Files
snek/src/snek/system/model.py
T
2025-07-12 20:58:19 +02:00

381 lines
11 KiB
Python

# Written by retoor@molodetz.nl
# The script defines a flexible validation and field management system for models, with capabilities for setting attributes, validation, error handling, and JSON conversion. It includes classes for managing various field types with specific properties such as UUID, timestamps for creation and updates, and custom validation rules.
# This script utilizes external Python libraries such as 're' for regex operations, 'uuid' for generating unique identifiers, and 'json' for data interchange. The 'datetime' and 'timezone' modules from the Python standard library are used for date and time operations. 'OrderedDict' from 'collections' provides enhanced dictionary capabilities, and 'copy' allows deep copying of objects.
# MIT License
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
import copy
import json
import re
import uuid
from collections import OrderedDict
from datetime import datetime, timezone
TIMESTAMP_REGEX = r"^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{6}\+\d{2}:\d{2}$"
def now():
return str(datetime.now(timezone.utc))
def add_attrs(**kwargs):
def decorator(func):
for key, value in kwargs.items():
setattr(func, key, value)
return func
return decorator
def validate_attrs(
required=False, min_length=None, max_length=None, regex=None, **kwargs
):
def decorator(func):
return add_attrs(
required=required,
min_length=min_length,
max_length=max_length,
regex=regex,
**kwargs,
)(func)
class Validator:
_index = 0
@property
def value(self):
return self._value
@value.setter
def value(self, val):
self._value = json.loads(json.dumps(val, default=str))
@property
def initial_value(self):
return self.value
def custom_validation(self):
return True
def __init__(
self,
required=False,
min_num=None,
max_num=None,
min_length=None,
max_length=None,
regex=None,
value=None,
kind=None,
help_text=None,
app=None,
model=None,
**kwargs,
):
self.index = Validator._index
Validator._index += 1
self.app = app
self.model = model
self.required = required
self.min_num = min_num
self.max_num = max_num
self.min_length = min_length
self.max_length = max_length
self.regex = regex
self._value = None
self.value = value
self.kind = kind
self.help_text = help_text
self.__dict__.update(kwargs)
@property
async def errors(self):
error_list = []
if self.value is None and self.required:
error_list.append("Field is required.")
return error_list
if self.value is None:
return error_list
if self.kind in [int, float]:
if self.min_num is not None and self.value < self.min_num:
error_list.append(f"Field should be minimal {self.min_num}.")
if self.max_num is not None and self.value > self.max_num:
error_list.append(f"Field should be maximal {self.max_num}.")
if self.min_length is not None and len(self.value) < self.min_length:
error_list.append(
f"Field should be minimal {self.min_length} characters long."
)
if self.max_length is not None and len(self.value) > self.max_length:
error_list.append(
f"Field should be maximal {self.max_length} characters long."
)
if self.regex and self.value and not re.match(self.regex, self.value):
error_list.append("Invalid value.")
if self.kind and not isinstance(self.value, self.kind):
error_list.append(f"Invalid kind. It is supposed to be {self.kind}.")
return error_list
async def validate(self):
errors = await self.errors
if errors:
raise ValueError(f"Errors: {errors}.")
