genshi/genshi-test: genshi/builder.py comparison

comparison genshi/builder.py @ 230:24757b771651

Renamed Markup to Genshi in repository.

author	cmlenz
date	Mon, 11 Sep 2006 15:07:07 +0000
parents	markup/builder.py@41db0260ebb1
children	8e75b83d3e71 676b78a0c5a0

comparison

equal deleted inserted replaced

-:110d69dbbda3
+:24757b771651
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2006 Edgewall Software
+# All rights reserved.
+#
+# This software is licensed as described in the file COPYING, which
+# you should have received as part of this distribution. The terms
+# are also available at http://genshi.edgewall.org/wiki/License.
+#
+# This software consists of voluntary contributions made by many
+# individuals. For the exact contribution history, see the revision
+# history and logs, available at http://genshi.edgewall.org/log/.
+from genshi.core import Attrs, Namespace, QName, Stream, START, END, TEXT
+__all__ = ['Fragment', 'Element', 'tag']
+class Fragment(object):
+"""Represents a markup fragment, which is basically just a list of element
+or text nodes.
+"""
+__slots__ = ['children']
+def __init__(self):
+self.children = []
+def __add__(self, other):
+return Fragment()(self, other)
+def __call__(self, *args):
+map(self.append, args)
+return self
+def __iter__(self):
+return self._generate()
+def __repr__(self):
+return '<%s>' % self.__class__.__name__
+def __str__(self):
+return str(self.generate())
+def __unicode__(self):
+return unicode(self.generate())
+def append(self, node):
+"""Append an element or string as child node."""
+if isinstance(node, (Element, basestring, int, float, long)):
+# For objects of a known/primitive type, we avoid the check for
+# whether it is iterable for better performance
+self.children.append(node)
+elif isinstance(node, Fragment):
+self.children.extend(node.children)
+elif node is not None:
+try:
+map(self.append, iter(node))
+except TypeError:
+self.children.append(node)
+def _generate(self):
+for child in self.children:
+if isinstance(child, Fragment):
+for event in child._generate():
+yield event
+else:
+if not isinstance(child, basestring):
+child = unicode(child)
+yield TEXT, child, (None, -1, -1)
+def generate(self):
+"""Return a markup event stream for the fragment."""
+return Stream(self._generate())
+class Element(Fragment):
+"""Simple XML output generator based on the builder pattern.
+Construct XML elements by passing the tag name to the constructor:
+>>> print Element('strong')
+<strong/>
+Attributes can be specified using keyword arguments. The values of the
+arguments will be converted to strings and any special XML characters
+escaped:
+>>> print Element('textarea', rows=10, cols=60)
+<textarea rows="10" cols="60"/>
+>>> print Element('span', title='1 < 2')
+<span title="1 &lt; 2"/>
+>>> print Element('span', title='"baz"')
+<span title="&#34;baz&#34;"/>
+The " character is escaped using a numerical entity.
+The order in which attributes are rendered is undefined.
+If an attribute value evaluates to `None`, that attribute is not included
+in the output:
+>>> print Element('a', name=None)
+<a/>
+Attribute names that conflict with Python keywords can be specified by
+appending an underscore:
+>>> print Element('div', class_='warning')
+<div class="warning"/>
+Nested elements can be added to an element using item access notation.
+The call notation can also be used for this and for adding attributes
+using keyword arguments, as one would do in the constructor.
+>>> print Element('ul')(Element('li'), Element('li'))
+<ul><li/><li/></ul>
+>>> print Element('a')('Label')
+<a>Label</a>
+>>> print Element('a')('Label', href="target")
+<a href="target">Label</a>
+Text nodes can be nested in an element by adding strings instead of
