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See documentation in templates.txt and templates_python.txt for how everything works. Backwards incompatible if you're inserting raw HTML output via template variables. Based on an original design from Simon Willison and with debugging help from Michael Radziej. git-svn-id: http://code.djangoproject.com/svn/django/trunk@6671 bcc190cf-cafb-0310-a4f2-bffc1f526a37
1011 lines
37 KiB
Python
1011 lines
37 KiB
Python
"""
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This is the Django template system.
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How it works:
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The Lexer.tokenize() function converts a template string (i.e., a string containing
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markup with custom template tags) to tokens, which can be either plain text
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(TOKEN_TEXT), variables (TOKEN_VAR) or block statements (TOKEN_BLOCK).
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The Parser() class takes a list of tokens in its constructor, and its parse()
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method returns a compiled template -- which is, under the hood, a list of
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Node objects.
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Each Node is responsible for creating some sort of output -- e.g. simple text
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(TextNode), variable values in a given context (VariableNode), results of basic
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logic (IfNode), results of looping (ForNode), or anything else. The core Node
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types are TextNode, VariableNode, IfNode and ForNode, but plugin modules can
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define their own custom node types.
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Each Node has a render() method, which takes a Context and returns a string of
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the rendered node. For example, the render() method of a Variable Node returns
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the variable's value as a string. The render() method of an IfNode returns the
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rendered output of whatever was inside the loop, recursively.
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The Template class is a convenient wrapper that takes care of template
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compilation and rendering.
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Usage:
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The only thing you should ever use directly in this file is the Template class.
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Create a compiled template object with a template_string, then call render()
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with a context. In the compilation stage, the TemplateSyntaxError exception
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will be raised if the template doesn't have proper syntax.
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Sample code:
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>>> from django import template
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>>> s = u'<html>{% if test %}<h1>{{ varvalue }}</h1>{% endif %}</html>'
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>>> t = template.Template(s)
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(t is now a compiled template, and its render() method can be called multiple
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times with multiple contexts)
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>>> c = template.Context({'test':True, 'varvalue': 'Hello'})
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>>> t.render(c)
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u'<html><h1>Hello</h1></html>'
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>>> c = template.Context({'test':False, 'varvalue': 'Hello'})
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>>> t.render(c)
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u'<html></html>'
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"""
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import re
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from inspect import getargspec
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from django.conf import settings
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from django.template.context import Context, RequestContext, ContextPopException
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from django.utils.itercompat import is_iterable
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from django.utils.functional import curry, Promise
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from django.utils.text import smart_split
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from django.utils.encoding import smart_unicode, force_unicode
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from django.utils.translation import ugettext as _
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from django.utils.safestring import SafeData, EscapeData, mark_safe, mark_for_escaping
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from django.utils.html import escape
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__all__ = ('Template', 'Context', 'RequestContext', 'compile_string')
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TOKEN_TEXT = 0
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TOKEN_VAR = 1
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TOKEN_BLOCK = 2
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TOKEN_COMMENT = 3
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# template syntax constants
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FILTER_SEPARATOR = '|'
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FILTER_ARGUMENT_SEPARATOR = ':'
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VARIABLE_ATTRIBUTE_SEPARATOR = '.'
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BLOCK_TAG_START = '{%'
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BLOCK_TAG_END = '%}'
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VARIABLE_TAG_START = '{{'
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VARIABLE_TAG_END = '}}'
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COMMENT_TAG_START = '{#'
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COMMENT_TAG_END = '#}'
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SINGLE_BRACE_START = '{'
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SINGLE_BRACE_END = '}'
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ALLOWED_VARIABLE_CHARS = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_.'
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# what to report as the origin for templates that come from non-loader sources
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# (e.g. strings)
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UNKNOWN_SOURCE="<unknown source>"
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# match a variable or block tag and capture the entire tag, including start/end delimiters
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tag_re = re.compile('(%s.*?%s|%s.*?%s|%s.*?%s)' % (re.escape(BLOCK_TAG_START), re.escape(BLOCK_TAG_END),
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re.escape(VARIABLE_TAG_START), re.escape(VARIABLE_TAG_END),
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re.escape(COMMENT_TAG_START), re.escape(COMMENT_TAG_END)))
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# global dictionary of libraries that have been loaded using get_library
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libraries = {}
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# global list of libraries to load by default for a new parser
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builtins = []
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# True if TEMPLATE_STRING_IF_INVALID contains a format string (%s). None means
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# uninitialised.
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invalid_var_format_string = None
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class TemplateSyntaxError(Exception):
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def __str__(self):
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try:
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import cStringIO as StringIO
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except ImportError:
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import StringIO
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output = StringIO.StringIO()
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output.write(Exception.__str__(self))
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# Check if we wrapped an exception and print that too.
