root/trunk/test/w3c/testCSSWithMinidom.py

#!/usr/bin/env python
##~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
##~ Copyright (C) 2002-2004  TechGame Networks, LLC.
##~ 
##~ This library is free software; you can redistribute it and/or
##~ modify it under the terms of the BSD style License as found in the 
##~ LICENSE file included with this distribution.
##~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#~ Imports 
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

import unittest
import xml.dom.minidom
from TG.w3c import css
from TG.w3c.cssDOMElementInterface import CSSDOMElementInterface

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#~ Constants / Variables / Etc. 
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

stylesheet = """
    * {
        font-size: medium;
        bgcolor: orange;
        fgcolor: blue;
    }

    slideshow {
        bgcolor: black;
        fgcolor: white;
    }

    slideshow * {
        fgcolor: inherit;
        bgcolor: inherit;
    }

    slideshow > title {
        font-size: 80pt;
    }

    slide {
        image: url('page-image.png');
    }

    slide:last-child {
        fgcolor: yellow;
        image: url('last-page-image.png');
    }

    slide > title {
        font-size: 40pt;
    }

    point {
        font-size: medium;
    }

    point#special {
        font-size: xx-large;
        fgcolor: red;
        bgcolor: yellow;
    }
    """

document = """<?xml version='1.0' ?>
    <!-- Derived from 13.7.2 DOM Example of the Python 2.3 Documentation -->
    <slideshow>
        <title>Demo slideshow combined with CSS</title>

        <slide>
            <title>Intro CSS Slide</title>
            <point>This is a CSS demo for xml.dom</point>
            <point>for processing slides with CSS!</point>
        </slide>

        <slide>
            <title>Another CSS demo slide</title>

            <point>It is important</point>
            <point>To have more than</point>
            <point>one slide</point>
        </slide>

        <slide>
            <title>Last CSS demo slide title</title>
            <point id='special'>Thanks for looking at CSS!</point>
        </slide>

    </slideshow>
"""

documentParsedWithCSS = (u'slideshow',
 {'bgcolor': 'black', 'fgcolor': 'white'},
 [(u'title',
   {'bgcolor': 'black', 'font-size': ('80', 'pt'), 'fgcolor': 'white'},
   []),
  (u'slide',
   {'bgcolor': 'black', 'image': 'page-image.png', 'fgcolor': 'white'},
   [(u'title',
     {'bgcolor': 'black', 'font-size': ('40', 'pt'), 'fgcolor': 'white'},
     []),
    (u'point',
     {'bgcolor': 'black', 'font-size': 'medium', 'fgcolor': 'white'},
     []),
    (u'point',
     {'bgcolor': 'black', 'font-size': 'medium', 'fgcolor': 'white'},
     [])]),
  (u'slide',
   {'bgcolor': 'black', 'image': 'page-image.png', 'fgcolor': 'white'},
   [(u'title',
     {'bgcolor': 'black', 'font-size': ('40', 'pt'), 'fgcolor': 'white'},
     []),
    (u'point',
     {'bgcolor': 'black', 'font-size': 'medium', 'fgcolor': 'white'},
     []),
    (u'point',
     {'bgcolor': 'black', 'font-size': 'medium', 'fgcolor': 'white'},
     []),
    (u'point',
     {'bgcolor': 'black', 'font-size': 'medium', 'fgcolor': 'white'},
     [])]),
  (u'slide',
   {'bgcolor': 'black', 'image': 'last-page-image.png', 'fgcolor': 'yellow'},
   [(u'title',
     {'bgcolor': 'black', 'font-size': ('40', 'pt'), 'fgcolor': 'yellow'},
     []),
    (u'point',
     {'bgcolor': 'yellow', 'font-size': 'xx-large', 'fgcolor': 'red'},
     [])
   ]
  )
 ]
)

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#~ Definitions 
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

def getCSSAttr(self, cssCascade, attrName, default=NotImplemented):
    if attrName in self.cssAttrs:
        return self.cssAttrs[attrName]

    result = None

    attrValue = self.attributes.get(attrName, None)
    if attrValue is not None:
        result = cssCascade.parser.parseSingleAttr(attrValue.value)

    if result is None:
        result = cssCascade.findStyleFor(self.cssElement, attrName, default)

    if result == 'inherit':
        if hasattr(self.parentNode, 'getCSSAttr'):
            result = self.parentNode.getCSSAttr(cssCascade, attrName, default)
        elif default is not NotImplemented:
            return default
        else:
            raise LookupError("Could not find inherited CSS attribute value for '%s'" % (attrName,))

    self.cssAttrs[attrName] = result
    return result

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#~ Setup code derived from a demo
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

# this is an informal schema that maps tag names to the css attributes they
# should have
tagToAttrNames = {
    'slideshow': 'fgcolor bgcolor'.split(),
    'title': 'font-size fgcolor bgcolor'.split(),
    'slide': 'image fgcolor bgcolor'.split(),
    'point': 'font-size fgcolor bgcolor'.split(),
    }

def visitElement(element, children, cssCascade):
    """Visits individual elements, and sets css attributes on them"""
    element.cssElement = CSSDOMElementInterface(element)
    element.cssAttrs = {}

    cssAttrMap = {}
    for cssAttrName in tagToAttrNames.get(element.tagName, []):
        cssAttrMap[cssAttrName] = element.getCSSAttr(cssCascade, cssAttrName)

    return (element.tagName, cssAttrMap, list(children))

def visitElementNodes(root, visit=visitElement, **kw):
    """Visits all ELEMENT_NODEs of a dom recursively"""
    for node in root.childNodes:
        if node.nodeType == node.ELEMENT_NODE:
            children = visitElementNodes(node, visit, **kw)
            yield visit(node, children, **kw)

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#~ Unittest
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

class TestCSSWithMinidom(unittest.TestCase):
    def setUp(self):
        # parse the document into a dom
        self.dom = xml.dom.minidom.parseString(document)

        # parse the stylesheet
        cssParser = css.CSSParser()
        authorSS = cssParser.parse(stylesheet)
        # create the css cascade from the stylesheet
        self.cssCascade = css.CSSCascadeStrategy(authorSS)
        self.cssCascade.parser = cssParser

        xml.dom.minidom.Element.getCSSAttr = getCSSAttr

    def tearDown(self):
        del xml.dom.minidom.Element.getCSSAttr

    def test(self):
        slideshow = visitElementNodes(self.dom, cssCascade=self.cssCascade).next()
        self.assertEqual(slideshow, documentParsedWithCSS)

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#~ Unittest Main 
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

if __name__=='__main__':
    unittest.main()