页面完全加载事件

Question

I have a page with multiple dropdown boxes. I want to make some dropdowns as ready only after the AJAX finish the dropdown content load and the default value selection.

So in each dropdown's Ajax function, I have

complete: function () {
        $("#Country").enable();
        $("#ORG_ID").enable();
        $('#Country option[value="@TempData["Country"]"]').prop('selected', true).change();
        $('#ORG_ID option[value="@TempData["ORG_ID"]"]').prop('selected', true).change();
        }

"@TempData["Country"]"] is an ASP.NET MVC Razor variable.

I hope after all the Ajax events are fired and completed, the JavaScript DOM can set the Country and ORG_ID field as ready only with the codes -

<script type="text/javascript">
    function pageLoad() {
      document.getElementById('Country').readOnly = true;
      document.getElementById('ORG_ID').readOnly = true;
    }
</script>

It is supposed that pageLoad or window.onload will be fired after AJAX's complete event is finished. But after pageLoad has been set the Ajax events still continue to fire for the changes. The readOnly can never be set for these fields.

What have I missed? Is there a more complete page load event than pageLoad or window.onload in Javescript?

Thanks

Update: The AJAX call is from

$(document).ready(function () {
  GetCountry();
}

The above AJAX function codes are in

function GetCountry() {
    $("#Country").disable();
    $("#ORG_ID").disable();

    $.ajax({
        type: 'POST',
        url: '@Url.Action("GetCountry/" + ViewBag.Id.ToString(), "RequestList")',
        data: { Direct: isDirect },
        success: function (data, textStatus, jqXHR) {
            if (textStatus != "success") {
                alert("There was an error processing your request.");
                return;
            }

            $.each(data, function (i, item) {
                $('#Country').append($('<option>').val(item.Id).text(item.Text));
            });
        },
        error: function (jqXHR, textStatus, errorThrown) {
            alert("There was an error processing your request.");
        },
        complete: function () {
            $("#Country").enable();
            $("#ORG_ID").enable();
            $('#Country option[value="@TempData["Country"]"]').prop('selected', true).change();
            }
    })
}

Answer 1

The first A in AJAX stand for asynchronous, which means nothing waits on it, including window.load or document.ready.

The lazy method is to make your ajax synchronous using the "async" setting in $.ajax(), but this will pause all code execution and file loading while it waits on each reply. Not good.

The proper way to do this would be to use $.when(). Here is the relevant example from that page.

$.when( $.ajax( "/page1.php" ), $.ajax( "/page2.php" ) ).done(function( a1, a2 ) {
  // a1 and a2 are arguments resolved for the page1 and page2 ajax requests, respectively.
  // Each argument is an array with the following structure: [ data, statusText, jqXHR ]
  var data = a1[ 0 ] + a2[ 0 ]; // a1[ 0 ] = "Whip", a2[ 0 ] = " It"
  if ( /Whip It/.test( data ) ) {
    alert( "We got what we came for!" );
  }
});

EDIT:

Is this not what you're trying to do? Fire a function after all of your ajax calls have completed?

$(document).ready(function () {
  GetCountry();
});

function GetCountry() {
    $("#Country").disable();
    $("#ORG_ID").disable();

    $.when(
        $.ajax({ // box 1
            type: 'POST',
            url: '@Url.Action("GetCountry/" + ViewBag.Id.ToString(), "RequestList")',
            data: { Direct: isDirect },
            success: function (data, textStatus, jqXHR) {
                if (textStatus != "success") {
                    alert("There was an error processing your request.");
                    return;
                }

                $.each(data, function (i, item) {
                    $('#Country').append($('<option>').val(item.Id).text(item.Text));
                });
            },
            error: function (jqXHR, textStatus, errorThrown) {
                alert("There was an error processing your request.");
            },
            complete: function () {
                $("#Country").enable();
                $("#ORG_ID").enable();
                $('#Country option[value="@TempData["Country"]"]').prop('selected', true).change();
            }
        }),
        $.ajax({ // box 2
            type: 'POST',
            url: '@Url.Action("GetCountry/" + ViewBag.Id.ToString(), "RequestList")',
            data: { Direct: isDirect },
            success: function (data, textStatus, jqXHR) {
                if (textStatus != "success") {
                    alert("There was an error processing your request.");
                    return;
                }

                $.each(data, function (i, item) {
                    $('#Country').append($('<option>').val(item.Id).text(item.Text));
                });
            },
            error: function (jqXHR, textStatus, errorThrown) {
                alert("There was an error processing your request.");
            },
            complete: function () {
                $("#Country").enable();
                $("#ORG_ID").enable();
                $('#Country option[value="@TempData["Country"]"]').prop('selected', true).change();
            }
        })

    ).done(function(){
        // fires after the two ajax calls are done
        document.getElementById('Country').readOnly = true;
        document.getElementById('ORG_ID').readOnly = true;
    });
}

Answer 2

You need to add async:false.

if you Setting async to false means that the statement you are calling has to complete before the next statement in your function can be called. If you set async: true then that statement will begin it's execution and the next statement will be called regardless of whether the async statement has completed yet.

Please try this code

  $.ajax({
        type: 'POST',
        url: '@Url.Action("GetCountry/" + ViewBag.Id.ToString(), "RequestList")',
        async:false,
        data: { Direct: isDirect },
        success: function (data, textStatus, jqXHR) {
            if (textStatus != "success") {
                alert("There was an error processing your request.");
                return;
            }

            $.each(data, function (i, item) {
                $('#Country').append($('<option>').val(item.Id).text(item.Text));
            });
        },
        error: function (jqXHR, textStatus, errorThrown) {
            alert("There was an error processing your request.");
        },
        complete: function () {
            $("#Country").enable();
            $("#ORG_ID").enable();
            $('#Country option[value="@TempData["Country"]"]').prop('selected', true).change();
            }
    })