# -*- test-case-name: twisted.web.test.test_static -*- # Copyright (c) Twisted Matrix Laboratories. # See LICENSE for details. """ Static resources for L{twisted.web}. """ import errno import itertools import mimetypes import os import time import warnings from html import escape from typing import Any, Callable, Dict from urllib.parse import quote, unquote from zope.interface import implementer from incremental import Version from twisted.internet import abstract, interfaces from twisted.python import components, filepath, log from twisted.python.compat import nativeString, networkString from twisted.python.deprecate import deprecated from twisted.python.runtime import platformType from twisted.python.url import URL from twisted.python.util import InsensitiveDict from twisted.web import http, resource, server from twisted.web.util import redirectTo dangerousPathError = resource._UnsafeNoResource("Invalid request URL.") def isDangerous(path): return path == b".." or b"/" in path or networkString(os.sep) in path class Data(resource.Resource): """ This is a static, in-memory resource. """ def __init__(self, data, type): """ @param data: The bytes that make up this data resource. @type data: L{bytes} @param type: A native string giving the Internet media type for this content. @type type: L{str} """ resource.Resource.__init__(self) self.data = data self.type = type def render_GET(self, request): request.setHeader(b"content-type", networkString(self.type)) request.setHeader(b"content-length", b"%d" % (len(self.data),)) if request.method == b"HEAD": return b"" return self.data render_HEAD = render_GET @deprecated(Version("Twisted", 16, 0, 0)) def addSlash(request): """ Add a trailing slash to C{request}'s URI. Deprecated, do not use. """ return _addSlash(request) def _addSlash(request): """ Add a trailing slash to C{request}'s URI. @param request: The incoming request to add the ending slash to. @type request: An object conforming to L{twisted.web.iweb.IRequest} @return: A URI with a trailing slash, with query and fragment preserved. @rtype: L{bytes} """ url = URL.fromText(request.uri.decode("ascii")) # Add an empty path segment at the end, so that it adds a trailing slash url = url.replace(path=list(url.path) + [""]) return url.asText().encode("ascii") class Redirect(resource.Resource): def __init__(self, request): resource.Resource.__init__(self) self.url = _addSlash(request) def render(self, request): return redirectTo(self.url, request) class Registry(components.Componentized): """ I am a Componentized object that will be made available to internal Twisted file-based dynamic web content such as .rpy and .epy scripts. """ def __init__(self): components.Componentized.__init__(self) self._pathCache = {} def cachePath(self, path, rsrc): self._pathCache[path] = rsrc def getCachedPath(self, path): return self._pathCache.get(path) def loadMimeTypes(mimetype_locations=None, init=mimetypes.init): """ Produces a mapping of extensions (with leading dot) to MIME types. It does this by calling the C{init} function of the L{mimetypes} module. This will have the side effect of modifying the global MIME types cache in that module. Multiple file locations containing mime-types can be passed as a list. The files will be sourced in that order, overriding mime-types from the files sourced beforehand, but only if a new entry explicitly overrides the current entry. @param mimetype_locations: Optional. List of paths to C{mime.types} style files that should be used. @type mimetype_locations: iterable of paths or L{None} @param init: The init function to call. Defaults to the global C{init} function of the C{mimetypes} module. For internal use (testing) only. @type init: callable """ init(mimetype_locations) mimetypes.types_map.update( { ".conf": "text/plain", ".diff": "text/plain", ".flac": "audio/x-flac", ".java": "text/plain", ".oz": "text/x-oz", ".swf": "application/x-shockwave-flash", ".wml": "text/vnd.wap.wml", ".xul": "application/vnd.mozilla.xul+xml", ".patch": "text/plain", } ) return mimetypes.types_map def getTypeAndEncoding(filename, types, encodings, defaultType): p, ext = filepath.FilePath(filename).splitext() ext = filepath._coerceToFilesystemEncoding("", ext.lower()) if ext in encodings: enc = encodings[ext] ext = os.path.splitext(p)[1].lower() else: enc = None type = types.get(ext, defaultType) return type, enc class File(resource.Resource, filepath.FilePath): """ File is a resource that represents a plain non-interpreted file (although it can look for an extension like .rpy or .cgi and hand the file to a processor for interpretation if you wish). Its constructor takes a file path. Alternatively, you can give a directory path to the constructor. In this case the resource will represent that directory, and its children will be