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Converts json schema to django models.py
"""
Json Schema to Django Model
"""
import json
import argparse
import logging
import os
def determine_model_name(model_id=None, filename=None):
"""
Get the model name
:param model_id: str, model id
:param filename: str, filename
:return: str, model name
"""
model_name = ''
if model_id:
try:
model_name = model_id.split('/')[-1].replace('.json', '')
except Exception as e:
logging.exception("Unhandled exception {}".format(e))
if not model_name and filename:
filename = filename.strip(os.sep)
model_name = filename.split(os.sep)[-1]
model_name = model_name.split('.')[0]
return model_name.capitalize() or 'UnknownModel'
def get_required_string(key_name, required_fields, field_type='string', is_pk_field=False):
"""
Gets the required portion of model field
:param key_name:
:param required_fields:
:return: str, required model string
"""
if is_pk_field:
return 'primary_key=True'
if field_type in ('number', 'array', 'object'):
if key_name in required_fields:
return 'null=False'
return 'null=True'
else: # string, boolean
if key_name in required_fields:
return 'null=False, blank=False'
return 'null=True, blank=True'
def parse_model():
parser = argparse.ArgumentParser()
parser.add_argument('filename')
args = parser.parse_args()
filename = args.filename
with open(filename) as f:
json_model = json.load(f)
# Make sure not list, but object
if json_model['type'] != 'object':
print("Model type has to be object to convert to model, got {}".format(json_model['type']))
if 'oneOf' in json_model:
print("Optional required fields detected: {}".format(json_model['oneOf']))
# Default model string
model_str = "\nfrom djongo import models\nfrom djongo.models import json\n\n"
model_name = determine_model_name(json_model.get('id'), args.filename)
model_str += "class {}(models.Model):\n".format(model_name)
model_str += ' """Generated model from json schema"""\n'
print("Model name is {}".format(model_name))
if 'title' in json_model:
print("Title of model is {}".format(json_model['title']))
if 'description' in json_model:
print("Description of model is {}".format(json_model['description']))
required_fields = []
if 'required' in json_model:
required_fields = json_model['required']
for key_name, key_attributes in json_model['properties'].items():
if key_name.endswith('_id') and key_name != '_id':
print("WARNING: Possible ForeignKey {}".format(key_name))
# if key_attributes['type'] == 'array':
# print("ERROR: Unsupported type array, skipping for field {}".format(key_name))
if key_attributes['type'] == 'null':
print("ERROR: Unsupported type null, skipping for field {}".format(key_name))
# PK field
is_pk_field = False
if key_name in ['id', '_id']:
is_pk_field = True
# If required field
required_str = get_required_string(key_name, required_fields, key_attributes['type'], is_pk_field)
field_str = ''
# String choice field, enum
if key_attributes['type'] == 'string' and 'enum' in key_attributes:
if not key_attributes['enum']:
print("ERROR: Missing enum for enum choice field {}, skipping..".format(key_name))
continue
if len(key_attributes['enum']) == 1:
print("WARNING: enum value with single choice for field {}, choice {}."
"".format(key_name, key_attributes['enum']))
continue
# Max length find
max_length = 255
for choice in key_attributes['enum']:
if len(choice) > 255:
max_length = len(choice)
choices = tuple(set(zip(key_attributes['enum'], key_attributes['enum'])))
field_str = " {} = models.CharField(choices={}, max_length={}, " \
"default='{}', {})\n" \
"".format(key_name, choices, max_length, key_attributes['enum'][0], required_str)
# Date time field
elif key_attributes['type'] == 'string' and key_attributes.get('format') == 'date-time':
auto_now_add = False
editable = True
if key_name in ['created_on', 'modified_on']:
auto_now_add = True
editable = False
field_str = " {} = models.DateTimeField(auto_now_add={}, editable={}, {})\n" \
"".format(key_name, auto_now_add, editable, required_str)
elif key_attributes['type'] == 'string':
field_str = " {} = models.TextField({})\n".format(key_name, required_str)
elif key_attributes['type'] == 'number':
field_str = " {} = models.IntegerField({})\n".format(key_name, required_str)
elif key_attributes['type'] == 'array':
field_str = " {} = json.JSONField(default=[], {})\n".format(key_name, required_str)
elif key_attributes['type'] == 'object':
field_str = " {} = json.JSONField(default={{}}, {})\n".format(key_name, required_str)
elif key_attributes['type'] == 'boolean':
field_str = " {} = models.BooleanField(default=False, {})\n".format(key_name, required_str)
model_str += field_str
model_str += "\n class Meta:\n db_table = '{}s'\n".format(model_name.lower())
print(model_str)
if __name__ == "__main__":
parse_model()
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