The annotation, which is used for the constraints of the `anydata[]` type.


Array

ArrayConstraints

The annotation, which is used for the constraints of the `float` type.


Float

FloatConstraints

The annotation, which is used for the constraints of the `int` type.


IntConstraints

The annotation, which is used for the constraints of the `int`, `float`, and `decimal` types.


Number

NumberConstraints

The annotation, which is used for the constraints of the `string` type.


String

StringConstraints

## Overview

This module provides features to validate the values that have been assigned to Ballerina types.

The Ballerina `constraint` module facilitates APIs to do validations on the Ballerina types further with the use of annotations.


Represents the error type of the module.


Error

Validates the provided value against the configured annotations.



validate

The `anydata` type value to be constrained


value

anydata

The type descriptor of the value to be constrained


The type descriptor of the value which is validated or else an `constraint:Error` in case of an error


Represents the constraints associated with `anydata[]` type.



The number of members of the constrained type


length

The inclusive lower bound of the number of members of the constrained type


minLength

The inclusive upper bound of the number of members of the constrained type


maxLength

Represents the constraints associated with `float` type.



The inclusive lower bound of the constrained type


minValue

float

The inclusive upper bound of the constrained type


maxValue

The exclusive lower bound of the constrained type


minValueExclusive

The exclusive upper bound of the constrained type


maxValueExclusive

Represents the constraints associated with `int` type.



Represents the constraints associated with `int`, `float` and `decimal` types.



decimal

Represents the constraints associated with `string` type.



The number of characters of the constrained `string` type


The inclusive lower bound of the number of characters of the constrained `string` type


The inclusive upper bound of the number of characters of the constrained `string` type


This module provides features to validate the values that have been assigned to Ballerina types.


@cloud:Expose annotation marks a port that has to be exposed in a custom listener initializer.
```ballerina
public function init(@cloud:Expose int port) {}
```


@cloud:Task annotation to configure cron job.


The annotation to configure a GraphQL service.


The annotation to designate a GraphQL object type as a federated entity.


The annotation to designate a GraphQL service as a federated GraphQL subgraph.


The annotation which is used to configure a gRPC service.


The annotation which is used to define the response cache configuration. This annotation only supports `anydata` and
Success(2XX) `StatusCodeResponses` return types. Default annotation adds `must-revalidate,public,max-age=3600` as
`cache-control` header in addition to `etag` and `last-modified` headers.


The annotation which is used to configure the type of the response.


The annotation which is used to define the Header resource signature parameter.


The annotation which is used to define the Payload resource signature parameter and return parameter.


The annotation which is used to define the query resource signature parameter.


The annotation which is used to configure an HTTP resource.


The annotation which is used to configure an HTTP service.


Describes the Java class representing a Ballerina binding.
```ballerina
@java:Binding {
  'class: "java.io.File"
}
```


Describes a Java constructor, which provides an implementation of a Ballerina function of which the body is marked as
`external`. If the Ballerina function body is marked as `external`, it means that the implementation of the
function is not provided in the Ballerina source module.

The following code snippet shows an example usage of this annotation. Here, the `newJavaLinkedList` Ballerina function's
implementation is provided by the default constructor of the `java.util.LinkedList` class.
```ballerina
function newJavaLinkedList() returns handle = @java:Constructor {
     'class: "java.util.LinkedList"
} external;
```


Describes a Java Field access, which provides an implementation of a Ballerina function of which the body is marked as
`external`.
```ballerina
function getError() returns handle = @java:FieldGet {
    name:"err",
    'class:"java/lang/System"
} external;
```


Describes a Java Field mutate, which provides an implementation of a Ballerina function of which the body is marked as
`external`.
```ballerina
function setContractId(handle contractId) = @java:FieldSet {
  name:"contractId",
  'class:"org/lang/impl/JavaFieldAccessMutate"
} external;
```


Describes a Java method, which provides an implementation of a Ballerina function of which the body is marked as
`external`. If the Ballerina function body is marked as `external`, it means that the implementation of the
function is not provided in the Ballerina source module.

