How to Effortlessly Populate Cascading Dropdowns in ASP.Net MVC 5 using a Reusable

Question

How to Effortlessly Populate Cascading Dropdowns in ASP.Net MVC 5 using a Reusable

I am currently working on an ASP.Net MVC 5 application that has multiple edit pages. Each edit page consists of various input elements such as textboxes, checkboxes, and dropdowns. I want to implement a functionality where the values of one dropdown are changed based on the selected values of another dropdown.

In order to achieve this, I aim to create a reusable and generic JavaScript function that will make an AJAX call with specific parameters and update the content of a designated HTML tag with the result (either HTML or JSON).

Considering the high probability of someone else already having similar requirements, I don't want to reinvent the wheel. Is there any existing solution or jQuery plugin available for accomplishing this task that I might have missed while searching?

To be more specific, here is my envisaged approach:

Input parameters:

Ajax URL to invoke the necessary controller action
Arguments to send to the controller (by default, it should include the selected value of the first dropdown, but there may be cases where additional values or even the entire form needs to be sent)
Target: A jQuery selector indicating the HTML element where the resulting HTML should be placed
(Possibly other parameters: configuring the request method as POST or GET; specifying whether the target should be added or replaced; defining OnSuccess/OnError handlers; etc.)

I initially thought that jQuery Unobtrusive would provide something like this, but unfortunately, it doesn't meet my requirements.

(I am not using any JavaScript frameworks like Knockout or AngularJS, and I don't want to introduce them solely for this specific functionality.)

javascript jquery ajax asp.net-mvc-5

Answer 1

Answer №1

I would suggest creating your own solution for this task. One approach could be to develop a function that takes in parameters such as the post URL, newly selected value, and step number. This function can then return a JSON list of values which can be used to populate the next dropdown menu.

Here is an example implementation:

<select name="Countries" multiple="multiple">
    <option value="USA">United States</option>
    <option value="UK">United Kingdom</option>
    <option value="JP">Japan</option>
</select>
<select name="Cities">
</select>

.... // later inside the script

var fetchStepOptions = function(postUrl, newSelectValue, currentStep){
    var postData = {
        NewSelectValue: newSelectValue,
        CurrentStep: currentStep
    }

    $.ajax(
    {
        type: "POST",
        data: JSON.stringify(postData),
        url: "postUrl",
        contentType: 'application/json; charset=utf-8'
    }).done(function(values) {
        return values; // parsing may be required
    })
    .fail(function() {
        return ["failed"];
    });
}

var updateSelectedValues = function($select, selectedVal, step){
    $select.empty();
    var newSelectVals = fetchStepOptions("fetchOptionValuesUrl", selectedVal, step);
    $.each(newSelectVals, function(val){
        $select.append($("<option></option>")
            .attr("value", val).text(val));
    });
}

$("[name='Countries']").click(function(e) {
    var $selectToModify = $("[name='Cities']");

    updateSelectedValues($selectToModify, $selectToModify.val(), 1);
}

Please note that I wrote this code directly in this window without executing it, so there may be potential errors. If I have time, I might run the code later and make any necessary corrections.

Answer 2

I would suggest creating your own solution for this task. One approach could be to develop a function that takes in parameters such as the post URL, newly selected value, and step number. This function can then return a JSON list of values which can be used to populate the next dropdown menu.

Here is an example implementation:

<select name="Countries" multiple="multiple">
    <option value="USA">United States</option>
    <option value="UK">United Kingdom</option>
    <option value="JP">Japan</option>
</select>
<select name="Cities">
</select>

.... // later inside the script

var fetchStepOptions = function(postUrl, newSelectValue, currentStep){
    var postData = {
        NewSelectValue: newSelectValue,
        CurrentStep: currentStep
    }

    $.ajax(
    {
        type: "POST",
        data: JSON.stringify(postData),
        url: "postUrl",
        contentType: 'application/json; charset=utf-8'
    }).done(function(values) {
        return values; // parsing may be required
    })
    .fail(function() {
        return ["failed"];
    });
}

var updateSelectedValues = function($select, selectedVal, step){
    $select.empty();
    var newSelectVals = fetchStepOptions("fetchOptionValuesUrl", selectedVal, step);
    $.each(newSelectVals, function(val){
        $select.append($("<option></option>")
            .attr("value", val).text(val));
    });
}

$("[name='Countries']").click(function(e) {
    var $selectToModify = $("[name='Cities']");

    updateSelectedValues($selectToModify, $selectToModify.val(), 1);
}

Please note that I wrote this code directly in this window without executing it, so there may be potential errors. If I have time, I might run the code later and make any necessary corrections.

How to Effortlessly Populate Cascading Dropdowns in ASP.Net MVC 5 using a Reusable

Answer №1

Similar questions

Required Field Validation - Ensuring a Field is Mandatory Based on Property Length Exceeding 0

Incorporating an external HTML page's <title> tag into a different HTML page using jQuery

PhantomJS Karma encountering SyntaxError when trying to export variables

What could be causing the fourth tab to not show any data while the first three tabs are functioning as expected?

What are the differences between a Chrome app and extension? Is there any other way to access the tabs currently open in your

Retrieve file from Ajax request within MVC C# Application

Using Vue.js to dynamically calculate elapsed time

Updating Text within a Label with jQuery

Shopify's Ajax Cart experiences persistent loading issues when attempting to insert an <img> element within the code

Vue and Vuex retrieve state data from the server in a single request

What is the most effective way in MongoDB to insert data only if it does not already exist in the database?

Utilizing styled-components or personalized components alongside cypress

Storing input values in the state using Typescript by default

Creative jQuery hover effects tailored to the size of the viewport

What is the process of setting up various initialization parameters for a DataTable?

How can I personalize the color of a Material UI button?

What is the correct way to navigate data through my Node.js API?

Update a separate React component in response to the interaction with a different React component

Bringing the value from the codebehind to the jquery function on the client side

Guide to extracting the values associated with a specific key across all elements within an array of objects