rules 1.0.0 | Dart package

Introduction #

Rules - Powerful and feature-rich validation library for both Dart and Flutter.

Rules is a simple yet powerful and feature-rich validation library for both dart and flutter. Less boilerplate code, easy to understand and developer-friendly.

Installation #

Go to https://pub.dev/packages/rules#-installing-tab- for the latest version of rules

Concept #

The Rules library has three parts

Rule: Basic rule
GroupRule: Group the basic rules together
CombinedRule: Manage Rules and GroupRules

Usage #

Import the library

import 'package:rules/rules.dart';

1. Rule (Basic Rule)

This is the basic building block, everything starts here.

Basic example

const textFieldValue = 'abc@xyz.com';

final rule = Rule(
  textFieldValue, // value; string and null are accepted
  name: 'Text field' // placeholder value which will be used while displaying errors
);

print(rule.error);
// output: null
print(rule.hasError);
// output: false

Example 1

const textFieldValue = '';  // or const textFieldValue = null;

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  isRequired: true,
);

print(rule.error);
// output: 'Text field is required'
print(rule.hasError);
// output: true

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

Example 2

const textFieldValue = 'abc@xyz';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  isRequired: true,
  isEmail: true,
);

print(rule.error);
// output: 'Text field is not a valid email address'
print(rule.hasError);
// output: true

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

Available options

final String name; // mandatory

final bool isRequired;

final bool isEmail;

final bool isUrl;

final bool isPhone;

final bool isIp;

final bool isNumeric;

bool isNumericDecimal;

final bool isAlphaSpace;

final bool isAlphaNumeric;

final bool isAlphaNumericSpace;

final String regex;

final int length;

final int minLength;

final int maxLength;

final double greaterThan;

final double greaterThanEqualTo;

final double lessThan;

final double lessThanEqualTo;

final double equalTo;

final double notEqualTo;

final List<double> equalToInList;

final List<double> notEqualToInList;

final String shouldMatch;

final String shouldNotMatch;

final List<String> inList;

final List<String> notInList;

final String customErrorText;

final Map<String, String> customErrors;

isRequired: `bool`

const textFieldValue = '123';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  isRequired: true, // throws an error for value = null or an empty string
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

IMPORTANT: If the value is empty or null and 'isRequired' is false or not set then no errors will be thrown for the subsequent constraints.

const textFieldValue = ''; // or null

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  isRequired: false,
  isEmail: true,
);

print(rule.hasError);
// output: false

isEmail: `bool`

const textFieldValue = 'abc@xyz.com';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  isEmail: true,
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

isUrl: `bool`

const textFieldValue = 'http://www.google.com';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  isUrl: true,
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

isPhone: `bool`

It recognizes phone numbers starting with + or 0, no length limitations and handles #, x, ext, extension extension conventions.

const textFieldValue = '+1-9090909090';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  isPhone: true,
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

isIp: `bool`

It accepts both IPv4 and IPv6 addresses.

const textFieldValue = '1.1.1.1';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  isIp: true,
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

isNumeric: `bool`

It accepts both 0, positive and negative integers. Decimals are not allowed.

const textFieldValue = '1'; // '-1', '0'

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  isNumeric: true,
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

isNumericDecimal: `bool`

It accepts 0, postive and negative integers and decimals numbers.

const textFieldValue = '10.01'; // '-10.01' or '0.001'

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  isNumericDecimal: true,
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

isAlphaSpace: `bool`

It accepts multiple spaces and alphabets (both upper and lower case).

const textFieldValue = 'Jane Doe';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  isAlphaSpace: true,
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

isAlphaNumeric: `bool`

It accepts alphabets (both upper and lower case) and numbers.

const textFieldValue = 'username123';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  isAlphaNumeric: true,
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

isAlphaNumericSpace: `bool`

It accepts multiple spaces, alphabets (both upper and lower case) and numbers.

const textFieldValue = 'Bread 20';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  isAlphaNumericSpace: true,
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

regex: `String`

It accepts a custom regular expression string.

