1 """This module contains single a function for normalizing JSON strings."""
2 # Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
4 # This program and the accompanying materials are made available under the
5 # terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 # and is available at http://www.eclipse.org/legal/epl-v10.html
8 import collections as _collections
10 import simplejson as _json
11 except ImportError: # Python2.7 calls it json.
15 __author__ = "Vratko Polak"
16 __copyright__ = "Copyright(c) 2015-2016, Cisco Systems, Inc."
17 __license__ = "Eclipse Public License v1.0"
18 __email__ = "vrpolak@cisco.com"
21 # Internal details; look down below for Robot Keywords.
26 Hashable sorted frozen list implementation stub.
28 Supports only __init__, __repr__ and __hash__ methods.
29 Other list methods are available, but they may break contract.
32 def __init__(self, *args, **kwargs):
33 """Contruct super, sort and compute repr and hash cache values."""
34 sup = super(_Hsfl, self)
35 sup.__init__(*args, **kwargs)
37 self.__repr = repr(tuple(self))
38 self.__hash = hash(self.__repr)
41 """Return cached repr string."""
45 """Return cached hash."""
49 class _Hsfod(_collections.OrderedDict):
51 Hashable sorted (by key) frozen OrderedDict implementation stub.
53 Supports only __init__, __repr__ and __hash__ methods.
54 Other OrderedDict methods are available, but they may break contract.
57 def __init__(self, *args, **kwargs):
58 """Put arguments to OrderedDict, sort, pass to super, cache values."""
59 self_unsorted = _collections.OrderedDict(*args, **kwargs)
60 items_sorted = sorted(self_unsorted.items(), key=repr)
61 sup = super(_Hsfod, self) # possibly something else than OrderedDict
62 sup.__init__(items_sorted)
63 # Repr string is used for sorting, keys are more important than values.
64 self.__repr = '{' + repr(self.keys()) + ':' + repr(self.values()) + '}'
65 self.__hash = hash(self.__repr)
68 """Return cached repr string."""
72 """Return cached hash."""
76 def _hsfl_array(s_and_end, scan_once, **kwargs):
77 """Scan JSON array as usual, but return hsfl instead of list."""
78 values, end = _json.decoder.JSONArray(s_and_end, scan_once, **kwargs)
79 return _Hsfl(values), end
82 class _Decoder(_json.JSONDecoder):
83 """Private class to act as customized JSON decoder.
85 Based on: http://stackoverflow.com/questions/10885238/
86 python-change-list-type-for-json-decoding"""
88 def __init__(self, **kwargs):
89 """Initialize decoder with special array implementation."""
90 _json.JSONDecoder.__init__(self, **kwargs)
91 # Use the custom JSONArray
92 self.parse_array = _hsfl_array
93 # Use the python implemenation of the scanner
94 self.scan_once = _json.scanner.py_make_scanner(self)
97 # Robot Keywords; look above for internal details.
100 def loads_sorted(text, strict=False):
101 """Return Python object with sorted arrays and dictionary keys."""
102 object_decoded = _json.loads(text, cls=_Decoder, object_hook=_Hsfod)
103 return object_decoded
106 def dumps_indented(obj, indent=1):
108 Wrapper for json.dumps with default indentation level. Adds newline.
110 The main value is that BuiltIn.Evaluate cannot easily accept Python object
111 as part of its argument.
112 Also, allows to use something different from RequestsLibrary.To_Json
114 pretty_json = _json.dumps(obj, separators=(',', ': '), indent=indent)
115 return pretty_json + '\n' # to avoid diff "no newline" warning line
118 def sort_bits(obj, keys_with_bits=[]):
120 Rearrange string values of list bits names in alphabetical order.
122 This function looks at dict items with known keys.
123 If the value is string, space-separated names are sorted.
124 This function is recursive over dicts and lists.
125 Current implementation performs re-arranging in-place (to save memory),
126 so it is not required to store the return value.
128 The intended usage is for composite objects which contain
129 OrderedDict elements. The implementation makes sure that ordering
130 (dictated by keys) is preserved. Support for generic dicts is an added value.
132 Sadly, dict (at least in Python 2.7) does not have __updatevalue__(key) method
133 which would guarantee iteritems() is not affected when value is updated.
134 Current "obj[key] = value" implementation is safe for dict and OrderedDict,
135 but it may be not safe for other subclasses of dict.
137 TODO: Should this docstring include links to support dict and OrderedDict safety?
139 if isinstance(obj, dict):
140 for key, value in obj.iteritems():
141 # Unicode is not str and vice versa, isinstance has to check for both.
142 # Luckily, "in" recognizes equivalent strings in different encodings.
143 # Type "bytes" is added for Python 3 compatibility.
144 if key in keys_with_bits and isinstance(value, (unicode, str, bytes)):
145 obj[key] = " ".join(sorted(value.split(" ")))
147 sort_bits(value, keys_with_bits)
148 # A string is not a list, so there is no risk of recursion over characters.
149 elif isinstance(obj, list):
151 sort_bits(item, keys_with_bits)
155 def normalize_json_text(text, strict=False, indent=1, keys_with_bits=[]):
157 Attempt to return sorted indented JSON string.
159 If parse error happens:
160 If strict is true, raise the exception.
161 If strict is not true, return original text with error message.
162 If keys_with_bits is non-empty, run sort_bits on intermediate Python object.
165 object_decoded = loads_sorted(text)
166 except ValueError as err:
170 return str(err) + '\n' + text
172 sort_bits(object_decoded, keys_with_bits)
173 pretty_json = dumps_indented(object_decoded, indent=indent)