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if hasattr(self, 'exc_info'):
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import traceback
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output.write('\n\nOriginal ')
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e = self.exc_info
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traceback.print_exception(e[0], e[1], e[2], 500, output)
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return output.getvalue()
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class TemplateDoesNotExist(Exception):
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pass
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class TemplateEncodingError(Exception):
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pass
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class VariableDoesNotExist(Exception):
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def __init__(self, msg, params=()):
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self.msg = msg
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self.params = params
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def __str__(self):
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return self.msg % self.params
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class InvalidTemplateLibrary(Exception):
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pass
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class Origin(object):
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def __init__(self, name):
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self.name = name
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def reload(self):
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raise NotImplementedError
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def __str__(self):
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return self.name
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class StringOrigin(Origin):
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def __init__(self, source):
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super(StringOrigin, self).__init__(UNKNOWN_SOURCE)
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self.source = source
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def reload(self):
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return self.source
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class Template(object):
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def __init__(self, template_string, origin=None, name='<Unknown Template>'):
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"Compilation stage"
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try:
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template_string = smart_unicode(template_string)
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except UnicodeDecodeError:
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raise TemplateEncodingError("Templates can only be constructed from unicode or UTF-8 strings.")
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if settings.TEMPLATE_DEBUG and origin == None:
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origin = StringOrigin(template_string)
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# Could do some crazy stack-frame stuff to record where this string
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# came from...
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self.nodelist = compile_string(template_string, origin)
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self.name = name
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def __iter__(self):
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for node in self.nodelist:
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for subnode in node:
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yield subnode
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def render(self, context):
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"Display stage -- can be called many times"
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return self.nodelist.render(context)
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def compile_string(template_string, origin):
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"Compiles template_string into NodeList ready for rendering"
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lexer = lexer_factory(template_string, origin)
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parser = parser_factory(lexer.tokenize())
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return parser.parse()
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class Token(object):
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def __init__(self, token_type, contents):
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"The token_type must be TOKEN_TEXT, TOKEN_VAR, TOKEN_BLOCK or TOKEN_COMMENT"
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self.token_type, self.contents = token_type, contents
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def __str__(self):
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return '<%s token: "%s...">' % \
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({TOKEN_TEXT: 'Text', TOKEN_VAR: 'Var', TOKEN_BLOCK: 'Block', TOKEN_COMMENT: 'Comment'}[self.token_type],
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self.contents[:20].replace('\n', ''))
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def split_contents(self):
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return list(smart_split(self.contents))
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class Lexer(object):
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def __init__(self, template_string, origin):
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self.template_string = template_string
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self.origin = origin
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def tokenize(self):
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"Return a list of tokens from a given template_string"
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in_tag = False
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result = []
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for bit in tag_re.split(self.template_string):
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if bit:
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result.append(self.create_token(bit, in_tag))
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in_tag = not in_tag
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return result
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def create_token(self, token_string, in_tag):
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"""
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Convert the given token string into a new Token object and return it.
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If in_tag is True, we are processing something that matched a tag,
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otherwise it should be treated as a literal string.
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"""
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if in_tag:
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if token_string.startswith(VARIABLE_TAG_START):
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token = Token(TOKEN_VAR, token_string[len(VARIABLE_TAG_START):-len(VARIABLE_TAG_END)].strip())
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elif token_string.startswith(BLOCK_TAG_START):
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token = Token(TOKEN_BLOCK, token_string[len(BLOCK_TAG_START):-len(BLOCK_TAG_END)].strip())
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elif token_string.startswith(COMMENT_TAG_START):
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token = Token(TOKEN_COMMENT, '')
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else:
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token = Token(TOKEN_TEXT, token_string)
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return token
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class DebugLexer(Lexer):
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def __init__(self, template_string, origin):
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super(DebugLexer, self).__init__(template_string, origin)
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def tokenize(self):
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"Return a list of tokens from a given template_string"
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result, upto = [], 0
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for match in tag_re.finditer(self.template_string):
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start, end = match.span()
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if start > upto:
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result.append(self.create_token(self.template_string[upto:start], (upto, start), False))
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upto = start
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result.append(self.create_token(self.template_string[start:end], (start, end), True))
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upto = end
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last_bit = self.template_string[upto:]
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if last_bit:
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result.append(self.create_token(last_bit, (upto, upto + len(last_bit)), False))
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return result
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def create_token(self, token_string, source, in_tag):
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token = super(DebugLexer, self).create_token(token_string, in_tag)
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token.source = self.origin, source
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return token
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class Parser(object):
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def __init__(self, tokens):
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self.tokens = tokens
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self.tags = {}
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self.filters = {}
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for lib in builtins:
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self.add_library(lib)
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def parse(self, parse_until=None):
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if parse_until is None: parse_until = []
