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resolve intra-module cyclic imports
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@graingert
graingert committed Aug 6, 2021
1 parent 90ecca2 commit 770b886
Showing 1 changed file with 181 additions and 180 deletions.
361 changes: 181 additions & 180 deletions src/twisted/web/_template_util.py
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Original file line number Diff line number Diff line change
Expand Up @@ -34,7 +34,7 @@
from twisted.python.failure import Failure
from twisted.python.filepath import FilePath
from twisted.python.reflect import fullyQualifiedName
from twisted.web import resource, server
from twisted.web import resource
from twisted.web._element import Element, renderer
from twisted.web._flatten import Flattenable, flatten, flattenString
from twisted.web._stan import CDATA, Comment, Tag, slot
Expand Down Expand Up @@ -344,184 +344,6 @@ def frames(self, request, tag):
]


@implementer(ITemplateLoader)
class XMLString:
"""
An L{ITemplateLoader} that loads and parses XML from a string.
"""

def __init__(self, s: Union[str, bytes]):
"""
Run the parser on a L{StringIO} copy of the string.
@param s: The string from which to load the XML.
@type s: L{str}, or a UTF-8 encoded L{bytes}.
"""
if not isinstance(s, str):
s = s.decode("utf8")

self._loadedTemplate: List["Flattenable"] = _flatsaxParse(StringIO(s))
"""The loaded document."""

def load(self) -> List["Flattenable"]:
"""
Return the document.
@return: the loaded document.
"""
return self._loadedTemplate


class FailureElement(Element):
"""
L{FailureElement} is an L{IRenderable} which can render detailed information
about a L{Failure<twisted.python.failure.Failure>}.
@ivar failure: The L{Failure<twisted.python.failure.Failure>} instance which
will be rendered.
@since: 12.1
"""

loader = XMLString(
"""
<div xmlns:t="http://twistedmatrix.com/ns/twisted.web.template/0.1">
<style type="text/css">
div.error {
color: red;
font-family: Verdana, Arial, helvetica, sans-serif;
font-weight: bold;
}
div {
font-family: Verdana, Arial, helvetica, sans-serif;
}
div.stackTrace {
}
div.frame {
padding: 1em;
background: white;
border-bottom: thin black dashed;
}
div.frame:first-child {
padding: 1em;
background: white;
border-top: thin black dashed;
border-bottom: thin black dashed;
}
div.location {
}
span.function {
font-weight: bold;
font-family: "Courier New", courier, monospace;
}
div.snippet {
margin-bottom: 0.5em;
margin-left: 1em;
background: #FFFFDD;
}
div.snippetHighlightLine {
color: red;
}
span.code {
font-family: "Courier New", courier, monospace;
}
</style>
<div class="error">
<span t:render="type" />: <span t:render="value" />
</div>
<div class="stackTrace" t:render="traceback">
<div class="frame" t:render="frames">
<div class="location">
<span t:render="filename" />:<span t:render="lineNumber" /> in
<span class="function" t:render="function" />
</div>
<div class="snippet" t:render="source">
<div t:render="sourceLines">
<span class="lineno" t:render="lineNumber" />
<code class="code" t:render="sourceLine" />
</div>
</div>
</div>
</div>
<div class="error">
<span t:render="type" />: <span t:render="value" />
</div>
</div>
"""
)

def __init__(self, failure, loader=None):
Element.__init__(self, loader)
self.failure = failure

@renderer
def type(self, request, tag):
"""
Render the exception type as a child of C{tag}.
"""
return tag(fullyQualifiedName(self.failure.type))

@renderer
def value(self, request, tag):
"""
Render the exception value as a child of C{tag}.
"""
return tag(str(self.failure.value).encode("utf8"))

@renderer
def traceback(self, request, tag):
"""
Render all the frames in the wrapped
L{Failure<twisted.python.failure.Failure>}'s traceback stack, replacing
C{tag}.
"""
return _StackElement(TagLoader(tag), self.failure.frames)


def formatFailure(myFailure):
"""
Construct an HTML representation of the given failure.
Consider using L{FailureElement} instead.
@type myFailure: L{Failure<twisted.python.failure.Failure>}
@rtype: L{bytes}
@return: A string containing the HTML representation of the given failure.
"""
result = []
flattenString(None, FailureElement(myFailure)).addBoth(result.append)
if isinstance(result[0], bytes):
# Ensure the result string is all ASCII, for compatibility with the
# default encoding expected by browsers.
return result[0].decode("utf-8").encode("ascii", "xmlcharrefreplace")
result[0].raiseException()


TEMPLATE_NAMESPACE = "http://twistedmatrix.com/ns/twisted.web.template/0.1"

# Go read the definition of NOT_DONE_YET. For lulz. This is totally
# equivalent. And this turns out to be necessary, because trying to import
# NOT_DONE_YET in this module causes a circular import which we cannot escape
# from. From which we cannot escape. Etc. glyph is okay with this solution for
# now, and so am I, as long as this comment stays to explain to future
# maintainers what it means. ~ C.
#
# See http://twistedmatrix.com/trac/ticket/5557 for progress on fixing this.
NOT_DONE_YET = 1
_moduleLog = Logger()


class _NSContext:
"""
A mapping from XML namespaces onto their prefixes in the document.
Expand Down Expand Up @@ -559,6 +381,9 @@ def __getitem__(self, k: Optional[str]) -> Optional[str]:
return self.nss.__getitem__(k)


