diff options
| -rw-r--r-- | Doc/lib/xmldom.tex | 30 | ||||
| -rw-r--r-- | Lib/xml/dom/__init__.py | 2 | ||||
| -rw-r--r-- | Lib/xml/dom/domreg.py | 76 | ||||
| -rw-r--r-- | Lib/xml/dom/minidom.py | 3 |
4 files changed, 111 insertions, 0 deletions
diff --git a/Doc/lib/xmldom.tex b/Doc/lib/xmldom.tex index 5e752a0..87070b9 100644 --- a/Doc/lib/xmldom.tex +++ b/Doc/lib/xmldom.tex @@ -85,6 +85,36 @@ the strict mapping from IDL). See section \ref{dom-conformance}, {This specifies the mapping from OMG IDL to Python.} \end{seealso} +\subsection{Module Contents} + +The \module{xml.dom} contains the following functions: + +\begin{funcdesc}{registerDOMImplementation}{name, factory} +Register the \var{factory} function with the \var{name}. The factory +function should return an object which implements the +\code{DOMImplementation| interface. The factory function can either return +the same object, or a new one (e.g. if that implementation supports +some customization). +\end{funcdesc} + +\begin{funcdesc}{getDOMImplementation}{name = None, features = ()} +Return a suitable DOM implementation. The \var{name} is either +well-known, the module name of a DOM implementation, or +\code{None}. If it is not \code{None}, imports the corresponding module and +returns a \class{DOMImplementation} object if the import succeeds. If +no name is given, and if the environment variable \code{PYTHON_DOM} is +set, this variable is used to find the implementation. + +If name is not given, consider the available implementations to find +one with the required feature set. If no implementation can be found, +raise an \exception{ImportError}. The features list must be a sequence of +(feature, version) pairs which are passed to hasFeature. +\end{funcdesc} + +% Should the Node documentation go here? + +In addition, \module{xml.dom} contains the \class{Node}, and the DOM +exceptions. \subsection{Objects in the DOM \label{dom-objects}} diff --git a/Lib/xml/dom/__init__.py b/Lib/xml/dom/__init__.py index 2dbb695..aa19ca1 100644 --- a/Lib/xml/dom/__init__.py +++ b/Lib/xml/dom/__init__.py @@ -115,3 +115,5 @@ class NamespaceErr(DOMException): class InvalidAccessErr(DOMException): code = INVALID_ACCESS_ERR + +from domreg import getDOMImplementation,registerDOMImplementation diff --git a/Lib/xml/dom/domreg.py b/Lib/xml/dom/domreg.py new file mode 100644 index 0000000..14b87d6 --- /dev/null +++ b/Lib/xml/dom/domreg.py @@ -0,0 +1,76 @@ +"""Registration facilities for DOM. This module should not be used +directly. Instead, the functions getDOMImplementation and +registerDOMImplementation should be imported from xml.dom.""" + +# This is a list of well-known implementations. Well-known names +# should be published by posting to xml-sig@python.org, and are +# subsequently recorded in this file. + +well_known_implementations = { + 'minidom':'xml.dom.minidom', + '4DOM': 'xml.dom.DOMImplementation', + } + +# DOM implementations not officially registered should register +# themselves with their + +registered = {} + +def registerDOMImplementation(name, factory): + """registerDOMImplementation(name, factory) + + Register the factory function with the name. The factory function + should return an object which implements the DOMImplementation + interface. The factory function can either return the same object, + or a new one (e.g. if that implementation supports some + customization).""" + + registered[name] = factory + +def _good_enough(dom, features): + "_good_enough(dom, features) -> Return 1 if the dom offers the features" + for f,v in features: + if not dom.hasFeature(f,v): + return 0 + return 1 + +def getDOMImplementation(name = None, features = ()): + """getDOMImplementation(name = None, features = ()) -> DOM implementation. + + Return a suitable DOM implementation. The name is either + well-known, the module name of a DOM implementation, or None. If + it is not None, imports the corresponding module and returns + DOMImplementation object if the import succeeds. + + If name is not given, consider the available implementations to + find one with the required feature set. If no implementation can + be found, raise an ImportError. The features list must be a sequence + of (feature, version) pairs which are passed to hasFeature.""" + + import os + creator = None + mod = well_known_implementations.get(name) + if mod: + mod = __import__(mod, {}, {}, ['getDOMImplementation']) + return mod.getDOMImplementation() + elif name: + return registered[name]() + elif os.environ.has_key("PYTHON_DOM"): + return getDOMImplementation(name = os.environ["PYTHON_DOM"]) + + # User did not specify a name, try implementations in arbitrary + # order, returning the one that has the required features + for creator in registered.values(): + dom = creator() + if _good_enough(dom, features): + return dom + + for creator in well_known_implementations.keys(): + try: + dom = getDOMImplementation(name = creator) + except StandardError: # typically ImportError, or AttributeError + continue + if _good_enough(dom, features): + return dom + + raise ImportError,"no suitable DOM implementation found" diff --git a/Lib/xml/dom/minidom.py b/Lib/xml/dom/minidom.py index b4ae267..35adfd5 100644 --- a/Lib/xml/dom/minidom.py +++ b/Lib/xml/dom/minidom.py @@ -782,3 +782,6 @@ def parseString(*args, **kwargs): """Parse a file into a DOM from a string.""" from xml.dom import pulldom return _doparse(pulldom.parseString, args, kwargs) + +def getDOMImplementation(): + return Document.implementation |