HTTPRequest
The HTTPRequest class allows you to handle HTTPRequest objects that can be used to configure and send requests to an HTTP server, as well as to process the HTTP server responses.
The HTTPRequest class is available from the 4D class store. You create and send HTTP requests using the 4D.HTTPRequest.new() function, that returns a HTTPRequest object.
History
| Release | Changes |
|---|---|
| 19 R6 | Class added |
Example
Create a MyHttpRequestOptions class for the request options:
Class constructor($method : Text; $headers : Object; $body : Text)
This.method:=$method
This.headers:=$headers
This.body:=$body
Function onResponse($request : 4D.HTTPRequest; $event : Object)
//My onResponse method, if you want to handle the request asynchronously
Function onError($request : 4D.HTTPRequest; $event : Object)
//My onError method, if you want to handle the request asynchronously
You can now create your request:
var $headers : Object
$headers:=New object()
$headers["field1"]:="value1"
var myHttpRequestOptions : cs.MyHttpRequestOptions
myHttpRequestOptions := cs.MyHttpRequestOptions.new("GET"; $headers; "")
var $request : 4D.HTTPRequest
$request:=4D.HTTPRequest.new("www.google.com"; myHttpRequestOptions)
$request.wait() //If you want to handle the request synchronously
//Now you can use $request.response to access the result of the request or $request.error to check the error that happened.
HTTPRequest Object
An HTTPRequest object is a non-sharable object.
HTTPRequest objects provide the following properties and functions:
| agent : 4D.HTTPAgent the agentobject passed in options or the global agent object if it was omitted |
| dataType : Text the dataType passed in the options object when calling new(), "auto" if it was omitted |
| encoding : Text the encoding passed in the options object when calling new(), "UTF-8" if it was omitted |
| errors : Collection the collection of all the errors if at least one error has been triggered |
| headers : Object the headers passed in the options object when calling new() |
| method : Text the method passed in the options object when calling new() |
| protocol : Text the protocol passed in the options object when calling new() |
| response : Object the response to the request if it has received at least the status code, undefined otherwise |
| returnResponseBody : Boolean the returnResponseBody passed in the options object when calling new() |
| .terminate() aborts the HTTP request |
| terminated : Boolean True if the request is terminated (after the call to onTerminate), false otherwise |
| timeout : Real the timeout passed in the options object when calling new() |
| url : Text the URL of the HTTP request |
| .wait( { time : Real } ) : 4D.HTTPRequest waits for the response from the server |
4D.HTTPRequest.new()
History
| Release | Changes |
|---|---|
| 20 | TLS validation by default |
| 19 R7 | Support of automaticRedirections and decodeData properties |
4D.HTTPRequest.new( url : Text { ; options : Object } ) : 4D.HTTPRequest
| Parameter | Type | Description | |
|---|---|---|---|
| url | Text | -> | URL to which to send the request |
| options | Object | -> | Request configuration properties |
| Result | 4D.HTTPRequest | <- | New HTTPRequest object |
Description
The 4D.HTTPRequest.new() function creates and sends a HTTP request to the HTTP server defined in url with the defined options, and returns a 4D.HTTPRequest object.
The returned HTTPRequest object is used to process responses from the HTTP server and call methods.
In url, pass the URL where you want to send the request. The syntax to use is:
{http://}[{user}:[{password}]@]host[:{port}][/{path}][?{queryString}]
{https://}[{user}:[{password}]@]host[:{port}][/{path}][?{queryString}]
If you omit the scheme part (http:// or https://), a https request is sent.
