module documentation
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Context-free flattener/serializer for rendering Python objects, possibly complex or arbitrarily nested, as strings.
Function attribute​Escaping​Done​Outside No summary
Function escaped​CDATA Escape CDATA for inclusion in a document.
Function escaped​Comment Escape a comment for inclusion in a document.
Function escape​For​Content Escape some character or UTF-8 byte data for inclusion in an HTML or XML document, by replacing metacharacters (&<>) with their entity equivalents (&amp;&lt;&gt;).
Function write​With​Attribute​Escaping Decorate a write callable so that all output written is properly quoted for inclusion within an XML attribute value.
Function _flatten​Element Make root slightly more flat by yielding all its immediate contents as strings, deferreds or generators that are recursive calls to itself.
Function _flatten​Tree Make root into an iterable of bytes and Deferred by doing a depth first traversal of the tree.
Function _get​Slot​Value Find the value of the named slot in the given stack of slot data.
Function _write​Flattened​Data Take strings from an iterator and pass them to a writer function.
def attributeEscapingDoneOutside(data): (source)
Escape some character or UTF-8 byte data for inclusion in the top level of an attribute. attributeEscapingDoneOutside actually passes the data through unchanged, because writeWithAttributeEscaping handles the quoting of the text within attributes outside the generator returned by _flattenElement; this is used as the dataEscaper argument to that _flattenElement call so that that generator does not redundantly escape its text output.
Parameters
data:bytes or unicodeThe string to escape.
Returns
bytesThe string, unchanged, except for encoding.
def escapedCDATA(data): (source)
Escape CDATA for inclusion in a document.
Parameters
data:str or unicodeThe string to escape.
Returns
strThe quoted form of data. If data is unicode, return a utf-8 encoded string.
def escapedComment(data): (source)
Escape a comment for inclusion in a document.
Parameters
data:str or unicodeThe string to escape.
Returns
strThe quoted form of data. If data is unicode, return a utf-8 encoded string.
def escapeForContent(data): (source)

Escape some character or UTF-8 byte data for inclusion in an HTML or XML document, by replacing metacharacters (&<>) with their entity equivalents (&amp;&lt;&gt;).

This is used as an input to _flattenElement's dataEscaper parameter.

Parameters
data:bytes or unicodeThe string to escape.
Returns
bytesThe quoted form of data. If data is unicode, return a utf-8 encoded string.
def writeWithAttributeEscaping(write): (source)

Decorate a write callable so that all output written is properly quoted for inclusion within an XML attribute value.

If a Tag x is flattened within the context of the contents of another Tag y, the metacharacters (<>&") delimiting x should be passed through unchanged, but the textual content of x should still be quoted, as usual. For example: <y><x>&amp;</x></y>. That is the default behavior of _flattenElement when escapeForContent is passed as the dataEscaper.

However, when a Tag x is flattened within the context of an attribute of another Tag y, then the metacharacters delimiting x should be quoted so that it can be parsed from the attribute's value. In the DOM itself, this is not a valid thing to do, but given that renderers and slots may be freely moved around in a twisted.web.template template, it is a condition which may arise in a document and must be handled in a way which produces valid output. So, for example, you should be able to get <y attr="&lt;x /&gt;" />. This should also be true for other XML/HTML meta-constructs such as comments and CDATA, so if you were to serialize a comment in an attribute you should get <y attr="&lt;-- comment --&gt;" />. Therefore in order to capture these meta-characters, flattening is done with write callable that is wrapped with writeWithAttributeEscaping.

The final case, and hopefully the much more common one as compared to serializing Tag and arbitrary IRenderable objects within an attribute, is to serialize a simple string, and those should be passed through for writeWithAttributeEscaping to quote without applying a second, redundant level of quoting.

Parameters
writeA callable which will be invoked with the escaped bytes.
Returns
A callable that writes data with escaping.
def _flattenElement(request, root, write, slotData, renderFactory, dataEscaper): (source)
Make root slightly more flat by yielding all its immediate contents as strings, deferreds or generators that are recursive calls to itself.
Parameters
requestA request object which will be passed to IRenderable.render.
rootAn object to be made flatter. This may be of type unicode, str, slot, Tag, tuple, list, types.GeneratorType, Deferred, or an object that implements IRenderable.
writeA callable which will be invoked with each bytes produced by flattening root.
slot​DataA list of dict mapping str slot names to data with which those slots will be replaced.
render​FactoryIf not None, an object that provides IRenderable.
data​EscaperA 1-argument callable which takes bytes or unicode and returns bytes, quoted as appropriate for the rendering context. This is really only one of two values: attributeEscapingDoneOutside or escapeForContent, depending on whether the rendering context is within an attribute or not. See the explanation in writeWithAttributeEscaping.
Returns
An iterator which yields bytes, Deferred, and more iterators of the same type.An iterator that eventually yields bytes that should be written to the output. However it may also yield other iterators or Deferreds; if it yields another iterator, the caller will iterate it; if it yields a Deferred, the result of that Deferred will either be bytes, in which case it's written, or another generator, in which case it is iterated. See _flattenTree for the trampoline that consumes said values.
def _flattenTree(request, root, write): (source)
Make root into an iterable of bytes and Deferred by doing a depth first traversal of the tree.
Parameters
requestA request object which will be passed to IRenderable.render.
rootAn object to be made flatter. This may be of type unicode, bytes, slot, Tag, tuple, list, types.GeneratorType, Deferred, or something providing IRenderable.
writeA callable which will be invoked with each bytes produced by flattening root.
Returns
An iterator which yields objects of type bytes and Deferred. A Deferred is only yielded when one is encountered in the process of flattening root. The returned iterator must not be iterated again until the Deferred is called back.
def _getSlotValue(name, slotData, default=None): (source)
Find the value of the named slot in the given stack of slot data.
def _writeFlattenedData(state, write, result): (source)
Take strings from an iterator and pass them to a writer function.
Parameters
stateAn iterator of str and Deferred. str instances will be passed to write. Deferred instances will be waited on before resuming iteration of state.
writeA callable which will be invoked with each str produced by iterating state.
resultA Deferred which will be called back when state has been completely flattened into write or which will be errbacked if an exception in a generator passed to state or an errback from a Deferred from state occurs.
Returns
None