Part of twisted.words.xish.domish View Source View In Hierarchy
Known subclasses: twisted.words.protocols.jabber.client.IQ, twisted.words.protocols.jabber.xmlstream.IQ
Implements interfaces: twisted.words.xish.domish.IElementRepresents an XML element node. An Element contains a series of attributes (name/value pairs), content (character data), and other child Element objects. When building a document with markup (such as HTML or XML), use this object as the starting point. Element objects fully support XML Namespaces. The fully qualified name of the XML Element it represents is stored in the C{uri} and C{name} attributes, where C{uri} holds the namespace URI. There is also a default namespace, for child elements. This is stored in the C{defaultUri} attribute. Note that C{''} means the empty namespace. Serialization of Elements through C{toXml()} will use these attributes for generating proper serialized XML. When both C{uri} and C{defaultUri} are not None in the Element and all of its descendents, serialization proceeds as expected: >>> from twisted.words.xish import domish >>> root = domish.Element(('myns', 'root')) >>> root.addElement('child', content='test') <twisted.words.xish.domish.Element object at 0x83002ac> >>> root.toXml() u"<root xmlns='myns'><child>test</child></root>" For partial serialization, needed for streaming XML, a special value for namespace URIs can be used: C{None}. Using C{None} as the value for C{uri} means: this element is in whatever namespace inherited by the closest logical ancestor when the complete XML document has been serialized. The serialized start tag will have a non-prefixed name, and no xmlns declaration will be generated. Similarly, C{None} for C{defaultUri} means: the default namespace for my child elements is inherited from the logical ancestors of this element, when the complete XML document has been serialized. To illustrate, an example from a Jabber stream. Assume the start tag of the root element of the stream has already been serialized, along with several complete child elements, and sent off, looking like this: <stream:stream xmlns:stream='http://etherx.jabber.org/streams' xmlns='jabber:client' to='example.com'> ... Now suppose we want to send a complete element represented by an object C{message} created like: >>> message = domish.Element((None, 'message')) >>> message['to'] = 'user@example.com' >>> message.addElement('body', content='Hi!') <twisted.words.xish.domish.Element object at 0x8276e8c> >>> message.toXml() u"<message to='user@example.com'><body>Hi!</body></message>" As, you can see, this XML snippet has no xmlns declaration. When sent off, it inherits the C{jabber:client} namespace from the root element. Note that this renders the same as using C{''} instead of C{None}: >>> presence = domish.Element(('', 'presence')) >>> presence.toXml() u"<presence/>" However, if this object has a parent defined, the difference becomes clear: >>> child = message.addElement(('http://example.com/', 'envelope')) >>> child.addChild(presence) <twisted.words.xish.domish.Element object at 0x8276fac> >>> message.toXml() u"<message to='user@example.com'><body>Hi!</body><envelope xmlns='http://example.com/'><presence xmlns=''/></envelope></message>" As, you can see, the <presence/> element is now in the empty namespace, not in the default namespace of the parent or the streams'. @type uri: L{unicode} or None @ivar uri: URI of this Element's name @type name: L{unicode} @ivar name: Name of this Element @type defaultUri: L{unicode} or None @ivar defaultUri: URI this Element exists within @type children: L{list} @ivar children: List of child Elements and content @type parent: L{Element} @ivar parent: Reference to the parent Element, if any. @type attributes: L{dict} @ivar attributes: Dictionary of attributes associated with this Element. @type localPrefixes: L{dict} @ivar localPrefixes: Dictionary of namespace declarations on this element. The key is the prefix to bind the namespace uri to.
Method | __init__ | |
Method | __getattr__ | Undocumented |
Method | __getitem__ | Undocumented |
Method | __delitem__ | Undocumented |
Method | __setitem__ | Undocumented |
Method | __str__ | Retrieve the first CData (content) node |
Method | _dqa | Dequalify an attribute key as needed |
Method | getAttribute | Retrieve the value of attribname, if it exists |
Method | hasAttribute | Determine if the specified attribute exists |
Method | compareAttribute | Safely compare the value of an attribute against a provided value. |
Method | swapAttributeValues | Swap the values of two attribute. |
Method | addChild | Add a child to this Element. |
Method | addContent | Add some text data to this Element. |
Method | addElement | Create an element and add as child. |
Method | addRawXml | Add a pre-serialized chunk o' XML as a child of this Element. |
Method | addUniqueId | Add a unique (across a given Python session) id attribute to this |
Method | elements | Iterate across all children of this Element that are Elements. |
Method | toXml | Serialize this Element and all children to a string. |
Method | firstChildElement | Undocumented |
Parameters | qname | Tuple of (uri, name) |
defaultUri | The default URI of the element; defaults to the URI specified in
qname
| |
attribs | Dictionary of attributes | |
localPrefixes | Dictionary of namespace declarations on this element. The key is the prefix to bind the namespace uri to. |
Safely compare the value of an attribute against a provided value.
None
-safe.
Create an element and add as child.
The new element is added to this element as a child, and will have this element as its parent.Parameters | name | element name. This can be either a unicode object that
contains the local name, or a tuple of (uri, local_name) for a fully
qualified name. In the former case, the namespace URI is inherited from
this element.
(type: unicode or tuple of (unicode ,
unicode )
) |
defaultUri | default namespace URI for child elements. If None , this
is inherited from this element.
(type: unicode
) | |
content | text contained by the new element.
(type: unicode
) | |
Returns | the created element
(type: object providing IElement
) |