# Validation and Errors Handling ## VGSTextField Input Validation VGSCollectSDK provides built-in validation for input data and files. Validation is based on defined validation rules set for each specific `VGSTextField`. These rule sets are defined by default for each `FieldType`, but you still have possibility to customize them. `VGSTextField` will be validating after each textfield's editing event. You can check validation results through textfield's state fields: `textfield.state.isValid` & `textfield.state.validationErrors`. ### Default Validation Here are few examples how default validation works for specific `FieldType`: | **FieldType** | **Validation Details** | | ------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **.none** | Any input will be valid if no other validation rules will be applied | | **.ssn** | US social security number, should be 9 digits, don't start with \[000,666,9] or contain sequences of the same digits. Ignores some SSNs used in advertising | | **.cardNumer** | Card number validation with checkSum algorithm(Luhn algorithm), available card lengths for defined card types | | **.date** | Any date that match the selected format. By default valid date should be in `mm-dd-yyyy` | | **.expDate** | Any date starting from current month. By default valid expiration date should be in short year format - `MM/yy` | | **.cardHolderName** | Name, should be 2 or more symbols, valid characters shold match pattern: `[a-zA-Z0-9]` | | **.cvc** | card cvc number, should be 3-4 digits. If in same `VGSCollect` instance there is associated `.cardNumer` field, **cvc** validation will be dynamic. It depends on input Card Brand type. For example: for **AMEX** valid cvc only with 4 digits, while for **Visa** 3 digits only. | If you didn't find specific `FieldType` for your use case, you can always configure `VGSTextField` with `VGSConfiguration.fieldType = .none`. Then assign any specific rule set to the field and use other configuration attributes. Check more on our code examples below. > • To get full details about how validation rules work for each specific fields you can check `VGSCollectSDK` source code. ### Available Validation Rules VGSCollect SDK provide pre-build validation rules that you can apply to `VGSTextField` object through it's configuration. Here are some examples of the available rules: | **VGSValidationRule** | **Description** | | ----------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | VGSValidationRuleLength | Validate input in scope of `min` & `max` lengths | | VGSValidationRulePattern | Validate input in scope of matching the regex `pattern` | | VGSValidationRuleDateRange | Validate input in scope of matching date range. It also validate dates is in specific range. Supports `VGSDateFormat` date formats validation | | VGSValidationRuleCardExpirationDate | Validate input in scope of matching card expiration date format and time range. Supports `VGSCardExpDateFormat` date formats validation | | VGSValidationRulePaymentCard | Validate input in scope of matching supported card brands, available lengths and checkSum algorithms. Support optional validation of cards that are not defined in SDK - `CardBrand.unknown` | | VGSValidationRuleLuhnCheck | Validate input in scope of matching Luhn algorithm | | VGSValidationRuleLengthMatch | Validate input in scope of multiple lengths, e.x.: \[16, 19] | | VGSValidationRuleABARoutingNumber | Validate input against ABA (American Bankers Association) routing number requirements. | When you don't want to send to your organization vault data that is not valid, you can also set up additional `VGSConfiguration` attributes: * **.isRequired** - if `true`, then the SDK will check if the input data in the field is **not empty** or **nil** on `VGSCollect.sendData(_:)` request. When validation failed, the DK will return a specific `VGSError` with `extraInfo` field that contains info about not valid fields. * **.isRequiredValidOnly** - if `true`, then the SDK will check if the input data in the field is **valid** on `VGSCollect.sendData(_:)` request. When validation failed, Sthe DK will return specific `VGSError` with `extraInfo` field that contains info about not valid fields. ### How to customize VGSTextField Validation? Here are a few examples of how to create your own validation rules set or edit existing rules that will validate input in `VGSTextField`. Create a textfield that should be valid when input is **6-9 digits** long and starts with **555** ```swift let configuration = VGSConfiguration(collector: collector, fieldName: "secretNumber") configuration.type = .none configuration.formatPattern = "XXX-XXX-XXX" configuration.validationRules = VGSValidationRuleSet(rules: [ VGSValidationRuleLength.init(min: 6, max: 9, error: "WRONG LENGTH"), VGSValidationRulePattern.init(pattern: "^555\\d*$", error: "PATTERN FAILED") ]) textField.configuration = configuration textField.placeholder = "XXX-XXX-XXX" ``` Validate payment cards that are not supported by the SDK. In this case, all `.unknown` card types will go through `Luhn` check