const textFieldValue = r'^[a-zA-Z0-9\s]+$';

final rule = Rule(
  textFieldValue,
  name: 'Text field'
  regex: r'^[a-zA-Z0-9\s]+$',
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

length: `int`

Defines the length of the input string.

const textFieldValue = '9090909090';

final rule = Rule(
  textFieldValue,
  name: 'Phone Number'
  length: 10,
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

minLength: `int`

Defines the minimum length of the input string.

const textFieldValue = 'abcd12345';

final rule = Rule(
  textFieldValue,
  name: 'Password',
  minLength: 6,
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

maxLength: `int`

Defines the maximum length of the input string.

const textFieldValue = 'username12';

final rule = Rule(
  textFieldValue,
  name: 'Username',
  minLength: 10,
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

greaterThan: `double`

Checks if the input value is greater than the 'greaterThan' value.
if 'isNumeric' is not set then the 'isNumericDecimal' constraint will be applied automatically.

const textFieldValue = '10';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  greaterThan: 0,
  isNumeric: true, // optional
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

greaterThanEqualTo: `double`

Checks if the input value is greater than or equal to the 'greaterThanEqualTo' value.
if 'isNumeric' is not set then 'isNumericDecimal' constraint will be applied automatically.

const textFieldValue = '5.1';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  greaterThanEqualTo: 5.0,
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

lessThan: `double`

Checks if the input value is greater than or equal to the 'lessThan' value.
if 'isNumeric' is not set then 'isNumericDecimal' constraint will be applied automatically.

const textFieldValue = '1';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  lessThan: 2.0,
  isNumericDecimal: true, // optional
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

lessThanEqualTo: `double`

Checks if the input value is greater than or equal to the 'lessThanEqualTo' value.
if 'isNumeric' is not set then 'isNumericDecimal' constraint will be applied automatically.

const textFieldValue = '2.0';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  lessThanEqualTo: 2.0,
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

equalTo: `double`

Checks if the input value is equal to the 'equalTo' value.
if 'isNumeric' is not set then 'isNumericDecimal' constraint will be applied automatically.

const textFieldValue = '2.0';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  equalTo: 2.0,
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

notEqualTo: `double`

Checks if the input value is equal to the 'notEqualTo' value.
It will throw an error if the values match.
if 'isNumeric' is not set then 'isNumericDecimal' constraint will be applied automatically.

const textFieldValue = '2.0';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  notEqualTo: 2.0,
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

equalToInList: `List<double>`

Checks if the input value matches with any of the 'equalToInList' values.
Note: This is a float comparison. 10.00 == 10 will be true.

const textFieldValue = '10';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  equalToInList: [0, 10],
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

notEqualToInList: `List<double>`

Checks if the input value matches with any of the 'notEqualToInList' values.
It will throw an error if there is a value match.
Note: This is a float comparison. 10.00 == 10 will be true.

const textFieldValue = '10';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  notEqualToInList: [0, 10],
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

shouldMatch: `String`

Checks if the input value matches with the 'shouldMatch' value.
Note: This is a string comparison.

const textFieldValue = 'abc';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  shouldMatch: 'abc',
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

shouldNotMatch: `String`

Checks if the input value matches with the 'shouldNotMatch' value.
It will throw an error if the values match.
Note: This is a string comparison.

const textFieldValue = 'abc';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  shouldNotMatch: 'xyz',
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

inList: `List<String>`

Checks if the input value matches with any of the 'inList' values.
Note: This is a string comparison.

const textFieldValue = 'abc';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  inList: ['abc', 'xyz'],
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

notInList: `List<String>`

Checks if the input value matches with any of the 'notInList' values.
It will throw an error if there is a value match.
Note: This is a string comparison.

const textFieldValue = 'abc';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  notInList: ['abc', 'xyz'],
);

if (rule.hasError) {
// some action on error
}
else {
// Some action on success
}