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nodelist = self.create_nodelist()
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while self.tokens:
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token = self.next_token()
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if token.token_type == TOKEN_TEXT:
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self.extend_nodelist(nodelist, TextNode(token.contents), token)
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elif token.token_type == TOKEN_VAR:
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if not token.contents:
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self.empty_variable(token)
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filter_expression = self.compile_filter(token.contents)
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var_node = self.create_variable_node(filter_expression)
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self.extend_nodelist(nodelist, var_node,token)
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elif token.token_type == TOKEN_BLOCK:
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if token.contents in parse_until:
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# put token back on token list so calling code knows why it terminated
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self.prepend_token(token)
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return nodelist
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try:
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command = token.contents.split()[0]
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except IndexError:
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self.empty_block_tag(token)
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# execute callback function for this tag and append resulting node
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self.enter_command(command, token)
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try:
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compile_func = self.tags[command]
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except KeyError:
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self.invalid_block_tag(token, command)
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try:
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compiled_result = compile_func(self, token)
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except TemplateSyntaxError, e:
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if not self.compile_function_error(token, e):
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raise
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self.extend_nodelist(nodelist, compiled_result, token)
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self.exit_command()
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if parse_until:
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self.unclosed_block_tag(parse_until)
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return nodelist
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def skip_past(self, endtag):
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while self.tokens:
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token = self.next_token()
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if token.token_type == TOKEN_BLOCK and token.contents == endtag:
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return
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self.unclosed_block_tag([endtag])
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def create_variable_node(self, filter_expression):
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return VariableNode(filter_expression)
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def create_nodelist(self):
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return NodeList()
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def extend_nodelist(self, nodelist, node, token):
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nodelist.append(node)
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def enter_command(self, command, token):
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pass
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def exit_command(self):
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pass
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def error(self, token, msg ):
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return TemplateSyntaxError(msg)
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def empty_variable(self, token):
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raise self.error( token, "Empty variable tag")
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def empty_block_tag(self, token):
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raise self.error( token, "Empty block tag")
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def invalid_block_tag(self, token, command):
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raise self.error( token, "Invalid block tag: '%s'" % command)
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def unclosed_block_tag(self, parse_until):
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raise self.error(None, "Unclosed tags: %s " % ', '.join(parse_until))
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def compile_function_error(self, token, e):
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pass
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def next_token(self):
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return self.tokens.pop(0)
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def prepend_token(self, token):
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self.tokens.insert(0, token)
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def delete_first_token(self):
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del self.tokens[0]
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def add_library(self, lib):
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self.tags.update(lib.tags)
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self.filters.update(lib.filters)
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def compile_filter(self, token):
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"Convenient wrapper for FilterExpression"
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return FilterExpression(token, self)
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def find_filter(self, filter_name):
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if filter_name in self.filters:
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return self.filters[filter_name]
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else:
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raise TemplateSyntaxError, "Invalid filter: '%s'" % filter_name
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class DebugParser(Parser):
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def __init__(self, lexer):
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super(DebugParser, self).__init__(lexer)
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self.command_stack = []
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def enter_command(self, command, token):
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self.command_stack.append( (command, token.source) )
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def exit_command(self):
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self.command_stack.pop()
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def error(self, token, msg):
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return self.source_error(token.source, msg)
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def source_error(self, source,msg):
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e = TemplateSyntaxError(msg)
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e.source = source
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return e
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def create_nodelist(self):
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return DebugNodeList()
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def create_variable_node(self, contents):
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return DebugVariableNode(contents)
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def extend_nodelist(self, nodelist, node, token):
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node.source = token.source
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super(DebugParser, self).extend_nodelist(nodelist, node, token)
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def unclosed_block_tag(self, parse_until):
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command, source = self.command_stack.pop()
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msg = "Unclosed tag '%s'. Looking for one of: %s " % (command, ', '.join(parse_until))
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raise self.source_error( source, msg)
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def compile_function_error(self, token, e):
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if not hasattr(e, 'source'):
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e.source = token.source
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def lexer_factory(*args, **kwargs):
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if settings.TEMPLATE_DEBUG:
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return DebugLexer(*args, **kwargs)
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else:
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return Lexer(*args, **kwargs)
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def parser_factory(*args, **kwargs):
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if settings.TEMPLATE_DEBUG:
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return DebugParser(*args, **kwargs)
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else:
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return Parser(*args, **kwargs)
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class TokenParser(object):
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"""
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Subclass this and implement the top() method to parse a template line. When
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instantiating the parser, pass in the line from the Django template parser.
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The parser's "tagname" instance-variable stores the name of the tag that
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the filter was called with.
