Defining Inputs

Feature inputs in Ductape allow you to define and enforce validation rules for data that flows into a feature. Inputs are expected in JSON format and are described using the IFeatureInput type from the SDK. This enables you to specify data types and apply constraints like minimum and maximum length, ensuring data consistency and reliability.

IFeatureInput Structure

Each input field is defined as an entry in a flat object, where the key is the input name and the value is an IFeatureInput object:

interface IFeatureInput {
  type: DataTypes | FileType; // Required: Specifies the expected data type
  minlength?: number;         // Optional: Minimum length of the value
  maxlength?: number;         // Optional: Maximum length of the value
}

Note: Only flat objects are supported for feature inputs. Nested objects are not accepted.

Example: Feature Input Definition

{
  username: {
    type: DataTypes.NOSPACES_STRING,  // Username must be a string without spaces
    minlength: 3,                     // Minimum length of 3 characters
    maxlength: 10,                    // Maximum length of 10 characters
  },
  email: {
    type: DataTypes.EMAIL_STRING,     // Must follow a valid email format
  },
  house_number: {
    type: DataTypes.INTEGER           // Expected to be an integer
  },
  country: {
    type: DataTypes.STRING            // Free-form text for country name
  },
  state: {
    type: DataTypes.STRING            // Free-form text for state name
  }
}

IFeatureInput Fields

Field	Type	Required	Description
type	DataTypes|FileType	Yes	The expected data type for the input.
minlength	number	No	Minimum length (for strings/arrays).
maxlength	number	No	Maximum length (for strings/arrays).

Available DataTypes

The following DataTypes are available for defining feature inputs:

Type	Description
STRING	Free-form text
NOSPACES_STRING	String without spaces
EMAIL_STRING	String in a valid email format
NUMBER_STRING	String representing a number
DATE_STRING	String in a valid date format
INTEGER	Integer value
FLOAT	Floating-point number
DOUBLE	Double-precision floating-point number
UUID	Universally Unique Identifier (UUID)
DATE	Date value
ARRAY	Array of items
OBJECT	JSON object
BOOLEAN	Boolean value (true or false)
STRING_ARRAY	Array of strings
INTEGER_ARRAY	Array of integers
FLOAT_ARRAY	Array of floats
DOUBLE_ARRAY	Array of doubles
UUID_ARRAY	Array of UUIDs
BOOLEAN_ARRAY	Array of booleans

Tip: Use the most specific DataTypes possible to ensure robust validation.

Best Practices

• Use descriptive and consistent input field names.
• Choose the most restrictive DataTypes that match your requirements.
• Set minlength and maxlength for strings and arrays to enforce data quality.
• Avoid nested objects; keep input schemas flat for compatibility.
• Document each input field's purpose for maintainability.

See Also

• Defining Output
• Features Overview
• Event Types Overview