"""Field list plugin""" from contextlib import contextmanager from typing import Iterator, Optional, Tuple from markdown_it import MarkdownIt from markdown_it.rules_block import StateBlock from mdit_py_plugins.utils import is_code_block def fieldlist_plugin(md: MarkdownIt) -> None: """Field lists are mappings from field names to field bodies, based on the `reStructureText syntax `_. .. code-block:: md :name *markup*: :name1: body content :name2: paragraph 1 paragraph 2 :name3: paragraph 1 paragraph 2 A field name may consist of any characters except colons (":"). Inline markup is parsed in field names. The field name is followed by whitespace and the field body. The field body may be empty or contain multiple body elements. Since the field marker may be quite long, the second and subsequent lines of the field body do not have to line up with the first line, but they must be indented relative to the field name marker, and they must line up with each other. """ md.block.ruler.before( "paragraph", "fieldlist", _fieldlist_rule, {"alt": ["paragraph", "reference", "blockquote"]}, ) def parseNameMarker(state: StateBlock, startLine: int) -> Tuple[int, str]: """Parse field name: `:name:` :returns: position after name marker, name text """ start = state.bMarks[startLine] + state.tShift[startLine] pos = start maximum = state.eMarks[startLine] # marker should have at least 3 chars (colon + character + colon) if pos + 2 >= maximum: return -1, "" # first character should be ':' if state.src[pos] != ":": return -1, "" # scan name length name_length = 1 found_close = False for ch in state.src[pos + 1 :]: if ch == "\n": break if ch == ":": # TODO backslash escapes found_close = True break name_length += 1 if not found_close: return -1, "" # get name name_text = state.src[pos + 1 : pos + name_length] # name should contain at least one character if not name_text.strip(): return -1, "" return pos + name_length + 1, name_text @contextmanager def set_parent_type(state: StateBlock, name: str) -> Iterator[None]: """Temporarily set parent type to `name`""" oldParentType = state.parentType state.parentType = name yield state.parentType = oldParentType def _fieldlist_rule( state: StateBlock, startLine: int, endLine: int, silent: bool ) -> bool: # adapted from markdown_it/rules_block/list.py::list_block if is_code_block(state, startLine): return False posAfterName, name_text = parseNameMarker(state, startLine) if posAfterName < 0: return False # For validation mode we can terminate immediately if silent: return True # start field list token = state.push("field_list_open", "dl", 1) token.attrSet("class", "field-list") token.map = listLines = [startLine, 0] # iterate list items nextLine = startLine with set_parent_type(state, "fieldlist"): while nextLine < endLine: # create name tokens token = state.push("fieldlist_name_open", "dt", 1) token.map = [startLine, startLine] token = state.push("inline", "", 0) token.map = [startLine, startLine] token.content = name_text token.children = [] token = state.push("fieldlist_name_close", "dt", -1) # set indent positions pos = posAfterName maximum: int = state.eMarks[nextLine] first_line_body_indent = ( state.sCount[nextLine] + posAfterName - (state.bMarks[startLine] + state.tShift[startLine]) ) # find indent to start of body on first line while pos < maximum: ch = state.src[pos] if ch == "\t": first_line_body_indent += ( 4 - (first_line_body_indent + state.bsCount[nextLine]) % 4 ) elif ch == " ": first_line_body_indent += 1 else: break pos += 1 contentStart = pos # to figure out the indent of the body, # we look at all non-empty, indented lines and find the minimum indent block_indent: Optional[int] = None _line = startLine + 1 while _line < endLine: # if start_of_content < end_of_content, then non-empty line if (state.bMarks[_line] + state.tShift[_line]) < state.eMarks[_line]: if state.tShift[_line] <= 0: # the line has no indent, so it's the end of the field break block_indent = ( state.tShift[_line] if block_indent is None else min(block_indent, state.tShift[_line]) ) _line += 1 has_first_line = contentStart < maximum if block_indent is None: # no body content if not has_first_line: # noqa: SIM108 # no body or first line, so just use default block_indent = 2 else: # only a first line, so use it's indent block_indent = first_line_body_indent else: block_indent = min(block_indent, first_line_body_indent) # Run subparser on the field body token = state.push("fieldlist_body_open", "dd", 1) token.map = [startLine, startLine] with temp_state_changes(state, startLine): diff = 0 if has_first_line and block_indent < first_line_body_indent: # this is a hack to get the first line to render correctly # we temporarily "shift" it to the left by the difference # between the first line indent and the block indent # and replace the "hole" left with space, # so that src indexes still match diff = first_line_body_indent - block_indent state.src = ( state.src[: contentStart - diff] + " " * diff + state.src[contentStart:] ) state.tShift[startLine] = contentStart - diff - state.bMarks[startLine] state.sCount[startLine] = first_line_body_indent - diff state.blkIndent = block_indent state.md.block.tokenize(state, startLine, endLine) state.push("fieldlist_body_close", "dd", -1) nextLine = startLine = state.line token.map[1] = nextLine if nextLine >= endLine: break contentStart = state.bMarks[startLine] # Try to check if list is terminated or continued. if state.sCount[nextLine] < state.blkIndent: break if is_code_block(state, startLine): break # get next field item posAfterName, name_text = parseNameMarker(state, startLine) if posAfterName < 0: break # Finalize list token = state.push("field_list_close", "dl", -1) listLines[1] = nextLine state.line = nextLine return True @contextmanager def temp_state_changes(state: StateBlock, startLine: int) -> Iterator[None]: """Allow temporarily changing certain state attributes.""" oldTShift = state.tShift[startLine] oldSCount = state.sCount[startLine] oldBlkIndent = state.blkIndent oldSrc = state.src yield state.blkIndent = oldBlkIndent state.tShift[startLine] = oldTShift state.sCount[startLine] = oldSCount state.src = oldSrc