| from __future__ import absolute_import, division, unicode_literals |
| |
| from . import _base |
| |
| |
| class Filter(_base.Filter): |
| def slider(self): |
| previous1 = previous2 = None |
| for token in self.source: |
| if previous1 is not None: |
| yield previous2, previous1, token |
| previous2 = previous1 |
| previous1 = token |
| yield previous2, previous1, None |
| |
| def __iter__(self): |
| for previous, token, next in self.slider(): |
| type = token["type"] |
| if type == "StartTag": |
| if (token["data"] or |
| not self.is_optional_start(token["name"], previous, next)): |
| yield token |
| elif type == "EndTag": |
| if not self.is_optional_end(token["name"], next): |
| yield token |
| else: |
| yield token |
| |
| def is_optional_start(self, tagname, previous, next): |
| type = next and next["type"] or None |
| if tagname in 'html': |
| # An html element's start tag may be omitted if the first thing |
| # inside the html element is not a space character or a comment. |
| return type not in ("Comment", "SpaceCharacters") |
| elif tagname == 'head': |
| # A head element's start tag may be omitted if the first thing |
| # inside the head element is an element. |
| # XXX: we also omit the start tag if the head element is empty |
| if type in ("StartTag", "EmptyTag"): |
| return True |
| elif type == "EndTag": |
| return next["name"] == "head" |
| elif tagname == 'body': |
| # A body element's start tag may be omitted if the first thing |
| # inside the body element is not a space character or a comment, |
| # except if the first thing inside the body element is a script |
| # or style element and the node immediately preceding the body |
| # element is a head element whose end tag has been omitted. |
| if type in ("Comment", "SpaceCharacters"): |
| return False |
| elif type == "StartTag": |
| # XXX: we do not look at the preceding event, so we never omit |
| # the body element's start tag if it's followed by a script or |
| # a style element. |
| return next["name"] not in ('script', 'style') |
| else: |
| return True |
| elif tagname == 'colgroup': |
| # A colgroup element's start tag may be omitted if the first thing |
| # inside the colgroup element is a col element, and if the element |
| # is not immediately preceeded by another colgroup element whose |
| # end tag has been omitted. |
| if type in ("StartTag", "EmptyTag"): |
| # XXX: we do not look at the preceding event, so instead we never |
| # omit the colgroup element's end tag when it is immediately |
| # followed by another colgroup element. See is_optional_end. |
| return next["name"] == "col" |
| else: |
| return False |
| elif tagname == 'tbody': |
| # A tbody element's start tag may be omitted if the first thing |
| # inside the tbody element is a tr element, and if the element is |
| # not immediately preceeded by a tbody, thead, or tfoot element |
| # whose end tag has been omitted. |
| if type == "StartTag": |
| # omit the thead and tfoot elements' end tag when they are |
| # immediately followed by a tbody element. See is_optional_end. |
| if previous and previous['type'] == 'EndTag' and \ |
| previous['name'] in ('tbody', 'thead', 'tfoot'): |
| return False |
| return next["name"] == 'tr' |
| else: |
| return False |
| return False |
| |
| def is_optional_end(self, tagname, next): |
| type = next and next["type"] or None |
| if tagname in ('html', 'head', 'body'): |
| # An html element's end tag may be omitted if the html element |
| # is not immediately followed by a space character or a comment. |
| return type not in ("Comment", "SpaceCharacters") |
| elif tagname in ('li', 'optgroup', 'tr'): |
| # A li element's end tag may be omitted if the li element is |
| # immediately followed by another li element or if there is |
| # no more content in the parent element. |
| # An optgroup element's end tag may be omitted if the optgroup |
| # element is immediately followed by another optgroup element, |
| # or if there is no more content in the parent element. |
| # A tr element's end tag may be omitted if the tr element is |
| # immediately followed by another tr element, or if there is |
| # no more content in the parent element. |
| if type == "StartTag": |
| return next["name"] == tagname |
| else: |
| return type == "EndTag" or type is None |
| elif tagname in ('dt', 'dd'): |