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"""
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def __init__(self, subject):
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self.subject = subject
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self.pointer = 0
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self.backout = []
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self.tagname = self.tag()
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def top(self):
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"Overload this method to do the actual parsing and return the result."
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raise NotImplemented
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def more(self):
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"Returns True if there is more stuff in the tag."
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return self.pointer < len(self.subject)
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def back(self):
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"Undoes the last microparser. Use this for lookahead and backtracking."
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if not len(self.backout):
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raise TemplateSyntaxError, "back called without some previous parsing"
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self.pointer = self.backout.pop()
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def tag(self):
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"A microparser that just returns the next tag from the line."
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subject = self.subject
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i = self.pointer
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if i >= len(subject):
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raise TemplateSyntaxError, "expected another tag, found end of string: %s" % subject
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p = i
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while i < len(subject) and subject[i] not in (' ', '\t'):
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i += 1
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s = subject[p:i]
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while i < len(subject) and subject[i] in (' ', '\t'):
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i += 1
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self.backout.append(self.pointer)
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self.pointer = i
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return s
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|
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def value(self):
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"A microparser that parses for a value: some string constant or variable name."
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subject = self.subject
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i = self.pointer
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if i >= len(subject):
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raise TemplateSyntaxError, "Searching for value. Expected another value but found end of string: %s" % subject
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if subject[i] in ('"', "'"):
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p = i
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i += 1
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|
while i < len(subject) and subject[i] != subject[p]:
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|
i += 1
|
|
if i >= len(subject):
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raise TemplateSyntaxError, "Searching for value. Unexpected end of string in column %d: %s" % (i, subject)
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i += 1
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|
res = subject[p:i]
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|
while i < len(subject) and subject[i] in (' ', '\t'):
|
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i += 1
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|
self.backout.append(self.pointer)
|
|
self.pointer = i
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|
return res
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|
else:
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|
p = i
|
|
while i < len(subject) and subject[i] not in (' ', '\t'):
|
|
if subject[i] in ('"', "'"):
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c = subject[i]
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i += 1
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while i < len(subject) and subject[i] != c:
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i += 1
|
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if i >= len(subject):
|
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raise TemplateSyntaxError, "Searching for value. Unexpected end of string in column %d: %s" % (i, subject)
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i += 1
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s = subject[p:i]
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|
while i < len(subject) and subject[i] in (' ', '\t'):
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|
i += 1
|
|
self.backout.append(self.pointer)
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|
self.pointer = i
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|
return s
|
|
|
|
filter_raw_string = r"""
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|
^%(i18n_open)s"(?P<i18n_constant>%(str)s)"%(i18n_close)s|
|
|
^"(?P<constant>%(str)s)"|
|
|
^(?P<var>[%(var_chars)s]+)|
|
|
(?:%(filter_sep)s
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|
(?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'
|
|
|
|
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:
|
|
var = '"%s"' % _(i18n_constant)
|
|
elif constant:
|
|
var = '"%s"' % constant
|
|
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(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':'News'}}
|
|
>>> Variable('article.section').resolve(c)
|
|
u'News'
|
|
>>> Variable('article').resolve(c)
|
|
{'section': 'News'}
|
|
>>> class AClass: pass
|
|
>>> c = AClass()
|
|
>>> c.article = AClass()
|
|
>>> c.article.section = '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
|
|
|
|
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 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 = 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
|
|
return self._resolve_lookup(context)
|
|
else:
|
|
# We're dealing with a literal, so it's already been "resolved"
|
|
return self.literal
|
|
|
|
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):
|
|
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):
|
|
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 ''.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 DebugNodeList(NodeList):
|
|
def render_node(self, node, context):
|
|
try:
|
|
result = node.render(context)
|
|
except TemplateSyntaxError, e:
|
|
if not hasattr(e, 'source'):
|
|
e.source = node.source
|
|
raise
|
|
except Exception, e:
|
|
from sys import exc_info
|
|
wrapped = TemplateSyntaxError('Caught an exception while rendering: %s' % e)
|
|
wrapped.source = node.source
|
|
wrapped.exc_info = exc_info()
|
|
raise wrapped
|
|
return result
|
|
|
|
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)
|
|
|
|
class DebugVariableNode(VariableNode):
|
|
def render(self, context):
|
|
try:
|
|
output = force_unicode(self.filter_expression.resolve(context))
|
|
except TemplateSyntaxError, e:
|
|
if not hasattr(e, 'source'):
|
|
e.source = self.source
|
|
raise
|
|
except UnicodeDecodeError:
|
|
return ''
|
|
if (context.autoescape and not isinstance(output, SafeData)) or isinstance(output, EscapeData):
|
|
return escape(output)
|
|
else:
|
|
return 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')
|