Custom Error

Default errors

{
    'isRequired': '{name} is required',
    'isEmail': '{name} is not a valid email address',
    'isPhone': '{name} is not a valid phone number',
    'isUrl': '{name} is not a valid URL',
    'isIp': '{name} is not a valid IP address',
    'isNumeric': '{name} is not a valid number',
    'isNumericDecimal': '{name} is not a valid decimal number',
    'isAlphaSpace': 'Only alphabets and spaces are allowed in {name}',
    'isAlphaNumeric': 'Only alphabets and numbers are allowed in {name}',
    'isAlphaNumericSpace': 'Only alphabets, numbers and spaces are allowed in {name}',
    'regex': '{name} should match the pattern: {value}',
    'length': '{name} should be $length characters long',
    'minLength': '{name} should contain at least $minLength characters',
    'maxLength': '{name} should not exceed more than $maxLength characters',
    'greaterThan': '{name} should be greater than $greaterThan',
    'greaterThanEqualTo': '{name} should be greater than or equal to $greaterThanEqualTo',
    'lessThan': '{name} should be less than $lessThan',
    'lessThanEqualTo': '{name} should be less than or equal to $lessThanEqualTo',
    'equalTo': '{name} should be equal to $equalTo',
    'notEqualTo': '{name} should not be equal to $notEqualTo',
    'equalToInList': '{name} should be equal to any of these values ${(equalToInList ?? []).join(', ')}',
    'notEqualToInList': '{name} should not be equal to any of these values ${(notEqualToInList ?? []).join(', ')}',
    'shouldMatch': '{name} should be same as $shouldMatch',
    'shouldNotMatch': '{name} should not same as $shouldNotMatch',
    'inList': '{name} should be any of these values ${(inList ?? []).join(', ')}',
    'notInList': '{name} should not be any of these values ${(notInList ?? []).join(', ')}',
}

Override the default errors

To override the error text of a particular option, set 'customErrors' as {'optionName': '<Error Text>'}.
The 'optionName' key should match with one of the 'Available Options' for overriding the error text.
Use {value} and {name} template variables in the 'customErrors' to display the input name and value respectively.
To override all the error texts set 'customErrorText'.
'customErrorText' will override all the errors including 'customErrors'

const textFieldValue = ''; // or textFieldValue = 'xyz';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  isRequired: true,
  isEmail: true,
  customErrors: {
                  'isRequired': 'Input is invalid.',
                  'isEmail': '{value} is an invalid value. Try another {name}.',
                },
);

// when textFieldValue = '';
print(rule.error);
// output: Input is invalid.

// when textFieldValue = 'xyz';
print(rule.error);
// output: xyz is an invalid value. Try another Text field.

const textFieldValue = '';

final rule = Rule(
  textFieldValue,
  name: 'Text field',
  isRequired: true,
  isEmail: true,
  customErrorText: 'Invalid email address',
);

print(rule.error);
// output: Invalid email address

2. GroupRule

Group the basic rules together

Basic example

const textFieldValue = 'abc@xyz.com';

final rule = Rule(
  textFieldValue, 
  name: 'Text field',
);

final groupRule = GroupRule(
  [rule], // value; List of Rule
  name: 'Group name', // placeholder value which will be used while displaying errors
);

print(groupRule.error);
// output: null
print(groupRule.hasError);
// output: false

if (groupRule.hasError) {
// some action on error
}
else {
// Some action on success
}

Example 1

const textFieldValue1 = '';  // or const textFieldValue = null;
const textFieldValue2 = '';

final rule1 = Rule(
  textFieldValue1,
  name: 'Text field 1',
  isRequired: true,
);

final rule2 = Rule(
  textFieldValue2,
  name: 'Text field 2',
  isEmail: true,
);

final groupRule = GroupRule(
  [rule1, rule2], // value; List of Rule
  name: 'Group name', // placeholder value which will be used while displaying errors
);

print(groupRule.error);
// output: 'Text field 1 is required'
print(groupRule.hasError);
// output: true

