Updating javascript global variable

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I am working in asp.net development, I have Two files i.e.
i) UserControl
ii).js (javascript)
In .js File following is code

var varBindNewSalesTranGrid = '';
function BindNewSalesAttribute() {
    $.ajax({
        type: "POST",
        url: "/url of Webmthod returns string",
        data: '{}',
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        success: function (data) {
            varBindNewSalesTranGrid += data.d;
        },
        error: function (xhr, ajaxOptions, thrownError) {
        }
    });
}

In Usercontrol file

 $(document).ready(function () {
        BindNewSalesAttribute();
        alert(varBindNewSalesTranGrid);
    });
//Which is file referenced above .js file

When I run my usercontrol file I see the value of varBindNewSalesTranGrid is empty ('').Function returns value 'TestString' and I am assigning value varBindNewSalesTranGrid in BindNewSalesAttribute function but still value is not getting updated.

if you have any ideas then let me know.

Posted 13-Oct-14 4:01am

RAHUL(10217975)

Updated 13-Oct-14 5:17am

sankarsan parida

v2

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[no name] 13-Oct-14 11:59am

The variable should be declared inside the Document.ready so that it gets memory on the page load itself, once the script is loaded.

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Satya Ranjan Sahoo · Answer 1 · 2014-10-13T06:05:00

Solution 1

In the above code you are assigning the value to the global variable inside a ajax call success function. If you look into the steps of execution in $(doument).ready function it first calls the "BindNewSalesAttribute()" function which is asynchronous in nature. Then it executes the "alert(varBindNewSalesTranGrid)" statement which do not wait for completion of "BindNewSalesAttribute()" method due to asynchronous nature of the function.

Thats why when alert is executed the value has not been updated.
But in background the value is being updated and you can check it by placing the alert inside the success function or by making "async:fasle" in ajax call.

Hope this helps:)

Posted 13-Oct-14 6:05am

Satya Ranjan Sahoo

Comments

RAHUL(10217975) 13-Oct-14 14:57pm

Yes value is being updated in success function but I am not able to receive updated value in my usercontrol..How should I achieve that? Its still showing empty in usercontrol

Satya Ranjan Sahoo 14-Oct-14 1:47am

Make "async:fasle" in ajax call:
function BindNewSalesAttribute() {
$.ajax({
type: "POST",
url: "/url of Webmthod returns string",
async: false,
data: '{}',
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (data) {
varBindNewSalesTranGrid += data.d;
},
error: function (xhr, ajaxOptions, thrownError) {
}
});
}
This will work but its not good to have "async:fasle" in an ajax call.Its better that perform your task related to that global variable inside the success function of ajax call.