Validator

Validator is a Python library for dealing with request validating.

Table of Contents

• Installation
• Overview
  • Usage
  • Validated Data/Error Messages
  • Validating Arrays
  • Available Validation Rules
  • Rules
  • Rules Interconnection
  • Custom Rules
• Examples
• Contributing
• License

Installation

Use the package manager pip to install Validator.

bash pip install validator

Usage

User should pass request dictionary and rules dictionary for validating data in the request.

Please see examples below:

```python from validator import validate

request = {"name": "John Doe", "age": 33, "mail": "john_doe@gmail.com"}

rules = {"name": "required", "age": "integer|min:18", "mail": "required|mail"}

result = validate(request, rules) # True `` validate()` returns either True or False.

Another option is to use Validator class ```python from validator import Validator

request = {...} rules = {...}

val = Validator(request, rules) result = val.validate() # True ```

Validated Data/Error Messages

Validator allows user to have a look at failed validations and passed validations. validated_data is extremly useful when request contains data that is not needed for initialization of model, you can get rid of them and validate at the same time. See examples below:

• Validated Data

  ```python from validator import validate

  request = {"firstname": "John", "lastname": "Doe", "age": 33, "mail": "johndoe@gmail.com", "token": "WpH0UPfy0AXzMtK2UWtJ", "cookiedata": "e9Uixp8hzUySy6bw3MuZ", "session_id": "ZB7q7uIVdWBKgSCSSWAa"}

  rule = {"firstname": "required", "lastname": "required", "age": "required|min:18", "mail": "required|mail"}

  result, validateddata, _ = validate(request, rule, returninfo=True) """ result = True validateddata = {"firstname": "John", "last_name": "Doe", "age": 33, "mail": "johndoe@gmail.com"} """ ```

• Error Messages ```python from validator import validate

  request = {"name": "", "mail": "john_doe"}

  rule = {"name": "required", "mail": "mail"}

  result, , errors = validate(request, rule, returninfo=True)

  """ result = False errors = {"name": {"Required': "Field was empty"}, "mail": {"Mail': "Expected a Mail, Got: john_doe"}} """ ```

Or you can use Validator class for error messages as well as for validated data.

python val = Validator(request, rules) result = val.validate() validated_data = val.get_validated_data() errors = val.get_errors()

Validating Arrays

Validator comes with validate_many() function, which validates multiple requests. Function takes list of requests and one rule. This rule is checked for all the requests. If one or more requests fail validation function returns False, otherwise (if all pass) True. For more details see example below:

Validation Passes: ```python from validator import validate_many

requests = [{"name": "John"}, {"name": "Rob"}, {"name": "Tom"}, {"name": "Greg"}] rule = {"name": "required|min:3"}

result = validatemany(requests, rule) # True `` We can also have a look at failed validations and error messages.validatemany()` takes third argument as boolean, indicating return of error messages.

Validation Fails: ```python from validator import validate_many

requests = [{"name": "John"}, {"name": ""}, {"name": "Yo"}, {"name": "Greg"}] rule = {"name": "required|min:3"}

result, errors = validatemany(requests, rule, returninfo=True) """ result = False errors = [{}, {"name": {"Min": "Expected Maximum: 3, Got: 0", "Required": "Field was empty"}}, {"name": {"Min": "Expected Maximum: 3, Got: 2"}}, {}] """ ```

Available Validation Rules

Validator comes with pre initialized rules. All of rules are listed in RULES.md file

Rules

Validator Rules can be used in different ways. Please see some examples below:

Strings

python rule = {"name": "required", "age": "integer|min:18", "mail": "required|mail"}

Array of Strings

python rule = {"name": ["required"], "age": ["integer", "min:18"], "mail": ["required", "mail"]}

Array of Rules

```python from validator import rules as R

rules = {"name": [R.Required()], "age": [R.Integer(), R.Min(18)], "mail": [R.Requried(), R.Mail()]} ```

Other Miscellaneous

```python from validator import rules as R

rules = {"name": R.Required(), # no need for Array Brackets if one rule "age": [R.Integer, R.Min(18)], "mail": [R.Requried, R.Mail]} # no need for class initialization with brakcets () # if no arguments are passed to rule ```

Rules Interconnection

Rules can affect each other. Let's take a look at Size rule. It takes 1 argument and checks if data is equal to given value (example: 'size:10').

• Case 1: checks for length of '18' to be 18. len('18') is 2, therefore it is False. ```python request = {"age" : "18"} rule = {"age" : "size:18"}

validate(request, rule) """ result = False errors = {"age": {"Size": "Expected Size:18, Got:2"}} """ ```

• Case 2: checks if int representation of '18' is equal to 18. (int('18') = 18), therefore it is True. ```python request = {"age" : "18"} rule = {"age" : "integer|size:18"}

validate(request, rule) # True ```

For more details please view Size Rule

Custom Rules

We give users ability to advance and use their own checkers. Write function and use is as a rule. See examples below: 1. Use defined functions: ```python3 from validator import validate

def func_age(x):
    return x >= 18

req = {"age": 30}
rules = {"age": func_age}

validate(req, rules)
```

1. Use Lambda functions: ```python3 from validator import validate

   req = {"age": 30} rules = {"age": lambda x: x >= 18}

   validate(req, rules) ```

2. Any callable class (NOTE: Pass class instance and not class itself): ```python3 from validator import validate

   class checker: def init(self): pass

   def call(self, x): return x >= 456

   req = {"age": 30} rules = {"age": checker()}

   validate(req, rules) ```

3. Custom Rule: ```python3 from validator import validate from validator.rules import Rule

   class AgeRule(Rule): def init(self, min): Rule.init(self) self.min = min

   def check(self, arg):
       return self.min <= arg
   

   req = {"age": 30} rules = {"age": AgeRule(18)}

   validate(req, rules) ```

Examples

We have written some examples for you to get started easier. Please view Examples folder, where you can find validator usages with frameworks like Flask, Django and etc.

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please see CONTRIBUTING.md before making PR :)

License

MIT