t.render(c) |
|
u'<html><h1>Hello</h1></html>' |
|
>>> c = template.Context({'test':False, 'varvalue': 'Hello'}) |
|
>>> t.render(c) |
|
u'<html></html>' |
|
""" |
|
import re |
|
from inspect import getargspec |
|
from django.conf import settings |
|
from django.template.context import Context, RequestContext, ContextPopException |
|
from django.utils.itercompat import is_iterable |
|
from django.utils.functional import curry, Promise |
|
from django.utils.text import smart_split |
|
from django.utils.encoding import smart_unicode, force_unicode |
|
from django.utils.translation import ugettext as _ |
|
from django.utils.safestring import SafeData, EscapeData, mark_safe, mark_for_escaping |
|
from django.utils.html import escape |
|
|
|
__all__ = ('Template', 'Context', 'RequestContext', 'compile_string') |
|
|
|
TOKEN_TEXT = 0 |
|
TOKEN_VAR = 1 |
|
TOKEN_BLOCK = 2 |
|
TOKEN_COMMENT = 3 |
|
|
|
# template syntax constants |
|
FILTER_SEPARATOR = '|' |
|
FILTER_ARGUMENT_SEPARATOR = ':' |
|
VARIABLE_ATTRIBUTE_SEPARATOR = '.' |
|
BLOCK_TAG_START = '{%' |
|
BLOCK_TAG_END = '%}' |
|
VARIABLE_TAG_START = '{{' |
|
VARIABLE_TAG_END = '}}' |
|
COMMENT_TAG_START = '{#' |
|
COMMENT_TAG_END = '#}' |
|
SINGLE_BRACE_START = '{' |
|
SINGLE_BRACE_END = '}' |
|
|
|
ALLOWED_VARIABLE_CHARS = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_.' |
|
|
|
# what to report as the origin for templates that come from non-loader sources |
|
# (e.g. strings) |
|
UNKNOWN_SOURCE="<unknown source>" |
|
|
|
# match a variable or block tag and capture the entire tag, including start/end delimiters |
|
tag_re = re.compile('(%s.*?%s|%s.*?%s|%s.*?%s)' % (re.escape(BLOCK_TAG_START), re.escape(BLOCK_TAG_END), |
|
re.escape(VARIABLE_TAG_START), re.escape(VARIABLE_TAG_END), |
|
re.escape(COMMENT_TAG_START), re.escape(COMMENT_TAG_END))) |
|
|
|
# global dictionary of libraries that have been loaded using get_library |
|
libraries = {} |
|
# global list of libraries to load by default for a new parser |
|
builtins = [] |
|
|
|
# True if TEMPLATE_STRING_IF_INVALID contains a format string (%s). None means |
|
# uninitialised. |
|
invalid_var_format_string = None |
|
|
|
class TemplateSyntaxError(Exception): |
|
def __str__(self): |
|
try: |
|
import cStringIO as StringIO |
|
except ImportError: |
|
import StringIO |
|
output = StringIO.StringIO() |
|
output.write(Exception.__str__(self)) |
|
# Check if we wrapped an exception and print that too. |
|
if hasattr(self, 'exc_info'): |
|
import traceback |
|
output.write('\n\nOriginal ') |
|
e = self.exc_info |
|
traceback.print_exception(e[0], e[1], e[2], 500, output) |
|
return output.getvalue() |
|
|
|
class TemplateDoesNotExist(Exception): |
|
pass |
|
|
|
class TemplateEncodingError(Exception): |
|
pass |
|
|
|
class VariableDoesNotExist(Exception): |
|
|
|
def __init__(self, msg, params=()): |
|
self.msg = msg |
|
self.params = params |
|
|
|
def __str__(self): |
|
return unicode(self).encode('utf-8') |
|
|
|
def __unicode__(self): |
|
return self.msg % tuple([force_unicode(p, errors='replace') for p in self.params]) |
|
|
|
class InvalidTemplateLibrary(Exception): |
|
pass |
|
|
|
class Origin(object): |
|
def __init__(self, name): |
|
self.name = name |
|
|
|
def reload(self): |
|
raise NotImplementedError |
|
|
|
def __str__(self): |
|
return self.name |
|
|
|
class StringOrigin(Origin): |
|
def __init__(self, source): |
|
super(StringOrigin, self).__init__(UNKNOWN_SOURCE) |
|
self.source = source |
|
|
|
def reload(self): |
|
return self.source |
|
|
|
class Template(object): |
|
def __init__(self, template_string, origin=None, name='<Unknown Template>'): |
|
try: |
|
template_string = smart_unicode(template_string) |
|
except UnicodeDecodeError: |
|
