Constraints

Constraints define set of rules that are applied for validation of the Attribute content as input. The Attribute content is validated when the Attribute is created or updated. Validation is controlled consistently by the platform and ensures that the Attribute content is valid and can be used for further processing.

Attributes that support constraints

For more information about Attribute types that support constraints, see Attributes.

Constraint properties

Every constraint is extended from the base class of BaseAttributeConstraint which is abstracted from AttributeConstraint.

The constraint has the following properties defined and inherited from the BaseAttributeConstraint:

Property	Type	Short description	Required
description	string	Description of the constraint	No
errorMessage	string	Error message to be displayed when the constraint is violated	No
type	AttributeConstraintType	Type of the constraint	Yes
data	AttributeConstraint	Data to be used for the constraint	Yes

Supported constraints types

Supported constraint types are defined in the AttributeConstraintType. The following content types are available and supported:

AttributeConstraintType	Class	Data
REGEXP	RegexpAttributeConstraint	string
RANGE	RangeAttributeConstraint	RangeAttributeConstraintData
DATETIME	DateTimeAttributeConstraint	DateTimeAttributeConstraintData

Constraint type description and samples

RegExpAttributeConstraint

Use this constraint when the content needs to be validated against a regular expression.

JSON

{
    "description": "Alphanumeric Regex Constraint",
    "errorMessage": "Only alphanumeric characters are allowed",
    "type": "RegExp",
    "data": "^[a-zA-Z0-9]*$"
}

Java

AttributeConstraint constraint = new RegexpAttributeConstraint()
constraint.setDescription("Alphanumeric Regex Constraint")
constraint.setErrorMessage("Only alphanumeric characters are allowed")
constraint.setData("^[a-zA-Z0-9]*$");
constraint.setType(AttributeConstraintType.REGEXP);

RangeAttributeConstraint

Use this constraint when the content needs to be validated against a range of integers.

JSON

{
    "description": "Range Constraint",
    "errorMessage": "Value should be between 1 and 10",
    "type": "range",
    "data": {
        "from": 1,
        "to": 10
    }
}

Java

RangeAttributeConstraintData data = new RangeAttributeConstraintData();
data.setFrom(1);
data.setTo(10);

RangeAttributeConstraint constraint = new RangeAttributeConstraint();
constraint.setDescription("Range Constraint");
constraint.setErrorMessage("Value should be between 1 and 10");
constraint.setData(data);
constraint.setType(AttributeConstraintType.RANGE);

DateTimeAttributeConstraint

Use this constraint when you need to validate date and time.

JSON

{
    "description": "Date Time Constraint",
    "errorMessage": "Value should be between 1 and 10",
    "type": "datetime",
    "data": {
        "from": "2020-01-01T00:00:00.000Z",
        "to": "2020-12-31T00:00:00.000Z"
    }
}

Java

DateTimeAttributeConstraintData data = new DateTimeAttributeConstraintData();
data.setFrom(LocalDateTime.now());
data.setTo(LocalDateTime.of(2023, Month.JULY, 29, 19, 30, 40));

DateTimeAttributeConstraint constraint = new DateTimeAttributeConstraint();
constraint.setDescription("Date Time Constraint");
constraint.setErrorMessage("Value should be between the provided range");
constraint.setData(data);
constraint.setType(AttributeConstraintType.DATETIME);

Constraint model

The following diagram represents the constraint model inherited from the AttributeConstraint. Details can be found in the CZERTAINLY Interfaces repository.