The following code snippet shows an example usage of this annotation. Here, the `getUUID` Ballerina function's
implementation is provided by the `java.util.UUID.randomUUID` static method.
```ballerina
function getUUID() returns handle = @java:Method {
    name: "randomUUID",
    'class: "java.util.UUID"
} external;
```
The `name` field is optional. If it is not provided, the name of the Java method is inferred
from the Ballerina function.


This is used for making a function observable.
Can be applied to functions which are not observable by default to make them observable.



Annotation for additional OpenAPI information of a Ballerina service.


The Annotation used to specify which database column matches the Typed record field.


Identifies test factory function for dynamic test registration.
Identifies beforeSuite function.


The annotation which is used to configure local transaction participant function.


The annotation which is used to configure a WebSocket service.


WebSub Subscriber Configuration for the service, indicating subscription related parameters.


WebSub Hub Configuration for the service.


The annotation is used to denote the field that is considered an attribute.
In the XML-record conversion, this annotation can be used to add XML attribute using the `xmldata:toXML` API and
validate the XML attribute with record fields in the `xmldata:fromXml` API.


The annotation is used to specify the new name of the existing record name or field name according to the XML format.
In the XML-record conversion, this annotation can be used to override the default XML element name using the
`xmldata:toXML` API and validate the overridden XML element name with record field using the `xmldata:fromXml` API.


The annotation is used to specify the namespace's prefix and URI of the XML element.
In the XML-record conversion, this annotation can be used to add XML namespace using the `xmldata:toXML` API and
validate the the XML namespace with record in the `xmldata:fromXml` API.


Represents the client Basic Auth provider, which is used to authenticate with an external endpoint by generating a
Basic Auth token against the provided credential configurations.
```ballerina
auth:CredentialsConfig config = {
    username: "tom",
    password: "123"
}
auth:ClientBasicAuthProvider provider = new(config);
```


Represents the file user store based listener Basic Auth provider, which is used to authenticate the provided
credentials against the provided file user store configurations.
```ballerina
auth:ListenerFileUserStoreBasicAuthProvider provider = new;
```
The users are denoted by a section in the `Config.toml` file. The username, password, and the scopes of a particular
user are denoted as keys under the users section as shown below. For multiple users, the complete section has to be
duplicated.
```
[[ballerina.auth.users]]
username = "alice"
password = "password1"
scopes = ["scope1", "scope2"]
```


Represents the LDAP-based listener Basic Auth provider, which is used to authenticate the provided credentials
against the provided LDAP user store configurations. This connects to an active directory or an LDAP, retrieves
the necessary user information, and performs authentication and authorization.
```ballerina
auth:LdapUserStoreConfig config = {
    domainName: "ballerina.io",
    connectionURL: "ldap://localhost:389",
    connectionName: "cn=admin,dc=avix,dc=lk"
};
auth:ListenerLdapUserStoreBasicAuthProvider provider = new(config);
```


The `cache:Cache` object, which is used for all the cache-related operations. It is not recommended to insert `()`
as the value of the cache since it doesn't make any sense to cache a nil.


Represents a service listener that monitors the email server location.


The GraphQL context object used to pass the meta information between resolvers.


Represents the information about a particular field of a GraphQL document.


Defines the Basic Auth handler for client authentication.


Defines the Bearer token auth handler for client authentication.


Defines the self signed JWT handler for client authentication.


Defines the file store Basic Auth handler for listener authentication.


Defines the JWT auth handler for listener authentication.


Represents a default persistent cookie handler, which stores persistent cookies in a CSV file.



Represents the headers of the inbound request.


Implements a cache for storing HTTP responses. This cache complies with the caching policy set when configuring
HTTP caching in the HTTP client endpoint.



Represents a 'future' that returns as a result of an asynchronous HTTP request submission.
This can be used as a reference to fetch the results of the submission.


Implementation of round robin load balancing strategy.



Represents an HTTP/2 `PUSH_PROMISE` frame.



Configures the cache control directives for an `http:Request`.



Represents an HTTP Context that allows user to pass data between interceptors.


Configures cache control directives for an `http:Response`.