Available options

final String name; // mandatory

final bool requiredAll;

final int requiredAtleast;

final int maxAllowed;

final String customErrorText;

final Map<String, String> customErrors;

requiredAll: `bool`

Checks if all basic rules have a value.

const textFieldValue1 = 'abc';
const textFieldValue2 = '';

final rule1 = Rule(
  textFieldValue1,
  name: 'Text field',
  isRequired: true,
); // Validation OK

final rule2 = Rule(
  textFieldValue2,
  name: 'Text field',
); // Validation OK

final groupRule = GroupRule(
  [rule1, rule2],
  name: 'Group name',
  requiredAll: true,
);

print(groupRule.error);
// output: All fields are mandatory in Group name

IMPORTANT: If any of the basic rules have validation errors then GroupRule will throw those errors first.
The group validation wouldn't happen until all basic rules pass the validation.

const textFieldValue1 = 'abc';  // or const textFieldValue = null;
const textFieldValue2 = 'xyz@abc';

final rule1 = Rule(
  textFieldValue1,
  name: 'Text field 1',
  isRequired: true,
); // Validation OK

final rule2 = Rule(
  textFieldValue2,
  name: 'Text field 2',
  isEmail: true,
); // Validation FAILED

final groupRule = GroupRule(
  [rule1, rule2],
  name: 'Group name'
);

print(groupRule.error);
// output: 'Text field 2 is not a valid email address'
print(groupRule.hasError);
// output: true

if (groupRule.hasError) {
// some action on error
}
else {
// Some action on success
}

IMPORTANT: If the input basic rules list is an empty array or null and 'isRequiredAll' is false or not set then no errors will be thrown for the subsequent constraints.

final groupRule = GroupRule(
  [],
  name: 'Group name'
);

print(groupRule.hasError);
// output: false

requiredAtleast: `int`

Defines the minimum number of basic rules that should have a value.
The number of basic rules in a GroupRule should be greater than the 'requiredAtleast' value else it will throw an exception.
If the 'requiredAtleast' is 0 then it will pass the validation.

const textFieldValue1 = 'abc';
const textFieldValue2 = '';

final rule1 = Rule(
  textFieldValue1,
  name: 'Text field',
); // Validation OK

final rule2 = Rule(
  textFieldValue2,
  name: 'Text field',
); // Validation OK

final groupRule = GroupRule(
  [rule1, rule2],
  name: 'Group name',
  requiredAtleast: 2,
);

print(groupRule.error);
// output: At least 2 fields are required in Group name

const textFieldValue1 = 'abc';
const textFieldValue2 = 'xyz';

final rule1 = Rule(
  textFieldValue1,
  name: 'Text field',
); // Validation OK

final rule2 = Rule(
  textFieldValue2,
  name: 'Text field',
); // Validation OK

final groupRule = GroupRule(
  [rule1, rule2],
  name: 'Group name',
  requiredAtleast: 2,
);

print(groupRule.error);
// output: null

print(groupRule.hasError);
// output: false

maxAllowed: `int`

The maximum number of basic rules that are allowed to have a value.

const textFieldValue1 = 'abc';
const textFieldValue2 = 'xyz';

final rule1 = Rule(
  textFieldValue1,
  name: 'Text field',
); // Validation OK

final rule2 = Rule(
  textFieldValue2,
  name: 'Text field',
); // Validation OK

final groupRule = GroupRule(
  [rule1, rule2],
  name: 'Group name',
  maxAllowed: 1,
);

print(groupRule.error);
// output: A maximum of 1 field is allowed in Group name

const textFieldValue1 = 'abc';
const textFieldValue2 = '';

final rule1 = Rule(
  textFieldValue1,
  name: 'Text field',
); // Validation OK

final rule2 = Rule(
  textFieldValue2,
  name: 'Text field',
); // Validation OK

final groupRule = GroupRule(
  [rule1, rule2],
  name: 'Group name',
  maxAllowed: 1,
);

print(groupRule.error);
// output: null

print(groupRule.hasError);
// output: false

Custom Error

Default errors

Plurality for 'requiredAtleast' and 'maxAllowed' error texts will be automatically detected.

