FetchRemote

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This function allows you to post and receive data from HTTP servers. The calls are asynchronous so you do not get an immediate result from the call, instead a callback function you specify is called when the download completes.

In the case when the call fails, a string containing "ERROR" followed by an integer containing the error reason will be passed to the callback function. The reason for failure will be similar to errors found with websites - file not found, server not found and timeouts.

If you are using fetchRemote to connect to a PHP script, you can use file_get_contents("php://input") to read the postData sent from this function.

[[{{{image}}}|link=]] Note: Client side function only works with the server the player is connected to unless the domain has been accepted with requestBrowserDomains

Syntax

bool fetchRemote ( string URL[, string queueName = "default" ][, int connectionAttempts = 10, int connectTimeout = 10000 ], function callbackFunction, [ string postData = "", bool postIsBinary = false, [ arguments... ] ] )

Required Arguments

  • URL: A full URL in the format http://hostname/path/file.ext. A port can be specified with a colon followed by a port number appended to the hostname.
  • callbackFunction: This is the function that should receive the data returned from the remote server. The callback argument list should be:
    • responseData - A string containing the remote response or "ERROR" if there was a problem
    • errno - A number containing the error number or zero if there was no error. A list of possible error values are:
  • 1-89: See cURL website or its mirror at cURL errors
  • 400-599: See HTTP status codes
  • 1002: Download aborted
  • 1003: Failed to initialize
  • 1004: Unable to parse url
  • 1005: Unable to resolve host name
  • 1006: Destination IP not allowed
  • 1007: File error
  • arguments... - The arguments that were passed into fetchRemote

Optional Arguments

FROM VERSION 1.5.3-9.11270 ONWARDS
  • queueName: Name of the queue to use. Any name can be used. If not set, the queue name is "default". Requests in the same queue are processed in order, one at a time.
  • connectionAttempts: Number of times to retry if the remote host does not respond. In the case of a non-responding remote server, each connection attempt will timeout after 10 seconds. Therefore, the default setting of 10 connection attempts means it will be 100 seconds before your script gets a callback about the error. Reducing this value to 2 for example, will decrease that period to 20 seconds
  • connectTimeout: Number of milliseconds each connection attempt will take before timing out
  • postData: A string specifying any data you want to send to the remote HTTP server.
  • postIsBinary : A boolean specifying if the data is text, or binary.
  • arguments: Any arguments you may want to pass to the callback.


FROM VERSION 1.5.4-9.11342 ONWARDS

Syntax

bool fetchRemote ( string URL[, table options ], callback callbackFunction[, table callbackArguments ] )

Required Arguments

  • URL: A full URL in the format http://hostname/path/file.ext. A port can be specified with a colon followed by a port number appended to the hostname.
  • callbackFunction: This is the function that should receive the data returned from the remote server. The callback argument list should be:
    • responseData - A string containing the remote response
    • responseInfo - A table containing:
      • success - A boolean indicating if the request was successful.
      • statusCode - An integer status/error code
      • headers - A table containing the HTTP response headers
    • arguments... - The arguments that were passed into fetchRemote

Optional Arguments

  • options: A table containing any request options:
    • queueName: Name of the queue to use. Any name can be used. If not set, the queue name is "default". Requests in the same queue are processed in order, one at a time.
    • connectionAttempts: Number of times to retry if the remote host does not respond. (Defaults to 10)
    • connectTimeout: Number of milliseconds each connection attempt will take before timing out. (Defaults to 10000)
    • postData: A string specifying any data you want to send to the remote HTTP server.
    • postIsBinary : A boolean specifying if the data is text, or binary. (Defaults to false)
    • method: A string specifying the request method. (Defaults to GET or POST)
    • headers: A table containing HTTP request headers. e.g.{ Pragma="no-cache" }
    • maxRedirects: An integer limiting the number of HTTP redirections to automatically follow. (Defaults to 8)
    • username: A string specifying the username for protected pages.
    • password: A string specifying the password for protected pages.
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    • formFields: A table containing form items to submit. e.g.{ name="bob", email="bob@example.com" }
  • arguments: A table containing arguments you may want to pass to the callback.

Returns

Returns true if the arguments are correct, false otherwise.

Example

This example shows you how you can fetch an image from a web page, and transfer it to a particular client:

Click to collapse [-]
Server

function startImageDownload( playerToReceive )
    fetchRemote ( "http://www.example.com/image.jpg", myCallback, "", false, playerToReceive )
end

function myCallback( responseData, errno, playerToReceive )
    if errno == 0 then
        triggerClientEvent( playerToReceive, "onClientGotImage", resourceRoot, responseData )
    end
end
Click to collapse [-]
Client
addEvent( "onClientGotImage", true )
addEventHandler( "onClientGotImage", resourceRoot,
    function( pixels )
        if myTexture then
            destroyElement( myTexture )
        end
        myTexture = dxCreateTexture( pixels )
    end
)

addEventHandler("onClientRender", root,
    function()
        if myTexture then
            local w,h = dxGetMaterialSize( myTexture )
            dxDrawImage( 200, 100, w, h, myTexture )
        end
    end
)


FROM VERSION 1.5.4-9.11413 ONWARDS

Example sending email via a web service (adopted from examples on https://documentation.mailgun.com/user_manual.html)

Click to collapse [-]
Server
sendOptions = {
    queueName = "My Mailgun queue",
    connectionAttempts = 3,
    connectTimeout = 5000,
    formFields = {
        from="Excited User <excited@samples.mailgun.org>",
        to="devs@mailgun.net",
        subject="Hello",
        text="Testing some Mailgun awesomness!",
    },
    username="api",
    password="key-3ax6xnjp29jd6fds4gc373sgvjxteol0",
}
fetchRemote( "https://api.mailgun.net/v3/samples.mailgun.org/messages", sendOptions, mailgunCompleteCallback )

function mailgunCompleteCallback(data, info)
    outputDebugString( "mailgunComplete"
            .. " success:" .. tostring(info.success)
            .. " statusCode:" .. tostring(info.statusCode)
            .. " data:" .. tostring(data)
            )
end

Requirements

Minimum supported server 1.3.0-9.03739
Minimum supported client 1.3.2
Note: Using this function requires the resource to have the above minimum version declared in the meta.xml <min_mta_version> section. e.g. <min_mta_version server="1.3.0-9.03739" client="1.3.2" />

Changelog

Version Description
1.3.1-9.04605 Added connectionAttempts argument
1.3.2 Added client side
1.5.3-9.11270 Added queueName argument
1.5.4-9.11342 Added alternative syntax
1.5.4-9.11413 Added formFields

See Also

FROM VERSION 1.5.5 r11533 ONWARDS