For example, you can pass the following strings:
http://www.myserver.com
www.myserver.com/path
http://www.myserver.com/path?name="jones"
https://www.myserver.com/login
http://123.45.67.89:8083
http://john:smith@123.45.67.89:8083
http://[2001:0db8:0000:0000:0000:ff00:0042:8329]
http://[2001:0db8:0000:0000:0000:ff00:0042:8329]:8080/index.html (**)
options parameter
In the options parameter, pass an object that can contain the following properties:
| Property | Type | Description | Default |
|---|---|---|---|
| agent | 4D.HTTPAgent | HTTPAgent to use for the HTTPRequest. Agent options will be merged with request options (request options take precedence). If no specific agent is defined, a global agent with default values is used. | Global agent object |
| automaticRedirections | Boolean | If true, redirections are performed automatically (up to 5 redirections are handled, the 6th redirection response is returned if any) | True |
| body | Variant | Body of the request (required in case of post or put requests). Can be a text, a blob, or an object. The content-type is determined from the type of this property unless it is set inside the headers | undefined |
| certificatesFolder | Folder | Sets the active client certificates folder | undefined |
| dataType | Text | Type of the response body attribute. Values: "text", "blob", "object", or "auto". If "auto", the type of the body content will be deduced from its MIME type (object for JSON, text for text, javascript, xml, http message and url encoded form, blob otherwise) | "auto" |
| decodeData | Boolean | If true, the data received in the onData callback is uncompressed | False |
| encoding | Text | Used only in case of requests with a body (post or put methods). Encoding of the request body content if it's a text, ignored if content-type is set inside the headers | "UTF-8" |
| headers | Object | Headers of the request. Syntax: headers.key=value (value can be a Collection if the same key must appear multiple times) | Empty object |
| method | Text | "POST", "GET", or other method | "GET" |
| minTLSVersion | Text | Sets the minimum version of TLS: "TLSv1_0", "TLSv1_1", "TLSv1_2", "TLSv1_3" | "TLSv1_2" |
| onData | Function | Callback when data from the body is received. It receives two objects as parameters (see below) | undefined |
| onError | Function | Callback when an error occurs. It receives two objects as parameters (see below) | undefined |
| onHeaders | Function | Callback when the headers are received. It receives two objects as parameters (see below) | undefined |
| onResponse | Function | Callback when a response is received. It receives two objects as parameters (see below) | undefined |
| onTerminate | Function | Callback when the request is over. It receives two objects as parameters (see below) | undefined |
| protocol | Text | "auto" or "HTTP1". "auto" means HTTP1 in the current implementation | "auto" |
| proxyAuthentication | authentication object | Object handling proxy authentication | undefined |
| serverAuthentication | authentication object | Object handling server authentication | undefined |
| returnResponseBody | Boolean | If false, the response body is not returned in the response object. Returns an error if false and onData is undefined | True |
| timeout | Real | Timeout in seconds. Undefined = no timeout | Undefined |
| validateTLSCertificate | Boolean | If false, 4D does not validate the TLS certificate and does not return an error if it is invalid (i.e. expired, self-signed...). Important: In the current implementation, the Certification Authority itself is not verified. | True |
Callback functions
All callback functions receive two object parameters:
| Parameter | Type |
|---|---|
| $param1 | HTTPRequest object |
| $param2 | Event object |
Here is the sequence of callback calls:
-
onHeadersis always called once -
onDatais called zero or several times (not called if the request does not have a body) -
If no error occured,
onResponseis always called once -
If an error occurs,
onErroris executed once (and terminates the request) -
onTerminateis always executed once
For the callback functions to be called when you do not use wait() (asynchronous call), the process must be a worker created with CALL WORKER, NOT New process.
event object
An event object is returned when a callback function is called. It contains the following properties:
| Property | Type | Description |
|---|---|---|
| .data | blob | Received data. It is always undefined except in the onData callback |
| .type | text | Type of event. Possible values: "response", "error", "headers", "data", or "terminate |
authentication object
An authentication object handles the options.serverAuthentication or options.proxyAuthentication property. It can contain the following properties:
| Property | Type | Description | Default |
|---|---|---|---|
| name | Text | Name used for authentication | undefined |
| password | Text | Password used for authentication | undefined |
| method | Text | Method used for authentication:"basic", "digest", "auto" | "auto" |
HTTP Parse message
History
| Release | Changes |
|---|---|
| 20 R4 | Added |
HTTP Parse message( data : Text ) : Object
HTTP Parse message( data : Blob ) : Object
| Parameter | Type | Description | |
|---|---|---|---|
| data | Text, Blob | -> | Data to be parsed |
| Result | Object | <- | Object, each property is a part of the multipart data |
Description
The HTTP Parse message command parses a multipart/form-data text or blob (HTTP "response" message) and extracts the content to an object. Each property of the returned object corresponds to a part of the multipart data.
HTTP itself is a stateless communication protocol. Within this framework, clients initiate communication by sending "request" messages to servers, specifying details like method, target, headers, content, etc. Servers, in turn, respond with "response" messages that include the same details. HTTP Parse message parses either the "request" or the "response" message into a well-organized object.
Example
In the following example, we parse the data from a text file containing HTTP requests.
