Shows two sample functions; one returning a file as an attachment, and another example
returning a file in the message response body.
Example 1: downloading file using
WSAttachment
IMPORT com
IMPORT os
PUBLIC DEFINE myerror RECORD ATTRIBUTE(WSError="My error")
code INTEGER,
reason STRING
END RECORD
FUNCTION downloadImageFile()
ATTRIBUTES (WSGet, WSPath="/files3/down",
WSDescription="download image file to the client as attachment with WSAttachment",
WSThrows="400:myerror")
RETURNS (STRING ATTRIBUTE(WSAttachment, WSMedia="image/*") )
DEFINE ret, fn STRING
DEFINE ok INTEGER
LET fn="favicon.ico"
LET ok = os.Path.exists(fn)
IF ok THEN
LET ret = fn
ELSE
LET myerror.reason = SFMT("File (%1) does not exist", fn)
CALL com.WebServiceEngine.SetRestError(400,myerror)
END IF
RETURN ret
END FUNCTION
In
order to send a file as an attachment, your function must have one output parameter only. In
the sample function, a STRING type is defined with a WSAttachment attribute. A WSMedia attribute is added to handle the
data format for images.
The Content-Disposition response header in the output
indicates that the content is expected as an attachment. Therefore, when the function is called,
the file is downloaded and saved to the client locally in its TMP directory. Figure: Output of HTTP response with image file
Example 2: downloading file without WSAttachment
PUBLIC FUNCTION help3()
ATTRIBUTES (WSGet,
WSDescription="download text file to the client without WSAttachment",
WSPath="/help/file3")
RETURNS ( INTEGER ATTRIBUTE(WSHeader), TEXT )
DEFINE t TEXT
LOCATE t IN MEMORY
CALL t.readFile("file3.txt")
RETURN 3, t
END FUNCTION
In this example the help3 function returns a text file. The content is transferred as text in the
message body as shown in the output. Data of integer type is transferred in a response header.
Figure: Output of HTTP response
In the output the header is given the default name, "rv0", at runtime. You can change default
header naming via the WSName attribute, for example with:
