from __future__ import absolute_import, print_function
import json
from collections import OrderedDict
from ..dom import Group, And, Or, Not, Term
[docs]class JSONParser(object):
"""
Transforms a JSON string into a DOM. The DOM is identical to what
QueryParser generates. Example JSON input::
{
"Device":
{
"Hostname":
[
[["contains": "s-"],["contains": "-ea1"]],
[["startswith", ""]]
],
"Tags":
[
[["neq":"asdasd"]]
]
}
"Component":
{
"Slot": [[]]
}
}
"""
[docs] def parse_operators(self, termgroup, term, fieldname):
for operator, value in term:
if operator.startswith('not'):
term = Not(Term(fieldname, operator[3:], value))
else:
term = Term(fieldname, operator, value)
termgroup.add(term)
[docs] def parse_terms(self, fieldgroup, terms, fieldname):
for term in terms:
termgroup = And()
fieldgroup.add(termgroup)
if not term:
termgroup.add(Term(fieldname, 'any', ''))
continue
self.parse_operators(termgroup, term, fieldname)
[docs] def parse_criteria(self, clsgroup, criteria, clsname):
for fieldname, terms in criteria.items():
fieldname = clsname + '.' + fieldname
fieldgroup = Or()
clsgroup.add(fieldgroup)
self.parse_terms(fieldgroup, terms, fieldname)
[docs] def parse(self, json_string):
json_tree = json.loads(json_string, object_pairs_hook=OrderedDict)
result = Group(is_root=True)
for clsname, criteria in json_tree.items():
clsgroup = And()
result.add(clsgroup)
self.parse_criteria(clsgroup, criteria, clsname)
return result.optimize()