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Diffstat (limited to 'third_party/python/Mako/mako/runtime.py')
| -rw-r--r-- | third_party/python/Mako/mako/runtime.py | 970 |
1 files changed, 970 insertions, 0 deletions
diff --git a/third_party/python/Mako/mako/runtime.py b/third_party/python/Mako/mako/runtime.py new file mode 100644 index 0000000000..465908e6d8 --- /dev/null +++ b/third_party/python/Mako/mako/runtime.py @@ -0,0 +1,970 @@ +# mako/runtime.py +# Copyright 2006-2020 the Mako authors and contributors <see AUTHORS file> +# +# This module is part of Mako and is released under +# the MIT License: http://www.opensource.org/licenses/mit-license.php + +"""provides runtime services for templates, including Context, +Namespace, and various helper functions.""" + +import functools +import sys + +from mako import compat +from mako import exceptions +from mako import util +from mako.compat import compat_builtins + + +class Context(object): + + """Provides runtime namespace, output buffer, and various + callstacks for templates. + + See :ref:`runtime_toplevel` for detail on the usage of + :class:`.Context`. + + """ + + def __init__(self, buffer, **data): + self._buffer_stack = [buffer] + + self._data = data + + self._kwargs = data.copy() + self._with_template = None + self._outputting_as_unicode = None + self.namespaces = {} + + # "capture" function which proxies to the + # generic "capture" function + self._data["capture"] = functools.partial(capture, self) + + # "caller" stack used by def calls with content + self.caller_stack = self._data["caller"] = CallerStack() + + def _set_with_template(self, t): + self._with_template = t + illegal_names = t.reserved_names.intersection(self._data) + if illegal_names: + raise exceptions.NameConflictError( + "Reserved words passed to render(): %s" + % ", ".join(illegal_names) + ) + + @property + def lookup(self): + """Return the :class:`.TemplateLookup` associated + with this :class:`.Context`. + + """ + return self._with_template.lookup + + @property + def kwargs(self): + """Return the dictionary of top level keyword arguments associated + with this :class:`.Context`. + + This dictionary only includes the top-level arguments passed to + :meth:`.Template.render`. It does not include names produced within + the template execution such as local variable names or special names + such as ``self``, ``next``, etc. + + The purpose of this dictionary is primarily for the case that + a :class:`.Template` accepts arguments via its ``<%page>`` tag, + which are normally expected to be passed via :meth:`.Template.render`, + except the template is being called in an inheritance context, + using the ``body()`` method. :attr:`.Context.kwargs` can then be + used to propagate these arguments to the inheriting template:: + + ${next.body(**context.kwargs)} + + """ + return self._kwargs.copy() + + def push_caller(self, caller): + """Push a ``caller`` callable onto the callstack for + this :class:`.Context`.""" + + self.caller_stack.append(caller) + + def pop_caller(self): + """Pop a ``caller`` callable onto the callstack for this + :class:`.Context`.""" + + del self.caller_stack[-1] + + def keys(self): + """Return a list of all names established in this :class:`.Context`.""" + + return list(self._data.keys()) + + def __getitem__(self, key): + if key in self._data: + return self._data[key] + else: + return compat_builtins.__dict__[key] + + def _push_writer(self): + """push a capturing buffer onto this Context and return + the new writer function.""" + + buf = util.FastEncodingBuffer() + self._buffer_stack.append(buf) + return buf.write + + def _pop_buffer_and_writer(self): + """pop the most recent capturing buffer from this Context + and return the current writer after the pop. + + """ + + buf = self._buffer_stack.pop() + return buf, self._buffer_stack[-1].write + + def _push_buffer(self): + """push a capturing buffer onto this Context.""" + + self._push_writer() + + def _pop_buffer(self): + """pop the most recent capturing buffer from this Context.""" + + return self._buffer_stack.pop() + + def get(self, key, default=None): + """Return a value from this :class:`.Context`.""" + + return self._data.get(key, compat_builtins.__dict__.get(key, default)) + + def write(self, string): + """Write a string to this :class:`.Context` object's + underlying output buffer.""" + + self._buffer_stack[-1].write(string) + + def writer(self): + """Return the current writer function.""" + + return self._buffer_stack[-1].write + + def _copy(self): + c = Context.__new__(Context) + c._buffer_stack = self._buffer_stack + c._data = self._data.copy() + c._kwargs = self._kwargs + c._with_template = self._with_template + c._outputting_as_unicode = self._outputting_as_unicode + c.namespaces = self.namespaces + c.caller_stack = self.caller_stack + return c + + def _locals(self, d): + """Create a new :class:`.Context` with a copy of this + :class:`.Context`'s current state, + updated with the given dictionary. + + The :attr:`.Context.kwargs` collection remains + unaffected. + + + """ + + if not d: + return self + c = self._copy() + c._data.update(d) + return c + + def _clean_inheritance_tokens(self): + """create a new copy of this :class:`.Context`. with + tokens related to inheritance state removed.""" + + c = self._copy() + x = c._data + x.pop("self", None) + x.pop("parent", None) + x.pop("next", None) + return c + + +class CallerStack(list): + def __init__(self): + self.nextcaller = None + + def __nonzero__(self): + return self.__bool__() + + def __bool__(self): + return len(self) and self._get_caller() and True or False + + def _get_caller(self): + # this method can be removed once + # codegen MAGIC_NUMBER moves past 7 + return self[-1] + + def __getattr__(self, key): + return getattr(self._get_caller(), key) + + def _push_frame(self): + frame = self.nextcaller or None + self.append(frame) + self.nextcaller = None + return frame + + def _pop_frame(self): + self.nextcaller = self.pop() + + +class Undefined(object): + + """Represents an undefined value in a template. + + All template modules have a constant value + ``UNDEFINED`` present which is an instance of this + object. + + """ + + def __str__(self): + raise NameError("Undefined") + + def __nonzero__(self): + return self.__bool__() + + def __bool__(self): + return False + + +UNDEFINED = Undefined() +STOP_RENDERING = "" + + +class LoopStack(object): + + """a stack for LoopContexts that implements the context manager protocol + to automatically pop off the top of the stack on context exit + """ + + def __init__(self): + self.stack = [] + + def _enter(self, iterable): + self._push(iterable) + return self._top + + def _exit(self): + self._pop() + return self._top + + @property + def _top(self): + if self.stack: + return self.stack[-1] + else: + return self + + def _pop(self): + return self.stack.pop() + + def _push(self, iterable): + new = LoopContext(iterable) + if self.stack: + new.parent = self.stack[-1] + return self.stack.append(new) + + def __getattr__(self, key): + raise exceptions.RuntimeException("No loop context is established") + + def __iter__(self): + return iter(self._top) + + +class LoopContext(object): + + """A magic loop variable. + Automatically accessible in any ``% for`` block. + + See the section :ref:`loop_context` for usage + notes. + + :attr:`parent` -> :class:`.LoopContext` or ``None`` + The parent loop, if one exists. + :attr:`index` -> `int` + The 0-based iteration count. + :attr:`reverse_index` -> `int` + The number of iterations remaining. + :attr:`first` -> `bool` + ``True`` on the first iteration, ``False`` otherwise. + :attr:`last` -> `bool` + ``True`` on the last iteration, ``False`` otherwise. + :attr:`even` -> `bool` + ``True`` when ``index`` is even. + :attr:`odd` -> `bool` + ``True`` when ``index`` is odd. + """ + + def __init__(self, iterable): + self._iterable = iterable + self.index = 0 + self.parent = None + + def __iter__(self): + for i in self._iterable: + yield i + self.index += 1 + + @util.memoized_instancemethod + def __len__(self): + return len(self._iterable) + + @property + def reverse_index(self): + return len(self) - self.index - 1 + + @property + def first(self): + return self.index == 0 + + @property + def last(self): + return self.index == len(self) - 1 + + @property + def even(self): + return not self.odd + + @property + def odd(self): + return bool(self.index % 2) + + def cycle(self, *values): + """Cycle through values as the loop progresses. + """ + if not values: + raise ValueError("You must provide values to cycle through") + return values[self.index % len(values)] + + +class _NSAttr(object): + def __init__(self, parent): + self.__parent = parent + + def __getattr__(self, key): + ns = self.__parent + while ns: + if hasattr(ns.module, key): + return getattr(ns.module, key) + else: + ns = ns.inherits + raise AttributeError(key) + + +class Namespace(object): + + """Provides access to collections of rendering methods, which + can be local, from other templates, or from imported modules. + + To access a particular rendering method referenced by a + :class:`.Namespace`, use plain attribute access: + + .. sourcecode:: mako + + ${some_namespace.foo(x, y, z)} + + :class:`.Namespace` also contains several built-in attributes + described here. + + """ + + def __init__( + self, + name, + context, + callables=None, + inherits=None, + populate_self=True, + calling_uri=None, + ): + self.name = name + self.context = context + self.inherits = inherits + if callables is not None: + self.callables = dict([(c.__name__, c) for c in callables]) + + callables = () + + module = None + """The Python module referenced by this :class:`.Namespace`. + + If the namespace references a :class:`.Template`, then + this module is the equivalent of ``template.module``, + i.e. the generated module for the template. + + """ + + template = None + """The :class:`.Template` object referenced by this + :class:`.Namespace`, if any. + + """ + + context = None + """The :class:`.Context` object for this :class:`.Namespace`. + + Namespaces are often created with copies of contexts that + contain slightly different data, particularly in inheritance + scenarios. Using the :class:`.Context` off of a :class:`.Namespace` one + can traverse an entire chain of templates that inherit from + one-another. + + """ + + filename = None + """The path of the filesystem file used for this + :class:`.Namespace`'s module or template. + + If this is a pure module-based + :class:`.Namespace`, this evaluates to ``module.__file__``. If a + template-based namespace, it evaluates to the original + template file location. + + """ + + uri = None + """The URI for this :class:`.Namespace`'s template. + + I.e. whatever was sent to :meth:`.TemplateLookup.get_template()`. + + This is the equivalent of :attr:`.Template.uri`. + + """ + + _templateuri = None + + @util.memoized_property + def attr(self): + """Access module level attributes by name. + + This accessor allows templates to supply "scalar" + attributes which are particularly handy in inheritance + relationships. + + .. seealso:: + + :ref:`inheritance_attr` + + :ref:`namespace_attr_for_includes` + + """ + return _NSAttr(self) + + def get_namespace(self, uri): + """Return a :class:`.Namespace` corresponding to the given ``uri``. + + If the given ``uri`` is a relative URI (i.e. it does not + contain a leading slash ``/``), the ``uri`` is adjusted to + be relative to the ``uri`` of the namespace itself. This + method is therefore mostly useful off of the built-in + ``local`` namespace, described in :ref:`namespace_local`. + + In + most cases, a template wouldn't need this function, and + should instead use the ``<%namespace>`` tag to load + namespaces. However, since all ``<%namespace>`` tags are + evaluated before the body of a template ever runs, + this method can be used to locate namespaces using + expressions that were generated within the body code of + the template, or to conditionally use a particular + namespace. + + """ + key = (self, uri) + if key in self.context.namespaces: + return self.context.namespaces[key] + else: + ns = TemplateNamespace( + uri, + self.context._copy(), + templateuri=uri, + calling_uri=self._templateuri, + ) + self.context.namespaces[key] = ns + return ns + + def get_template(self, uri): + """Return a :class:`.Template` from the given ``uri``. + + The ``uri`` resolution is relative to the ``uri`` of this + :class:`.Namespace` object's :class:`.Template`. + + """ + return _lookup_template(self.context, uri, self._templateuri) + + def get_cached(self, key, **kwargs): + """Return a value from the :class:`.Cache` referenced by this + :class:`.Namespace` object's :class:`.Template`. + + The advantage to this method versus direct access to the + :class:`.Cache` is that the configuration parameters + declared in ``<%page>`` take effect here, thereby calling + up the same configured backend as that configured + by ``<%page>``. + + """ + + return self.cache.get(key, **kwargs) + + @property + def cache(self): + """Return the :class:`.Cache` object referenced + by this :class:`.Namespace` object's + :class:`.Template`. + + """ + return self.template.cache + + def include_file(self, uri, **kwargs): + """Include a file at the given ``uri``.""" + + _include_file(self.context, uri, self._templateuri, **kwargs) + + def _populate(self, d, l): + for ident in l: + if ident == "*": + for (k, v) in self._get_star(): + d[k] = v + else: + d[ident] = getattr(self, ident) + + def _get_star(self): + if self.callables: + for key in self.callables: + yield (key, self.callables[key]) + + def __getattr__(self, key): + if key in self.callables: + val = self.callables[key] + elif self.inherits: + val = getattr(self.inherits, key) + else: + raise AttributeError( + "Namespace '%s' has no member '%s'" % (self.name, key) + ) + setattr(self, key, val) + return val + + +class TemplateNamespace(Namespace): + + """A :class:`.Namespace` specific to a :class:`.Template` instance.""" + + def __init__( + self, + name, + context, + template=None, + templateuri=None, + callables=None, + inherits=None, + populate_self=True, + calling_uri=None, + ): + self.name = name + self.context = context + self.inherits = inherits + if callables is not None: + self.callables = dict([(c.__name__, c) for c in callables]) + + if templateuri is not None: + self.template = _lookup_template(context, templateuri, calling_uri) + self._templateuri = self.template.module._template_uri + elif template is not None: + self.template = template + self._templateuri = template.module._template_uri + else: + raise TypeError("'template' argument is required.") + + if populate_self: + lclcallable, lclcontext = _populate_self_namespace( + context, self.template, self_ns=self + ) + + @property + def module(self): + """The Python module referenced by this :class:`.Namespace`. + + If the namespace references a :class:`.Template`, then + this module is the equivalent of ``template.module``, + i.e. the generated module for the template. + + """ + return self.template.module + + @property + def filename(self): + """The path of the filesystem file used for this + :class:`.Namespace`'s module or template. + """ + return self.template.filename + + @property + def uri(self): + """The URI for this :class:`.Namespace`'s template. + + I.e. whatever was sent to :meth:`.TemplateLookup.get_template()`. + + This is the equivalent of :attr:`.Template.uri`. + + """ + return self.template.uri + + def _get_star(self): + if self.callables: + for key in self.callables: + yield (key, self.callables[key]) + + def get(key): + callable_ = self.template._get_def_callable(key) + return functools.partial(callable_, self.context) + + for k in self.template.module._exports: + yield (k, get(k)) + + def __getattr__(self, key): + if key in self.callables: + val = self.callables[key] + elif self.template.has_def(key): + callable_ = self.template._get_def_callable(key) + val = functools.partial(callable_, self.context) + elif self.inherits: + val = getattr(self.inherits, key) + + else: + raise AttributeError( + "Namespace '%s' has no member '%s'" % (self.name, key) + ) + setattr(self, key, val) + return val + + +class ModuleNamespace(Namespace): + + """A :class:`.Namespace` specific to a Python module instance.""" + + def __init__( + self, + name, + context, + module, + callables=None, + inherits=None, + populate_self=True, + calling_uri=None, + ): + self.name = name + self.context = context + self.inherits = inherits + if callables is not None: + self.callables = dict([(c.