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— Statements —

REQUEST DOCUMENT

`REQUEST` `DOCUMENT FROM` `operand1`
		`WITH`
		[ `USER` `operand2`]
		[`PASSWORD` `operand3`]
		[`HEADER`[[`NAME`] `operand4` [`VALUE`] `operand5`]}...]
		`DATA`	`ALL` `operand6` [`ENCODED` [[`IN`] `CODEPAGE` `operand7`]]
			{[`NAME`] `operand8` [`VALUE`] `operand9`}...

	`RETURN`
	`HEADER` [`ALL` `operand10`] [[`NAME`] `operand11` [`VALUE`] `operand12`]...
	[`PAGE` `operand13` [`ENCODED` [[`FOR TYPES`[`S`] `operand14`...] [`IN`] `CODEPAGE` `operand15`]]]
	`RESPONSE` `operand16`
[`GIVING` `operand17`]

This document covers the following topics:

Function
Syntax Description
Encoding of Incoming/Outgoing Data
Examples

For an explanation of the symbols used in the syntax diagram, see Syntax Symbols.

Belongs to Function Group: Internet and XML

Function

The REQUEST DOCUMENT statement gives you the means to access an external system, see Statements for Internet and XML Access in the Programming Guide.

For information on Unicode support, see Statements in the Unicode and Code Page Support documentation.

See also the description of the Natural profile and session parameter RQTOUT, which specifies the timeouts used for HTTP requests issued internally by the REQUEST DOCUMENT statement.

Restrictions for Cookies

Under the HTTP Protocol, a server uses cookies to maintain state information on the client workstation.

REQUEST DOCUMENT is implemented using internet option settings. This means that, depending on the security settings, cookies will be used.

If the internet option setting Disabled is set, no cookies will be sent, even if a cookie header (operand4/operand5) is sent.

For server environments, do not use the internet option setting Prompt. This setting leads to a "hanging" server, because no client will be able to answer the prompt.

In mainframe environments, cookies are not supported and are ignored.

Cookies are handled automatically by the Windows API. This means that, if cookies are enabled in the browser, all incoming cookies will be saved and sent automatically with the next request.

Syntax Description

Operand Definition Table:

Operand	Possible Structure		Possible Formats										Referencing Permitted	Dynamic Definition
`operand1`	C	S	A										yes	no
`operand2`	C	S	A										yes	no
`operand3`	C	S	A										yes	no
`operand4`	C	S	A										yes	no
`operand5`	C	S	A		N	P	I	F		D	T	L	yes	no
`operand6`	C	S	A	U	N	P	I	F	B	D	T	L	yes	no
`operand7`	C	S	A										yes	no
`operand8`	C	S	A										yes	no
`operand9`	C	S	A		N	P	I	F		D	T	L	yes	no
`operand10`		S	A										yes	yes
`operand11`	C	S	A										yes	no
`operand12`		S	A		N	P	I	F	B	D	T	L	yes	yes
`operand13`		S	A	U					B				yes	yes
`operand14`	C	S	A										yes	no
`operand15`	C	S	A										yes	no
`operand16`		S					I4						yes	yes
`operand17`		S					I4						yes	no

Syntax Element Description:

Syntax Element	Description
`DOCUMENT FROM operand1`	Location of Document: `operand1` is the URL to access a document. Note: The information below is only valid if `operand1` begins with `http://` or `https://`.
`WITH`	WITH Clause: This clause may be used to specify optional user/password, header and data details for the request.
`USER operand2`	User Name: `operand2` is the name of the user that will be used for the request.
`PASSWORD operand3`	User Password: `operand3` is the password of the user that will be used for the request.
`HEADER {[[NAME] operand4 [VALUE] operand5]}...`	Header Clause: `operand4` and `operand5` can only be used in conjunction with each other: `operand4` is the name of a `HEADER` variable sent with this request. `operand5` is the value of a `HEADER` variable sent with this request. Note: Header Name for `operand4`: Header names must not contain a carriage return (CR), a line feed (LF) or a colon (:). This will not be checked by the `REQUEST DOCUMENT` statement. For valid header names, please see the HTTP specifications. For compatibility with the web interface, header names can be written with underscore (_) instead of a dash (-). (Internally, the underscore is replaced by a dash). Header Value for `operand5`: Header values are not allowed to contain CR/LF. This will not be checked by the `REQUEST DOCUMENT` statement. For valid header values and formats, please see the HTTP specifications. General Information on Headers: For a HTTP request, some headers are required, for example: Request-Method or Content-Type. These headers will be automatically generated depending on the parameters given with the `REQUEST DOCUMENT` statement. See also Automatically Generated Headers.
`DATA`	DATA Clause: You may specify either a specific `DATA` variable name and value (see `operand8` and `operand9` below) or the complete document (see DATA ALL Clause below).
`ALL operand6`	`operand6` is a complete document that is to be sent. This value is needed for the HTTP request method `PUT` (see Automatically Generated Headers). See Encoding of Incoming/Outgoing Data, DATA ALL Clause.
`[ENCODED [[IN] CODEPAGE operand7]`	`operand6` will be encoded from the default code page (value of the system variable `*CODEPAGE`) to the code page given in `operand7`. See Encoding of Incoming/Outgoing Data, DATA ALL Clause.
`{[NAME] operand8 [VALUE] operand9}...`	DATA Variable Name and Value: `operand8` and `operand9` can only be used in conjunction with each other: `operand8` is the name of a `DATA` variable to be sent with this request. `operand9` is the value of a `DATA` variable to be sent with this request. This value is needed for the HTTP request method POST (URL-encoding necessary, especially ampersand (&), equal sign (=), percent sign (%) characters). Restriction: If `operand8`/`operand9` is given, and the communication is `http://` or `https://` by default, the request method `POST` (see Automatically Generated Headers) with content type `application/x-www-form-urlencoded` is used. During the request, `operand8`/`operand9` will be separated by equal sign (=) and ampersand (&) characters. Therefore the operands are not allowed to contain equal sign (=), ampersand (&) and, because of URL-encoding, percent sign (%) characters. These characters are considered "unsafe" and need to be encoded as:
	Character	URL-Encoding Syntax
	%	%25
	&	%26
	=	%3D
	See also General Note for URL-Encoding.
`RETURN`	RETURN Clause: This clause can be used to specify the `HEADER` and/or `PAGE` return information.
`HEADER [ALL operand10]`	RETURN HEADER ALL Clause: When this clause is specified, `operand10` contains all header values delivered with the HTTP response. The first line contains the status information and all following lines contain the headers as pairs of name and value. The names always end in a colon (:) and the values end in a linefeed (LF). Internally, all carriage returns/line feeds (CR/LF) are transformed into line feeds (LF).
`HEADER [[NAME] operand11] [VALUE] operand12]...`	RETURN HEADER NAME/VALUE Clause: When this clause is specified, only specific header information is returned. `operand11` and `operand12` can only be used in conjunction with each other: `operand11` is the name of a `HEADER` received with this request. The `HEADER` is needed for HTTP. `operand12` is the value of a `HEADER` received with this request. The `HEADER` is needed for HTTP. Return Header Name for `operand11`: For compatibility with the web interface, header names can be written with underscore (_) instead of dash (-) characters. Internally, the underscore is replaced by a dash. If `operand11` is a blank string, the status information is returned. HTTP/1.0 200 OK
`RETURN PAGE`	RETURN PAGE Clause: You can use the `PAGE` clause if you want to have the incoming data encoded in a specific code page. See Encoding of Incoming/Outgoing Data, RETURN PAGE Clause below.
`PAGE operand13`	`operand13` is the document returned for this request. See Encoding of Incoming/Outgoing Data, RETURN PAGE Clause below.
`[ENCODED [[FOR TYPE[S] operand14...] [IN] CODEPAGE operand15]]`	`operand14` is the list of mime-types for which an encoding of the returned document in `operand13` will be performed. See Encoding of Incoming/Outgoing Data, RETURN PAGE Clause below.
	`operand15` is the code page which, if necessary, will be used for the encoding of `operand13`. If the value of `operator15` is blank, no conversion occurs. `operand13` is then encoded in the default code page (profile parameter `CP` in the Configuration Utility). See Encoding of Incoming/Outgoing Data, RETURN PAGE Clause below.
`RESPONSE operand16`	RESPONSE Clause: The `RESPONSE` clause is used to display the response code number of the request. `operand16` is the response code number of the request, for example: 200 (Request Completed). See also Overview of Response Numbers for HTTP Requests.
`GIVING operand17`	GIVING Clause: `operand17` contains the Natural error if the request could not be performed.

