1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
|
"""Application base class for displaying data.
"""
import abc
try:
from itertools import compress
except ImportError:
# for py26 compat
from itertools import izip
def compress(data, selectors):
return (d for d, s in izip(data, selectors) if s)
import logging
import six
import stevedore
from .command import Command
LOG = logging.getLogger(__name__)
@six.add_metaclass(abc.ABCMeta)
class DisplayCommandBase(Command):
"""Command base class for displaying data about a single object.
"""
def __init__(self, app, app_args):
super(DisplayCommandBase, self).__init__(app, app_args)
self._formatter_plugins = self._load_formatter_plugins()
@abc.abstractproperty
def formatter_namespace(self):
"String specifying the namespace to use for loading formatter plugins."
@abc.abstractproperty
def formatter_default(self):
"String specifying the name of the default formatter."
def _load_formatter_plugins(self):
# Here so tests can override
return stevedore.ExtensionManager(
self.formatter_namespace,
invoke_on_load=True,
)
def get_parser(self, prog_name):
parser = super(DisplayCommandBase, self).get_parser(prog_name)
formatter_group = parser.add_argument_group(
title='output formatters',
description='output formatter options',
)
formatter_choices = sorted(self._formatter_plugins.names())
formatter_default = self.formatter_default
if formatter_default not in formatter_choices:
formatter_default = formatter_choices[0]
formatter_group.add_argument(
'-f', '--format',
dest='formatter',
action='store',
choices=formatter_choices,
default=formatter_default,
help='the output format, defaults to %s' % formatter_default,
)
formatter_group.add_argument(
'-c', '--column',
action='append',
default=[],
dest='columns',
metavar='COLUMN',
help='specify the column(s) to include, can be repeated',
)
for formatter in self._formatter_plugins:
formatter.obj.add_argument_group(parser)
return parser
@abc.abstractmethod
def produce_output(self, parsed_args, column_names, data):
"""Use the formatter to generate the output.
:param parsed_args: argparse.Namespace instance with argument values
:param column_names: sequence of strings containing names
of output columns
:param data: iterable with values matching the column names
"""
def run(self, parsed_args):
self.formatter = self._formatter_plugins[parsed_args.formatter].obj
column_names, data = self.take_action(parsed_args)
self.produce_output(parsed_args, column_names, data)
return 0
@staticmethod
def _compress_iterable(iterable, selectors):
return compress(iterable, selectors)
|
