mvc Archives - Taswar Bhatti

Was coding some new functionality and though I would post this, so that others can find it helpful. Lets say you have a form that has a checkbox that will update the select dropdown box with different values, when the checkbox is clicked. Something like the UI below. Your html code might look like

<input type="hidden" name="fieldId" value="123" />
Parent: <select name="FieldType" id="fieldTypeDropDown">
                        <option value="16">None</option>
                        <option value="4">Apple</option>
                        <option value="3">Orange</option>
                    </select>

Multiple: <input type="checkbox" name="fieldMultiple" id="fieldMultiple" />

Parent: <select name="FieldType" id="fieldTypeDropDown">

<option value="4">Apple</option>

<option value="3">Orange</option>

</select>

Multiple: <input type="checkbox" name="fieldMultiple" id="fieldMultiple" />

[…]

So I was going through some code of codebettercanvas and found it interesting of Karl Seguin using Html Helper extension for his form tags, which has its elegance. e.g

<form id="login" action="!{Html.LinkTo<HomeController>(c => c.Login()) }" method="post">

1	<form id="login" action="!{Html.LinkTo<HomeController>(c => c.Login()) }" method="post">

Basically it calls an extension method called LinkTo with a generic controller and a lamda for calling its action, the extension method looks like

public static class HtmlExtensions
    {

private static readonly string _applicationPath = HttpContext.Current.Request.ApplicationPath == "/" ? string.Empty : HttpContext.Current.Request.ApplicationPath;

//other method removed

public static string LinkTo(this HtmlHelper html, Expression<Func<T, ActionResult>> action)
        {
            var body = action.Body as MethodCallExpression;
            if (body == null)
            {
                throw new InvalidOperationException("Expression must be a method call");
            }
            var controller = typeof(T).Name.Replace("Controller", string.Empty);
            return string.Format("{0}/{1}/{2}", _applicationPath, controller, body.Method.Name);
        }
}

public static class HtmlExtensions

{

private static readonly string _applicationPath = HttpContext.Current.Request.ApplicationPath == "/" ? string.Empty : HttpContext.Current.Request.ApplicationPath;

//other method removed

public static string LinkTo(this HtmlHelper html, Expression<Func<T, ActionResult>> action)

{

var body = action.Body as MethodCallExpression;

if (body == null)

{

throw new InvalidOperationException("Expression must be a method call");

}

var controller = typeof(T).Name.Replace("Controller", string.Empty);

return string.Format("{0}/{1}/{2}", _applicationPath, controller, body.Method.Name);

}

[…]

ASP MVC, Jquery modifying a select drop down with Json data

Url Helper Extension Method for ASP MVC in form tags when using IIS 6

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