Automatically Generated Headers (`operand4/5`)

Request-Method

The following values are supported for operand5: HEAD, POST, GET, and PUT.

The following table shows the automatic calculation of Request-Method depending on the given operands:

Operand	Request Method
Operand	HEAD	POST	GET	PUT
WITH HEADER (`operand4/operand5`)	optional	optional	optional	optional
WITH DATA (`operand7/operand8`)	not specified	specified	not specified	only with option `ALL (operand6)`
RETURN HEADER (`operand10` to `operand12`)	specified	optional	optional	optional
RETURN PAGE (`operand13`)	not specified	specified	specified	optional

Content-Type

If the request method is POST, a content-type header has to be delivered with the HTTP request. If no content-type is set explicitly, the automatically generated value of operand5 is:

application/x-www-form-urlencoded

Note:
It is possible to overwrite the automatically generated headers. Natural will not check them for errors. Unexpected errors may occur.

General Note for URL-Encoding

When sending POST data with the content type application/x-www-form-urlencoded, certain characters must be represented by means of URL-encoding, which means substituting the character with %hexadecimal-character-code. The full details of when and why URL-encoding is necessary are discussed in RFC 1630, RFC 1738 and RFC 1808. Some basic details are given here. All non-ASCII characters (that is, valid ISO 8859/1 characters that are not also ASCII characters) must be URL-encoded, for example, the file köln.html would appear in an URL as k%F6ln.html.

Some characters are considered to be "unsafe" when web pages are requested by e-mail.

These characters are:

Character	URL-Encoding Syntax
the tab character	%09
the space character	%20
[	%5B
\	%5C
]	%5D
^	%5E
`	%60
{	%7B
\|	%7C
}	%7D
~	%7E

When writing URLs, you should URL-encode these characters.

Some characters have special meanings in URLs, such as the colon (:) that separates the URL scheme from the rest of the URL, the double slash (//) that indicates that the URL conforms to the Common Internet Scheme syntax and the percent sign (%). Generally, when these characters appear as parts of file names, they must be URL-encoded to distinguish them from their special meaning in URLs (this is a simplification, read the RFCs for full details).

These characters are:

Character	URL-Encoding Syntax
"	%22
#	%23
%	%25
&	%26
+	%2B
,	%2C
/	%2F
:	%3A
<	%3C
=	%3D
>	%3E
?	%3F
@	%40