raise TemplateEncodingError("Templates can only be constructed from unicode or UTF-8 strings.") |
|
if settings.TEMPLATE_DEBUG and origin is None: |
|
origin = StringOrigin(template_string) |
|
self.nodelist = compile_string(template_string, origin) |
|
self.name = name |
|
|
|
def __iter__(self): |
|
for node in self.nodelist: |
|
for subnode in node: |
|
yield subnode |
|
|
|
def render(self, context): |
|
"Display stage -- can be called many times" |
|
return self.nodelist.render(context) |
|
|
|
def compile_string(template_string, origin): |
|
"Compiles template_string into NodeList ready for rendering" |
|
if settings.TEMPLATE_DEBUG: |
|
from debug import DebugLexer, DebugParser |
|
lexer_class, parser_class = DebugLexer, DebugParser |
|
else: |
|
lexer_class, parser_class = Lexer, Parser |
|
lexer = lexer_class(template_string, origin) |
|
parser = parser_class(lexer.tokenize()) |
|
return parser.parse() |
|
|
|
class Token(object): |
|
def __init__(self, token_type, contents): |
|
# token_type must be TOKEN_TEXT, TOKEN_VAR, TOKEN_BLOCK or TOKEN_COMMENT. |
|
self.token_type, self.contents = token_type, contents |
|
|
|
def __str__(self): |
|
return '<%s token: "%s...">' % \ |
|
({TOKEN_TEXT: 'Text', TOKEN_VAR: 'Var', TOKEN_BLOCK: 'Block', TOKEN_COMMENT: 'Comment'}[self.token_type], |
|
self.contents[:20].replace('\n', '')) |
|
|
|
def split_contents(self): |
|
split = [] |
|
bits = iter(smart_split(self.contents)) |
|
for bit in bits: |
|
# Handle translation-marked template pieces |
|
if bit.startswith('_("') or bit.startswith("_('"): |
|
sentinal = bit[2] + ')' |
|
trans_bit = [bit] |
|
while not bit.endswith(sentinal): |
|
bit = bits.next() |
|
trans_bit.append(bit) |
|
bit = ' '.join(trans_bit) |
|
split.append(bit) |
|
return split |
|
|
|
class Lexer(object): |
|
def __init__(self, template_string, origin): |
|
self.template_string = template_string |
|
self.origin = origin |
|
|
|
def tokenize(self): |
|
"Return a list of tokens from a given template_string." |
|
in_tag = False |
|
result = [] |
|
for bit in tag_re.split(self.template_string): |
|
if bit: |
|
result.append(self.create_token(bit, in_tag)) |
|
in_tag = not in_tag |
|
return result |
|
|
|
def create_token(self, token_string, in_tag): |
|
""" |
|
Convert the given token string into a new Token object and return it. |
|
If in_tag is True, we are processing something that matched a tag, |
|
otherwise it should be treated as a literal string. |
|
""" |
|
if in_tag: |
|
if token_string.startswith(VARIABLE_TAG_START): |
|
token = Token(TOKEN_VAR, token_string[len(VARIABLE_TAG_START):-len(VARIABLE_TAG_END)].strip()) |
|
elif token_string.startswith(BLOCK_TAG_START): |
|
token = Token(TOKEN_BLOCK, token_string[len(BLOCK_TAG_START):-len(BLOCK_TAG_END)].strip()) |
|
elif token_string.startswith(COMMENT_TAG_START): |
|
token = Token(TOKEN_COMMENT, '') |
|
else: |
|
token = Token(TOKEN_TEXT, token_string) |
|
return token |
|
|
|
class Parser(object): |
|
def __init__(self, tokens): |
|
self.tokens = tokens |
|
self.tags = {} |
|
self.filters = {} |
|
for lib in builtins: |
|
self.add_library(lib) |
|
|
|
def parse(self, parse_until=None): |
|
if parse_until is None: parse_until = [] |
|
nodelist = self.create_nodelist() |
|
while self.tokens: |
|
token = self.next_token() |
|
if token.token_type == TOKEN_TEXT: |
|
self.extend_nodelist(nodelist, TextNode(token.contents), token) |
|
elif token.token_type == TOKEN_VAR: |
|
if not token.contents: |
|
self.empty_variable(token) |
|
filter_expression = self.compile_filter(token.contents) |
|
var_node = self.create_variable_node(filter_expression) |
|
self.extend_nodelist(nodelist, var_node,token) |
|
elif token.token_type == TOKEN_BLOCK: |
|
if token.contents in parse_until: |