TEMPLATE_NAMESPACE = "http://twistedmatrix.com/ns/twisted.web.template/0.1"


class _ToStan(handler.ContentHandler, handler.EntityResolver):
"""
A SAX parser which converts an XML document to the Twisted STAN
Expand Down Expand Up @@ -831,6 +656,182 @@ def _flatsaxParse(fl: Union[FilePath, IO[AnyStr], str]) -> List["Flattenable"]:
return s.document


@implementer(ITemplateLoader)
class XMLString:
"""
An L{ITemplateLoader} that loads and parses XML from a string.
"""

def __init__(self, s: Union[str, bytes]):
"""
Run the parser on a L{StringIO} copy of the string.
@param s: The string from which to load the XML.
@type s: L{str}, or a UTF-8 encoded L{bytes}.
"""
if not isinstance(s, str):
s = s.decode("utf8")

self._loadedTemplate: List["Flattenable"] = _flatsaxParse(StringIO(s))
"""The loaded document."""

def load(self) -> List["Flattenable"]:
"""
Return the document.
@return: the loaded document.
"""
return self._loadedTemplate


class FailureElement(Element):
"""
L{FailureElement} is an L{IRenderable} which can render detailed information
about a L{Failure<twisted.python.failure.Failure>}.
@ivar failure: The L{Failure<twisted.python.failure.Failure>} instance which
will be rendered.
@since: 12.1
"""

loader = XMLString(
"""
<div xmlns:t="http://twistedmatrix.com/ns/twisted.web.template/0.1">
<style type="text/css">
div.error {
color: red;
font-family: Verdana, Arial, helvetica, sans-serif;
font-weight: bold;
}
div {
font-family: Verdana, Arial, helvetica, sans-serif;
}
div.stackTrace {
}
div.frame {
padding: 1em;
background: white;
border-bottom: thin black dashed;
}
div.frame:first-child {
padding: 1em;
background: white;
border-top: thin black dashed;
border-bottom: thin black dashed;
}
div.location {
}
span.function {
font-weight: bold;
font-family: "Courier New", courier, monospace;
}
div.snippet {
margin-bottom: 0.5em;
margin-left: 1em;
background: #FFFFDD;
}
div.snippetHighlightLine {
color: red;
}
span.code {
font-family: "Courier New", courier, monospace;
}
</style>
<div class="error">
<span t:render="type" />: <span t:render="value" />
</div>
<div class="stackTrace" t:render="traceback">
<div class="frame" t:render="frames">
<div class="location">
<span t:render="filename" />:<span t:render="lineNumber" /> in
<span class="function" t:render="function" />
</div>
<div class="snippet" t:render="source">
<div t:render="sourceLines">
<span class="lineno" t:render="lineNumber" />
<code class="code" t:render="sourceLine" />
</div>
</div>
</div>
</div>
<div class="error">
<span t:render="type" />: <span t:render="value" />
</div>
</div>
"""
)

def __init__(self, failure, loader=None):
Element.__init__(self, loader)
self.failure = failure

@renderer
def type(self, request, tag):
"""
Render the exception type as a child of C{tag}.
"""
return tag(fullyQualifiedName(self.failure.type))

@renderer
def value(self, request, tag):
"""
Render the exception value as a child of C{tag}.
"""
return tag(str(self.failure.value).encode("utf8"))

@renderer
def traceback(self, request, tag):
"""
Render all the frames in the wrapped
L{Failure<twisted.python.failure.Failure>}'s traceback stack, replacing
C{tag}.
"""
return _StackElement(TagLoader(tag), self.failure.frames)


def formatFailure(myFailure):
"""
Construct an HTML representation of the given failure.
Consider using L{FailureElement} instead.
@type myFailure: L{Failure<twisted.python.failure.Failure>}
@rtype: L{bytes}
@return: A string containing the HTML representation of the given failure.
"""
result = []
flattenString(None, FailureElement(myFailure)).addBoth(result.append)
if isinstance(result[0], bytes):
# Ensure the result string is all ASCII, for compatibility with the
# default encoding expected by browsers.
return result[0].decode("utf-8").encode("ascii", "xmlcharrefreplace")
result[0].raiseException()


# Go read the definition of NOT_DONE_YET. For lulz. This is totally
# equivalent. And this turns out to be necessary, because trying to import
# NOT_DONE_YET in this module causes a circular import which we cannot escape
# from. From which we cannot escape. Etc. glyph is okay with this solution for
# now, and so am I, as long as this comment stays to explain to future
# maintainers what it means. ~ C.
#
# See http://twistedmatrix.com/trac/ticket/5557 for progress on fixing this.
NOT_DONE_YET = 1
_moduleLog = Logger()


@implementer(ITemplateLoader)
class TagLoader:
"""
Expand Down Expand Up @@ -1089,7 +1090,7 @@ def eb(failure: Failure) -> Optional[Deferred[None]]:
_moduleLog.failure(
"An error occurred while rendering the response.", failure=failure
)
site: Optional["server.Site"] = getattr(request, "site", None)
site = getattr(request, "site", None)
if site is not None and site.displayTracebacks:
assert _failElement is not None
return flatten(request, _failElement(failure), request.write)
Expand Down

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