files underneath that directory. This provides access to an entire filesystem tree with a single Resource. If you map the URL 'http://server/FILE' to a resource created as File('/tmp'), then http://server/FILE/ will return an HTML-formatted listing of the /tmp/ directory, and http://server/FILE/foo/bar.html will return the contents of /tmp/foo/bar.html . @cvar childNotFound: L{Resource} used to render 404 Not Found error pages. @cvar forbidden: L{Resource} used to render 403 Forbidden error pages. @ivar contentTypes: a mapping of extensions to MIME types used to set the default value for the Content-Type header. It is initialized with the values returned by L{loadMimeTypes}. @type contentTypes: C{dict} @ivar contentEncodings: a mapping of extensions to encoding types used to set default value for the Content-Encoding header. @type contentEncodings: C{dict} """ contentTypes = loadMimeTypes() contentEncodings = {".gz": "gzip", ".bz2": "bzip2"} processors: Dict[str, Callable[[str, Any], Data]] = {} indexNames = ["index", "index.html", "index.htm", "index.rpy"] type = None def __init__( self, path, defaultType="text/html", ignoredExts=(), registry=None, allowExt=0 ): """ Create a file with the given path. @param path: The filename of the file from which this L{File} will serve data. @type path: C{str} @param defaultType: A I{major/minor}-style MIME type specifier indicating the I{Content-Type} with which this L{File}'s data will be served if a MIME type cannot be determined based on C{path}'s extension. @type defaultType: C{str} @param ignoredExts: A sequence giving the extensions of paths in the filesystem which will be ignored for the purposes of child lookup. For example, if C{ignoredExts} is C{(".bar",)} and C{path} is a directory containing a file named C{"foo.bar"}, a request for the C{"foo"} child of this resource will succeed with a L{File} pointing to C{"foo.bar"}. @param registry: The registry object being used to handle this request. If L{None}, one will be created. @type registry: L{Registry} @param allowExt: Ignored parameter, only present for backwards compatibility. Do not pass a value for this parameter. """ resource.Resource.__init__(self) filepath.FilePath.__init__(self, path) self.defaultType = defaultType if ignoredExts in (0, 1) or allowExt: warnings.warn("ignoredExts should receive a list, not a boolean") if ignoredExts or allowExt: self.ignoredExts = ["*"] else: self.ignoredExts = [] else: self.ignoredExts = list(ignoredExts) self.registry = registry or Registry() def ignoreExt(self, ext): """Ignore the given extension. Serve file.ext if file is requested """ self.ignoredExts.append(ext) childNotFound = resource._UnsafeNoResource("File not found.") forbidden = resource._UnsafeForbiddenResource() def directoryListing(self): """ Return a resource that generates an HTML listing of the directory this path represents. @return: A resource that renders the directory to HTML. @rtype: L{DirectoryLister} """ path = self.path names = self.listNames() return DirectoryLister( path, names, self.contentTypes, self.contentEncodings, self.defaultType ) def getChild(self, path, request): """ If this L{File}"s path refers to a directory, return a L{File} referring to the file named C{path} in that directory. If C{path} is the empty string, return a L{DirectoryLister} instead. @param path: The current path segment. @type path: L{bytes} @param request: The incoming request. @type request: An that provides L{twisted.web.iweb.IRequest}. @return: A resource representing the requested file or directory, or L{NoResource} if the path cannot be accessed. @rtype: An object that provides L{resource.IResource}. """ if isinstance(path, bytes): try: # Request calls urllib.unquote on each path segment, # leaving us with raw bytes. path = path.decode("utf-8") except UnicodeDecodeError: log.err(None, f"Could not decode path segment as utf-8: {path!r}") return self.childNotFound self.restat(reraise=False) if not self.isdir(): return self.childNotFound if path: try: fpath = self.child(path) except filepath.InsecurePath: return self.childNotFound else: fpath = self.childSearchPreauth(*self.indexNames) if fpath is None: return self.directoryListing() if not fpath.exists(): fpath = fpath.siblingExtensionSearch(*self.ignoredExts) if fpath is None: return self.childNotFound extension = fpath.splitext()[1] if platformType == "win32": # don't want .RPY to be different than .rpy, since that would allow # source disclosure. processor = InsensitiveDict(self.processors).get(extension) else: processor = self.processors.get(extension) if processor: return resource.IResource(processor(fpath.path, self.registry)) return self.createSimilarFile(fpath.path) # methods to allow subclasses to e.g. decrypt files on the fly: def openForReading(self): """Open a