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Diffstat (limited to 'webapp/django/template/__init__.py')
| -rw-r--r-- | webapp/django/template/__init__.py | 939 |
1 files changed, 939 insertions, 0 deletions
diff --git a/webapp/django/template/__init__.py b/webapp/django/template/__init__.py new file mode 100644 index 0000000000..ffdb4e4809 --- /dev/null +++ b/webapp/django/template/__init__.py @@ -0,0 +1,939 @@ +""" +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') |