ready_validation

Description:

ready validation

how to use #
first if you are using localizations you must add localization delegate to your material app or we will use arabic #
return MaterialApp(
localizationsDelegates: [
ReadyValidationMessages.delegate,
...other delegates
],
home: MyApplicationHome(),
);
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if you want to use specified messages across the app you can do so #
ValidationMessagesConfig(
messages: ReadyValidationMessagesAr(),
child: // screen or material app
);
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don't worry every validation has a parameter for custom message
usage #
/// its very simple

TextFormField(

validator: context
.string()
.required()
.notEmpty()
.hasMaxLength(10)
.hasMinLength(15)
.isNumber()
.greaterThan(10),

);

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explanation #


it get the validator for String? values


it check if the value is not null and convert the validator to String instead of String?

at this point we can use non nullable string validations



checks that string is not empty


check the max length of string


check the min length of string


check if string is number and if it pass transform validator to num validator

at this point we can use all number validations like greaterThan



check if the transformed number is greater than 10


is any of the validations fails it will return its validation message and will not continue validations


non context validation #
BuildContext is used to apply localization and global config localization but some times you need to check if is valid
this is also supported and this time you don't need to validate required is the value is non nullable as we already know its not null
var number = "7";

var isValid = number
.validateWith((v) => v.isNumber())
.validateWith((v) => v.isBetween(5, 10))
.isValid();

/// or
isValid = number.validateWith((v) => v.isNumber().isBetween(5, 10)).isValid();

// ignore: avoid_print
print(isValid);
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Available validations #
all types #
required notEqual equal isIn isNotIn validateWith
strings #

isEmail isCreditCard startsWith contains endsWith notEmpty notEmptyOrWhiteSpace matches hasLength hasMinLength
hasMaxLength hasRange isAngelCompany isAngelJob isCrunchbaseOrganization isCrunchbasePerson isFacebookUrl isGitHubUrl
isGooglePlusUrl isHackerNewsUserUrl isHackerNewsItemUrl isInstagramUrl isLinkedInProfile isLinkedInCompany isLinkedInPost
isRedditUrl isSnapchatUrl isStackexchangeUrl isStackoverflowQuestionUrl isStackoverflowUserUrl isTelegramProfileUrl isMediumPostUrl
isMediumUserUrl isTwitterStatusUrl isTwitterUserUrl isYoutubeChannelUrl isYoutubeVideoUrl isYoutubeUserUrl

numbers #

lessThan greaterThan isBetween lessThanOrEqual greaterThanOrEqual isBetweenOrEqual isDivisibleBy
isNegative isPositive isEven isOdd

dates #

isAfter isAfterOrEqual isBefore isBeforeOrEqual isBetween isBetweenOrEqual


note : most of the validators has an alternatives with prefix Fn like startsWithFn which accepts function instead of value

validators #
/// string validators
context.string();

/// number validators
context.number();

/// integer validators
context.integer();

/// decimal validators
context.decimal(); // for doubles

/// boolean validators
context.boolean();

/// dateTime validators
context.dateTime();

/// dateTime validators
context.timeOfDay(); // will be added soon

/// list validators
context.list<T>();

/// map validators
context.map<K,V>();

/// other validators
context.validator<T>();
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transforming #
in any step you can transform your validator to another type and it can still be used with field
imagine we created a validator for our TextFormField which accepts a validator of type string
so our validator will be
context.string();
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now we need to transform it number validator
context
.string()
.required() // this to ensure it not null
.transform((v)=>int.parse(v))
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now you can use any number validation like greaterThan but you cant use hasMaxLength as it for string till you transform its again to the string validator
when , whenNot , allWhen , allWhenNot #
context
.string()
.required()
.hasMaxLength(10)
.hasMinLength(15)
.when((x) => false) /// at this point `hasMinLength` is ignored
.isNumber()
.greaterThan(10),
/// so the validations will be
/// `required` => `hasMaxLength` => `isNumber` => `greaterThan`
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Advanced #
Some times you want to use your own messages to that you has to create your own delegate and classes
the default delegate look like this

class _ReadyValidationMessagesDelegate
extends LocalizationsDelegate<ReadyValidationMessages> {
const _ReadyValidationMessagesDelegate();

@override
Future<ReadyValidationMessages> load(Locale locale) {
return SynchronousFuture<ReadyValidationMessages>(
lookupReadyValidationMessages(locale));
}

@override
bool isSupported(Locale locale) =>
<String>['ar', 'en', 'fr', 'ur'].contains(locale.languageCode);

@override
bool shouldReload(_ReadyValidationMessagesDelegate old) => false;
}

ReadyValidationMessages lookupReadyValidationMessages(Locale locale) {
// Lookup logic when only language code is specified.
switch (locale.languageCode) {
case 'ar':
return ReadyValidationMessagesAr();
case 'en':
return ReadyValidationMessagesEn();
case 'fr':
return ReadyValidationMessagesFr();
case 'ur':
return ReadyValidationMessagesUr();
}

throw FlutterError(
'ReadyValidationMessages.delegate failed to load unsupported locale "$locale". This is likely '
'an issue with the localizations generation tool. Please file an issue '
'on GitHub with a reproducible sample app and the gen-l10n configuration '
'that was used.');
}

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you also need to create your custom ReadyValidationMessages classes
now instead of using our delegate use your own
return MaterialApp(
localizationsDelegates: [
CustomReadyValidationMessages(),
...other delegates
],
home: MyApplicationHome(),
);
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injectable #
what if you need to make your own validation that can be used with other validations
-like this

TextFormField(

validator: context
.string()
.required()
.myCustomValidation() /// this your custom validation
.hasMaxLength(10)
.hasMinLength(15)
.isNumber()
.greaterThan(10),

);

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to do this you have to extend the field validator

extension MyCustomValidationExtension<T> on FieldValidator<T, String> {
FieldValidator<T, String> myCustomValidation() {
return next(
(messages, value) => !validate(value)/// validate your text here
? "My custom message"
: null,
);
}
}

/// FieldValidator takes 2 generic arguments
/// the first is the caller which means what is the type of value that will be passed to the validator
/// as we need our validator to work with string values and any type that is transformed to string we use T as the first arg

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