zulip/tools/lib/template_parser.py

443 lines
13 KiB
Python

from typing import Callable, List, Optional, Text
class TemplateParserException(Exception):
def __init__(self, message):
# type: (str) -> None
self.message = message
def __str__(self):
# type: () -> str
return self.message
class TokenizationException(Exception):
def __init__(self, message, line_content=None):
# type: (str, Optional[str]) -> None
self.message = message
self.line_content = line_content
class TokenizerState:
def __init__(self):
# type: () -> None
self.i = 0
self.line = 1
self.col = 1
class Token:
def __init__(self, kind, s, tag, line, col, line_span):
# type: (str, str, str, int, int, int) -> None
self.kind = kind
self.s = s
self.tag = tag
self.line = line
self.col = col
self.line_span = line_span
def tokenize(text):
# type: (str) -> List[Token]
def advance(n):
# type: (int) -> None
for _ in range(n):
state.i += 1
if state.i >= 0 and text[state.i - 1] == '\n':
state.line += 1
state.col = 1
else:
state.col += 1
def looking_at(s):
# type: (str) -> bool
return text[state.i:state.i+len(s)] == s
def looking_at_htmlcomment():
# type: () -> bool
return looking_at("<!--")
def looking_at_handlebarcomment():
# type: () -> bool
return looking_at("{{!")
def looking_at_djangocomment():
# type: () -> bool
return looking_at("{#")
def looking_at_handlebarpartial() -> bool:
return looking_at("{{>")
def looking_at_html_start():
# type: () -> bool
return looking_at("<") and not looking_at("</")
def looking_at_html_end():
# type: () -> bool
return looking_at("</")
def looking_at_handlebars_start():
# type: () -> bool
return looking_at("{{#") or looking_at("{{^")
def looking_at_handlebars_end():
# type: () -> bool
return looking_at("{{/")
def looking_at_django_start():
# type: () -> bool
return looking_at("{% ") and not looking_at("{% end")
def looking_at_django_end():
# type: () -> bool
return looking_at("{% end")
def looking_at_jinja2_end_whitespace_stripped():
# type: () -> bool
return looking_at("{%- end")
def looking_at_jinja2_start_whitespace_stripped_type2():
# type: () -> bool
# This function detects tag like {%- if foo -%}...{% endif %}
return looking_at("{%-") and not looking_at("{%- end")
state = TokenizerState()
tokens = []
while state.i < len(text):
try:
if looking_at_htmlcomment():
s = get_html_comment(text, state.i)
tag = s[4:-3]
kind = 'html_comment'
elif looking_at_handlebarcomment():
s = get_handlebar_comment(text, state.i)
tag = s[3:-2]
kind = 'handlebar_comment'
elif looking_at_djangocomment():
s = get_django_comment(text, state.i)
tag = s[2:-2]
kind = 'django_comment'
elif looking_at_handlebarpartial():
s = get_handlebar_partial(text, state.i)
tag = s[9:-2]
kind = 'handlebars_singleton'
elif looking_at_html_start():
s = get_html_tag(text, state.i)
tag_parts = s[1:-1].split()
if not tag_parts:
raise TemplateParserException("Tag name missing")
tag = tag_parts[0]
if is_special_html_tag(s, tag):
kind = 'html_special'
elif is_self_closing_html_tag(s, tag):
kind = 'html_singleton'
else:
kind = 'html_start'
elif looking_at_html_end():
s = get_html_tag(text, state.i)