file and return it.""" return self.open() def getFileSize(self): """Return file size.""" return self.getsize() def _parseRangeHeader(self, range): """ Parse the value of a Range header into (start, stop) pairs. In a given pair, either of start or stop can be None, signifying that no value was provided, but not both. @return: A list C{[(start, stop)]} of pairs of length at least one. @raise ValueError: if the header is syntactically invalid or if the Bytes-Unit is anything other than "bytes'. """ try: kind, value = range.split(b"=", 1) except ValueError: raise ValueError("Missing '=' separator") kind = kind.strip() if kind != b"bytes": raise ValueError(f"Unsupported Bytes-Unit: {kind!r}") unparsedRanges = list(filter(None, map(bytes.strip, value.split(b",")))) parsedRanges = [] for byteRange in unparsedRanges: try: start, end = byteRange.split(b"-", 1) except ValueError: raise ValueError(f"Invalid Byte-Range: {byteRange!r}") if start: try: start = int(start) except ValueError: raise ValueError(f"Invalid Byte-Range: {byteRange!r}") else: start = None if end: try: end = int(end) except ValueError: raise ValueError(f"Invalid Byte-Range: {byteRange!r}") else: end = None if start is not None: if end is not None and start > end: # Start must be less than or equal to end or it is invalid. raise ValueError(f"Invalid Byte-Range: {byteRange!r}") elif end is None: # One or both of start and end must be specified. Omitting # both is invalid. raise ValueError(f"Invalid Byte-Range: {byteRange!r}") parsedRanges.append((start, end)) return parsedRanges def _rangeToOffsetAndSize(self, start, end): """ Convert a start and end from a Range header to an offset and size. This method checks that the resulting range overlaps with the resource being served (and so has the value of C{getFileSize()} as an indirect input). Either but not both of start or end can be L{None}: - Omitted start means that the end value is actually a start value relative to the end of the resource. - Omitted end means the end of the resource should be the end of the range. End is interpreted as inclusive, as per RFC 2616. If this range doesn't overlap with any of this resource, C{(0, 0)} is returned, which is not otherwise a value return value. @param start: The start value from the header, or L{None} if one was not present. @param end: The end value from the header, or L{None} if one was not present. @return: C{(offset, size)} where offset is how far into this resource this resource the range begins and size is how long the range is, or C{(0, 0)} if the range does not overlap this resource. """ size = self.getFileSize() if start is None: start = size - end end = size elif end is None: end = size elif end < size: end += 1 elif end > size: end = size if start >= size: start = end = 0 return start, (end - start) def _contentRange(self, offset, size): """ Return a string suitable for the value of a Content-Range header for a range with the given offset and size. The offset and size are not sanity checked in any way. @param offset: How far into this resource the range begins. @param size: How long the range is. @return: The value as appropriate for the value of a Content-Range header. """ return networkString( "bytes %d-%d/%d" % (offset, offset + size - 1, self.getFileSize()) ) def _doSingleRangeRequest(self, request, startAndEnd): """ Set up the response for Range headers that specify a single range. This method checks if the request is satisfiable and sets the response code and Content-Range header appropriately. The return value indicates which part of the resource to return. @param request: The Request object. @param startAndEnd: A 2-tuple of start of the byte range as specified by the header and the end of the byte range as specified by the header. At most one of the start and end may be L{None}. @return: A 2-tuple of the offset and size of the range to return. offset == size == 0 indicates that the request is not satisfiable. """ start, end = startAndEnd offset, size = self._rangeToOffsetAndSize(start, end) if offset == size == 0: # This range doesn't overlap with any of this resource, so the # request is unsatisfiable. request.setResponseCode(http.REQUESTED_RANGE_NOT_SATISFIABLE) request.setHeader( b"content-range", networkString("bytes */%d" % (self.getFileSize(),)) ) else: request.setResponseCode(http.PARTIAL_CONTENT) request.setHeader(b"content-range", self._contentRange(offset, size)) return offset, size def _doMultipleRangeRequest(self, request, byteRanges): """ Set up the response for Range headers that specify a single range. This method checks if the request is satisfiable and sets the response code and Content-Type and Content-Length headers appropriately. The return value, which is a little complicated, indicates which parts of the resource to return and the