OutgoingMessage

The 4D.OutgoingMessage class allows you to build messages to be returned by your application functions in response to REST requests. If the response is of type 4D.OutgoingMessage, the REST server does not return an object but the object instance of the OutgoingMessage class.

Typically, this class can be used in custom HTTP request handler functions or in functions declared with the onHttpGet keyword and designed to handle HTTP GET requests. Such requests are used, for example, to implement features such as download file, generate and download picture as well as receiving any content-type via a browser.

An instance of this class is built on 4D Server and can be sent to the browser by the 4D REST Server only. This class allows to use other technologies than HTTP (e.g. mobile).

Historia

Lanzamiento	Modificaciones
20 R7	Clase añadida

Ejemplo

In this example, a getFile() function is implemented in the Datastore class and can be called by a REST request. The purpose is to return a testFile.pdf file as a response to the request:

Class extends DataStoreImplementation

exposed onHTTPGet Function getFile() : 4D.OutgoingMessage
	
	var $result:=4D.OutgoingMessage.new()
	var $file:=File("/RESOURCES/testFile.pdf")
	
	$result.setBody($file.getContent())  // This is binary content
	$result.setHeader("Content-Type"; "application/pdf")
	return $result

OutgoingMessage Object

4D.OutgoingMessage objects provide the following properties and functions:

body : any the outgoing message body
headers : Object the current headers of the outgoing message as key/value pairs
.setBody( body : any ) sets the outgoing message body
.setHeader( key : Text ; value : Text ) sets the outgoing message header key with the provided value
.setStatus( status : Integer ) sets the status property with the given status
status : Integer the current status of the outgoing message

nota

A 4D.OutgoingMessage object is a non-sharable object.

.body

body : any

Descripción

La propiedad .body contiene el cuerpo del mensaje saliente. The following data types are supported in the .body property:

• text
• blob
• object
• image

La propiedad .body es de lectura-escritura.

También puede definir la propiedad .body utilizando la función setBody(), en cuyo caso el encabezado content-type se define automáticamente.

.headers

headers : Object

Descripción

The .headers property contains the current headers of the outgoing message as key/value pairs.

La propiedad .headers es de sólo lectura. Para definir un encabezado, use la función setHeader().

.setBody()

.setBody( body : any )

Parámetros	Tipo		Descripción
body	any	->	Body of the outgoing message

Descripción

The .setBody() function sets the outgoing message body.

The following data types are supported in the body:

• Text
• Blob
• Object
• Imagen

When this function is used, the content-type header is automatically set depending on the body type:

• Content-Type:text/plain if the body is a Text
• Content-Type:application/octet-stream if body is a Blob
• Content-Type:application/json if body is an Object
• Content-Type:image/jpeg, image/gif... if body is an Image

If body is not of a supported value type, an error is returned.

.setHeader()

.setHeader( key : Text ; value : Text )

Parámetros	Tipo		Descripción
key	Text	->	Propiedad de encabezado a definir
value	Text	->	Valor de la propiedad del encabezado

Descripción

The .setHeader() function sets the outgoing message header key with the provided value. If both parameters are not Text values, an error is raised.

When returning a 4D.OutgoingMessage object instance, 4D automatically sets some headers (e.g. Set-Cookie with WASID4D=... and 4DSID__ProjectName_=....).

nota

If you set a value for the "Content-Type" header key, make sure you call this function after the call to setBody(), because setBody() automatically fills this header. For a list of "Content-Type" header values, please refer to the WEB SEND BLOB documentation.

.setStatus()

.setStatus( status : Integer )

Parámetros	Tipo		Descripción
status	Integer	->	Estado a definir

Descripción

The .setStatus() function sets the status property with the given status.

If status is not an integer value, an error is raised.

For a list of HTTP status codes, please refer the HTTP status code list on Wikipedia.

.status

status : Integer

Descripción

The .status property contains the current status of the outgoing message. This property can be set using the setStatus() function.