|
# put token back on token list so calling code knows why it terminated |
|
self.prepend_token(token) |
|
return nodelist |
|
try: |
|
command = token.contents.split()[0] |
|
except IndexError: |
|
self.empty_block_tag(token) |
|
# execute callback function for this tag and append resulting node |
|
self.enter_command(command, token) |
|
try: |
|
compile_func = self.tags[command] |
|
except KeyError: |
|
self.invalid_block_tag(token, command) |
|
try: |
|
compiled_result = compile_func(self, token) |
|
except TemplateSyntaxError, e: |
|
if not self.compile_function_error(token, e): |
|
raise |
|
self.extend_nodelist(nodelist, compiled_result, token) |
|
self.exit_command() |
|
if parse_until: |
|
self.unclosed_block_tag(parse_until) |
|
return nodelist |
|
|
|
def skip_past(self, endtag): |
|
while self.tokens: |
|
token = self.next_token() |
|
if token.token_type == TOKEN_BLOCK and token.contents == endtag: |
|
return |
|
self.unclosed_block_tag([endtag]) |
|
|
|
def create_variable_node(self, filter_expression): |
|
return VariableNode(filter_expression) |
|
|
|
def create_nodelist(self): |
|
return NodeList() |
|
|
|
def extend_nodelist(self, nodelist, node, token): |
|
if node.must_be_first and nodelist: |
|
try: |
|
if nodelist.contains_nontext: |
|
raise AttributeError |
|
except AttributeError: |
|
raise TemplateSyntaxError("%r must be the first tag in the template." % node) |
|
if isinstance(nodelist, NodeList) and not isinstance(node, TextNode): |
|
nodelist.contains_nontext = True |
|
nodelist.append(node) |
|
|
|
def enter_command(self, command, token): |
|
pass |
|
|
|
def exit_command(self): |
|
pass |
|
|
|
def error(self, token, msg): |
|
return TemplateSyntaxError(msg) |
|
|
|
def empty_variable(self, token): |
|
raise self.error(token, "Empty variable tag") |
|
|
|
def empty_block_tag(self, token): |
|
raise self.error(token, "Empty block tag") |
|
|
|
def invalid_block_tag(self, token, command): |
|
raise self.error(token, "Invalid block tag: '%s'" % command) |
|
|
|
def unclosed_block_tag(self, parse_until): |
|
raise self.error(None, "Unclosed tags: %s " % ', '.join(parse_until)) |
|
|
|
def compile_function_error(self, token, e): |
|
pass |
|
|
|
def next_token(self): |
|
return self.tokens.pop(0) |
|
|
|
def prepend_token(self, token): |
|
self.tokens.insert(0, token) |
|
|
|
def delete_first_token(self): |
|
del self.tokens[0] |
|
|
|
def add_library(self, lib): |
|
self.tags.update(lib.tags) |
|
self.filters.update(lib.filters) |
|
|
|
def compile_filter(self, token): |
|
"Convenient wrapper for FilterExpression" |
|
return FilterExpression(token, self) |
|
|
|
def find_filter(self, filter_name): |
|
if filter_name in self.filters: |
|
return self.filters[filter_name] |
|
else: |
|
raise TemplateSyntaxError("Invalid filter: '%s'" % filter_name) |
|
|
|
class TokenParser(object): |
|
""" |
|
Subclass this and implement the top() method to parse a template line. When |
|
instantiating the parser, pass in the line from the Django template parser. |
|
|
|
The parser's "tagname" instance-variable stores the name of the tag that |
|
the filter was called with. |
|
""" |
|
def __init__(self, subject): |
|
self.subject = subject |
|
self.pointer = 0 |
|
self.backout = [] |
|
self.tagname = self.tag() |
|
|
|
def top(self): |
|
"Overload this method to do the actual parsing and return the result." |
|
raise NotImplementedError() |
|
|
|
def more(self): |
|
"Returns True if there is more stuff in the tag." |
|
return self.pointer < len(self.subject) |
|
|
|
def back(self): |
|
"Undoes the last microparser. Use this for lookahead and backtracking." |
|
if not len(self.backout): |
|
raise TemplateSyntaxError("back called without some previous parsing") |