Overview of Response Numbers for HTTP Requests

Status	Value	Response
`STATUS CONTINUE`	`100`	OK to continue with request
`STATUS SWITCH_PROTOCOLS`	`101`	Server has switched protocols in upgrade header
`STATUS OK`	`200`	Request completed
`STATUS CREATED`	`201`	Object created, reason = new URL
`STATUS ACCEPTED`	`202`	Async completion (TBS)
`STATUS PARTIAL`	`203`	Partial completion
`STATUS NO_CONTENT`	`204`	No info to return
`STATUS RESET_CONTENT`	`205`	Request completed, but clear form
`STATUS PARTIAL_CONTENT`	`206`	Partial `GET` fulfilled
`STATUS AMBIGUOUS`	`300`	Server could not decide what to return
`STATUS MOVED`	`301`	Object permanently moved
`STATUS REDIRECT`	`302`	Object temporarily moved
`STATUS REDIRECT_METHOD`	`303`	Redirection w/o new access method
`STATUS NOT_MODIFIED`	`304`	If-modified-since was not modified
`STATUS USE_PROXY`	`305`	Redirection to proxy, location header specifies proxy to use
`STATUS REDIRECT_KEEP_VERB`	`307`	HTTP/1.1: keep same verb
`STATUS BAD_REQUEST`	`400`	Invalid syntax
`STATUS DENIED`	`401`	Access denied
`STATUS PAYMENT_REQ`	`402`	Payment required
`STATUS FORBIDDEN`	`403`	Request forbidden
`STATUS NOT_FOUND`	`404`	Object not found
`STATUS BAD_METHOD`	`405`	Method is not allowed
`STATUS NONE_ACCEPTABLE`	`406`	No response acceptable to client found
`STATUS PROXY_AUTH_REQ`	`407`	Proxy authentication required
`STATUS REQUEST_TIMEOUT`	`408`	Server timed out waiting for request
`STATUS CONFLICT`	`409`	User should resubmit with more info
`STATUS GONE`	`410`	The resource is no longer available
`STATUS LENGTH_REQUIRED`	`411`	The server refused to accept request w/o a length
`STATUS PRECOND_FAILED`	`412`	Precondition given in request failed
`STATUS REQUEST_TOO_LARGE`	`413`	Request entity was too large
`STATUS URL_TOO_LONG`	`414`	Request URL too long
`STATUS UNSUPPORTED_MEDIA`	`415`	Unsupported media type
`STATUS SERVER_ERROR`	`500`	Internal server error
`STATUS NOT_SUPPORTED`	`501`	"Required" not supported
`STATUS BAD_GATEWAY`	`502`	Error response received from gateway
`STATUS SERVICE_UNAVAIL`	`503`	Temporarily overloaded
`STATUS GATEWAY_TIMEOUT`	`504`	Timed out waiting for gateway
`STATUS VERSION_NOT_SUP`	`505`	HTTP version not supported

Response 301 - 303 (Redirection)

Redirection means that the requested URL has moved. As a response, the Return Header with the name LOCATION will be displayed. This header contains the URL where the requested page has moved to. A new REQUEST DOCUMENT request can be used to retrieve the page moved.

HTTP browsers redirect automatically to the new URL, but the REQUEST DOCUMENT statement does not handle redirection automatically.

Response 401 (Denied)

The response Access Denied means that the requested page can only be accessed if a valid user ID and password are provided with the request. As a response, the Return Header with the name WWW-AUTHENTICATE will be delivered with the realm needed for this request.

HTTP browsers normally display a dialog with user ID and password, but with the REQUEST DOCUMENT statement, no dialog is displayed.

Encoding of Incoming/Outgoing Data

Data transfer with the REQUEST DOCUMENT statement normally does not involve any code page conversion. If you want to have the outgoing and/or incoming data encoded in a specific code page, you can use the DATA ALL clause and/or the RETURN PAGE clause to specify this.

DATA ALL Clause
RETURN PAGE Clause

DATA ALL Clause

For the encoding of outgoing data, the DATA ALL clause is used:

ALL operand6 [ENCODED [[IN] CODEPAGE operand7]]

Syntax Element Description:

Syntax Element	Description
`ALL operand6`	`operand6` is a complete document that is to be sent. This value is normally needed for the automatically HTTP request method `PUT` (see Automatically Generated Headers).
`[ENCODED [[IN] CODEPAGE operand7]]`	`operand6` will be encoded from the default code page (value of system variable `*CODEPAGE`) to the code page given in `operand7`.

