How to VBA callback function when XMLHTTP onTimeOut?
callback, excel, msxml, timeout, vba
Solution
The line;
`XMLHTTP.OnTimeOut = OnTimeOutMessage`
Is not a method assignment; rather it immediately executes `OnTimeOutMessage()` (and assigns its useless return value to `OnTimeOut`).
The equivalent line in JavaScript as per your example link correctly assigns a `Function` object to `OnTimeOut` for subsequent invokation - this is not supported by VBA.
Instead, you could trap the timeout error raised after `.send` or use early binding, `WithEvents`, & inline event handlers.
Problem
I'm trying get xml data from webserver to excel, then I wrote a `sendRequest` function to call in excel `=sendRequest("http://abb.com/index.php?id=111")` When web-server having trouble, cannot connect or cannot find, excel is not responding, it was horrible! To avoid it, i think we should set timeOut. These are my function: ``` Function sendRequest(Url) 'Call service Set XMLHTTP = CreateObject("Msxml2.ServerXMLHTTP.6.0") 'Timeout values are in milli-seconds lResolve = 10 * 1000 lConnect = 10 * 1000 lSend = 10 * 1000 lReceive = 15 * 1000 'waiting time to receive data from server XMLHTTP.setTimeOuts lResolve, lConnect, lSend, lReceive XMLHTTP.OnTimeOut = OnTimeOutMessage 'callback function XMLHTTP.Open "GET", Url, False On Error Resume Next XMLHTTP.Send On Error GoTo 0 sendRequest = (XMLHTTP.responseText) End Function Private Function OnTimeOutMessage() 'Application.Caller.Value = "Server error: request time-out" MsgBox ("Server error: request time-out") End Function ``` Normally, when `XMLHTTP`'s timeout occurs, event `OnTimeOutMessage` will be executed (reference #1, #2). But as in my test, `OnTimeOutMessage` is executed right at the beginning of `sendRequest()` How to use callback function when Msxml2.ServerXMLHTTP.6.0 request is time-out? Thank for your help!