Execution behind Proxy Servers is not possible about vba-web

[timhall]

@ststreck It appears ServerXMLHTTP (which Excel-REST uses) does not auto-discover proxy settings. I'll switch back to the traditional XMLHTTP seems better suited for spreadsheet applications anyways.

[Kyle123]

I think that WinHTTP may be a better choice than XMLHTTP, it also offers the benefit of handling the cookies when required

[timhall]

WinHTTP looks interesting, seems like the more modern solution. I'll try it out right now and see how it works.

[ststreck]

What I liked with the ServerXMLHTTP is the possibility to work with Cookie Headers.
An working Cookie Management and Proxy support would be the 100% solution.

[timhall]

Quick update: I'm running into some issues with Requests being released from memory before handling async responses, but I have some ideas on possible solutions so it's looking like switching over to WinHTTPRequest should work.

Another very nice side effect of switching to WinHTTPRequest is that sync requests don't lock up Excel as badly thanks to WaitForResponse. You still can't do anything while the request is executing, but I haven't seen any "Stopped Responding" notices during execution like I used to see before during long running requests and it isn't as CPU intensive as a DoEvents loop was when I tried that before.

[timhall]

@ststreck I've pushed a patch that uses the setProxy method with ServerXMLHTTP to use the default proxy settings for the computer. Do you mind testing this for your case? (I don't have access to a computer with a proxy setup) You should only need to update the RestClient class from the proxy-functionality branch:

https://raw.github.com/timhall/Excel-REST/proxy-functionality/src/RestClient.cls

While switching to the more modern WinHTTPRequest would have been nice (and still may be possible) I ran into too many memory issues with objects being released while waiting for the request to callback. Hopefully ServerXMLHTTP will be a good compromise with cookies included and (hopefully) proxy functionality sorted out.

[timhall]

I got an email response from @ststreck

The new Proxy line does not work, but I have no Idea why it does not get the right settings.
When I use Fiddler all Traffic is routed thru "localhost"
When I replace Http.setProxy 0 with Http.setProxy 2, "127.0.0.1:8888" then it is working.

But I know this is only a local solution for me.

I'll look back into switching to WinHTTPRequest to hopefully resolve this issue.

[timhall]

(Sorry for the delay) Based on the amount of code that would need to switched to use WinHTTPRequest, I've pushed default proxy functionality to v3.0 of Excel-REST sometime in the future. In the meantime, I've added a RestClient.SetProxy method that allows you to set a proxy without having to dig into the Excel-REST source. Not the most ideal solution, but I think it's the best approach for now.

Example:

' RestClient.SetProxy(ProxyServer As String, _
'     Optional Username As String, _
'     Optional Password As String, _
'     Optional BypassList As Variant)

Dim Client As New RestClient
Client.BaseUrl = "https://api.website.com"
Client.SetProxy "127.0.0.1:8888"
' Client.Execute ...

[paolodemo]

I'm working into a network with proxy configuration trying to access the google services.
I tested v3.1.4 and I see 2 problems:

1. Into HttpSetup function the PrepareProxyForHttpRequest must be moved after the HttpOpen
2. The GoogleAuthenticator doesn't use the proxy so its request provide 408 (timout) error
   Fixing both this I again have:

    ERROR - GoogleAuthenticator.Token: Failed to load token: 400 - {
      "error" : "invalid_request",
      "error_description" : "Missing required parameter: code"
    }

I'm checking if this last error is related to the proxy or not.

[paolodemo]

Update:
Setting LoginByDefault = True in the authenticator does the flow works.

[timhall]

Hi @paolodemo thanks for bringing this up. I'll look into the GoogleAuthenticator and ordering and see if I can patch it and will definitely make sure it's fixed in v4