+elements. Any special characters in the strings are escaped automatically:
+>>> print Element('em')('Hello world')
+<em>Hello world</em>
+>>> print Element('em')(42)
+<em>42</em>
+>>> print Element('em')('1 < 2')
+<em>1 &lt; 2</em>
+This technique also allows mixed content:
+>>> print Element('p')('Hello ', Element('b')('world'))
+<p>Hello <b>world</b></p>
+Quotes are not escaped inside text nodes:
+>>> print Element('p')('"Hello"')
+<p>"Hello"</p>
+Elements can also be combined with other elements or strings using the
+addition operator, which results in a `Fragment` object that contains the
+operands:
+>>> print Element('br') + 'some text' + Element('br')
+<br/>some text<br/>
+Elements with a namespace can be generated using the `Namespace` and/or
+`QName` classes:
+>>> from genshi.core import Namespace
+>>> xhtml = Namespace('http://www.w3.org/1999/xhtml')
+>>> print Element(xhtml.html, lang='en')
+<html lang="en" xmlns="http://www.w3.org/1999/xhtml"/>
+"""
+__slots__ = ['tag', 'attrib']
+def __init__(self, tag_, **attrib):
+Fragment.__init__(self)
+self.tag = QName(tag_)
+self.attrib = Attrs()
+for attr, value in attrib.items():
+if value is not None:
+if not isinstance(value, basestring):
+value = unicode(value)
+self.attrib.append((QName(attr.rstrip('_').replace('_', '-')),
+value))
+def __call__(self, *args, **kwargs):
+for attr, value in kwargs.items():
+if value is not None:
+if not isinstance(value, basestring):
+value = unicode(value)
+self.attrib.set(attr.rstrip('_').replace('_', '-'), value)
+Fragment.__call__(self, *args)
+return self
+def __repr__(self):
+return '<%s "%s">' % (self.__class__.__name__, self.tag)
+def _generate(self):
+yield START, (self.tag, self.attrib), (None, -1, -1)
+for kind, data, pos in Fragment._generate(self):
+yield kind, data, pos
+yield END, self.tag, (None, -1, -1)
+def generate(self):
+"""Return a markup event stream for the fragment."""
+return Stream(self._generate())
+class ElementFactory(object):
+"""Factory for `Element` objects.
+A new element is created simply by accessing a correspondingly named
+attribute of the factory object:
+>>> factory = ElementFactory()
+>>> print factory.foo
+<foo/>
+>>> print factory.foo(id=2)
+<foo id="2"/>
+Markup fragments (lists of nodes without a parent element) can be created
+by calling the factory:
+>>> print factory('Hello, ', factory.em('world'), '!')
+Hello, <em>world</em>!
+A factory can also be bound to a specific namespace:
+>>> factory = ElementFactory('http://www.w3.org/1999/xhtml')
+>>> print factory.html(lang="en")
+<html lang="en" xmlns="http://www.w3.org/1999/xhtml"/>
+The namespace for a specific element can be altered on an existing factory
+by specifying the new namespace using item access:
+>>> factory = ElementFactory()
+>>> print factory.html(factory['http://www.w3.org/2000/svg'].g(id=3))
+<html><g id="3" xmlns="http://www.w3.org/2000/svg"/></html>
+Usually, the `ElementFactory` class is not be used directly. Rather, the
+`tag` instance should be used to create elements.
+"""
+def __init__(self, namespace=None):
+"""Create the factory, optionally bound to the given namespace.
+@param namespace: the namespace URI for any created elements, or `None`
+for no namespace
+"""
+if namespace and not isinstance(namespace, Namespace):
+namespace = Namespace(namespace)
+self.namespace = namespace
+def __call__(self, *args):
+return Fragment()(*args)
+def __getitem__(self, namespace):
+"""Return a new factory that is bound to the specified namespace."""
+return ElementFactory(namespace)
+def __getattr__(self, name):
+"""Create an `Element` with the given name."""
+return Element(self.namespace and self.namespace[name] or name)
+tag = ElementFactory()

Mercurial > genshi > genshi-test

comparison genshi/builder.py @ 230:24757b771651