{
  'requiredAll': 'All fields are mandatory in {name}',
  'requiredAtleast': 'At least $requiredAtleast field(s) is/are required in {name}',
  'maxAllowed': 'A maximum of $maxAllowed field(s) is/are allowed in {name}',
}

Override the default errors

To override the error text of a particular option, set 'customErrors' as {'optionName': '<Error Text>'}.
The 'optionName' key should match with one of the 'Available Options' for overriding the error text.
Use {value} and {name} template variables in the 'customErrors' to display the input name and value respectively.
To override all the error texts set 'customErrorText'.
'customErrorText' will override all the errors including 'customErrors'.

const textFieldValue1 = 'abc';
const textFieldValue2 = '';

final rule1 = Rule(
  textFieldValue1,
  name: 'Text field',
  isRequired: true,
); // Validation OK

final rule2 = Rule(
  textFieldValue2,
  name: 'Text field',
); // Validation OK

final groupRule = GroupRule(
  [rule1, rule2],
  name: 'Group name',
  requiredAll: true,
  customErrors: {
                  'requiredAll': 'Input is invalid.',
                },
);

print(groupRule.error);
// output: Input is invalid.

const textFieldValue1 = 'abc';
const textFieldValue2 = '';

final rule1 = Rule(
  textFieldValue1,
  name: 'Text field',
  isRequired: true,
); // Validation OK

final rule2 = Rule(
  textFieldValue2,
  name: 'Text field',
); // Validation OK

final groupRule = GroupRule(
  [rule1, rule2],
  name: 'Group name',
  requiredAll: true,
  customErrorText: 'Invalid input.',
);

print(rule.error);
// output: Invalid input.

1. CombinedRule

Manage Rules and GroupRules

Both 'Rule' and/or 'GroupRule' are accepted as inputs.
Errors of both 'Rule' and 'GroupRule', if any, are combined into a list.
Order of appearance of error texts in CombinedRule errorList:
1. Rule
2. GroupRule

Basic example

const textFieldValue1 = '';
const textFieldValue2 = 'abc@xyz.com';

final rule1 = Rule(
  textFieldValue1, 
  name: 'Text field 1',
); // Validation OK
final rule2 = Rule(
  textFieldValue2, 
  name: 'Text field 2',
  isEmail: true,
); // Validation OK
final groupRule = GroupRule(
  [rule1, rule2],
  name: 'Group name',
  requiredAll: true
); // Validation FAILED


const textFieldValue3 = '';
final rule3 = Rule(
  textFieldValue3, 
  name: 'Text field 3',
  isRequired: true,
);  // Validation FAILED


final combinedRule = CombinedRule(
  rules: [rule3],
  groupRules: [groupRule],
);

print(combinedRule.errorList);
// output: ['Text field 3 is required', 'All fields are mandatory in Group name']

print(combinedRule.hasError);
// output: true

if (combinedRule.hasError) {
// some action on error
}
else {
// Some action on success
}

Available options

final List<Rule> rules;

final List<GroupRule> groupRules;

rules: `List<Rule>`

const textFieldValue1 = '';
const textFieldValue2 = 'abc@xyz';
const textFieldValue3 = '';

final rule1 = Rule(
  textFieldValue1, 
  name: 'Text field 1',
); // Validation OK
final rule2 = Rule(
  textFieldValue2, 
  name: 'Text field 2',
  isEmail: true,
); // Validation FAILED
final rule3 = Rule(
  textFieldValue3, 
  name: 'Text field 3',
  isRequired: true,
  customErrorText: 'Invalid field input',
); // Validation FAILED


final combinedRule = CombinedRule(
  rules: [rule1, rule2, rule3],
);

print(combinedRule.errorList);
// output: ['Text field 2 is not a valid email address', 'Invalid field input']

