""" Helper classes for parsers. """ from __future__ import unicode_literals from django.utils import timezone from django.utils.datastructures import SortedDict from django.utils.functional import Promise from rest_framework.compat import force_text from rest_framework.serializers import DictWithMetadata, SortedDictWithMetadata import datetime import decimal import types import json class JSONEncoder(json.JSONEncoder): """ JSONEncoder subclass that knows how to encode date/time/timedelta, decimal types, and generators. """ def default(self, o): # For Date Time string spec, see ECMA 262 # http://ecma-international.org/ecma-262/5.1/#sec-15.9.1.15 if isinstance(o, Promise): return force_text(o) elif isinstance(o, datetime.datetime): r = o.isoformat() if o.microsecond: r = r[:23] + r[26:] if r.endswith('+00:00'): r = r[:-6] + 'Z' return r elif isinstance(o, datetime.date): return o.isoformat() elif isinstance(o, datetime.time): if timezone and timezone.is_aware(o): raise ValueError("JSON can't represent timezone-aware times.") r = o.isoformat() if o.microsecond: r = r[:12] return r elif isinstance(o, datetime.timedelta): return str(o.total_seconds()) elif isinstance(o, decimal.Decimal): return str(o) elif hasattr(o, 'tolist'): return o.tolist() elif hasattr(o, '__getitem__'): try: return dict(o) except: pass elif hasattr(o, '__iter__'): return [i for i in o] return super(JSONEncoder, self).default(o) try: import yaml except ImportError: SafeDumper = None else: # Adapted from http://pyyaml.org/attachment/ticket/161/use_ordered_dict.py class SafeDumper(yaml.SafeDumper): """ Handles decimals as strings. Handles SortedDicts as usual dicts, but preserves field order, rather than the usual behaviour of sorting the keys. """ def represent_decimal(self, data): return self.represent_scalar('tag:yaml.org,2002:str', str(data)) def represent_mapping(self, tag, mapping, flow_style=None): value = [] node = yaml.MappingNode(tag, value, flow_style=flow_style) if self.alias_key is not None: self.represented_objects[self.alias_key] = node best_style = True if hasattr(mapping, 'items'): mapping = list(mapping.items()) if not isinstance(mapping, SortedDict): mapping.sort() for item_key, item_value in mapping: node_key = self.represent_data(item_key) node_value = self.represent_data(item_value) if not (isinstance(node_key, yaml.ScalarNode) and not node_key.style): best_style = False if not (isinstance(node_value, yaml.ScalarNode) and not node_value.style): best_style = False value.append((node_key, node_value)) if flow_style is None: if self.default_flow_style is not None: node.flow_style = self.default_flow_style else: node.flow_style = best_style return node SafeDumper.add_representer(decimal.Decimal, SafeDumper.represent_decimal) SafeDumper.add_representer(SortedDict, yaml.representer.SafeRepresenter.represent_dict) SafeDumper.add_representer(DictWithMetadata, yaml.representer.SafeRepresenter.represent_dict) SafeDumper.add_representer(SortedDictWithMetadata, yaml.representer.SafeRepresenter.represent_dict) SafeDumper.add_representer(types.GeneratorType, yaml.representer.SafeRepresenter.represent_list)