return True
def __repr__(self):
return str(self.to_json())
@property
async def is_valid(self):
try:
await self.validate()
return True
except ValueError:
return False
async def to_json(self):
errors = await self.errors
is_valid = await self.is_valid
return {
"required": self.required,
"min_num": self.min_num,
"max_num": self.max_num,
"min_length": self.min_length,
"max_length": self.max_length,
"regex": self.regex,
"value": self.value,
"kind": str(self.kind),
"help_text": self.help_text,
"errors": errors,
"is_valid": is_valid,
"index": self.index,
}
class ModelField(Validator):
index = 1
def __init__(self, name=None, save=True, *args, **kwargs):
self.name = name
self.save = save
super().__init__(*args, **kwargs)
async def to_json(self):
result = await super().to_json()
result["name"] = self.name
return result
class CreatedField(ModelField):
@property
def initial_value(self):
return now()
def update(self):
if not self.value:
self.value = now()
class UpdatedField(ModelField):
def update(self):
self.value = now()
class DeletedField(ModelField):
def update(self):
self.value = now()
class UUIDField(ModelField):
@property
def value(self):
return str(self._value)
@value.setter
def value(self, val):
self._value = str(val)
@property
def initial_value(self):
return str(uuid.uuid4())
class BaseModel:
uid = UUIDField(name="uid", required=True)
created_at = CreatedField(
name="created_at",
required=True,
regex=TIMESTAMP_REGEX,
place_holder="Created at",
)
updated_at = UpdatedField(
name="updated_at", regex=TIMESTAMP_REGEX, place_holder="Updated at"
)
deleted_at = DeletedField(
name="deleted_at", regex=TIMESTAMP_REGEX, place_holder="Deleted at"
)
@classmethod
async def from_record(cls, record, mapper):
model = cls()
model.mapper = mapper
model.record = record
return model
@property
def mapper(self):
return self._mapper
def save(self):
return self.mapper.save(self)
@mapper.setter
def mapper(self, value):
self._mapper = value
@property
def record(self):
return {key: field.value for key, field in self.fields.items()}
@record.setter
def record(self, val):
for key, value in val.items():
field = self.fields.get(key)
if not field:
continue
self[key] = value
return self
def __init__(self, *args, **kwargs):
self._mapper = kwargs.get("mapper")
self.app = kwargs.get("app")
self.fields = {}
for key in dir(self.__class__):
obj = getattr(self.__class__, key)
if isinstance(obj, Validator):
self.__dict__[key] = copy.deepcopy(obj)
self.__dict__[key].value = kwargs.pop(
key, self.__dict__[key].initial_value
)
self.fields[key] = self.__dict__[key]
self.fields[key].model = self
self.fields[key].app = kwargs.get("app")
def __setitem__(self, key, value):
obj = self.__dict__.get(key)
if isinstance(obj, Validator):
obj.value = value
def __getattr__(self, key):
obj = self.__dict__.get(key)
if isinstance(obj, Validator):
return obj.value
return obj
def set_user_data(self, data):
for key, value in data.items():
field = self.fields.get(key)
if not field:
continue
if value.get("name"):
value = value.get("value")
field.value = value
@property
async def is_valid(self):
return all([await field.is_valid for field in self.fields.values()])
def __getitem__(self, key):
obj = self.__dict__.get(key)
if isinstance(obj, Validator):
return obj.value
def __setattr__(self, key, value):
obj = getattr(self, key)
if isinstance(obj, Validator):
obj.value = value
else:
self.__dict__[key] = value
@property
async def recordz(self):
obj = await self.to_json()
record = {}
for key, value in obj.items():
if not isinstance(value, dict) or "value" not in value:
continue
if getattr(self, key).save:
record[key] = value.get("value")
return record
async def to_json(self, encode=False):
model_data = OrderedDict(
{
"uid": self.uid.value,
"created_at": self.created_at.value,
"updated_at": self.updated_at.value,
"deleted_at": self.deleted_at.value,
"is_valid": await self.is_valid,
}
)
for key, value in self.fields.items():
if key == "record":
continue
value = self.__dict__[key]
if hasattr(value, "value"):
model_data[key] = await value.to_json()
if encode:
return json.dumps(model_data, indent=2)
return model_data
class FormElement(ModelField):
def __init__(self, place_holder=None, *args, **kwargs):
super().__init__(*args, **kwargs)
self.place_holder = place_holder
class FormElement(ModelField):
def __init__(self, place_holder=None, *args, **kwargs):
self.place_holder = place_holder
super().__init__(*args, **kwargs)
async def to_json(self):
data = await super().to_json()
data["name"] = self.name
data["place_holder"] = self.place_holder
return data