Input Validator
Validate input value with an efficient way.
Installation
Run this command:
flutter pub add input_validator
Usages
The make method will return null if the validation passed.
/// import 'package:input_validator/input_validator.dart';
/// here is a basic example
InputValidator.make(rules:"required|min_length:6",value:"password");
Rules
rules parameter is a string that guide what to do with the value. You can provide as many as posable rules, which should be separated by | sign. Some rules required extra params like rule:param,param, here parameters are separated by comma. A quick example: you want to get user gender in male,female or other, so it would be like in:male,female,other. See Available Validation Rules and explanation.
Value
The value is the given payload for validation.
Customizing Validation Messages
You can pass messages parameter to the make method. It accept Map<String, dynamic>. The messages key should match with rule name. The message value should be either String or CustomHandler.
Example:
InputValidator.make(
rules:"required|min_length:6",
value:null,
messages:{
"required": "Password is required."
},
);
Custom Rule
Here is an example of custom rule.
/// A strong password validation,
/// Minimum 1 Upper case
/// Minimum 1 lowercase
/// Minimum 1 Numeric Number
/// Minimum 1 Special Character
/// Common Allow Character ( ! @ # $ & \* ~ )
InputValidator.make(
rules:"strongPassword",
value:null,
messages:{
"strongPassword": CustomHandler(onHandle: (payload, _) {
String pattern = r'^(?=.*?[A-Z])(?=.*?[a-z])(?=.*?[0-9])(?=.*?[!@#\$&*~]).{8,}$';
RegExp regExp = new RegExp(pattern);
return regExp.hasMatch(payload) ? null:"Invalid password!";
})
},
);
Form builder
Build form via form builder. See the full example on the example tab.
var _form = InputValidator.builder(
fields: {
"full_name": FieldData(rules: "required|min_length:4"),
"username": FieldData(rules: "required|min_length:4"),
"age": FieldData(rules: "required|min:10"),
},
);
Container(
child: _form.build(context, child: (state) => ....)
)
Available Validation Rules
Below is a list of all available validation rules and their function:
Required, Min (Number), Max (Number), Numeric (Number), Size (Number), Length (String), Max Length (String), Min Length (String), Email, In, Date, Date Between, Date Before, Date After, Date Before Inclusive, Date After Inclusive, Custom Rule,
Required
The field under validation must be present in the input data and not empty. A field is considered "empty" if one of the following conditions are true:
The value is null.
The value is an empty string.
Min
The field under validation must have a minimum value and not empty and the value should be convertible to numeric value.
// example
InputValidator.make(value: "5", rules: "min:10");
// reuslt: Provide at least 10.
Max
The field under validation must have a maximum value and not empty and the value should be convertible to numeric value.
// example
InputValidator.make(value: "15", rules: "max:10");
// reuslt: Maximum limit is 10.
Numeric
The field under validation must be convertible to a numeric value.
// example
InputValidator.make(value: "abc", rules: "numeric");
// reuslt: Invalid number input.
Size
The field under validation must be convertible to a numeric value and exec as the given size.
// example
InputValidator.make(value: "5", rules: "size:10");
// reuslt: The size should be 10.
Length
It will call the toString() method on the value and check the length of the string and match with the given length.
// example
InputValidator.make(value: "5", rules: "length:10");
// reuslt: The input should be 10 characters.
Min Length
It will call the toString() method on the value and check the length of the string and match with the given length.
// example
InputValidator.make(value: "5", rules: "min_length:10");
// reuslt: Provide at least 5 characters
Max Length
It will call the toString() method on the value and check the length of the string and match with the given length.
// example
InputValidator.make(value: "15", rules: "max_length:10");
// reuslt: Provide maximum 10 characters
It will check with a RegEx pattern. You can customize the pattern by override the custom handler.
// example
InputValidator.make(value: "example@gmail", rules: "email");
// reuslt: Invalid email address.
In
The field under validation must be included in the given list of values.
// example
InputValidator.make(value: "world", rules: "in:1,hello,world");
// reuslt: null
Date
Valid date that could be parsed with DateTime.parse()
// example
InputValidator.make(value: "date", rules: "date");
// reuslt: Invalid date
Date Between
Valid date that could be parsed with DateTime.parse(). It will make sure that the given date is newer then minimum date and older then maximum date.
// example 'date_between:min,max'
InputValidator.make(value: "2021-04-10", rules: "date_between:2021-05-17,2021-07-17");
// reuslt: Date out of range.
Date Before
Valid date that could be parsed with DateTime.parse(). It will make sure that the given date is older then checking date. Also you can try Date Before Inclusive.
// example 'date_before:date'
InputValidator.make(value: "2021-04-10", rules: "date_between:2021-05-17");
// reuslt: null
Date After
Valid date that could be parsed with DateTime.parse(). It will make sure that the given date is newer then checking date. Also you can try Date After Inclusive.
// example 'date_after:date'
InputValidator.make(value: "2021-04-10", rules: "date_after:2021-05-17");
// reuslt: Provide newer date.
Date After Inclusive
Valid date that could be parsed with DateTime.parse(). It will make sure that the given date is newer or equal to the checking date.
// example 'date_after_inclusive:date'
InputValidator.make(value: "2021-05-17", rules: "date_after_inclusive:2021-05-17");
// reuslt: null
Date Before Inclusive
Valid date that could be parsed with DateTime.parse(). It will make sure that the given date is older or equal to the checking date.
// example 'date_before_inclusive:date'
InputValidator.make(value: "2021-05-17", rules: "date_before_inclusive:2021-05-17");
// reuslt: null