| # A dt element's end tag may be omitted if the dt element is |
| # immediately followed by another dt element or a dd element. |
| # A dd element's end tag may be omitted if the dd element is |
| # immediately followed by another dd element or a dt element, |
| # or if there is no more content in the parent element. |
| if type == "StartTag": |
| return next["name"] in ('dt', 'dd') |
| elif tagname == 'dd': |
| return type == "EndTag" or type is None |
| else: |
| return False |
| elif tagname == 'p': |
| # A p element's end tag may be omitted if the p element is |
| # immediately followed by an address, article, aside, |
| # blockquote, datagrid, dialog, dir, div, dl, fieldset, |
| # footer, form, h1, h2, h3, h4, h5, h6, header, hr, menu, |
| # nav, ol, p, pre, section, table, or ul, element, or if |
| # there is no more content in the parent element. |
| if type in ("StartTag", "EmptyTag"): |
| return next["name"] in ('address', 'article', 'aside', |
| 'blockquote', 'datagrid', 'dialog', |
| 'dir', 'div', 'dl', 'fieldset', 'footer', |
| 'form', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', |
| 'header', 'hr', 'menu', 'nav', 'ol', |
| 'p', 'pre', 'section', 'table', 'ul') |
| else: |
| return type == "EndTag" or type is None |
| elif tagname == 'option': |
| # An option element's end tag may be omitted if the option |
| # element is immediately followed by another option element, |
| # or if it is immediately followed by an <code>optgroup</code> |
| # element, or if there is no more content in the parent |
| # element. |
| if type == "StartTag": |
| return next["name"] in ('option', 'optgroup') |
| else: |
| return type == "EndTag" or type is None |
| elif tagname in ('rt', 'rp'): |
| # An rt element's end tag may be omitted if the rt element is |
| # immediately followed by an rt or rp element, or if there is |
| # no more content in the parent element. |
| # An rp element's end tag may be omitted if the rp element is |
| # immediately followed by an rt or rp element, or if there is |
| # no more content in the parent element. |
| if type == "StartTag": |
| return next["name"] in ('rt', 'rp') |
| else: |
| return type == "EndTag" or type is None |
| elif tagname == 'colgroup': |
| # A colgroup element's end tag may be omitted if the colgroup |
| # element is not immediately followed by a space character or |
| # a comment. |
| if type in ("Comment", "SpaceCharacters"): |
| return False |
| elif type == "StartTag": |
| # XXX: we also look for an immediately following colgroup |
| # element. See is_optional_start. |
| return next["name"] != 'colgroup' |
| else: |
| return True |
| elif tagname in ('thead', 'tbody'): |
| # A thead element's end tag may be omitted if the thead element |
| # is immediately followed by a tbody or tfoot element. |
| # A tbody element's end tag may be omitted if the tbody element |
| # is immediately followed by a tbody or tfoot element, or if |
| # there is no more content in the parent element. |
| # A tfoot element's end tag may be omitted if the tfoot element |
| # is immediately followed by a tbody element, or if there is no |
| # more content in the parent element. |
| # XXX: we never omit the end tag when the following element is |
| # a tbody. See is_optional_start. |
| if type == "StartTag": |
| return next["name"] in ['tbody', 'tfoot'] |
| elif tagname == 'tbody': |
| return type == "EndTag" or type is None |
| else: |
| return False |
| elif tagname == 'tfoot': |
| # A tfoot element's end tag may be omitted if the tfoot element |
| # is immediately followed by a tbody element, or if there is no |
| # more content in the parent element. |
| # XXX: we never omit the end tag when the following element is |
| # a tbody. See is_optional_start. |
| if type == "StartTag": |
| return next["name"] == 'tbody' |
| else: |
| return type == "EndTag" or type is None |
| elif tagname in ('td', 'th'): |
| # A td element's end tag may be omitted if the td element is |
| # immediately followed by a td or th element, or if there is |
| # no more content in the parent element. |
| # A th element's end tag may be omitted if the th element is |
| # immediately followed by a td or th element, or if there is |
| # no more content in the parent element. |
| if type == "StartTag": |
| return next["name"] in ('td', 'th') |
| else: |
| return type == "EndTag" or type is None |
| return False |
