Jquery – ASP.NET MVC Listbox handling selected item events

asp.net-mvcjquery

I am using a HTML.ListBox within a view as such:

<%= Html.ListBox("projects", Model.Projects)  %>

This is populated with an IEnumerable<SelectListItem> in the model as such:

Projects = project.Select(a => new System.Web.Mvc.SelectListItem
        {
            Value = "foo",
            Text = a.project + "(" + a.count + ")",
            Selected = false
        });

        return Projects;

Which in turn is returned to the controller for passing into a strongly typed view.

My question is, how can I monitor for select item events? I need to be able to perform some action when the user makes a selection and/or de-selection.

Thanks.

Best Answer

If you're familiar with jQuery you can trap a change even and submit your FORM:

$('#projects').change(function () {
    $(this).parents('form').submit();
});

or you can use ajax to submit some data to an action

$('#projects').change(function () {
    $.ajax({
        type: 'POST',
        url: '<%=Url.Action("<action>", "<controller>")%>',
            data: { id: $('#projects').val() },
            dataType: 'json',
        complete: function(XMLHttpRequest, textStatus) {
            // Do something here.
            }
        });
});

UPDATE:

Since you're using jQuery Dropdown Check List you can trap the onItemClick even and call an action of your controller passing the value of the selected option and the status checked/non checked :

$("#projects").dropdownchecklist({
    emptyText: "select something",
    width: 150,
    onItemClick: function(checkbox, selector){
        var isChecked = checkbox.prop("checked");
        alert("element id: " + checkbox.prop("value"));

        $.ajax({
        type: 'POST',
        url: '<%=Url.Action("<action>", "<controller>")%>',
            data: { selecteId: checkbox.prop("value"), isChecked: isChecked },
            dataType: 'json',
        complete: function(XMLHttpRequest, textStatus) {
            // Do something here.
            }
        });
   }
});

You can have a look at this fiddle.

Related Solutions

Asp.net-mvc – Compile Views in ASP.NET MVC

From the readme word doc for RC1 (not indexed by google)

ASP.NET Compiler Post-Build Step

Currently, errors within a view file are not detected until run time. To let you detect these errors at compile time, ASP.NET MVC projects now include an MvcBuildViews property, which is disabled by default. To enable this property, open the project file and set the MvcBuildViews property to true, as shown in the following example:

<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    <MvcBuildViews>true</MvcBuildViews>
  </PropertyGroup>

Note Enabling this feature adds some overhead to the build time.

You can update projects that were created with previous releases of MVC to include build-time validation of views by performing the following steps:

Open the project file in a text editor.
Add the following element under the top-most <PropertyGroup> element: <MvcBuildViews>true</MvcBuildViews>
At the end of the project file, uncomment the <Target Name="AfterBuild"> element and modify it to match the following:

<Target Name="AfterBuild" Condition="'$(MvcBuildViews)'=='true'">
    <AspNetCompiler VirtualPath="temp" PhysicalPath="$(ProjectDir)\..\$(ProjectName)" />
</Target>

C# – How to create a dropdownlist from an enum in ASP.NET MVC

For MVC v5.1 use Html.EnumDropDownListFor

@Html.EnumDropDownListFor(
    x => x.YourEnumField,
    "Select My Type", 
    new { @class = "form-control" })

For MVC v5 use EnumHelper

@Html.DropDownList("MyType", 
   EnumHelper.GetSelectList(typeof(MyType)) , 
   "Select My Type", 
   new { @class = "form-control" })

For MVC 5 and lower

I rolled Rune's answer into an extension method:

namespace MyApp.Common
{
    public static class MyExtensions{
        public static SelectList ToSelectList<TEnum>(this TEnum enumObj)
            where TEnum : struct, IComparable, IFormattable, IConvertible
        {
            var values = from TEnum e in Enum.GetValues(typeof(TEnum))
                select new { Id = e, Name = e.ToString() };
            return new SelectList(values, "Id", "Name", enumObj);
        }
    }
}

This allows you to write:

ViewData["taskStatus"] = task.Status.ToSelectList();

by using MyApp.Common