|
self.pointer = self.backout.pop() |
|
|
|
def tag(self): |
|
"A microparser that just returns the next tag from the line." |
|
subject = self.subject |
|
i = self.pointer |
|
if i >= len(subject): |
|
raise TemplateSyntaxError("expected another tag, found end of string: %s" % subject) |
|
p = i |
|
while i < len(subject) and subject[i] not in (' ', '\t'): |
|
i += 1 |
|
s = subject[p:i] |
|
while i < len(subject) and subject[i] in (' ', '\t'): |
|
i += 1 |
|
self.backout.append(self.pointer) |
|
self.pointer = i |
|
return s |
|
|
|
def value(self): |
|
"A microparser that parses for a value: some string constant or variable name." |
|
subject = self.subject |
|
i = self.pointer |
|
if i >= len(subject): |
|
raise TemplateSyntaxError("Searching for value. Expected another value but found end of string: %s" % subject) |
|
if subject[i] in ('"', "'"): |
|
p = i |
|
i += 1 |
|
while i < len(subject) and subject[i] != subject[p]: |
|
i += 1 |
|
if i >= len(subject): |
|
raise TemplateSyntaxError("Searching for value. Unexpected end of string in column %d: %s" % (i, subject)) |
|
i += 1 |
|
res = subject[p:i] |
|
while i < len(subject) and subject[i] in (' ', '\t'): |
|
i += 1 |
|
self.backout.append(self.pointer) |
|
self.pointer = i |
|
return res |
|
else: |
|
p = i |
|
while i < len(subject) and subject[i] not in (' ', '\t'): |
|
if subject[i] in ('"', "'"): |
|
c = subject[i] |
|
i += 1 |
|
while i < len(subject) and subject[i] != c: |
|
i += 1 |
|
if i >= len(subject): |
|
raise TemplateSyntaxError("Searching for value. Unexpected end of string in column %d: %s" % (i, subject)) |
|
i += 1 |
|
s = subject[p:i] |
|
while i < len(subject) and subject[i] in (' ', '\t'): |
|
i += 1 |
|
self.backout.append(self.pointer) |
|
self.pointer = i |
|
return s |
|
|
|
filter_raw_string = r""" |
|
^%(i18n_open)s"(?P<i18n_constant>%(str)s)"%(i18n_close)s| |
|
^"(?P<constant>%(str)s)"| |
|
^(?P<var>[%(var_chars)s]+)| |
|
(?:%(filter_sep)s |
|
(?P<filter_name>\w+) |
|
(?:%(arg_sep)s |
|
(?: |
|
%(i18n_open)s"(?P<i18n_arg>%(str)s)"%(i18n_close)s| |
|
"(?P<constant_arg>%(str)s)"| |
|
(?P<var_arg>[%(var_chars)s]+) |
|
) |
|
)? |
|
)""" % { |
|
'str': r"""[^"\\]*(?:\\.[^"\\]*)*""", |
|
'var_chars': "\w\." , |
|
'filter_sep': re.escape(FILTER_SEPARATOR), |
|
'arg_sep': re.escape(FILTER_ARGUMENT_SEPARATOR), |
|
'i18n_open' : re.escape("_("), |
|
'i18n_close' : re.escape(")"), |
|
} |
|
|
|
filter_raw_string = filter_raw_string.replace("\n", "").replace(" ", "") |
|
filter_re = re.compile(filter_raw_string, re.UNICODE) |
|
|
|
class FilterExpression(object): |
|
""" |
|
Parses a variable token and its optional filters (all as a single string), |
|
and return a list of tuples of the filter name and arguments. |
|
Sample: |
|
>>> token = 'variable|default:"Default value"|date:"Y-m-d"' |
|
>>> p = Parser('') |
|
>>> fe = FilterExpression(token, p) |
|
>>> len(fe.filters) |
|
2 |
|
>>> fe.var |
|
<Variable: 'variable'> |
|
|
|
This class should never be instantiated outside of the |
|
get_filters_from_token helper function. |
|
""" |
|
def __init__(self, token, parser): |
|
self.token = token |
|
matches = filter_re.finditer(token) |
|
var = None |
|
filters = [] |
|
upto = 0 |
|
for match in matches: |
|
start = match.start() |
|
if upto != start: |
|
raise TemplateSyntaxError("Could not parse some characters: %s|%s|%s" % \ |
|
(token[:upto], token[upto:start], token[start:])) |
|
if var == None: |
|
var, constant, i18n_constant = match.group("var", "constant", "i18n_constant") |
|
if i18n_constant is not None: |
|
# Don't pass the empty string to gettext, because the empty |
|
# string translates to meta information. |
|
if i18n_constant == "": |
|
var = '""' |
|
else: |
|