Represents the status code of `STATUS_ACCEPTED`.



Represents the status code of `STATUS_ALREADY_REPORTED`.



Represents the status code of `STATUS_BAD_GATEWAY`.



Represents the status code of `STATUS_BAD_REQUEST`.



Represents the status code of `STATUS_CONFLICT`.



Represents the status code of `STATUS_CONTINUE`.



Represents the status code of `STATUS_CREATED`.



Represents the status code of `STATUS_EARLY_HINTS`.



Represents the status code of `STATUS_EXPECTATION_FAILED`.



Represents the status code of `STATUS_FAILED_DEPENDENCY`.



Represents the status code of `STATUS_FORBIDDEN`.



Represents the status code of `STATUS_FOUND`.



Represents the status code of `STATUS_GATEWAY_TIMEOUT`.



Represents the status code of `STATUS_GONE`.



Represents the status code of `STATUS_HTTP_VERSION_NOT_SUPPORTED`.



Represents the status code of `STATUS_IM_USED`.



Represents the status code of `STATUS_INSUFFICIENT_STORAGE`.



Represents the status code of `STATUS_INTERNAL_SERVER_ERROR`.



Represents the status code of `STATUS_LENGTH_REQUIRED`.



Represents the status code of `STATUS_LOCKED`.



Represents the status code of `STATUS_LOOP_DETECTED`.



Represents the status code of `STATUS_METHOD_NOT_ALLOWED`.



Represents the status code of `STATUS_MISDIRECTED_REQUEST`.



Represents the status code of `STATUS_MOVED_PERMANENTLY`.



Represents the status code of `STATUS_MULTIPLE_CHOICES`.



Represents the status code of `STATUS_MULTI_STATUS`.



Represents the status code of `STATUS_NETWORK_AUTHENTICATION_REQUIRED`.



Represents the status code of `STATUS_NO_CONTENT`.



Represents the status code of `STATUS_NON_AUTHORITATIVE_INFORMATION`.



Represents the status code of `STATUS_NOT_ACCEPTABLE`.



Represents the status code of `STATUS_NOT_EXTENDED`.



Represents the status code of `STATUS_NOT_FOUND`.



Represents the status code of `STATUS_NOT_IMPLEMENTED`.



Represents the status code of `STATUS_NOT_MODIFIED`.



Represents the status code of `STATUS_OK`.



Represents the status code of `STATUS_PARTIAL_CONTENT`.



Represents the status code of `STATUS_PAYLOAD_TOO_LARGE`.



Represents the status code of `STATUS_PAYMENT_REQUIRED`.



Represents the status code of `STATUS_PERMANENT_REDIRECT`.



Represents the status code of `STATUS_PRECONDITION_FAILED`.



Represents the status code of `STATUS_PRECONDITION_REQUIRED`.



Represents the status code of `STATUS_PROCESSING`.



Represents the status code of `STATUS_PROXY_AUTHENTICATION_REQUIRED`.



Represents the status code of `STATUS_RANGE_NOT_SATISFIABLE`.



Represents the status code of `STATUS_REQUEST_HEADER_FIELDS_TOO_LARGE`.



Represents the status code of `STATUS_REQUEST_TIMEOUT`.



Represents the status code of `STATUS_RESET_CONTENT`.



Represents the status code of `STATUS_SEE_OTHER`.



Represents the status code of `STATUS_SERVICE_UNAVAILABLE`.



Represents the status code of `STATUS_SWITCHING_PROTOCOLS`.



Represents the status code of `STATUS_TEMPORARY_REDIRECT`.



Represents the status code of `STATUS_TOO_EARLY`.



Represents the status code of `STATUS_TOO_MANY_REQUESTS`.



Represents the status code of `STATUS_UNAUTHORIZED`.



Represents the status code of `STATUS_UNAVAILABLE_DUE_TO_LEGAL_REASONS`.



Represents the status code of `STATUS_UNPROCESSABLE_ENTITY`.



Represents the status code of `STATUS_UNSUPPORTED_MEDIA_TYPE`.



Represents the status code of `STATUS_UPGRADE_REQUIRED`.



