persoconf/metafile.py

82 lines
2.2 KiB
Python

#!/usr/bin/env python3
import json
class Metafile():
"""Representation of a metafile (default name META), containing (as its
name implies) metadata."""
def __init__(self, json_path=None, name=None):
self.name = name
# json_path given => we load it ; otherwise fill with default
if json_path is not None:
self.load_json(json_path) # raise FileNotFoundError
else:
self.load_default()
def load_default(self):
self.json_path = None
self.depends = {}
self.files = {}
# (Note that name is already written in __init__)
def load_json(self, json_path):
self.json_path = json_path
tmp = json.load( open(self.json_path) ) # Can raise a FileNotFoundError
try:
self.name = tmp["name"]
self.depends = tmp["depends"]
self.files = tmp["files"]
except KeyError:
raise MalformedMetafileError("Missing attribute (name, depends or files)")
def save(self):
if self.json_path is None:
raise NoPathDefinedError("json_path is not defined")
json.dump( { "name": self.name, "depends": self.depends, "files": self.files }, open(self.json_path, 'w') )
def get_files_dst2src(self):
dstdic = {}
try:
for (fname, finfo) in self.files.items():
dstdic[ finfo["dest"] ] = fname
except KeyError:
raise MalformedMetafileError("Missing 'dest' attribute in files infos")
return dstdic
def add_file(self, name, dest):
self.files[name] = { "dest": dest }
def del_file(self, name):
del self.files[name]
# Exceptions
########################################
class MalformedMetafileError(Exception):
"""A custom exception to alert that the metafile is malformed"""
def __init__(self, message):
Exception.__init__(self, message)
class NoPathDefinedError(Exception):
"""A custom exception to alert that the json_path properties of the
Metafile is not defined, therefore we cannot write the data."""
def __init__(self, message):
Exception.__init__(self, message)