如果还有关于ajax的结果

I am busy writing a web page for a company. I need to accomplish the following: If the output is nothing, alert "Rookswitch is turned off". If the output is "Hookswitch-Playlist", alert "Rookswitch is turned on". The data is grabbed from a REST API.

$(document).ready(function() {
    $.ajax({
        type: "GET",
        url: "http://192.168.0.15:8080/Cnario/REST/GetDevice?deviceName=Rook-Switch",
        dataType: "json",
        processdata: true,
        success: function(response) {
            alert("De Rookswitch staat al aan");
            if (response.GetDeviceResult.DevicePins.PinValue == 'Playlist-Roken')
                handleSuccess(response);
            else
                handleError(response);
        },
        error: function(message) {
            alert("Rookswitch is uit");
        }
    });
});

For some reason, the message is always on. even if it is off. How can i fix this?

In your success function, you're doing an alert for "switched on" in all cases. No matter whether the response is blank, or contains a value.

You've put the alert for "It's switched off" in the error function. This function will only be called if the AJAX request actually fails (i.e. there is a HTTP error).

I think what you probably want to do is put an if/else block in your success function to check the value of the appropriate field in the response object to see if it contains the string "Hookswitch-Playlist" or not.

If you are able to control the http://192.168.0.15:8080/Cnario/REST/GetDevice?deviceName=Rook-Switch response, I strongly recommend to use sth like

/* --------------------------------------- */
/*  Response will be generated according to which 
/*  prog lang you are using but as a result we should have sth like this
/* --------------------------------------- */

var response = {
    code: 200, // on
    message: 'Rookswitch is turned on'
}
/* OR */
var response = {
    code: 300, // off
    message: 'Rookswitch is turned off'
}

/* --------------------------------------- */
/* Response
/* --------------------------------------- */

$(document).ready(function() {
    $.ajax({
        type: "GET",
        url: "http://192.168.0.15:8080/Cnario/REST/GetDevice?deviceName=Rook-Switch",
        dataType: "json",
        processdata: true,
        success: function(response) {
            alert(response.message);
            /* --------------------------------------- */
            /* doing sth according to server response
            /* --------------------------------------- */
            if(response.code == 200){
                /* On function goes here */
            }else if(response.code == 300){
                /* Off function goes here */
            }
        },
        error: function(message) {
            alert("Rookswitch is uit");
        }
    });
});