tag = s[2:-1]
kind = 'html_end'
elif looking_at_handlebars_start():
s = get_handlebars_tag(text, state.i)
tag = s[3:-2].split()[0]
kind = 'handlebars_start'
elif looking_at_handlebars_end():
s = get_handlebars_tag(text, state.i)
tag = s[3:-2]
kind = 'handlebars_end'
elif looking_at_django_start():
s = get_django_tag(text, state.i)
tag = s[3:-2].split()[0]
kind = 'django_start'
if s[-3] == '-':
kind = 'jinja2_whitespace_stripped_start'
elif looking_at_django_end():
s = get_django_tag(text, state.i)
tag = s[6:-3]
kind = 'django_end'
elif looking_at_jinja2_end_whitespace_stripped():
s = get_django_tag(text, state.i)
tag = s[7:-3]
kind = 'jinja2_whitespace_stripped_end'
elif looking_at_jinja2_start_whitespace_stripped_type2():
s = get_jinja2_whitespace_stripped_tag(text, state.i)
tag = s[3:-3].split()[0]
kind = 'jinja2_whitespace_stripped_type2_start'
else:
advance(1)
continue
except TokenizationException as e:
raise TemplateParserException('''%s at Line %d Col %d:"%s"''' %
(e.message, state.line, state.col,
e.line_content))
line_span = len(s.split('\n'))
token = Token(
kind=kind,
s=s,
tag=tag,
line=state.line,
col=state.col,
line_span=line_span
)
tokens.append(token)
advance(len(s))
def add_pseudo_end_token(kind: str) -> None:
token = Token(
kind=kind,
s='</' + tag + '>',
tag=tag,
line=state.line,
col=state.col,
line_span=1
)
tokens.append(token)
if kind == 'html_singleton':
# Here we insert a Pseudo html_singleton_end tag so as to have
# ease of detection of end of singleton html tags which might be
# needed in some cases as with our html pretty printer.
add_pseudo_end_token('html_singleton_end')
if kind == 'handlebars_singleton':
# We insert a pseudo handlbar end tag for singleton cases of
# handlebars like the partials. This helps in indenting multi line partials.
add_pseudo_end_token('handlebars_singleton_end')
return tokens
def validate(fn=None, text=None, check_indent=True):
# type: (Optional[str], Optional[str], bool) -> None
assert fn or text
if fn is None:
fn = '<in memory file>'
if text is None:
text = open(fn).read()
tokens = tokenize(text)
class State:
def __init__(self, func):
# type: (Callable[[Token], None]) -> None
self.depth = 0
self.matcher = func
def no_start_tag(token):
# type: (Token) -> None
raise TemplateParserException('''
No start tag
fn: %s
end tag:
%s
line %d, col %d
''' % (fn, token.tag, token.line, token.col))
state = State(no_start_tag)
def start_tag_matcher(start_token):
# type: (Token) -> None
state.depth += 1
start_tag = start_token.tag.strip('~')
start_line = start_token.line
start_col = start_token.col
old_matcher = state.matcher
def f(end_token):
# type: (Token) -> None
end_tag = end_token.tag.strip('~')
end_line = end_token.line
end_col = end_token.col
if start_tag == 'a':
max_lines = 3
else:
max_lines = 1
problem = None
if (start_tag == 'code') and (end_line == start_line + 1):
problem = 'Code tag is split across two lines.'
if start_tag != end_tag:
problem = 'Mismatched tag.'
elif check_indent and (end_line > start_line + max_lines):
if end_col != start_col:
problem = 'Bad indentation.'