var = '"%s"' % _(i18n_constant.replace(r'\"', '"')) |
|
elif constant is not None: |
|
var = '"%s"' % constant.replace(r'\"', '"') |
|
upto = match.end() |
|
if var == None: |
|
raise TemplateSyntaxError("Could not find variable at start of %s" % token) |
|
elif var.find(VARIABLE_ATTRIBUTE_SEPARATOR + '_') > -1 or var[0] == '_': |
|
raise TemplateSyntaxError("Variables and attributes may not begin with underscores: '%s'" % var) |
|
else: |
|
filter_name = match.group("filter_name") |
|
args = [] |
|
constant_arg, i18n_arg, var_arg = match.group("constant_arg", "i18n_arg", "var_arg") |
|
if i18n_arg: |
|
args.append((False, _(i18n_arg.replace(r'\"', '"')))) |
|
elif constant_arg is not None: |
|
args.append((False, constant_arg.replace(r'\"', '"'))) |
|
elif var_arg: |
|
args.append((True, Variable(var_arg))) |
|
filter_func = parser.find_filter(filter_name) |
|
self.args_check(filter_name,filter_func, args) |
|
filters.append( (filter_func,args)) |
|
upto = match.end() |
|
if upto != len(token): |
|
raise TemplateSyntaxError("Could not parse the remainder: '%s' from '%s'" % (token[upto:], token)) |
|
self.filters = filters |
|
self.var = Variable(var) |
|
|
|
def resolve(self, context, ignore_failures=False): |
|
try: |
|
obj = self.var.resolve(context) |
|
except VariableDoesNotExist: |
|
if ignore_failures: |
|
obj = None |
|
else: |
|
if settings.TEMPLATE_STRING_IF_INVALID: |
|
global invalid_var_format_string |
|
if invalid_var_format_string is None: |
|
invalid_var_format_string = '%s' in settings.TEMPLATE_STRING_IF_INVALID |
|
if invalid_var_format_string: |
|
return settings.TEMPLATE_STRING_IF_INVALID % self.var |
|
return settings.TEMPLATE_STRING_IF_INVALID |
|
else: |
|
obj = settings.TEMPLATE_STRING_IF_INVALID |
|
for func, args in self.filters: |
|
arg_vals = [] |
|
for lookup, arg in args: |
|
if not lookup: |
|
arg_vals.append(mark_safe(arg)) |
|
else: |
|
arg_vals.append(arg.resolve(context)) |
|
if getattr(func, 'needs_autoescape', False): |
|
new_obj = func(obj, autoescape=context.autoescape, *arg_vals) |
|
else: |
|
new_obj = func(obj, *arg_vals) |
|
if getattr(func, 'is_safe', False) and isinstance(obj, SafeData): |
|
obj = mark_safe(new_obj) |
|
elif isinstance(obj, EscapeData): |
|
obj = mark_for_escaping(new_obj) |
|
else: |
|
obj = new_obj |
|
return obj |
|
|
|
def args_check(name, func, provided): |
|
provided = list(provided) |
|
plen = len(provided) |
|
# Check to see if a decorator is providing the real function. |
|
func = getattr(func, '_decorated_function', func) |
|
args, varargs, varkw, defaults = getargspec(func) |
|
# First argument is filter input. |
|
args.pop(0) |
|
if defaults: |
|
nondefs = args[:-len(defaults)] |
|
else: |
|
nondefs = args |
|
# Args without defaults must be provided. |
|
try: |
|
for arg in nondefs: |
|
provided.pop(0) |
|
except IndexError: |
|
# Not enough |
|
raise TemplateSyntaxError("%s requires %d arguments, %d provided" % (name, len(nondefs), plen)) |
|
|
|
# Defaults can be overridden. |
|
defaults = defaults and list(defaults) or [] |
|
try: |
|
for parg in provided: |
|
defaults.pop(0) |
|
except IndexError: |
|
# Too many. |
|
raise TemplateSyntaxError("%s requires %d arguments, %d provided" % (name, len(nondefs), plen)) |
|
|
|
return True |
|
args_check = staticmethod(args_check) |
|
|
|
def __str__(self): |
|
return self.token |
|
|
|
def resolve_variable(path, context): |
|
""" |
|
Returns the resolved variable, which may contain attribute syntax, within |
|
the given context. |
|
|
|
Deprecated; use the Variable class instead. |
|
""" |
|
return Variable(path).resolve(context) |
|
|
|
class Variable(object): |
|
""" |
|
A template variable, resolvable against a given context. The variable may be |
|
