ASP.NET user control executes C# but fails to trigger JavaScript or jQuery functions

Other Questions JavaScript
1

I’m developing an ASP.NET application and have encountered an issue with my user control. While the user control loads up fine on the main page and the C# backend executes without any problems, the JavaScript and jQuery functions contained within the control are not functioning at all.

The debugger shows that the page load event is firing, and the C# code is running properly. However, my jQuery function FETCH_PROJECTS_DATA is never called, which is very frustrating because I need both server-side and client-side code to communicate effectively.

Here’s how I have set up my main page:

<%@ Page Title="" Language="C#" MasterPageFile="~/WebPages/masterPage.Master" AutoEventWireup="true" CodeBehind="mainPage.aspx.cs" Inherits="MyWebApp.WebPages.mainPage" EnableEventValidation="false" %>

<%@ Register Src="~/UserControls/UserControl_Projects.ascx" TagPrefix="uc" TagName="UserControl_Projects" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
    <uc:UserControl_Projects runat="server" />
</asp:Content>

And here’s the code for my user control:

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="UserControl_Projects.ascx.cs" Inherits="MyWebApp.UserControls.UserControl_Projects" %>
<div class="dashboard-container">
    <div class="dashboard-content">
        <div id="projects-card" class="card">
            <div class="card-header">
                <h4 class="card-title text-center">
                    <label id="projLabel" runat="server" clientidmode="Static">Projects Overview</label>
                </h4>
            </div>
            <div class="card-body">
                <div class="row">
                    <div class="col-md-6 project-table">
                        <div class="table-card">
                            <div class="table-header">
                                Ongoing Projects
                            </div>
                            <div class="table-body">
                                <table id="ongoingProjects" class="table table-bordered">
                                    <thead></thead>
                                    <tbody></tbody>
                                </table>
                            </div>
                        </div>
                    </div>
                    <div class="col-md-6 project-table">
                        <div class="table-card">
                            <div class="table-header">
                                Completed Projects
                            </div>
                            <div class="table-body">
                                <table id="completedProjects" class="table table-bordered">
                                    <thead></thead>
                                    <tbody></tbody>
                                </table>
                            </div>
                        </div>
                    </div>
                </div>
            </div>
        </div>
    </div>
</div>

<script>
    $(document).ready(function () {
        if ($("#userPerm").val() == "admin") {
            FETCH_PROJECTS_DATA();
        }
    });
</script>

What might be preventing the JavaScript from running when the user control is loaded?

2

maybe jQuery loads too late or not at all. try putting your script at the end of your main page or use ScriptManager.RegisterStartupScript in codebehind. should help!

3

This happens because jQuery isn’t loaded before your script runs. User controls don’t inherit script references from the master page automatically. You’ve got two options: add the jQuery script reference directly in your user control, or register it in code-behind with Page.ClientScript.RegisterClientScriptInclude. Also double-check that the ‘userPerm’ element actually exists when your script runs - if it’s defined somewhere else on the page, it might not be ready at document ready time. I’ve hit this exact issue migrating legacy controls. Fixed it by adding explicit jQuery registration in the UserControl’s Page_Load event.

4

Had the same issue with user controls in webforms. Your script’s probably running before the DOM elements load. User controls inside master pages create timing conflicts with document ready. Try two things: wrap your script in setTimeout with a small delay, or move the script block to the bottom of your user control after the HTML elements. Also check if FETCH_PROJECTS_DATA is actually defined and accessible. If it’s in the master page or main page, your user control might not see it because of scoping issues.