View source for Legacy/fetchRemote

__NOTOC__ 
{{Server client function}}
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.
{{Note|Client side function only works with the server the player is connected to unless the domain has been accepted with [[requestBrowserDomains]]}}
{{ Warning| function won't trigger inside another fetchRemote function }}
{{ Warning| When using [[toJSON]] for submitting data, make sure to use '''string.sub(data, 2, -2)''' to remove the brackets as many APIs will not understand the request  }}

{{Note|This page only contains legacy implementations. For current implementation check [[fetchRemote]]}}

==Syntax== 
<syntaxhighlight lang="lua">
bool fetchRemote ( string URL, [ string queueName = "default" ], [ int connectionAttempts = 10, int connectTimeout = 10000 ], function callbackFunction, [ string postData = "",  bool postIsBinary = false ], [ arguments... ] )
</syntaxhighlight> 

===Required Arguments=== 
*'''URL:''' A full URL in the format ''<nowiki>http://hostname/path/file.ext</nowiki>''. 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
**'''''error''''' - A number containing the error number or zero if there was no error. A list of possible error values are:
{{Error_codes_for_callRemote_and_fetchRemote}}
<div style="padding-left:19px;">
*'''''arguments...''''' - The arguments that were passed into fetchRemote
</div>

===Optional Arguments=== 
{{New items|4.0153|1.5.3-9.11270|
*'''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.


{{New items|5.0154|1.5.4-9.11342|
==Syntax== 
<syntaxhighlight lang="lua">
bool fetchRemote ( string URL[, table options ], callback callbackFunction[, table callbackArguments ] )
</syntaxhighlight> 

===Required Arguments=== 
*'''URL:''' A full URL in the format ''<nowiki>http://hostname/path/file.ext</nowiki>''. 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&#61;"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.
{{New items|5.0154|1.5.4-9.11413|
**'''formFields:''' A table containing form items to submit. (for POST method only)  ''e.g.{ name&#61;"bob", email&#61;"bob@example.com" }''
}}
*'''arguments:''' A table containing arguments you may want to pass to the callback.
}}

===Returns===
{{New items|5.0154|1.5.7-9.20307|
Returns a '''''request''''' value which can be used with [[GetRemoteRequestInfo|getRemoteRequestInfo]] or [[AbortRemoteRequest|abortRemoteRequest]]
}}

==Example==
This example shows you how you can fetch an image from a web page, and transfer it to a particular client:
<section name="Server" class="server" show="true">
<syntaxhighlight lang="lua">

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

function myCallback( responseData, errorCode, playerToReceive )
    if errorCode == 0 then
        triggerClientEvent( playerToReceive, "onClientGotImage", resourceRoot, responseData )
    end
end
</syntaxhighlight>
</section>
<section name="Client" class="client" show="true">
<syntaxhighlight lang="lua">
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
)
</syntaxhighlight>
</section>
<br/>
{{New items|5.0154|1.5.4-9.11413|
Example sending email via a web service (adopted from examples on https://documentation.mailgun.com/en/latest/user_manual.html)
<section name="Server" class="server" show="true">
<syntaxhighlight lang="lua">
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
</syntaxhighlight>
</section>

Changing post content on IPS forum.
<section name="Server" class="server" show="true">
<syntaxhighlight lang="lua">
local apiKey = "12345678123456781234567812345678" -- key from ips admin panel
local forumAddress = "https://yourForum.com"
function setPostContent(postID,content)
  local sendOptions = {
    queueName = "updatePost",
    connectionAttempts = 1,
    connectTimeout = 50,
    formFields = {
      post = content,
    },
  }
  fetchRemote( forumAddress.."/api/forums/posts/"..postID.."?key="..apiKey, sendOptions, function()end)
end

setPostContent(1, "this is a first post on this forum")
</syntaxhighlight>
</section>
}}

==Changelog==
{{ChangelogHeader}}
{{ChangelogItem|1.3.1-9.04605|Added connectionAttempts argument}}
{{ChangelogItem|1.3.2|Added client side}}
{{ChangelogItem|1.5.3-9.11270|Added queueName argument}}
{{ChangelogItem|1.5.4-9.11342|Added alternative syntax}}
{{ChangelogItem|1.5.4-9.11413|Added formFields}}

==See Also==
{{Resource_functions}}