forked from mirrors/bookwyrm
51 lines
1.6 KiB
Python
51 lines
1.6 KiB
Python
''' html parser to clean up incoming text from unknown sources '''
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from html.parser import HTMLParser
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class InputHtmlParser(HTMLParser):
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''' Removes any html that isn't whitelisted from a block '''
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def __init__(self):
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HTMLParser.__init__(self)
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self.whitelist = ['p', 'b', 'i', 'pre']
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self.tag_stack = []
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self.output = []
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# if the html appears invalid, we just won't allow any at all
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self.allow_html = True
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def handle_starttag(self, tag, attrs):
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''' check if the tag is valid '''
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if self.allow_html and tag in self.whitelist:
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self.output.append(('tag', '<%s>' % tag))
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self.tag_stack.append(tag)
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else:
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self.output.append(('data', ' '))
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def handle_endtag(self, tag):
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''' keep the close tag '''
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if not self.allow_html or tag not in self.whitelist:
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self.output.append(('data', ' '))
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return
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if not self.tag_stack or self.tag_stack[-1] != tag:
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# the end tag doesn't match the most recent start tag
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self.allow_html = False
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self.output.append(('data', ' '))
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return
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self.tag_stack = self.tag_stack[:-1]
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self.output.append(('tag', '</%s>' % tag))
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def handle_data(self, data):
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''' extract the answer, if we're in an answer tag '''
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self.output.append(('data', data))
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def get_output(self):
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''' convert the output from a list of tuples to a string '''
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if not self.allow_html:
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return ''.join(v for (k, v) in self.output if k == 'data')
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return ''.join(v for (k, v) in self.output)
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