zulip/tools/lib/template_parser.py

431 lines
13 KiB
Python

from typing import Callable, List, Optional, Text
class FormattedException(Exception):
pass
class TemplateParserException(Exception):
def __init__(self, message: str) -> None:
self.message = message
def __str__(self) -> str:
return self.message
class TokenizationException(Exception):
def __init__(self, message: str, line_content: Optional[str] = None) -> None:
self.message = message
self.line_content = line_content
class TokenizerState:
def __init__(self) -> None:
self.i = 0
self.line = 1
self.col = 1
class Token:
def __init__(self, kind: str, s: str, tag: str, line: int, col: int, line_span: 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: str) -> List[Token]:
def advance(n: 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: str) -> bool:
return text[state.i:state.i+len(s)] == s
def looking_at_htmlcomment() -> bool:
return looking_at("<!--")
def looking_at_handlebarcomment() -> bool:
return looking_at("{{!")
def looking_at_djangocomment() -> bool:
return looking_at("{#")
def looking_at_handlebarpartial() -> bool:
return looking_at("{{>")
def looking_at_html_start() -> bool:
return looking_at("<") and not looking_at("</")
def looking_at_html_end() -> bool:
return looking_at("</")
def looking_at_handlebars_start() -> bool:
return looking_at("{{#") or looking_at("{{^")
def looking_at_handlebars_end() -> bool:
return looking_at("{{/")
def looking_at_django_start() -> bool:
return looking_at("{% ") and not looking_at("{% end")
def looking_at_django_end() -> bool:
return looking_at("{% end")
def looking_at_jinja2_end_whitespace_stripped() -> bool:
return looking_at("{%- end")
def looking_at_jinja2_start_whitespace_stripped_type2() -> 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)
if s.endswith('/>'):
end_offset = -2
else:
end_offset = -1
tag_parts = s[1:end_offset].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_django_tag(text, state.i, stripped=True)
tag = s[3:-3].split()[0]
kind = 'jinja2_whitespace_stripped_type2_start'
else:
advance(1)
continue
except TokenizationException as e:
raise FormattedException(
f'''{e.message} at Line {state.line} Col {state.col}:"{e.line_content}"''',
)
line_span = len(s.split('\n'))
token = Token(
kind=kind,
s=s,
tag=tag.strip(),
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: Optional[str] = None, text: Optional[str] = None, check_indent: bool = True) -> None:
assert fn or text
if fn is None:
fn = '<in memory file>'
if text is None:
with open(fn) as f:
text = f.read()
try:
tokens = tokenize(text)
except FormattedException as e:
raise TemplateParserException(f'''
fn: {fn}
{e}''')
class State:
def __init__(self, func: Callable[[Token], None]) -> None:
self.depth = 0
self.matcher = func
def no_start_tag(token: Token) -> None:
raise TemplateParserException(f'''
No start tag
fn: {fn}
end tag:
{token.tag}
line {token.line}, col {token.col}
''')
state = State(no_start_tag)
def start_tag_matcher(start_token: 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: 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(f'''
fn: {fn}
{problem}
start:
{start_token.s}
line {start_line}, col {start_col}
end tag:
{end_tag}
line {end_line}, col {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_start',
'jinja2_whitespace_stripped_type2_start'}:
if is_django_block_tag(tag):
start_tag_matcher(token)
elif kind in {'django_end', 'jinja2_whitespace_stripped_end'}:
state.matcher(token)
if state.depth != 0:
raise TemplateParserException('Missing end tag')
def is_special_html_tag(s: str, tag: str) -> bool:
return tag in ['link', 'meta', '!DOCTYPE']
OPTIONAL_CLOSING_TAGS = [
'circle',
'img',
'input',
'path',
'polygon',
'stop',
]
def is_self_closing_html_tag(s: Text, tag: Text) -> bool:
if s.endswith('/>'):
if tag in OPTIONAL_CLOSING_TAGS:
return True
raise TokenizationException('Singleton tag not allowed', tag)
self_closing_tag = tag in [
'area',
'base',
'br',
'col',
'embed',
'hr',
'img',
'input',
'param',
'source',
'track',
'wbr',
]
if self_closing_tag:
return True
return False
def is_django_block_tag(tag: str) -> bool:
return tag in [
'autoescape',
'block',
'comment',
'for',
'if',
'ifequal',
'macro',
'verbatim',
'blocktrans',
'trans',
'raw',
'with',
]
def get_handlebars_tag(text: str, i: 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: str, i: int, stripped: bool = False) -> str:
end = i + 2
if stripped:
end += 1
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_html_tag(text: str, i: 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: str, i: 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: str, i: 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: str, i: 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: str, i: 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])