validation and possible card lengths. ```swift let cardConfiguration = VGSConfiguration(collector: collector, fieldName: "card_number") cardConfiguration.type = .cardNumber cardConfiguration.validationRules = VGSValidationRuleSet(rules:[ VGSValidationRulePaymentCard(error: VGSValidationErrorType.cardNumber.rawValue, validateUnknownCardBrand: true) ]) cardTextField.configuration = cardConfiguration ``` Validate date with format `mm/dd/yyyy` that is in a date range from `01/02/2010` and `01/02/2020`. ```swift /// Define range validation /// The validation will fails if the date is before 02/01/2010 or after 02/01/2020 let startDate = VGSDate(day: 2, month: 1, year: 2010) let endDate = VGSDate(day: 2, month: 1, year: 2020) /// Use `VGSDateConfiguration` when you need to set validation date range let dateConfiguration = VGSDateConfiguration( collector: vgsCollect, fieldName: "date", datePickerStartDate: startDate, datePickerEndDate: endDate ) dateConfiguration.inputDateFormat = .mmddyyyy /// Update configuration in the text field dateField.configuration = dateFieldConfiguration /// Update validation rules, `start` and `end` should be the same used in the configuration `datePickerStartDate` and `datePickerEndDate` dateConfiguration.validationRules = VGSValidationRuleSet( rules: [ VGSValidationRuleDateRange( dateFormat: .mmddyyyy, error: VGSValidationErrorType.date.rawValue, start: startDate end: endDate ) ] ) ``` Validate expiration date with long year format `MM/yyyy`. ```swift let expDateConfiguration = VGSConfiguration(collector: collector, fieldName: "exp_date") expDateConfiguration.type = .expDate expDateConfiguration.validationRules = VGSValidationRuleSet(rules: [ VGSValidationRuleCardExpirationDate(dateFormat: .longYear, error: VGSValidationErrorType.expDate.rawValue) ]) expDateTextField.configuration = expDateConfiguration ``` Use the Input Validation results ```swift extension ViewController: VGSTextFieldDelegate { func vgsTextFieldDidChange(_ textField: VGSTextField) { /// update textfield color on validation state changes textField.borderColor = textField.state.isValid ? .lightGray : .red /// show the validation error message validationLabel.text = textField.state.isValid ? "All is OK!" : textField.state.validationErrors.first } } ``` ### File Data validation Before sending file data to your organization vault, `VGSCollectSDK` validates selected files. Here are a few examples of file data validation rules: * File source should be available for the App. * It should be possible to convert a file into **base64**. * File size doesn't exceed the limit of **24mb** and its size is not **0**. * File not removed from the directory where it was selected before uploading to your organization's vault. For each of these errors `VGSCollectSDK` will produce specific `VGSError` on `VGSCollect.sendFile(_:)`. ## Errors Handling This guide covers error handling features that will help you make your App more reliable and recover from errors produced by `VGSCollectSDK`. ### VGSError An object `VGSCollectSDK` used to produce errors inside the SDK. All `VGSCollectSDK` errors are produced under `VGSCollectSDKErrorDomain` domain. #### Declaration ```swift class VGSError: NSError ``` #### Attributes | **Attribute** | **Type/Description** | | ------------------------- | -------------------------------------------------------- | | key | **String**, error key defined in `VGSErrorInfoKey.swift` | | NSLocalizedDescriptionKey | **String**, error description for developer | | extraInfo | **Dictionary**, can contain additional error details | `VGSError` inherits iOS native `NSError` class and works similar. `VGSError` populates error codes, declared in `VGSErrorType`, and error keys, declared in [VGSCollectSDK Reference docs](https://verygoodsecurity.github.io/vgs-collect-ios/Error%20Keys.html). #### Error codes List of Error codes produced by VGS Collect iOS SDK locally. | **Code** | **Key** | **Description** | | -------- | ------------------------------ | ------------------------------------------------------ | | 1001 | `inputDataIsNotValid` | When input data is not valid, but required to be valid | | 1101 | `inputFileNotFound` | When can't find file on device | | 1102 | `inputFileTypeIsNotSupported` | When selected file type not supported | | 1103 | `inputFileSizeExceedsTheLimit` | When file size is larger then allowed limit | | 1150 | `sourceNotAvailable` | When can't get access to file source | | 1400 | `unexpectedResponseType` | When response type is not supported | | 1401 | `unexpectedResponseDataFormat` | When response data format is not supported | | 1480 | `invalidConfigurationURL` | When VGS configuration URL is not valid | | 1300 | `invalidAccessToken` | When access token is nil or empty | #### Code example ```swift vgsCollect.sendData(path: "/post", extraData: nil) { [weak self](../../response) in switch response { case .failure(let code, _, _, let error): switch code { /// Hande not valid fields data error case VGSErrorType.inputDataIsNotValid.rawValue: /// handle error /// ... return } } ```