How do I change the settings of this function to make it run only during the 1st load of the webpage and not every postback?

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Hi, I have these JavaScript function that runs every time on every pageload and postback. How do I change the settings of this function to make it run only during the 1st load of the webpage and not every postback?

Do I change $(window).ready(function ()? OR I set it in my aspx.cs file page load?

JavaScript

$(window).ready(function () {
    $("#Checkboxlist1 :checkbox").attr('disabled', 'disabled');
    $("#Checkboxlist1  :checkbox[value='Select All']").removeAttr('disabled');
    $("#Checkboxlist1  :checkbox[value='Select All']").prop("checked", true);
    });

Another way I tried doing:

HTML

<input type="hidden" id="hidden" value=""/>

JavaScript

$(function () {
    if ($("#hidden").val() == "") {
        $("#Checkboxlist1  :checkbox").attr('disabled', 'disabled');
        $("#Checkboxlist1  :checkbox[value='Select All']").removeAttr('disabled');
        $("#Checkboxlist1  :checkbox[value='Select All']").prop("checked", true);
        $("#hidden").val("set");
    }
});

Posted 24-Sep-15 20:56pm

waynetan123

Updated 24-Sep-15 22:36pm

v5

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Member 12003400 · Answer 1 · 2015-09-24T21:06:00

Solution 1

if aspx.cs file

:pageload()
{
if(!ispostback)
ClientScript.RegisterStartupScript(GetType(), "Javascript", "javascript:FUNCTIONNAME(); ", true);

}

Posted 24-Sep-15 21:06pm

Member 12003400

Comments

waynetan123 25-Sep-15 3:08am

Do I need to change $(window).ready(function () ?

Member 12003400 25-Sep-15 3:27am

Yes,Make a function and write your code in that function and call that function from aspx.cs page
like
function FUNCTIONNAME() {
$("#Checkboxlist1 :checkbox").attr('disabled', 'disabled');
$("#Checkboxlist1 :checkbox[value='Select All']").removeAttr('disabled');
$("#Checkboxlist1 :checkbox[value='Select All']").prop("checked", true);
});

Member 12003400 25-Sep-15 3:31am

OR TRY
$(window).load() or javascript's window.onload() or <body onload=""

waynetan123 25-Sep-15 3:52am

It still reloads during postback e.g when I click on submit button

Krunal Rohit · Answer 2 · 2015-09-24T21:09:00

You can use Local Storage[^] feature of HTML5.

JavaScript

$(window).ready(function () {
    localStorage.setItem("isDataLoaded", false);
    
    if(!localStorage.getItem("isDataLoaded"))
    {
        $("#Checkboxlist1 :checkbox").attr('disabled', 'disabled');
        $("#Checkboxlist1  :checkbox[value='Select All']").removeAttr('disabled');
        $("#Checkboxlist1  :checkbox[value='Select All']").prop("checked", true);
        
        localStorage.setItem("isDataLoaded", true);
    }
});

Haven't tested but it should work ;)

-KR

Palash Mondal_ · Answer 3 · 2015-09-24T21:18:00

Solution 3

In aspx code inside the page load event you can store the IsPostBack value like:

C#

ClientScript.RegisterClientScriptBlock(GetType(), "IsPostBack",
         String.Format("var IsPostBack = {0};", Page.IsPostBack.ToString().ToLower()), true);

And then in js code you can check it like

JavaScript

$(document).ready(function () {

    // For debugging purpose you can add a alert here like
    alert(IsPostback);

    if (!IsPostback) {

        // If not a post back then execute your logic here..
        $("#Checkboxlist1 :checkbox").attr('disabled', 'disabled');
        $("#Checkboxlist1  :checkbox[value='Select All']").removeAttr('disabled');
        $("#Checkboxlist1  :checkbox[value='Select All']").prop("checked", true);
    }
});

Let me know if you are still facing any issues.

UPDATE:

In aspx:

Add a hidden field like

ASP.NET

<asp:HiddenField ID="hfServerValue" runat="server" />

In cs (inside Page_Load):

C#

hfServerValue.Value = Page.IsPostBack.ToString().ToLower();

In js:

JavaScript

$(document).ready(function () {

    // For debugging purpose you can add a alert here like
    var IsPostback = $("[id$='hfServerValue']").val();
    IsPostback = (IsPostback == 'true');
    alert(IsPostback);

    if (!IsPostback) {

        // If not a post back then execute your logic here..
        $("#Checkboxlist1 :checkbox").attr('disabled', 'disabled');
        $("#Checkboxlist1  :checkbox[value='Select All']").removeAttr('disabled');
        $("#Checkboxlist1  :checkbox[value='Select All']").prop("checked", true);
    }
});

Let me know if it works!

Posted 24-Sep-15 21:18pm

Palash Mondal_

Updated 24-Sep-15 22:56pm

v4

Comments

waynetan123 25-Sep-15 3:25am

Hi! Here the error I received-0x800a1391 - JavaScript runtime error: 'IsPostback' is undefined @ if (!IsPostback)

Palash Mondal_ 25-Sep-15 3:35am

Hope you have added the first code in code behind. Also try replacing that with:


ScriptManager.RegisterStartupScript(this, this.GetType(), "IsPostBack", String.Format("var IsPostBack = {0};", Page.IsPostBack.ToString().ToLower()), true);

once.

waynetan123 25-Sep-15 3:44am

Hi I'm still receiving the same error

Palash Mondal_ 25-Sep-15 3:47am

ok, try this one:


ClientScript.RegisterStartupScript(GetType(), "IsPostBack", String.Format("var IsPostBack = {0};", Page.IsPostBack.ToString().ToLower()), true);

waynetan123 25-Sep-15 3:48am

sorry still the same error. From my research I roughly found out that if (postback) cant be used in javascript

Palash Mondal_ 25-Sep-15 4:08am

Give me sometime to figure out the issue here..

waynetan123 25-Sep-15 4:35am

yes sure. I have updated my question with another approach I tried but it still reloads during postback e.g when I click on submit button

Palash Mondal_ 25-Sep-15 4:39am

I have updated the code. Please try it out.

waynetan123 25-Sep-15 4:47am

Hi, I tried it. no error during debug but it does not do anything ( $("#Checkboxlist1 :checkbox").attr('disabled', 'disabled');
$("#Checkboxlist1 :checkbox[value='Select All']").removeAttr('disabled');
$("#Checkboxlist1 :checkbox[value='Select All']").prop("checked", true);) did not run on page load

waynetan123 25-Sep-15 4:49am

Do I have to put hfServerValue.Value = Page.IsPostBack.ToString().ToLower(); under if (!postback) or If(Postback) under pageload or just under pageload will do?

Palash Mondal_ 25-Sep-15 4:51am

Just under the page_load as we need to get the IsPostBack value here.

waynetan123 25-Sep-15 4:53am

yup I did that approach previously. Do you think there is a need to set value="" in apsx?

Palash Mondal_ 25-Sep-15 4:58am

Yup, got the issue. Ispostback value was coming as string, we need to convert it to boolean for it to work like `IsPostback = (IsPostback == 'true');`. I have also updated the code. try it out once.

waynetan123 25-Sep-15 5:47am

thanks for your previous help all these while

waynetan123 25-Sep-15 5:07am

I have solved my problem but another problem arise...

How do I change the settings of this function to make it run only during the 1st load of the webpage and not every postback?

3 solutions

Solution 1

Solution 2

Solution 3

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