Question

I’m taking a Javascript class and was wondering if there was a way to tell which button was selected when a function is called. I basically have a method like this:

function sendRequest()
{
    var url = "http://classwebsite/bookmarks.php";
    url += "?userid=crystal";
    var transmission = document.getElementById("transmission").value;
    url += "&response=" + transmission;
    var callback = {success:handleResponse, 
                    failure:handleFailure,
                    timeout:5000
                    };

    var transaction = YAHOO.util.Connect.asyncRequest("GET", url, callback, null);
}

This method gets called when a button is pressed. It basically gets back the prof’s response in the appropriate JSON, XML, etc format and displays it. I want to add an “add” feature to add new rows to the table. That’s done by calling the same URL in the above method and just manually putting this in the address bar:

http://classwebsite/bookmarks.php?userid=crystal&action=add&name=yahoo&url=yahoo.com&desc=Yahoo+website

In this scenario, if I had another button called “Add” to add in fields from a form, would I call the same sendRequest() method, and modify the url accordingly? If so, how do I know which button was pressed if both the “List” button and “Add” button would be tied to the same event handler.

Or is it a better design to have another method, that handles addRequest() and just adds fields from the form? Thanks.

Answer 1

You should be able to modify the parameters of your javascript function to see the sender.

There is also a hidden array called arguments, that will let you look at what parameters are available to a function, in case you are ever curious.

function sendRequest(sender, args) {
    //sender is your clicked button

    var url = "http://classwebsite/bookmarks.php";
    url += "?userid=crystal";
    var transmission = document.getElementById("transmission").value;
    url += "&response=" + transmission;
    var callback = {success:handleResponse, 
                    failure:handleFailure,
                    timeout:5000
                    };

    var transaction = YAHOO.util.Connect.asyncRequest("GET", url, callback, null);
}