a hard-coded string (if it begins and ends with single or double quote |
|
marks):: |
|
|
|
>>> c = {'article': {'section':u'News'}} |
|
>>> Variable('article.section').resolve(c) |
|
u'News' |
|
>>> Variable('article').resolve(c) |
|
{'section': u'News'} |
|
>>> class AClass: pass |
|
>>> c = AClass() |
|
>>> c.article = AClass() |
|
>>> c.article.section = u'News' |
|
>>> Variable('article.section').resolve(c) |
|
u'News' |
|
|
|
(The example assumes VARIABLE_ATTRIBUTE_SEPARATOR is '.') |
|
""" |
|
|
|
def __init__(self, var): |
|
self.var = var |
|
self.literal = None |
|
self.lookups = None |
|
self.translate = False |
|
|
|
try: |
|
# First try to treat this variable as a number. |
|
# |
|
# Note that this could cause an OverflowError here that we're not |
|
# catching. Since this should only happen at compile time, that's |
|
# probably OK. |
|
self.literal = float(var) |
|
|
|
# So it's a float... is it an int? If the original value contained a |
|
# dot or an "e" then it was a float, not an int. |
|
if '.' not in var and 'e' not in var.lower(): |
|
self.literal = int(self.literal) |
|
|
|
# "2." is invalid |
|
if var.endswith('.'): |
|
raise ValueError |
|
|
|
except ValueError: |
|
# A ValueError means that the variable isn't a number. |
|
if var.startswith('_(') and var.endswith(')'): |
|
# The result of the lookup should be translated at rendering |
|
# time. |
|
self.translate = True |
|
var = var[2:-1] |
|
# If it's wrapped with quotes (single or double), then |
|
# we're also dealing with a literal. |
|
if var[0] in "\"'" and var[0] == var[-1]: |
|
self.literal = mark_safe(var[1:-1]) |
|
else: |
|
# Otherwise we'll set self.lookups so that resolve() knows we're |
|
# dealing with a bonafide variable |
|
self.lookups = tuple(var.split(VARIABLE_ATTRIBUTE_SEPARATOR)) |
|
|
|
def resolve(self, context): |
|
"""Resolve this variable against a given context.""" |
|
if self.lookups is not None: |
|
# We're dealing with a variable that needs to be resolved |
|
value = self._resolve_lookup(context) |
|
else: |
|
# We're dealing with a literal, so it's already been "resolved" |
|
value = self.literal |
|
if self.translate: |
|
return _(value) |
|
return value |
|
|
|
def __repr__(self): |
|
return "<%s: %r>" % (self.__class__.__name__, self.var) |
|
|
|
def __str__(self): |
|
return self.var |
|
|
|
def _resolve_lookup(self, context): |
|
""" |
|
Performs resolution of a real variable (i.e. not a literal) against the |
|
given context. |
|
|
|
As indicated by the method's name, this method is an implementation |
|
detail and shouldn't be called by external code. Use Variable.resolve() |
|
instead. |
|
""" |
|
current = context |
|
for bit in self.lookups: |
|
try: # dictionary lookup |
|
current = current[bit] |
|
except (TypeError, AttributeError, KeyError): |
|
try: # attribute lookup |
|
current = getattr(current, bit) |
|
if callable(current): |
|
if getattr(current, 'alters_data', False): |
|
current = settings.TEMPLATE_STRING_IF_INVALID |
|
else: |
|
try: # method call (assuming no args required) |
|
current = current() |
|
except TypeError: # arguments *were* required |
|
# GOTCHA: This will also catch any TypeError |
|
# raised in the function itself. |
|
current = settings.TEMPLATE_STRING_IF_INVALID # invalid method call |
|
except Exception, e: |
|
if getattr(e, 'silent_variable_failure', False): |
|
current = settings.TEMPLATE_STRING_IF_INVALID |
|
else: |
|
raise |
|
except (TypeError, AttributeError): |
|
try: # list-index lookup |
|
current = current[int(bit)] |
|
except (IndexError, # list index out of range |
|
ValueError, # invalid literal for int() |
|
KeyError, # current is a dict without `int(bit)` key |
|
TypeError, # unsubscriptable object |
|
): |
|
