| """ |
| 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): |
| return list(smart_split(self.contents)) |
| |
| 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') |