__name__, c) for c in callables]) + + mod = __import__(module) + for token in module.split(".")[1:]: + mod = getattr(mod, token) + self.module = mod + + @property + def filename(self): + """The path of the filesystem file used for this + :class:`.Namespace`'s module or template. + """ + return self.module.__file__ + + def _get_star(self): + if self.callables: + for key in self.callables: + yield (key, self.callables[key]) + for key in dir(self.module): + if key[0] != "_": + callable_ = getattr(self.module, key) + if callable(callable_): + yield key, functools.partial(callable_, self.context) + + def __getattr__(self, key): + if key in self.callables: + val = self.callables[key] + elif hasattr(self.module, key): + callable_ = getattr(self.module, key) + val = functools.partial(callable_, self.context) + elif self.inherits: + val = getattr(self.inherits, key) + else: + raise AttributeError( + "Namespace '%s' has no member '%s'" % (self.name, key) + ) + setattr(self, key, val) + return val + + +def supports_caller(func): + """Apply a caller_stack compatibility decorator to a plain + Python function. + + See the example in :ref:`namespaces_python_modules`. + + """ + + def wrap_stackframe(context, *args, **kwargs): + context.caller_stack._push_frame() + try: + return func(context, *args, **kwargs) + finally: + context.caller_stack._pop_frame() + + return wrap_stackframe + + +def capture(context, callable_, *args, **kwargs): + """Execute the given template def, capturing the output into + a buffer. + + See the example in :ref:`namespaces_python_modules`. + + """ + + if not callable(callable_): + raise exceptions.RuntimeException( + "capture() function expects a callable as " + "its argument (i.e. capture(func, *args, **kwargs))" + ) + context._push_buffer() + try: + callable_(*args, **kwargs) + finally: + buf = context._pop_buffer() + return buf.getvalue() + + +def _decorate_toplevel(fn): + def decorate_render(render_fn): + def go(context, *args, **kw): + def y(*args, **kw): + return render_fn(context, *args, **kw) + + try: + y.__name__ = render_fn.__name__[7:] + except TypeError: + # < Python 2.4 + pass + return fn(y)(context, *args, **kw) + + return go + + return decorate_render + + +def _decorate_inline(context, fn): + def decorate_render(render_fn): + dec = fn(render_fn) + + def go(*args, **kw): + return dec(context, *args, **kw) + + return go + + return decorate_render + + +def _include_file(context, uri, calling_uri, **kwargs): + """locate the template from the given uri and include it in + the current output.""" + + template = _lookup_template(context, uri, calling_uri) + (callable_, ctx) = _populate_self_namespace( + context._clean_inheritance_tokens(), template + ) + kwargs = _kwargs_for_include(callable_, context._data, **kwargs) + if template.include_error_handler: + try: + callable_(ctx, **kwargs) + except Exception: + result = template.include_error_handler(ctx, compat.exception_as()) + if not result: + compat.reraise(*sys.exc_info()) + else: + callable_(ctx, **kwargs) + + +def _inherit_from(context, uri, calling_uri): + """called by the _inherit method in template modules to set + up the inheritance chain at the start of a template's + execution.""" + + if uri is None: + return None + template = _lookup_template(context, uri, calling_uri) + self_ns = context["self"] + ih = self_ns + while ih.inherits is not None: + ih = ih.inherits + lclcontext = context._locals({"next": ih}) + ih.inherits = TemplateNamespace( + "self:%s" % template.uri, + lclcontext, + template=template, + populate_self=False, + ) + context._data["parent"] = lclcontext._data["local"] = ih.inherits + callable_ = getattr(template.module, "_mako_inherit", None) + if callable_ is not None: + ret = callable_(template, lclcontext) + if ret: + return ret + + gen_ns = getattr(template.module, "_mako_generate_namespaces", None) + if gen_ns is not None: + gen_ns(context) + return (template.callable_, lclcontext) + + +def _lookup_template(context, uri, relativeto): + lookup = context._with_template.lookup + if lookup is None: + raise exceptions.TemplateLookupException( + "Template '%s' has no TemplateLookup associated" + % context._with_template.uri + ) + uri = lookup.adjust_uri(uri, relativeto) + try: + return lookup.get_template(uri) + except exceptions.TopLevelLookupException: + raise exceptions.TemplateLookupException(str(compat.exception_as())) + + +def _populate_self_namespace(context, template, self_ns=None): + if self_ns is None: + self_ns = TemplateNamespace( + "self:%s" % template.uri, + context, + template=template, + populate_self=False, + ) + context._data["self"] = context._data["local"] = self_ns + if hasattr(template.module, "_mako_inherit"): + ret = template.module._mako_inherit(template, context) + if ret: + return ret + return (template.callable_, context) + + +def _render(template, callable_, args, data, as_unicode=False): + """create a Context and return the string + output of the given template and template callable.""" + + if as_unicode: + buf = util.FastEncodingBuffer(as_unicode=True) + elif template.bytestring_passthrough: + buf = compat.StringIO() + else: + buf = util.FastEncodingBuffer( + as_unicode=as_unicode, + encoding=template.output_encoding, + errors=template.encoding_errors, + ) + context = Context(buf, **data) + context._outputting_as_unicode = as_unicode + context._set_with_template(template) + + _render_context( + template, + callable_, + context, + *args, + **_kwargs_for_callable(callable_, data) + ) + return context._pop_buffer().getvalue() + + +def _kwargs_for_callable(callable_, data): + argspec = compat.inspect_getargspec(callable_) + # for normal pages, **pageargs is usually present + if argspec[2]: + return data + + # for rendering defs from the top level, figure out the args + namedargs = argspec[0] + [v for v in argspec[1:3] if v is not None] + kwargs = {} + for arg in namedargs: + if arg != "context" and arg in data and arg not in kwargs: + kwargs[arg] = data[arg] + return kwargs + + +def _kwargs_for_include(callable_, data, **kwargs): + argspec = compat.inspect_getargspec(callable_) + namedargs = argspec[0] + [v for v in argspec[1:3] if v is not None] + for arg in namedargs: + if arg != "context" and arg in data and arg not in kwargs: + kwargs[arg] = data[arg] + return kwargs + + +def _render_context(tmpl, callable_, context, *args, **kwargs): + import mako.template as template + + # create polymorphic 'self' namespace for this + # template with possibly updated context + if not isinstance(tmpl, template.DefTemplate): + # if main render method, call from the base of the inheritance stack + (inherit, lclcontext) = _populate_self_namespace(context, tmpl) + _exec_template(inherit, lclcontext, args=args, kwargs=kwargs) + else: + # otherwise, call the actual rendering method specified + (inherit, lclcontext) = _populate_self_namespace(context, tmpl.parent) + _exec_template(callable_, context, args=args, kwargs=kwargs) + + +def _exec_template(callable_, context, args=None, kwargs=None): + """execute a rendering callable given the callable, a + Context, and optional explicit arguments + + the contextual Template will be located if it exists, and + the error handling options specified on that Template will + be interpreted here. + """ + template = context._with_template + if template is not None and ( + template.format_exceptions or template.error_handler + ): + try: + callable_(context, *args, **kwargs) + except Exception: + _render_error(template, context, compat.exception_as()) + except: + e = sys.exc_info()[0] + _render_error(template, context, e) + else: + callable_(context, *args, **kwargs) + + +def _render_error(template, context, error): + if template.error_handler: + result = template.error_handler(context, error) + if not result: + compat.reraise(*sys.exc_info()) + else: + error_template = exceptions.html_error_template() + if context._outputting_as_unicode: + context._buffer_stack[:] = [ + util.FastEncodingBuffer(as_unicode=True) + ] + else: + context._buffer_stack[:] = [ + util.FastEncodingBuffer( + error_template.output_encoding, + error_template.encoding_errors, + ) + ] + + context._set_with_template(error_template) + error_template.render_context(context, error=error) |