raise VariableDoesNotExist("Failed lookup for key [%s] in %r", (bit, current)) # missing attribute |
|
except Exception, e: |
|
if getattr(e, 'silent_variable_failure', False): |
|
current = settings.TEMPLATE_STRING_IF_INVALID |
|
else: |
|
raise |
|
|
|
return current |
|
|
|
class Node(object): |
|
# Set this to True for nodes that must be first in the template (although |
|
# they can be preceded by text nodes. |
|
must_be_first = False |
|
|
|
def render(self, context): |
|
"Return the node rendered as a string" |
|
pass |
|
|
|
def __iter__(self): |
|
yield self |
|
|
|
def get_nodes_by_type(self, nodetype): |
|
"Return a list of all nodes (within this node and its nodelist) of the given type" |
|
nodes = [] |
|
if isinstance(self, nodetype): |
|
nodes.append(self) |
|
if hasattr(self, 'nodelist'): |
|
nodes.extend(self.nodelist.get_nodes_by_type(nodetype)) |
|
return nodes |
|
|
|
class NodeList(list): |
|
# Set to True the first time a non-TextNode is inserted by |
|
# extend_nodelist(). |
|
contains_nontext = False |
|
|
|
def render(self, context): |
|
bits = [] |
|
for node in self: |
|
if isinstance(node, Node): |
|
bits.append(self.render_node(node, context)) |
|
else: |
|
bits.append(node) |
|
return mark_safe(''.join([force_unicode(b) for b in bits])) |
|
|
|
def get_nodes_by_type(self, nodetype): |
|
"Return a list of all nodes of the given type" |
|
nodes = [] |
|
for node in self: |
|
nodes.extend(node.get_nodes_by_type(nodetype)) |
|
return nodes |
|
|
|
def render_node(self, node, context): |
|
return node.render(context) |
|
|
|
class TextNode(Node): |
|
def __init__(self, s): |
|
self.s = s |
|
|
|
def __repr__(self): |
|
return "<Text Node: '%s'>" % self.s[:25] |
|
|
|
def render(self, context): |
|
return self.s |
|
|
|
class VariableNode(Node): |
|
def __init__(self, filter_expression): |
|
self.filter_expression = filter_expression |
|
|
|
def __repr__(self): |
|
return "<Variable Node: %s>" % self.filter_expression |
|
|
|
def render(self, context): |
|
try: |
|
output = force_unicode(self.filter_expression.resolve(context)) |
|
except UnicodeDecodeError: |
|
# Unicode conversion can fail sometimes for reasons out of our |
|
# control (e.g. exception rendering). In that case, we fail quietly. |
|
return '' |
|
if (context.autoescape and not isinstance(output, SafeData)) or isinstance(output, EscapeData): |
|
return force_unicode(escape(output)) |
|
else: |
|
return force_unicode(output) |
|
|
|
def generic_tag_compiler(params, defaults, name, node_class, parser, token): |
|
"Returns a template.Node subclass." |
|
bits = token.split_contents()[1:] |
|
bmax = len(params) |
|
def_len = defaults and len(defaults) or 0 |
|
bmin = bmax - def_len |
|
if(len(bits) < bmin or len(bits) > bmax): |
|
if bmin == bmax: |
|
message = "%s takes %s arguments" % (name, bmin) |
|
else: |
|
message = "%s takes between %s and %s arguments" % (name, bmin, bmax) |
|
raise TemplateSyntaxError(message) |
|
return node_class(bits) |
|
|
|
class Library(object): |
|
def __init__(self): |
|
self.filters = {} |
|
self.tags = {} |
|
|
|
def tag(self, name=None, compile_function=None): |
|
if name == None and compile_function == None: |
|
# @register.tag() |
|
return self.tag_function |
|
elif name != None and compile_function == None: |
|
if(callable(name)): |
|
# @register.tag |
|
return self.tag_function(name) |
|
else: |
|
# @register.tag('somename') or @register.tag(name='somename') |
|
def dec(func): |
|
return self.tag(name, func) |
|
return dec |
|
elif name != None and compile_function != None: |
|
# register.tag('somename', somefunc) |
|
self.tags[name] = compile_function |
|
return compile_function |
|
else: |
|
