nzbToMedia/libs/win/jaraco/ui/editor.py
2022-11-29 00:44:47 -05:00

112 lines
3.2 KiB
Python

import tempfile
import os
import sys
import subprocess
import mimetypes
import collections
import io
import difflib
from typing import Mapping
class EditProcessException(RuntimeError):
pass
class EditableFile(object):
"""
EditableFile saves some data to a temporary file, launches a
platform editor for interactive editing, and then reloads the data,
setting .changed to True if the data was edited.
e.g.::
x = EditableFile('foo')
x.edit()
if x.changed:
print(x.data)
The EDITOR environment variable can define which executable to use
(also XML_EDITOR if the content-type to edit includes 'xml'). If no
EDITOR is defined, defaults to 'notepad' on Windows and 'edit' on
other platforms.
"""
platform_default_editors: Mapping[str, str] = collections.defaultdict(
lambda: 'edit',
win32='notepad',
linux2='vi',
)
encoding = 'utf-8'
def __init__(self, data='', content_type='text/plain'):
self.data = str(data)
self.content_type = content_type
def __enter__(self):
extension = mimetypes.guess_extension(self.content_type) or ''
fobj, self.name = tempfile.mkstemp(extension)
os.write(fobj, self.data.encode(self.encoding))
os.close(fobj)
return self
def read(self):
with open(self.name, 'rb') as f:
return f.read().decode(self.encoding)
def __exit__(self, *tb_info):
os.remove(self.name)
def edit(self):
"""
Edit the file
"""
self.changed = False
with self:
editor = self.get_editor()
cmd = [editor, self.name]
try:
res = subprocess.call(cmd)
except Exception as e:
print("Error launching editor %(editor)s" % locals())
print(e)
return
if res != 0:
msg = '%(editor)s returned error status %(res)d' % locals()
raise EditProcessException(msg)
new_data = self.read()
if new_data != self.data:
self.changed = self._save_diff(self.data, new_data)
self.data = new_data
@staticmethod
def _search_env(keys):
"""
Search the environment for the supplied keys, returning the first
one found or None if none was found.
"""
matches = (os.environ[key] for key in keys if key in os.environ)
return next(matches, None)
def get_editor(self):
"""
Give preference to an XML_EDITOR or EDITOR defined in the
environment. Otherwise use a default editor based on platform.
"""
env_search = ['EDITOR']
if 'xml' in self.content_type:
env_search.insert(0, 'XML_EDITOR')
default_editor = self.platform_default_editors[sys.platform]
return self._search_env(env_search) or default_editor
@staticmethod
def _save_diff(*versions):
def get_lines(content):
return list(io.StringIO(content))
lines = map(get_lines, versions)
diff = difflib.context_diff(*lines)
return tuple(diff)