Represents the status code of `STATUS_URI_TOO_LONG`.



Represents the status code of `STATUS_USE_PROXY`.



Represents an IMAP Client, which interacts with an IMAP Server.


Represents a POP Client, which interacts with a POP Server.


Represents an SMTP Client, which interacts with an SMTP Server.


Represents an FTP caller that is passed to the onFileChange function


Represents an FTP client that intracts with an FTP server


The Ballerina GraphQL client that can be used to communicate with GraphQL APIs.


The base client used in the generated client code to provide remote functions for interacting with the caller.



The base client used in the generated client code to provide the capability for initiating the contact and executing remote calls with a remote gRPC service.


Defines the OAuth2 handler for client authentication.


Defines the LDAP store Basic Auth handler for listener authentication.


Defines the OAuth2 handler for listener authentication.


This is used for internal purposes to support reflection.


The base client used in the generated client code to provide the gRPC streaming client actions for
interacting  with the gRPC server.


The caller actions for responding to client requests.



The HTTP client provides the capability for initiating contact with a remote HTTP service. The API it
provides includes the functions for the standard HTTP methods forwarding a received request and sending requests
using custom HTTP verbs.


An HTTP client endpoint which provides failover support over multiple HTTP clients.



LoadBalanceClient endpoint provides load balancing functionality over multiple HTTP clients.



The client used by the generated persist clients to abstract and 
execute SQL queries that are required to perform CRUD operations.


Represents caller object in tcp service remote methods.



Initializes the TCP connection client based on the provided configurations.


Represents caller object in UDP service remote methods.



Initializes the UDP connectionless client based on the provided configurations.


Initializes the UDP connection oriented client based on the 
provided configurations.


Represents a WebSocket synchronous client endpoint.


Represents resource-discovery service which identify the `hub` and `topic` from `resource-URL`.


The HTTP based client for WebSub subscription and unsubscription.


HTTP Based client for WebSub content publishing to subscribers


The HTTP based client for WebSub topic registration and deregistration, and notifying the hub of new updates.


The `OAEPWithSHA256AndMGF1` padding mode.


The `OAEPwithSHA384andMGF1` padding mode.


The `OAEPwithSHA512andMGF1` padding mode.


The prefix used to denote the Basic authentication scheme.


The prefix used to denote the Bearer authentication scheme.


Always set accept-encoding/content-encoding in outbound request/response.


When service behaves as a HTTP gateway inbound request/response accept-encoding option is set as the
outbound request/response accept-encoding/content-encoding option.


Never set accept-encoding/content-encoding header in outbound request/response.


Define _Any Scalar type used in subgraph schema.


Represents the Authorization header name.


HTTP header key `age`. Gives the current age of a cached HTTP response. 


HTTP header key `cache-control`. Specifies the cache control directives required for the function of HTTP caches.


This is a more restricted mode of RFC 7234. Setting this as the caching policy restricts caching to instances
where the `cache-control` header and either the `etag` or `last-modified` header are present.


Represents the closed state of the circuit. When the Circuit Breaker is in `CLOSED` state, all requests will be
allowed to go through to the upstream service. If the failures exceed the configured threhold values, the circuit
will trip and move to the `OPEN` state.


ballerina/constraint

Overview

Functions

validate

Parameters

Return Type

Records

constraint: ArrayConstraints

Fields

constraint: FloatConstraints

Fields

constraint: IntConstraints

Fields

constraint: NumberConstraints

Fields

constraint: StringConstraints

Fields

Annotations

constraint: Array

constraint: Float

constraint: Int

constraint: Number

constraint: String

Errors

constraint: Error

functions

records

annotations

errors

ballerina/constraint

Overview

Functions

validate

Parameters

Return Type

Records

constraint: ArrayConstraints

Fields

constraint: FloatConstraints

Fields

constraint: IntConstraints

Fields

constraint: NumberConstraints

Fields

constraint: StringConstraints

Fields

Annotations

constraint: Array

constraint: Float

constraint: Int

constraint: Number

constraint: String

Errors

constraint: Error