Files
doc-forge/docforge/nav/spec.py

136 lines
3.8 KiB
Python

"""
Navigation specification model.
This module defines the ``NavSpec`` class, which represents the navigation
structure defined by the user in the doc-forge navigation specification
(typically ``docforge.nav.yml``).
"""
from pathlib import Path
from typing import Dict, List, Optional
import yaml
class NavSpec:
"""
Parsed representation of a navigation specification.
A ``NavSpec`` describes the intended documentation navigation layout before
it is resolved against the filesystem.
Attributes:
home: Relative path to the documentation home page (for example
``index.md``).
groups: Mapping of navigation group titles to lists of file patterns
or glob expressions.
"""
def __init__(
self,
home: Optional[str],
groups: Dict[str, List[str]],
) -> None:
"""
Initialize a NavSpec instance.
Args:
home: Relative path to the home document.
groups: Mapping of group names to lists of path patterns
(glob expressions).
"""
self.home = home
self.groups = groups
@classmethod
def load(cls, path: Path) -> "NavSpec":
"""
Load a navigation specification from a YAML file.
Args:
path: Filesystem path to the navigation specification file.
Returns:
A ``NavSpec`` instance representing the parsed configuration.
Raises:
FileNotFoundError: If the specified file does not exist.
ValueError: If the file contents are not a valid navigation
specification.
"""
if not path.exists():
raise FileNotFoundError(path)
data = yaml.safe_load(path.read_text(encoding="utf-8"))
if not isinstance(data, dict):
raise ValueError("Nav spec must be a mapping")
home = data.get("home")
groups = data.get("groups", {})
if home is not None and not isinstance(home, str):
raise ValueError("home must be a string")
if not isinstance(groups, dict):
raise ValueError("groups must be a mapping")
for key, value in groups.items():
if not isinstance(key, str):
raise ValueError("group names must be strings")
if not isinstance(value, list) or not all(
isinstance(v, str) for v in value
):
raise ValueError(f"group '{key}' must be a list of strings")
return cls(home=home, groups=groups)
def all_patterns(self) -> List[str]:
"""
Return all path patterns referenced by the specification.
Returns:
A list containing the home document (if defined) and all
group pattern entries.
"""
patterns: List[str] = []
if self.home:
patterns.append(self.home)
for items in self.groups.values():
patterns.extend(items)
return patterns
def load_nav_spec(path: Path) -> NavSpec:
"""
Load a navigation specification file.
This helper function reads a YAML navigation file and constructs a
corresponding ``NavSpec`` instance.
Args:
path: Path to the navigation specification file.
Returns:
A ``NavSpec`` instance representing the parsed specification.
Raises:
FileNotFoundError: If the specification file does not exist.
ValueError: If the YAML structure is invalid.
"""
if not path.exists():
raise FileNotFoundError(path)
data = yaml.safe_load(path.read_text(encoding="utf-8"))
if not isinstance(data, dict):
raise ValueError("Nav spec must be a YAML mapping")
return NavSpec(
home=data.get("home"),
groups=data.get("groups", {}),
)