print(combinedRule.hasError);
// output: true

groupRules: `List<GroupRule>`

const textFieldValue1 = '';
const textFieldValue2 = 'abc@xyz';

final rule1 = Rule(
  textFieldValue1, 
  name: 'Text field 1',
); // Validation OK
final rule2 = Rule(
  textFieldValue2, 
  name: 'Text field 2',
  isEmail: true,
); // Validation FAILED
final groupRule1 = GroupRule(
  [rule1, rule2],
  name: 'Group name',
  requiredAll: true,
  customErrorText: 'Invalid input',
); // Validation FAILED

final groupRule2 = GroupRule(
  [],
  name: 'Group name',
); // Validation OK


final combinedRule = CombinedRule(
  groupRules: [groupRule1, groupRule2],
);

print(combinedRule.errorList);
// output: ['Invalid input']

print(combinedRule.hasError);
// output: true

Flutter

class _MyStatefulWidgetState extends State<MyStatefulWidget> {
  String emailInput;

  String phoneInput;

  void _handleEmailTextFieldOnChange(String value) {
    setState(() {
      emailInput = value;
    });
  }

  void _handlePhoneTextFieldOnChange(String value) {
    setState(() {
      phoneInput = value;
    });
  }

  Rule get emailInputRule {
    return Rule(
      emailInput,
      name: 'Email',
      isAlphaSpace: true,
      isRequired: true,
      customErrorText: 'Invalid Email',
    );
  }

  Rule get phoneInputRule {
    return Rule(
      phoneInput,
      name: 'Phone',
      isPhone: true,
      isRequired: true,
      customErrorText: 'Invalid Phone',
    );
  }

  bool get isContinueBtnEnabled {
    final groupRule = GroupRule(
      [emailInputRule, phoneInputRule],
      name: 'Continue Button',
      requiredAll: true,
    );

    return !groupRule.hasError;
  }

  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          children: <Widget>[
            TextField(
              onChanged: (String value) {
                _handleEmailTextFieldOnChange(value);
              },
              decoration: InputDecoration(
                hintText: 'Email address',
                errorText: emailInputRule?.error ?? null,
              ),
            ),
            TextField(
              onChanged: (String value) {
                _handlePhoneTextFieldOnChange(value);
              },
              decoration: InputDecoration(
                hintText: 'Phone',
                errorText: phoneInputRule?.error ?? null,
              ),
            ),
            if (isContinueBtnEnabled)
              FlatButton(
                onPressed: () {
                  // call api
                },
                child: const Text('Continue'),
              )
            else
              Container()
          ],
        ),
      ),
    );
  }
}

Flutter Mobx

Mobx Store

class UpdateUserStore = _UpdateUserStoreBase
    with _$UpdateUserStore;

abstract class _UpdateUserStoreBase with Store {
  @observable
  String profileName;

  @observable
  String profileEmail;

  @computed
  Rules get profileNameInputRule {
    final rule = Rules(
      profileName,
      name: 'Name',
      isRequired: false,
      isAlphaSpace: true,
      customErrorText: 'Invalid name',
    );

    return rule;
  }

  @computed
  Rules get profileEmailInputRule {
    final rule = Rules(
      profileEmail,
      name: 'Name',
      isRequired: false,
      isEmail: true,
      customErrorText: 'Invalid email',
    );

    return rule;
  }

  @computed
  bool get isContinueButtonEnabled {
    final groupRule = GroupRules(
      [profileEmailInputRule, profileNameInputRule],
      name: 'Continue Button',
      requiredAll: true,
    );

    return !groupRule.hasError;
  }

  @action
  void setProfileName(String value) {
    profileName = value;
  }

  @action
  void setProfileEmail(String value) {
    profileEmail = value;
  }
}

Widget

class _UpdateUserScreen extends State<UpdateUserScreen> {
  UpdateUserStore _updateUserStore = UpdateUserStore();

  void _handleProfileNameOnChange(String value) {
    _updateUserStore.setProfileName(value);
  }

