http.abort() Question

[rfresh]

When i use ajax http.abort() do I need to follow that up with another http. cmd? Once I abort one of my ajax functions, I can no longer execute any other ajax functions - when I click on another ajax link, nothing happens.

Thanks

[A1ien51]

And your mystery code would be?

Eric

[rfresh]

Here is the code - once I execute the abort function the search_function won't work anymore.

PHP Code:

function search_operation()
{
    var url = "Ajax_Operation_ClickServer.php";
    var params = "search_text=" + search_text + "&replace_text=" + replace_text;
    http.open("POST", url, true);
    http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    http.setRequestHeader("Content-length", params.length);
    http.setRequestHeader("Connection", "close");
    http.onreadystatechange = function()
         {
           if (http.readyState == 4) //Finished loading the response
              {
                if (http.status == 200)
                   {
                     var response = http.responseText;
                     document.getElementById("id_search_results_container").innerHTML = response;
                   }
                else
                   {
                     alert("Ajax error: " + http.statusText);
                   }
              }
         }
    http.send(params);
} 


PHP Code:

function abort_search_operation()
{
    http.abort();
    return;
} 


[A1ien51]

create a new instance of the xmlHTTPRequest object and see if that fixes it.

Eric

[rfresh]

When I create this line

var http = createRequestObject();

the second time in the abort_operation(), will this work from a variable scoping point of view? I'm not too sure about how JS vars work with scoping their "visibility". I initially am creating the http instance at the top of my functions and then in abort_operation() I am trying to re-create it again - is this structure correct?

Recall the problem is that when I abort an ajax operation (such as expand_search_window_section) and then try to call it again, it doesn't work. I have not tried this code below yet because I want to make sure the recreation of the http instance is in the correct spot from a var scoping point of view.

The key question is where can/should I be recreating the var http = createRequestObject()?

PHP Code:

function createRequestObject() {
    if (window.XMLHttpRequest) { // Mozilla, Safari, Opera...
        var xmlhttp = new XMLHttpRequest();
        if (xmlhttp.overrideMimeType)
            xmlhttp.overrideMimeType('text/xml');
    }
    else if (window.ActiveXObject) { // IE
        try {
            var xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
        } catch (e) {
            try {
                var xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
            } catch (e) {}
        }
    }
    if (!xmlhttp) {
        alert('Giving up :( Cannot create an XMLHTTP instance');
        return false;
    }
    return xmlhttp;
}

var http = createRequestObject();

function abort_operation()
{
    http.abort();
    var http = createRequestObject();
    return;
}

function expand_search_window_section()
{
    var url = "Ajax_ExpandSearch_ClickServer.php";
    var params = "php_status=" + php_status;
    http.open("POST", url, true);
    http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    http.setRequestHeader("Content-length", params.length);
    http.setRequestHeader("Connection", "close");
    http.onreadystatechange = function()
         {
           if (http.readyState == 4) //Finished loading the response
              {
                if (http.status == 200)
                   {
                     var response = http.responseText;
                     //alert(response);
                   }
                else
                   {
                     alert("Ajax error: " + http.statusText);
                   }
              }
         }
    http.send(params);
} 


[A1ien51]

drop the var

function abort_operation()
{
    http.abort();
    http = createRequestObject();
    return;
}

or

    var params = "search_text=" + search_text + "&replace_text=" + replace_text;
    http = createRequestObject();
    http.open("POST", url, true);

Your best bet would find a library to make the calls with proper OO JavaScript.

Eric