raise InvalidTemplateLibrary("Unsupported arguments to Library.tag: (%r, %r)", (name, compile_function)) |
|
|
|
def tag_function(self,func): |
|
self.tags[getattr(func, "_decorated_function", func).__name__] = func |
|
return func |
|
|
|
def filter(self, name=None, filter_func=None): |
|
if name == None and filter_func == None: |
|
# @register.filter() |
|
return self.filter_function |
|
elif filter_func == None: |
|
if(callable(name)): |
|
# @register.filter |
|
return self.filter_function(name) |
|
else: |
|
# @register.filter('somename') or @register.filter(name='somename') |
|
def dec(func): |
|
return self.filter(name, func) |
|
return dec |
|
elif name != None and filter_func != None: |
|
# register.filter('somename', somefunc) |
|
self.filters[name] = filter_func |
|
return filter_func |
|
else: |
|
raise InvalidTemplateLibrary("Unsupported arguments to Library.filter: (%r, %r)", (name, filter_func)) |
|
|
|
def filter_function(self, func): |
|
self.filters[getattr(func, "_decorated_function", func).__name__] = func |
|
return func |
|
|
|
def simple_tag(self,func): |
|
params, xx, xxx, defaults = getargspec(func) |
|
|
|
class SimpleNode(Node): |
|
def __init__(self, vars_to_resolve): |
|
self.vars_to_resolve = map(Variable, vars_to_resolve) |
|
|
|
def render(self, context): |
|
resolved_vars = [var.resolve(context) for var in self.vars_to_resolve] |
|
return func(*resolved_vars) |
|
|
|
compile_func = curry(generic_tag_compiler, params, defaults, getattr(func, "_decorated_function", func).__name__, SimpleNode) |
|
compile_func.__doc__ = func.__doc__ |
|
self.tag(getattr(func, "_decorated_function", func).__name__, compile_func) |
|
return func |
|
|
|
def inclusion_tag(self, file_name, context_class=Context, takes_context=False): |
|
def dec(func): |
|
params, xx, xxx, defaults = getargspec(func) |
|
if takes_context: |
|
if params[0] == 'context': |
|
params = params[1:] |
|
else: |
|
raise TemplateSyntaxError("Any tag function decorated with takes_context=True must have a first argument of 'context'") |
|
|
|
class InclusionNode(Node): |
|
def __init__(self, vars_to_resolve): |
|
self.vars_to_resolve = map(Variable, vars_to_resolve) |
|
|
|
def render(self, context): |
|
resolved_vars = [var.resolve(context) for var in self.vars_to_resolve] |
|
if takes_context: |
|
args = [context] + resolved_vars |
|
else: |
|
args = resolved_vars |
|
|
|
dict = func(*args) |
|
|
|
if not getattr(self, 'nodelist', False): |
|
from django.template.loader import get_template, select_template |
|
if not isinstance(file_name, basestring) and is_iterable(file_name): |
|
t = select_template(file_name) |
|
else: |
|
t = get_template(file_name) |
|
self.nodelist = t.nodelist |
|
return self.nodelist.render(context_class(dict, |
|
autoescape=context.autoescape)) |
|
|
|
compile_func = curry(generic_tag_compiler, params, defaults, getattr(func, "_decorated_function", func).__name__, InclusionNode) |
|
compile_func.__doc__ = func.__doc__ |
|
self.tag(getattr(func, "_decorated_function", func).__name__, compile_func) |
|
return func |
|
return dec |
|
|
|
def get_library(module_name): |
|
lib = libraries.get(module_name, None) |
|
if not lib: |
|
try: |
|
mod = __import__(module_name, {}, {}, ['']) |
|
except ImportError, e: |
|
raise InvalidTemplateLibrary("Could not load template library from %s, %s" % (module_name, e)) |
|
try: |
|
lib = mod.register |
|
libraries[module_name] = lib |
|
except AttributeError: |
|
raise InvalidTemplateLibrary("Template library %s does not have a variable named 'register'" % module_name) |
|
return lib |
|
|
|
def add_to_builtins(module_name): |
|
builtins.append(get_library(module_name)) |
|
|
|
add_to_builtins('django.template.defaulttags') |
|
add_to_builtins('django.template.defaultfilters')
|
|
|