unable to retrieve controls generated from AJAX response

My web development stack includes ASP.NET C# with AJAX Professional (http://www.ajaxpro.info)

1) I am working on a scenario where I have a div container that holds a Panel control which should contain a dynamically generated DropDownList done in the codebehind function:

<div id="divDDL" runat="server">
    <asp:Panel ID="Panel1" runat="server">
    </asp:Panel>
</div>

2) There is a JavaScript function called "getDDL" that sends data to the codebehind function and then handles the response by updating the Panel with the generated DropDownList:

function getDDL(lng)
{
    MyCodebahindClass.GetDDL(0, lng, callbackDDL);
    //callbackDDL is a response function
}

function callbackDDL(response)
{
    //response containing the generated DropDownList and Panel control is updated in the div element
    document.getElementById('<%=divDDL.ClientID %>').innerHTML = response.value;
}

3) The codebehind function "GetDDL" needs to return the generated DropDownList within the Panel:

[Ajax.AjaxMethod]
public Panel GetDDL(int itemId, int lng)
{
     Panel panelID = Panel1.ID;
     DropDownList rubricDDL = new DropDownList();
     rubricDDL.ID = "Fashionable_Catheter";
     rubricDDL.DataTextField = "title";
     rubricDDL.DataValueField = "id";
     rubricDDL.DataSource = %LINQ STUFF%;
     rubricDDL.DataBind();

     panelID.Controls.Add(rubricDDL);
     return panelID;
}

4) However, I am facing an issue where when trying to access these controls through JS response, only "System.Web.UI.Design.Panel" or similar text is displayed. Interestingly, retrieving them directly from the codebehind works without any issues. What could be causing this discrepancy between accessing the controls via JS and codebehind? Your assistance would be greatly appreciated.

Answer №1

It appears that in order to view the panel, you must return the rendered HTML code within your method. Your function should output a string containing the rendered Panel Control before returning it.

Answer №2

[Ajax.AjaxMethod]
public string RetrieveDropdown(int item, int language)
{
    PanelIdentifier = Panel1.ID;
    DropDownList choicesDDL = new DropDownList();
    choicesDDL.ID = "Trendy_Tube";
    choicesDDL.DataTextField = "title";
    choicesDDL.DataValueField = "id";
    choicesDDL.DataSource = %LINQ THINGS%;
    choicesDDL.DataBind();
    panelID.Controls.Add(choicesDDL);
    StringBuilder stringBuilder = new StringBuilder();
    HtmlTextWriter htmlWriter = new HtmlTextWriter(new StringWriter(stringBuilder));
    panelID.RenderControl(htmlWriter);
    return stringBuilder.ToString(); 
}

Display the ajax response in control.html like this:

(e.g.) div1.html(ajaxresponseoutput)

Similar questions

If you have not found the answer to your question or you are interested in this topic, then look at other similar questions below or use the search

What is the best way to customize Node.js configuration when it is executed through npm?

Check out this documentation on node config: node myapp.js --NODE_CONFIG='{"Customer":{"dbConfig":{"host":"customerdb.prod"}}}' However, if I run a npm script, all parameters will be passed to npm instead of nodejs, right? How can I pass the -- ...

Looking for a way to merge PDF files using an API?

I'm working on a web application that allows users to upload PDF files. I'm trying to find a way to add an additional PDF to the one uploaded by the user, but I haven't been able to solve this task yet. I'm wondering if there's an ...

Retrieve data from each URL listed in a JSON array using React

My json file structure was as follows: [ { "name": "google", "route": "/google", "url": "www.google.com" }, { "name": "bing", "route": " ...

What is the most efficient way to retrieve the operating system's name and version using JavaScript?

I'm in the process of developing an object that will simplify accessing browser and system information by implementing a function. One particular function within this object is responsible for retrieving the operating system name and version, returnin ...

Developing versatile form elements with Formik and the Yup library for React and Vite

I'm currently working on a React and Vite project where I'm trying to implement reusable form components using Formik and Yup, but I haven't been able to achieve it yet. I've created a component called <AppInputField/>, which is e ...