boundaries that should separate the parts. In detail, the return value is a tuple rangeInfo C{rangeInfo} is a list of 3-tuples C{(partSeparator, partOffset, partSize)}. The response to this request should be, for each element of C{rangeInfo}, C{partSeparator} followed by C{partSize} bytes of the resource starting at C{partOffset}. Each C{partSeparator} includes the MIME-style boundary and the part-specific Content-type and Content-range headers. It is convenient to return the separator as a concrete string from this method, because this method needs to compute the number of bytes that will make up the response to be able to set the Content-Length header of the response accurately. @param request: The Request object. @param byteRanges: A list of C{(start, end)} values as specified by the header. For each range, at most one of C{start} and C{end} may be L{None}. @return: See above. """ matchingRangeFound = False rangeInfo = [] contentLength = 0 boundary = networkString(f"{int(time.time() * 1000000):x}{os.getpid():x}") if self.type: contentType = self.type else: contentType = b"bytes" # It's what Apache does... for start, end in byteRanges: partOffset, partSize = self._rangeToOffsetAndSize(start, end) if partOffset == partSize == 0: continue contentLength += partSize matchingRangeFound = True partContentRange = self._contentRange(partOffset, partSize) partSeparator = networkString( ( "\r\n" "--%s\r\n" "Content-type: %s\r\n" "Content-range: %s\r\n" "\r\n" ) % ( nativeString(boundary), nativeString(contentType), nativeString(partContentRange), ) ) contentLength += len(partSeparator) rangeInfo.append((partSeparator, partOffset, partSize)) if not matchingRangeFound: request.setResponseCode(http.REQUESTED_RANGE_NOT_SATISFIABLE) request.setHeader(b"content-length", b"0") request.setHeader( b"content-range", networkString("bytes */%d" % (self.getFileSize(),)) ) return [], b"" finalBoundary = b"\r\n--" + boundary + b"--\r\n" rangeInfo.append((finalBoundary, 0, 0)) request.setResponseCode(http.PARTIAL_CONTENT) request.setHeader( b"content-type", networkString(f'multipart/byteranges; boundary="{nativeString(boundary)}"'), ) request.setHeader( b"content-length", b"%d" % (contentLength + len(finalBoundary),) ) return rangeInfo def _setContentHeaders(self, request, size=None): """ Set the Content-length and Content-type headers for this request. This method is not appropriate for requests for multiple byte ranges; L{_doMultipleRangeRequest} will set these headers in that case. @param request: The L{twisted.web.http.Request} object. @param size: The size of the response. If not specified, default to C{self.getFileSize()}. """ if size is None: size = self.getFileSize() request.setHeader(b"content-length", b"%d" % (size,)) if self.type: request.setHeader(b"content-type", networkString(self.type)) if self.encoding: request.setHeader(b"content-encoding", networkString(self.encoding)) def makeProducer(self, request, fileForReading): """ Make a L{StaticProducer} that will produce the body of this response. This method will also set the response code and Content-* headers. @param request: The L{twisted.web.http.Request} object. @param fileForReading: The file object containing the resource. @return: A L{StaticProducer}. Calling C{.start()} on this will begin producing the response. """ byteRange = request.getHeader(b"range") if byteRange is None: self._setContentHeaders(request) request.setResponseCode(http.OK) return NoRangeStaticProducer(request, fileForReading) try: parsedRanges = self._parseRangeHeader(byteRange) except ValueError: log.msg(f"Ignoring malformed Range header {byteRange.decode()!r}") self._setContentHeaders(request) request.setResponseCode(http.OK) return NoRangeStaticProducer(request, fileForReading) if len(parsedRanges) == 1: offset, size = self._doSingleRangeRequest(request, parsedRanges[0]) self._setContentHeaders(request, size) return SingleRangeStaticProducer(request, fileForReading, offset, size) else: rangeInfo = self._doMultipleRangeRequest(request, parsedRanges) return MultipleRangeStaticProducer(request, fileForReading, rangeInfo) def render_GET(self, request): """ Begin sending the contents of this L{File} (or a subset of the contents, based on the 'range' header) to the given request. """ self.restat(False) if self.type is None: self.type, self.encoding = getTypeAndEncoding( self.basename(), self.contentTypes, self.contentEncodings, self.defaultType, ) if not self.exists(): return self.childNotFound.render(request) if self.isdir(): return self.redirect(request) request.setHeader(b"accept-ranges", b"bytes") try: fileForReading = self.openForReading() except OSError as e: if e.errno == errno.EACCES: return self.forbidden.render(request) else: raise if request.setLastModified(self.getModificationTime()) is http.CACHED: # `setLastModified` also sets the response code for us, so if the # request is cached, we close the file now that we've made sure that # the request would otherwise succeed and return an empty body. fileForReading.close() return b"" if request.method == b"HEAD": # Set the content headers here, rather than making a producer. self._setContentHeaders(request) # We've opened the file to make sure it's accessible, so close it # now that we don't need it. fileForReading.close() return b"" producer = self.makeProducer(request, fileForReading) producer.start() # and make sure the connection doesn't get closed return server.NOT_DONE_YET render_HEAD = render_GET def redirect(self, request): return redirectTo(_addSlash(request), request) def listNames(self): if not self.isdir(): return [] directory = self.listdir() directory.sort() return directory def listEntities(self): return list( map( lambda fileName, self=self: self.createSimilarFile( os.path.join(self.path, fileName) ), self.listNames(), ) ) def createSimilarFile(self, path): f = self.__class__(path, self.defaultType, self.ignoredExts, self.registry) # refactoring by steps, here - constructor should almost certainly take these f.processors = self.processors f.indexNames = self.indexNames[:] f.childNotFound = self.childNotFound return f @implementer(interfaces.IPullProducer) class StaticProducer: """ Superclass for classes that implement the business of producing. @ivar request: The L{IRequest} to write the contents of the file to. @ivar fileObject: The file the contents of which to write to the request. """ bufferSize = abstract.FileDescriptor.bufferSize def __init__(self, request, fileObject): """ Initialize the instance. """ self.request = request self.fileObject = fileObject def start(self): raise NotImplementedError(self.start) def resumeProducing(self): raise NotImplementedError(self.resumeProducing) def stopProducing(self): """ Stop producing data. L{twisted.internet.interfaces.IProducer.stopProducing} is called when our consumer has died, and subclasses also call this method when they are done producing data. """ self.fileObject.close() self.request = None class NoRangeStaticProducer(StaticProducer): """ A L{StaticProducer} that writes the entire file to the request. """ def start(self): self.request.registerProducer(self, False) def resumeProducing(self): if not self.request: return data = self.fileObject.read(self.bufferSize) if data: # this .write will spin the reactor, calling .doWrite and then # .resumeProducing again, so be prepared for a re-entrant call self.request.write(data) else: self.request.unregisterProducer() self.request.finish() self.stopProducing() class SingleRangeStaticProducer(StaticProducer): """ A L{StaticProducer} that writes a single chunk of a file to the request. """ def __init__(self, request, fileObject, offset, size): """ Initialize the instance. @param request: See L{StaticProducer}. @param fileObject: See L{StaticProducer}. @param offset: The offset into the file of the chunk to be written. @param size: The size of the chunk to write. """ StaticProducer.__init__(self, request, fileObject) self.offset = offset self.size = size def start(self): self.fileObject.seek(self.offset) self.bytesWritten = 0 self.request.registerProducer(self, 0) def resumeProducing(self): if not self.request: return data = self.fileObject.read(min(self.bufferSize, self.size - self.bytesWritten)) if data: self.bytesWritten += len(data) # this .write will spin the reactor, calling .doWrite and then # .resumeProducing again, so be prepared for a re-entrant call self.request.write(data) if self.request and self.bytesWritten == self.size: self.request.unregisterProducer() self.request.finish() self.stopProducing() class MultipleRangeStaticProducer(StaticProducer): """ A L{StaticProducer} that writes several chunks of a file to the request. """ def __init__(self, request, fileObject, rangeInfo): """ Initialize the instance. @param request: See L{StaticProducer}. @param fileObject: See L{StaticProducer}. @param rangeInfo: A list of tuples C{[(boundary, offset, size)]} where: - C{boundary} will be written to the request first. - C{offset} the offset into the file of chunk to write. - C{size} the size of the chunk to write. """ StaticProducer.