  void _handleProfileEmailOnChange(String value) {
    _updateUserStore.setProfileEmail(value);
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      width: Display.getWidth(context),
      height: Display.getHeight(context),
      child: Column(
        mainAxisAlignment: MainAxisAlignment.end,
        children: <Widget>[
          Observer(
            builder: (_) {
              final _errorText = _updateUserStore.profileNameInputRule?.error;

              return TextField(
                onChanged: (String value) {
                  _handleProfileNameOnChange(value);
                },
                decoration: InputDecoration(
                  hintText: 'Name',
                  errorText: _errorText,
                ),
              );
            },
          ),
          Observer(
            builder: (_) {
              final _errorText = _updateUserStore.profileEmailInputRule?.error;

              return TextField(
                onChanged: (String value) {
                  _handleProfileEmailOnChange(value);
                },
                decoration: InputDecoration(
                  hintText: 'Email',
                  errorText: _errorText,
                ),
              );
            },
          ),
          Observer(
            builder: (_) {
              final _isContinueButtonEnabled =
                  _updateUserStore.isContinueButtonEnabled;

              if (!_isContinueButtonEnabled) {
                return Container();
              }

              return FlatButton(
                onPressed: () {},
                child: const Text('Continue'),
              );
            },
          ),
        ],
      ),
    );
  }
}

Buy me a coffee #

Help me keep the app FREE and open for all. Paypal me: paypal.me/ganeshrvel

Contacts #

Please feel free to contact me at ganeshrvel@outlook.com

About #

Author: Ganesh Rathinavel
License: MIT
Package URL: https://pub.dev/packages/rules
Repo URL: https://github.com/ganeshrvel/pub-rules
Contacts: ganeshrvel@outlook.com

License #

Rules | Powerful and feature-rich validation library for both Dart and Flutter. MIT License.

rules 1.0.0 rules: ^1.0.0 copied to clipboard

Metadata

Introduction #

Rules - Powerful and feature-rich validation library for both Dart and Flutter.

Installation #

Concept #

Usage #

1. Rule (Basic Rule)

isRequired: bool

isEmail: bool

isUrl: bool

isPhone: bool

isIp: bool

isNumeric: bool

isNumericDecimal: bool

isAlphaSpace: bool

isAlphaNumeric: bool

isAlphaNumericSpace: bool

regex: String

length: int

minLength: int

maxLength: int

greaterThan: double

greaterThanEqualTo: double

lessThan: double

lessThanEqualTo: double

equalTo: double

notEqualTo: double

equalToInList: List<double>

notEqualToInList: List<double>

shouldMatch: String

shouldNotMatch: String

inList: List<String>

notInList: List<String>

Default errors

Override the default errors

2. GroupRule

requiredAll: bool

requiredAtleast: int

maxAllowed: int

Default errors

Override the default errors

1. CombinedRule

rules: List<Rule>

groupRules: List<GroupRule>

Flutter

Flutter Mobx

Buy me a coffee #

Contacts #

About #

License #

← Metadata

Publisher

Metadata

License

Dependencies

More

rules 1.0.0
rules: ^1.0.0 copied to clipboard

isRequired: `bool`

isEmail: `bool`

isUrl: `bool`

isPhone: `bool`

isIp: `bool`

isNumeric: `bool`

isNumericDecimal: `bool`

isAlphaSpace: `bool`

isAlphaNumeric: `bool`

isAlphaNumericSpace: `bool`

regex: `String`

length: `int`

minLength: `int`

maxLength: `int`

greaterThan: `double`

greaterThanEqualTo: `double`

lessThan: `double`

lessThanEqualTo: `double`

equalTo: `double`

notEqualTo: `double`

equalToInList: `List<double>`

notEqualToInList: `List<double>`

shouldMatch: `String`

shouldNotMatch: `String`

inList: `List<String>`

notInList: `List<String>`

requiredAll: `bool`

requiredAtleast: `int`

maxAllowed: `int`

rules: `List<Rule>`

groupRules: `List<GroupRule>`