rename main code directory

bookwyrm/sanitize_html.py

@@ -0,0 +1,52 @@
+''' html parser to clean up incoming text from unknown sources '''
+from html.parser import HTMLParser
+
+class InputHtmlParser(HTMLParser):
+    ''' Removes any html that isn't whitelisted from a block '''
+
+    def __init__(self):
+        HTMLParser.__init__(self)
+        self.whitelist = ['p', 'b', 'i', 'pre', 'a', 'span']
+        self.tag_stack = []
+        self.output = []
+        # if the html appears invalid, we just won't allow any at all
+        self.allow_html = True
+
+
+    def handle_starttag(self, tag, attrs):
+        ''' check if the tag is valid '''
+        if self.allow_html and tag in self.whitelist:
+            self.output.append(('tag', self.get_starttag_text()))
+            self.tag_stack.append(tag)
+        else:
+            self.output.append(('data', ''))
+
+
+    def handle_endtag(self, tag):
+        ''' keep the close tag '''
+        if not self.allow_html or tag not in self.whitelist:
+            self.output.append(('data', ''))
+            return
+
+        if not self.tag_stack or self.tag_stack[-1] != tag:
+            # the end tag doesn't match the most recent start tag
+            self.allow_html = False
+            self.output.append(('data', ''))
+            return
+
+        self.tag_stack = self.tag_stack[:-1]
+        self.output.append(('tag', '</%s>' % tag))
+
+
+    def handle_data(self, data):
+        ''' extract the answer, if we're in an answer tag '''
+        self.output.append(('data', data))
+
+
+    def get_output(self):
+        ''' convert the output from a list of tuples to a string '''
+        if self.tag_stack:
+            self.allow_html = False
+        if not self.allow_html:
+            return ''.join(v for (k, v) in self.output if k == 'data')
+        return ''.join(v for (k, v) in self.output)