Why doesn't this javascript ajax function return a value?

Well I did hack it to make it work, but I'd still like to fix it... basically all I did was to replace the "return" statement with this, doing a direct assignment of the value rather than returning it to the calling function:

var subobj=document.getElementById("subcontent2");
subobj.innerHTML = (myajax.responseText);

I did that because, yes, I had done exactly as you suggested by hard-coding a string in there, so I KNEW that I was close!

Maybe that function's not returning a string, but maybe an object instead?

I don't think so.  Since it works by replacing the return line with the line to write the innerHTML the responseText is just a string.  What calls the processGetPost() function?  The problem appears to be in that part of the script.  If you want to get it to work then you can provide more of the script and page.

If you want to find out the type of variable you can use ...

typeof variablename

Let me know if you have a question or need some more information.

bol

The calling function, activated by an onClick event, uses this code:

var myContent = ajaxpack.getAjaxRequest("getHelpContent.asp", "NavID=" + nav_id, processGetPost, "txt");
alert(myContent);

The alert returns the word "undefined", but if I think if I override the return value to be a hard coded value, it does return correctly. I'll try typeof in a bit.

Then were you inserting the response with something like the line below?

subobj.innerHTML = myContent;

If so then myContent may be an object.  It would depend on what ajaxpack.getAjaxRequest() function/method does and returns.  You could see with ...

alert(typeof myContent);

What information do you have about ajaxpack and the getAjaxRequest method/property?  You might have to adapt or not use this if it is meant for something else and returning something that isn't a string, etc.

Let me know the results and how I can continue to help you with this.  I'm starting to think that ajaxpack is a lot more work than it needs to be if you want to use AJAX. :)

bol

myajax.responseText only "lives" as long as the function is running.  Javascript doesn't "collapse" this to a string until the function is finished, so it disappears.

You solved the issue by setting the innerHTML inside the function, you can also do this:

var answer = myajax.responseText;  // this sets the value of the answer variable to the resulting string
return answer;  // which can then be used by another function

Stan

The a in Ajax is for ASYNCRONOUS
You cannot call an ajax function and expect the return to do anything
You EITHER call a new function with the string inside that if statement that does exactly what you did or do exactly what you did and fill the innerHTML  of something when you get a 4

I have not seen this return anything

function processGetPost(){
  if (myajax.readyState == 4){ //if request of file completed
    if (myajax.status==200 || window.location.href.indexOf("http")==-1){ //if request was successful or running script locally
       return(myajax.responseText);
    }
  }
}

alert(processGetPost())

since the script returns immediately it is called and does not wait for the result. It is not single threaded.

Michel

Ok, yeah, looks like this is a shortcoming of the DynamicDrive library. I think the solution to this thread lies with a split between stanscott2 and mark-b. Any objections?

If you want change the ajax pack javascript (ajaxroutine.js) to support synchronous calls, just change the two methods getAjaxRequest and postAjaxRequest to:

ajaxpack.getAjaxRequest=function(url, parameters, callbackfunc, filetype, sync){
 ajaxpack.ajaxobj=createAjaxObj() //recreate ajax object to defeat cache problem in IE
 if (ajaxpack.addrandomnumber==1) //Further defeat caching problem in IE?
  var parameters=parameters+"&ajaxcachebust="+new Date().getTime()
  if (this.ajaxobj){
   this.filetype=filetype
   this.ajaxobj.onreadystatechange=callbackfunc
   this.ajaxobj.open('GET', url+"?"+parameters, !sync)
   this.ajaxobj.send(null)
  }
}

ajaxpack.postAjaxRequest=function(url, parameters, callbackfunc, filetype, sync){
 ajaxpack.ajaxobj=createAjaxObj() //recreate ajax object to defeat cache problem in IE
 if (this.ajaxobj){
  this.filetype=filetype
  this.ajaxobj.onreadystatechange = callbackfunc;
  this.ajaxobj.open('POST', url, !sync);
  this.ajaxobj.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
  this.ajaxobj.setRequestHeader("Content-length", parameters.length);
  this.ajaxobj.setRequestHeader("Connection", "close");
  this.ajaxobj.send(parameters);
 }
}

Then change your ajax call to:

ajaxpack.getAjaxRequest("example.htm", "", processGetPost, "txt", true )

(I haven't tested this, but it should work)

-Mark

>>I think the solution to this thread lies with a split between stanscott2 and mark-b. Any objections?
I'm a little surprised that I was left out.  I was getting information but headed to the same conclusion as the comments you plan to accept.  It would be nice to have an explanation.  It is your question and you know who helped but I was just a little surprised.

bol

It doesn't matter to me who gets the points.  Split them as you see fit.

Hey Bol, well, maybe you're right, but now I'm looking at Mark-b's post, and it looks like we might have an actual code solution, so I guess it'd be between you and him for the points. (Which was why I posted a comment, rather than actually accepting a solution).

My question still, then, is how to get the content that was returned by the ajax call... Like this?

var myResponse = ajaxpack.getAjaxRequest("example.htm", "", processGetPost, "txt", true );

I believe you will not succeed as I already pointed out.
Treat ajax like a setTimeout