Here is the content of the file:
POST /batch/gmail/v1/ HTTP/1.1
Accept-Encoding: gzip, deflate
Authorization: Bearer xxxxxx
Connection: Close
Content-Length: 442
Content-Type: multipart/mixed; boundary=batch_19438756D576A14ABA87C112F56B9396; charset=UTF-8
Date: Wed, 29 Nov 2023 13:51:35 GMT
Host: gmail.googleapis.com
User-Agent: 4D/20.4.0
--batch_19438756D576A14ABA87C112F56B9396
Content-Type: application/http
Content-ID: <item1>
GET https://gmail.googleapis.com/gmail/v1/users/me/messages/18c1b58689824c92?format=raw HTTP/1.1
--batch_19438756D576A14ABA87C112F56B9396
Content-Type: application/http
Content-ID: <item2>
GET https://gmail.googleapis.com/gmail/v1/users/me/messages/18c1b58642b28e2b?format=raw HTTP/1.1
--batch_19438756D576A14ABA87C112F56B9396--
To parse the file:
var $message : Text:=File("/RESOURCES/HTTPrequest.txt").getText()
var $parsedMessage : Object:=HTTP Parse message($message)
//$parsedMessage= {
//headers:{"User-Agent":"4D/20.4.0",...},
//parts:[{"contentType":"application/http","contentID":"item1",...}],
//requestLine:"POST /batch/gmail/v1/ HTTP/1.1"
//}
.agent
agent : 4D.HTTPAgent
Description
The .agent property contains the agentobject passed in options or the global agent object if it was omitted.
.dataType
dataType : Text
Description
The .dataType property contains the dataType passed in the options object when calling new(), "auto" if it was omitted.
.encoding
encoding : Text
Description
The .encoding property contains the encoding passed in the options object when calling new(), "UTF-8" if it was omitted.
.errors
errors : Collection
Description
The .errors property contains the collection of all the errors if at least one error has been triggered.
Here is the contents of the .errors property:
| Property | Type | Description | |
|---|---|---|---|
| errors | Collection | 4D error stack in case of error | |
| [].errCode | Number | 4D error code | |
| [].message | Text | Description of the 4D error | |
| [].componentSignature | Text | Signature of the internal component which returned the error |
.headers
headers : Object
Description
The .headers property contains the headers passed in the options object when calling new(). If it was omitted, contains an empty object.
.method
method : Text
Description
The .method property contains the method passed in the options object when calling new(). If it was omitted, contains "GET".
.protocol
protocol : Text
Description
The .protocol property contains the protocol passed in the options object when calling new(). If it was omitted or if "auto" was used, contains the version of the protocol used.
.response
History
| Release | Changes |
|---|---|
| 19 R8 | .headers returns lowercase names. New .rawHeaders property |
response : Object
Description
The .response property contains the response to the request if it has received at least the status code, undefined otherwise.
A response object is a non-sharable object. It provides the following properties:
| Property | Type | Description |
|---|---|---|
| .body | Variant | Body of the response. The type of the message is defined according to the dataType property. Undefined if the body has not been received yet |
| .headers | Object | Headers of the response. Header names are returned in lowercase. <headername>.key = value (value can be a collection if the same key appears multiple times). Undefined if the headers have not been received yet. |
| .status | Number | Status code of the response |
| .statusText | Text | Message explaining the status code |
| .rawHeaders | Object | Headers of the response. Header names are returned untouched (with their original case). <headerName>.key = value (value can be a collection if the same key appears multiple times). Undefined if the headers have not been received yet. |
.returnResponseBody
returnResponseBody : Boolean
Description
The .returnResponseBody property contains the returnResponseBody passed in the options object when calling new(). If it was omitted, contains True.
.terminate()
.terminate()
| Parameter | Type | Description | |
|---|---|---|---|
| Does not require any parameters |
Description
This function is thread-safe.
The .terminate() function aborts the HTTP request. It triggers the onTerminate event.
.terminated
terminated : Boolean
Description
The .terminated property contains True if the request is terminated (after the call to onTerminate), false otherwise.
.timeout
timeout : Real
Description
The .timeout property contains the timeout passed in the options object when calling new(). If it was omitted, contains Undefined.
.url
url : Text
Description
The .url property contains the URL of the HTTP request.
.wait()
.wait( { time : Real } ) : 4D.HTTPRequest
| Parameter | Type | Description | |
|---|---|---|---|
| time | Real | -> | Maximum time in seconds to wait for the response |
| Result | 4D.HTTPRequest | <- | HTTPRequest object |
Description
This function is thread-safe.
The wait() function waits for the response from the server.
If a time parameter is passed, the function will wait at most the defined number of seconds.
If the response from the server has already arrived, the function returns immediately.
During a .wait() execution, callback functions are executed, whether from other HTTPRequest or SystemWorker instances, or other CALL WORKER calls. You can exit from a .wait() by calling terminate() from a callback.