http request from server to client

Question

User1448655074 posted

Hi All

I'm running a kiosk type setup and need to check if a certain application is running on the client from my server.

Server is on c# asp.net

The only way of checking that is by running a http request to the client using

http://<clientIP:9192>/omxcmd?cmd=position

All my clients are connected to the server via vpn so I can just use the IP of the client.

Currently I have tried doing this using ajax with the below but I'm getting errors around cross domain which despite my efforts cannot resolve... see https://stackoverflow.com/questions/51235842/http-request-with-javascript-ajax-no-access-control-allow-origin

   $.ajax({
    url: "http://VPNIPofCLIENT:9192/omxcmd?cmd=position",
    type: "GET",
    crossDomain: true,
    dataType: "json",
    success: function (response) {
        var resp = JSON.parse(response)
        alert(resp.status);
    },
    error: function (xhr, status) {
        alert("error");
    }
}); 

The return value is just a text/string

This does seem off as its a http request from the server to the client and not the other way round

I could probably do this from code-behind in c# and use curl or something but would rather do this on the client side if possible...

If there anything I can do to get this?

Answer 1

User-369506445 posted

hi

what is the <g class="gr_ gr_89 gr-alert gr_spell gr_inline_cards gr_run_anim ContextualSpelling" id="89" data-gr-id="89">omxcmd</g> exactly? what kind of technology do you <g class="gr_ gr_19 gr-alert gr_gramm gr_inline_cards gr_run_anim Style multiReplace" id="19" data-gr-id="19">use ?</g>

 

Answer 2

User-1171043462 posted

Try the dynamic script technique for Cross Domain calls work.

Comment your AJAX call and put this

	
	//Create a SCRIPT element.
        var script = document.createElement("script");
 
        //Set the Type.
        script.type = "text/javascript";
 
        //Set the source to the URL the JSON Service.
        script.src = 'http://VPNIPofCLIENT:9192/omxcmd?cmd=position&callback=OnSuccess';
 
        //Append the script element to the HEAD section.
        document.getElementsByTagName("head")[0].appendChild(script);

	

And then add this function

         function OnSuccess(response) {
	      var resp = JSON.parse(response)
	      alert(resp.status);
	 }

Answer 3

User1448655074 posted

this is real close 

gives the same error as my original ajax call or with using jsonp

Uncaught SyntaxError: Unexpected identifier

omxcmd?cmd=position&callback=OnSuccess:1 Uncaught SyntaxError: Unexpected identifier

return value if successful should be "no player"

Answer 4

User-1171043462 posted

Which line is throwing error? Can you please debug in Visual Studio?

Answer 5

User1448655074 posted

thanks Mudassar I managed to resolve this by using a webservice (asmx) which containted the http get request and then calling the webmethod using ajax

Ideally I wanted a pure client side solution using jquery/javascript but this will have to do....