__init__(self, request, fileObject) self.rangeInfo = rangeInfo def start(self): self.rangeIter = iter(self.rangeInfo) self._nextRange() self.request.registerProducer(self, 0) def _nextRange(self): self.partBoundary, partOffset, self._partSize = next(self.rangeIter) self._partBytesWritten = 0 self.fileObject.seek(partOffset) def resumeProducing(self): if not self.request: return data = [] dataLength = 0 done = False while dataLength < self.bufferSize: if self.partBoundary: dataLength += len(self.partBoundary) data.append(self.partBoundary) self.partBoundary = None p = self.fileObject.read( min( self.bufferSize - dataLength, self._partSize - self._partBytesWritten, ) ) self._partBytesWritten += len(p) dataLength += len(p) data.append(p) if self.request and self._partBytesWritten == self._partSize: try: self._nextRange() except StopIteration: done = True break self.request.write(b"".join(data)) if done: self.request.unregisterProducer() self.request.finish() self.stopProducing() class ASISProcessor(resource.Resource): """ Serve files exactly as responses without generating a status-line or any headers. Inspired by Apache's mod_asis. """ def __init__(self, path, registry=None): resource.Resource.__init__(self) self.path = path self.registry = registry or Registry() def render(self, request): request.startedWriting = 1 res = File(self.path, registry=self.registry) return res.render(request) def formatFileSize(size): """ Format the given file size in bytes to human readable format. """ if size < 1024: return "%iB" % size elif size < (1024 ** 2): return "%iK" % (size / 1024) elif size < (1024 ** 3): return "%iM" % (size / (1024 ** 2)) else: return "%iG" % (size / (1024 ** 3)) class DirectoryLister(resource.Resource): """ Print the content of a directory. @ivar template: page template used to render the content of the directory. It must contain the format keys B{header} and B{tableContent}. @type template: C{str} @ivar linePattern: template used to render one line in the listing table. It must contain the format keys B{class}, B{href}, B{text}, B{size}, B{type} and B{encoding}. @type linePattern: C{str} @ivar contentTypes: a mapping of extensions to MIME types used to populate the information of a member of this directory. It is initialized with the value L{File.contentTypes}. @type contentTypes: C{dict} @ivar contentEncodings: a mapping of extensions to encoding types. It is initialized with the value L{File.contentEncodings}. @type contentEncodings: C{dict} @ivar defaultType: default type used when no mimetype is detected. @type defaultType: C{str} @ivar dirs: filtered content of C{path}, if the whole content should not be displayed (default to L{None}, which means the actual content of C{path} is printed). @type dirs: L{None} or C{list} @ivar path: directory which content should be listed. @type path: C{str} """ template = """ %(header)s

%(header)s

%(tableContent)s
Filename Size Content type Content encoding
""" linePattern = """ %(text)s %(size)s %(type)s %(encoding)s """ def __init__( self, pathname, dirs=None, contentTypes=File.contentTypes, contentEncodings=File.contentEncodings, defaultType="text/html", ): resource.Resource.__init__(self) self.contentTypes = contentTypes self.contentEncodings = contentEncodings self.defaultType = defaultType # dirs allows usage of the File to specify what gets listed self.dirs = dirs self.path = pathname def _getFilesAndDirectories(self, directory): """ Helper returning files and directories in given directory listing, with attributes to be used to build a table content with C{self.linePattern}. @return: tuple of (directories, files) @rtype: C{tuple} of C{list} """ files = [] dirs = [] for path in directory: if isinstance(path, bytes): path = path.decode("utf8") url = quote(path, "/") escapedPath = escape(path) childPath = filepath.FilePath(self.path).child(path) if childPath.isdir(): dirs.append( { "text": escapedPath + "/", "href": url + "/", "size": "", "type": "[Directory]", "encoding": "", } ) else: mimetype, encoding = getTypeAndEncoding( path, self.contentTypes, self.contentEncodings, self.defaultType ) try: size = childPath.getsize() except OSError: continue files.append( { "text": escapedPath, "href": url, "type": "[%s]" % mimetype, "encoding": (encoding and "[%s]" % encoding or ""), "size": formatFileSize(size), } ) return dirs, files def _buildTableContent(self, elements): """ Build a table content using C{self.linePattern} and giving elements odd and even classes. """ tableContent = [] rowClasses = itertools.cycle(["odd", "even"]) for element, rowClass in zip(elements, rowClasses): element["class"] = rowClass tableContent.append(self.linePattern % element) return tableContent def render(self, request): """ Render a listing of the content of C{self.path}. """ request.setHeader(b"content-type", b"text/html; charset=utf-8") if self.dirs is None: directory = os.listdir(self.path) directory.sort() else: directory = self.dirs dirs, files = self._getFilesAndDirectories(directory) tableContent = "".join(self._buildTableContent(dirs + files)) header = "Directory listing for {}".format( escape(unquote(nativeString(request.uri))), ) done = self.template % {"header": header, "tableContent": tableContent} done = done.encode("utf8") return done def __repr__(self) -> str: return "" % self.path __str__ = __repr__