'''

Copyright (c) 2015, 2019 Tim Savannah under LGPLv3. All Rights Reserved.

See LICENSE (https://gnu.org/licenses/lgpl-3.0.txt) for more information.

Validator - A validating version of the HTML parser (vs the normal 'best effort' parser)

'''

from .Parser import AdvancedHTMLParser

from .Tags import isValidAttributeName

from .exceptions import InvalidCloseException, MissedCloseException, InvalidAttributeNameException

__all__ = ('InvalidCloseException', 'MissedCloseException', 'InvalidAttributeNameException',

'ValidatingAdvancedHTMLParser',

)

class ValidatingAdvancedHTMLParser(AdvancedHTMLParser):

'''

ValidatingAdvancedHTMLParser - A parser which will raise Exceptions for a couple HTML errors that would otherwise cause

an assumption to be made during parsing.

exceptions.InvalidCloseException - The parsed string/file tried to close something it shouldn't have.

exceptions.MissedCloseException - The parsed string/file missed closing an item.

'''

def handle_starttag(self, tagName, attributeList, isSelfClosing=False):

'''

handle_starttag - internal for parsing,

ValidatingAdvancedHTMLParser will run through the attributes list and make sure

none have an invalid name, or will raise an error.

@raises - InvalidAttributeNameException if an attribute name is passed with invalid character(s)

'''

# Iterate over the passed attributes, and validate them.

for (attrName, attrValue) in attributeList:

if isValidAttributeName(attrName) is False:

raise InvalidAttributeNameException(tagName, attrName, attrValue)

# Done validating, feed to parent.

return AdvancedHTMLParser.handle_starttag(self, tagName, attributeList, isSelfClosing)

def handle_endtag(self, tagName):

'''

Internal for parsing

'''

inTag = self._inTag

if len(inTag) == 0:

# Attempted to close, but no open tags

raise InvalidCloseException(tagName, [])

foundIt = False

i = len(inTag) - 1

while i >= 0:

if inTag[i].tagName == tagName:

foundIt = True

break

i -= 1

if not foundIt:

# Attempted to close, but did not match anything

raise InvalidCloseException(tagName, inTag)

if inTag[-1].tagName != tagName:

raise MissedCloseException(tagName, [x for x in inTag[-1 * (i+1): ] ] )

inTag.pop()