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).

História

Release	Mudanças
20 R7	Classe adicionada

Exemplo

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

Objeto OutgoingMessage

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 ) define a mensagem de saída 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 o status atual da mensagem de saída

nota

Um objeto 4D.OutgoingMessage é um objeto não compartilhável.

.body

body : any

Descrição

The .body property contains the outgoing message body. The following data types are supported in the .body property:

• text
• blob
• object
• image

The .body property is read-write.

Você também pode definir a propriedade .body usando a função setBody(), caso em que o cabeçalho content-type é automaticamente definido.

.headers

headers : Object

Descrição

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

The .headers property is read-only. Para definir um cabeçalho, use a função setHeader().

.setBody()

.setBody( body : any )

Parâmetro	Tipo		Descrição
body	any	->	Body of the outgoing message

Descrição

A função .setBody() define a mensagem de saída body.

The following data types are supported in the body:

• Text
• Blob
• Object
• Imagem

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 )

Parâmetro	Tipo		Descrição
|	Text	->	Propriedade de cabeçalho para definir
value	Text	->	Value of the header property

Descrição

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 )

Parâmetro	Tipo		Descrição
status	Integer	->	Status para definir

Descrição

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

Descrição

A propriedade .status contém o status atual da mensagem de saída . Essa propriedade pode ser definida com a função setStatus().