Issue encountered: The differ cannot recognize the provided object '[object Object]', which is of type 'object'. NgFor is limited to binding Iterables only

I have been following a tutorial on Ionic created by Paul Halliday, focusing on a shopping list project that utilizes Firebase and Angular. However, I am encountering an error every time I try to run the application: Error: Uncaught (in promise): Error: ...

What is the best location for storing shared functions in an express.js application?

Where should common functions be located in the express structure to be used across multiple routes? Are there any recommended best practices for this? The documentation does not provide any guidance on the matter. ...

Timeout for AngularJS Bootstrap UI Modal

I am having some trouble with opening a bootstrap modal using the $timeout function. The issue I am facing is that the modal keeps opening multiple times as the timeout fires repeatedly. Any assistance or suggestions on how to resolve this problem would be ...

Dynamic method for duplicating textboxes and checkboxes with repeaters

Currently, I am facing a challenge in my application. Here is the scenario: At first, I need to display two text boxes along with a checkbox and a button. When the button is clicked, another row should be generated dynamically. This process should continu ...

What makes YouTube videos load quicker on Chrome compared to Firefox?

After working as a Java UI & Backend developer for the past decade, I have come across some surprising browser behaviors: Firefox: When clicking on a related video on the YouTube website, there is a delay in figuring out the video followed by buffering ...

Display an input field in VueJS with a default value set

Dealing with a form containing various editable fields, I devised a solution. By incorporating a button, clicking it would conceal the label and button itself, while revealing a text box alongside a save button. The challenge lays in pre-filling the textbo ...

Chat Bot - EmbedMessage

JavaScript is still very new to me and I find the actual code quite challenging to grasp. However, I do have one specific question - how can I display the "cahbResponses" in a MessageEmbed? Despite consulting the Discord JS guides on MessageEmbeds, I' ...

How can items be categorized by their color, size, and design?

[{ boxNoFrom: 1, boxs: [{…}], color: "ESPRESSO", size: "2X", style: "ZIP UP" { boxNoFrom: 13, boxs: [{…}], color: "ESPRESSO", size: "2X", style: "ZIP UP" }, { boxNoFrom: ...

Submitting a form and using Ajax to upload an image

Is there a way to submit an image file to php using ajax without assigning the file to a variable with onchange event? I've tried triggering the request on submit click, but keep getting the error message: "cannot read property 0 of undefined." <ht ...

Transforming JSON data to an HTTPResponse Message

Struggling to convert the content of a response message into a list of items within the response message, I am facing issues with the returned JSON data: Jason output The complete response content is as follows: { "Version": 1, ... I wa ...

Neglecting a light source in the Three.js framework

Currently, I am in the process of constructing a 3D hex grid and my goal is to integrate a fog of war feature. This is a glimpse of what the grid looks like at present: The lighting setup I have arranged is as follows: // Setting up hemisphere light var ...

Elastic_Frame | "Error: Unable to process action as property 'toLowerCase' is not defined"

Attempting to create a personal and project portfolio using Vu Khanh Truong's "elastic_grid" jQuery plugin for the actual portfolio. You can access it here. However, encountering some issues on my page: 1) The header for the portfolio section disappe ...

Console log displays varied outputs for identical arrays

Having an array in a static form and one that is filled using the ajax post function, I initially planned to replace the static array with the dynamic one. However, upon closer inspection, it seems that the two arrays are not matching. Array 1 (static) ...

Creating a bouncy 3D sphere with THREE.js

Hello everyone, I am just getting started with THREE.js and have a few questions... I'm wondering if anyone can assist me with implementing a feature where the ball gets squished when it contacts the border and changes direction? Perhaps even scaling ...

Retrieve the data from the load file using jQuery

I have a JavaScript function that loads content as a lightbox and passes a value to the loaded file. Here is the code: $(document).ready(function() { $(".jq_btn_preview").click(function() { gl_popup_id = "#popup_content"; show_loader() ...