RETURN PAGE Clause

For the encoding of incoming data, the RETURN PAGE clause is used:

[PAGE operand13 [ENCODED [[FOR TYPE[S] operand14...] [IN] CODEPAGE operand15]]]

As a response of an HTTP/HTTPS request, incoming data may contain binary data (for example, image/gif) or character data (for example, text/html). Together with the response, the REQUEST DOCUMENT statement receives a parameter which specifies the type of content of the requested document (mime-type). This parameter may contain information about the code page in which the document is encoded.

This clause provides an automatic conversion to the default code page (value of system variable *CODEPAGE) of the Natural session.

Syntax Element Description:

Syntax Element	Description
`RETURN PAGE operand13`	No encoding at all of the returned page will be done; that is, the page will remain encoded as delivered from the http server.
`RETURN PAGE operand13 ENCODED`	If the returned mime-type contains an encoding, `operand13` will be encoded from this code page to the default code page (A/B) or (U). See note below.
`RETURN PAGE operand13 ENCODED [IN] CODEPAGE operand15`	If the returned mime-type does not contain an encoding, then `operand13` will be encoded from the code page defined with `operand15` to the default code page (value of system variable `*CODEPAGE`) (A/B) or (U).
`RETURN PAGE operand13 [ENCODED [[FOR TYPE[S] operand14...] [IN] CODEPAGE operand15]]`	If the returned mime-type does not contain an encoding, then an additional check is performed if the returned mime-type matches one of the types given with `operand14`. If a match occurs, `operand13` will be encoded from the code page defined with `operand15` to the default code page (A/B) or (U).

Note:
"Returned mime-type contains an encoding" means that the http server returns a content-type header with a charset= clause, for example: charset=ISO-8859-1.

Examples

Example 1 - General Request
Example 2 - Simple Get Request (no data)
Example 3 - Simple Head Request (no return page)
Example 4 - Simple Post Request (default)
Example 5 - Simple Put Request (with DATA ALL)

Note:
There is an example dialog V5-RDOC for this statement in the example library SYSEXV.

Example 1 - General Request

REQUEST DOCUMENT FROM "http://bolsap1:5555/invoke/sap.demo/handle_RFC_XML_POST" 
  WITH
    USER #User PASSWORD #Password
    DATA
    NAME 'XMLData'       VALUE #Queryxml
    NAME 'repServerName' VALUE 'NT2'
  RETURN
    PAGE #Resultxml
RESPONSE #rc

Example 2 - Simple Get Request (no data)

REQUEST DOCUMENT FROM "http://pcnatweb:8080"
  RETURN
    PAGE #Resultxml
RESPONSE #rc

Example 3 - Simple Head Request (no return page)

REQUEST DOCUMENT FROM "http://pcnatweb"
RESPONSE #rc

Example 4 - Simple Post Request (default)

REQUEST DOCUMENT FROM "http://pcnatweb/cgi-bin/nwwcgi.exe/sysweb/nat-env"
  WITH 
    DATA 
    NAME 'XMLData'       VALUE #Queryxml
    NAME 'repServerName' VALUE 'NT2'
  RETURN
    PAGE #Resultxml
RESPONSE #rc

Example 5 - Simple Put Request (with DATA ALL)

REQUEST DOCUMENT FROM "http://pcnatweb/test.txt"
  WITH 
    DATA ALL     #document
  RETURN
    PAGE #Resultxml
RESPONSE #rc

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REQUEST DOCUMENT

Function

Restrictions for Cookies

Syntax Description

Automatically Generated Headers (operand4/5)

Request-Method

Content-Type

General Note for URL-Encoding

Overview of Response Numbers for HTTP Requests

Response 301 - 303 (Redirection)

Response 401 (Denied)

Encoding of Incoming/Outgoing Data

DATA ALL Clause

RETURN PAGE Clause

Examples

Example 1 - General Request

Example 2 - Simple Get Request (no data)

Example 3 - Simple Head Request (no return page)

Example 4 - Simple Post Request (default)

Example 5 - Simple Put Request (with DATA ALL)

Automatically Generated Headers (`operand4/5`)