if problem:
raise TemplateParserException('''
fn: %s
%s
start:
%s
line %d, col %d
end tag:
%s
line %d, col %d
''' % (fn, problem, start_token.s, start_line, start_col, end_tag, end_line, end_col))
state.matcher = old_matcher
state.depth -= 1
state.matcher = f
for token in tokens:
kind = token.kind
tag = token.tag
if kind == 'html_start':
start_tag_matcher(token)
elif kind == 'html_end':
state.matcher(token)
elif kind == 'handlebars_start':
start_tag_matcher(token)
elif kind == 'handlebars_end':
state.matcher(token)
elif kind in {'django_start',
'jinja2_whitespace_stripped_type2_start'}:
if is_django_block_tag(tag):
start_tag_matcher(token)
elif kind == 'django_end':
state.matcher(token)
if state.depth != 0:
raise TemplateParserException('Missing end tag')
def is_special_html_tag(s, tag):
# type: (str, str) -> bool
return tag in ['link', 'meta', '!DOCTYPE']
def is_self_closing_html_tag(s: Text, tag: Text) -> bool:
self_closing_tag = tag in [
'area',
'base',
'br',
'col',
'embed',
'hr',
'img',
'input',
'param',
'source',
'track',
'wbr',
]
singleton_tag = s.endswith('/>')
return self_closing_tag or singleton_tag
def is_django_block_tag(tag):
# type: (str) -> bool
return tag in [
'autoescape',
'block',
'comment',
'for',
'if',
'ifequal',
'verbatim',
'blocktrans',
'trans',
'raw',
'with',
]
def get_handlebars_tag(text, i):
# type: (str, int) -> str
end = i + 2
while end < len(text) - 1 and text[end] != '}':
end += 1
if text[end] != '}' or text[end+1] != '}':
raise TokenizationException('Tag missing "}}"', text[i:end+2])
s = text[i:end+2]
return s
def get_django_tag(text, i):
# type: (str, int) -> str
end = i + 2
while end < len(text) - 1 and text[end] != '%':
end += 1
if text[end] != '%' or text[end+1] != '}':
raise TokenizationException('Tag missing "%}"', text[i:end+2])
s = text[i:end+2]
return s
def get_jinja2_whitespace_stripped_tag(text, i):
# type: (str, int) -> str
end = i + 3
while end < len(text) - 1 and text[end] != '%':
end += 1
if text[end-1] != '-' or text[end] != '%' or text[end+1] != '}':
raise TokenizationException('Tag missing "-%}"', text[i:end+2])
s = text[i:end+2]
return s
def get_html_tag(text, i):
# type: (str, int) -> str
quote_count = 0
end = i + 1
unclosed_end = 0
while end < len(text) and (text[end] != '>' or quote_count % 2 != 0 and text[end] != '<'):
if text[end] == '"':
quote_count += 1
if not unclosed_end and text[end] == '<':
unclosed_end = end
end += 1
if quote_count % 2 != 0:
if unclosed_end:
raise TokenizationException('Unbalanced Quotes', text[i:unclosed_end])
else:
raise TokenizationException('Unbalanced Quotes', text[i:end+1])
if end == len(text) or text[end] != '>':
raise TokenizationException('Tag missing ">"', text[i:end+1])
s = text[i:end+1]
return s
def get_html_comment(text, i):
# type: (str, int) -> str
end = i + 7
unclosed_end = 0
while end <= len(text):
if text[end-3:end] == '-->':
return text[i:end]
if not unclosed_end and text[end] == '<':
unclosed_end = end
end += 1
raise TokenizationException('Unclosed comment', text[i:unclosed_end])
def get_handlebar_comment(text, i):
# type: (str, int) -> str
end = i + 5
unclosed_end = 0
while end <= len(text):
if text[end-2:end] == '}}':
return text[i:end]
if not unclosed_end and text[end] == '<':
unclosed_end = end
end += 1
raise TokenizationException('Unclosed comment', text[i:unclosed_end])
def get_django_comment(text, i):
# type: (str, int) -> str
end = i + 4
unclosed_end = 0
while end <= len(text):
if text[end-2:end] == '#}':
return text[i:end]
if not unclosed_end and text[end] == '<':
unclosed_end = end
end += 1
raise TokenizationException('Unclosed comment', text[i:unclosed_end])
def get_handlebar_partial(text, i):
# type: (str, int) -> str
end = i + 10
unclosed_end = 0
while end <= len(text):
if text[end-2:end] == '}}':
return text[i:end]
if not unclosed_end and text[end] == '<':
unclosed_end = end
end += 1
raise TokenizationException('Unclosed partial', text[i:unclosed_end])