MVC3 Html.DisplayFor -- Is it possible to have this control generate an ID?

Question

I want to be able to display some text, but also have the text be modifiable via jQuery.

<%= Html.DisplayFor(model => model.DeviceComponentName)%>

If I used EditorFor instead of DisplayFor I would see an ID for the input control. I do not want the value to be editable in that way, though. So, I have made it a DisplayFor, but it does not generate an ID property for the element.

Should I just wrap the DisplayFor in a div and do something like:

<div id="<%= ViewData.TemplateInfo.GetFullHtmlFieldName("DeviceComponentName") %>">
    <%= Html.DisplayFor(model => model.DeviceComponentName)%>
</div>

$('#DeviceComponentName').text('newValue');

Or is there a cleaner way of achieving this?

Update: Is there a way which doesn't depend on hard-coded strings? Something that ties to the object itself so if my property name changes I'd get a compile error?

Also, I am using this code, but I do not see an ID value appear:

<td class="editableValue">
    <%--Label should be editable, so it needs an ID, but only will be edited by jQuery so it can't be an EditorFor--%>
    <%= Html.DisplayFor(model => model.DeviceComponentName, new { id = "DeviceComponentName" })%>
    <button type="button" id="ComponentTreeButton" class="nestedDialogButton">...</button>
</td>

Answer 1

To avoid 'magic string' inputs (in case your model properties change), you could do this with an extension. It also makes for much cleaner code:

public static MvcHtmlString DisplayWithIdFor<TModel, TValue>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TValue>> expression, string wrapperTag = "div")
{
    var id = helper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldId(ExpressionHelper.GetExpressionText(expression));
    return MvcHtmlString.Create(string.Format("<{0} id=\"{1}\">{2}</{0}>", wrapperTag, id, helper.DisplayFor(expression)));
}

Then simply use it like this:

@Html.DisplayWithIdFor(x => x.Name)

Will produce

<div id="Name">Bill</div>

Or if you want it to be wrapped in a span:

@Html.DisplayWithIdFor(x => x.Name, "span")

Which will make:

<span id="Name">Bill</span>

Non-Razor

For non Razor syntax, you simply use it like this:

<%= Html.DisplayWithIdFor(x => x.Name) %>

and:

<%= Html.DisplayWithIdFor(x => x.Name, "span") %>

Answer 2

you must be use:

Html.DisplayFor(model => model.DeviceComponentName, new { @id = "DeviceComponentName"})

For dynamic id and other properties, i use:

Class for metadata:

public class AdditionalHtml : Attribute, IMetadataAware
{
    public string Id { get; set; }

    public string Type { get; set; }

    public string CssClass { get; set; }

    public string PlaceHolder { get; set; }

    public string Style { get; set; }

    public string OnChange { get; set; }

    public int Rows { get; set; }

    public int MaxLength { get; set; }

    public bool ReadOnly { get; set; }

    public bool Disabled { get; set; }

    public Dictionary<string, object> OptionalAttributes ()
    {
        var options = new Dictionary<string, object>();

        if ( !string.IsNullOrWhiteSpace( Id ) )
            options.Add( "id", Id );

        if ( !string.IsNullOrWhiteSpace( Type ) )
            options.Add( "type", Type );

        if ( !string.IsNullOrWhiteSpace( CssClass ) )
            options.Add( "class", CssClass );

        if ( !string.IsNullOrWhiteSpace( PlaceHolder ) )
            options.Add( "placeholder", PlaceHolder );

        if ( !string.IsNullOrWhiteSpace( OnChange ) )
            options.Add( "onchange", OnChange );

        if ( !string.IsNullOrWhiteSpace( Style ) )
            options.Add( "style", Style );

        if ( Rows != 0 )
            options.Add( "rows", Rows );

        if ( MaxLength != 0 )
            options.Add( "maxlength", MaxLength );

        if ( ReadOnly )
            options.Add( "readonly", "readonly" );

        if ( Disabled )
            options.Add( "disabled", "disabled" );

        return options;
    }

Class for metadata provider:

public class MetadataProvider : DataAnnotationsModelMetadataProvider
{
    protected override ModelMetadata CreateMetadata ( IEnumerable<Attribute> attributes, Type containerType, Func<object> modelAccessor, Type modelType, string propertyName )
    {
        var metadata = base.CreateMetadata( attributes, containerType, modelAccessor, modelType, propertyName );

        var additionalHtmlValues = attributes.OfType<AdditionalHtml>().FirstOrDefault();

        if ( additionalHtmlValues != null )
        {
            metadata.AdditionalValues.Add( "AdditionalHtml", additionalHtmlValues );
        }

        return metadata;
    }
}

Add helper:

public static class HtmlAttributesHelper
{
    public static string GetHtmlAttribute<T> ( this T model, Expression<Func<T, object>> expression, string attribName )
    {
        string strDefault = String.Empty;
        MemberInfo member = null;

        switch ( expression.Body.NodeType )
        {
            case ExpressionType.Lambda:
            case ExpressionType.Convert:
                {
                    var body = expression.Body as UnaryExpression;
                    if ( body == null )
                        return strDefault;
                    var operand = body.Operand as MemberExpression;
                    if ( operand == null )
                        return strDefault;
                    member = operand.Member;
                    break;
                }
            case ExpressionType.MemberAccess:
                {
                    var body = expression.Body as MemberExpression;
                    if ( body == null )
                        return strDefault;
                    member = body.Member;
                    break;
                }
            default:
                {
                    return expression.Body.ToString() + " " + expression.Body.NodeType.ToString();
                }
        }

        if ( member == null )
            return strDefault;

        var attr = member.GetCustomAttributes( typeof( AdditionalHtml ), false );
        if ( attr.Length > 0 )
        {
            return ( attr [ 0 ] as AdditionalHtml ).OptionalAttributes() [ attribName.ToLower() ].ToString();
        }

        // Return Name of Property if AdditionalHtml.Id is empty
        return attribName == "Id" ? member.Name : strDefault;
    }

    public static string GetHtmlId<T> ( this T model, Expression<Func<T, object>> expression )
    {
        return model.GetHtmlAttribute( expression, "Id" );
    }
}

Register provider in Global.asax:

protected void Application_Start ()
    {
        AreaRegistration.RegisterAllAreas();

        //....
        ModelMetadataProviders.Current = new MetadataProvider();
    }

In your model u can use AdditionHtml like as:

[AdditionalHtml( Id = "OrderNo", CssClass = ShortTextStyle, Disabled = true )]
    public string OrderNo { get; set; }

And now you can use sintax for js (in view):

$('#@Model.GetHtmlId( x => x.PropertyName)')

And in view, you can use:

@Html.DisplayFor( x => x.FormDate )

Html attributes attached automatically

Answer 3

Just add a HiddenFor above the column. This will give you a ID to use for what you need. Simple and does the trick for you to grab that value by ID.

<%= Html.HiddenFor(model => model.DeviceComponentName)%>
<%= Html.DisplayFor(model => model.DeviceComponentName)%>

Answer 4

HtmlHelpers have overrides that allow you to pass in an object, or a dictionary, to add attributes to the generated html tag:

@Html.DisplayFor(model => model.DeviceComponentName, new { id = "myId" })

@Html.DisplayFor(model => model.DeviceComponentName, new Dictionary<string, object>() { { "id", "myId" } })

or

@Html.DisplayFor(model => model.DeviceComponentName, new { id = ViewData.TemplateInfo.GetFullHtmlFieldName("DeviceComponentName") })

@Html.DisplayFor(model => model.DeviceComponentName, new Dictionary<string, object>() { { "id", ViewData.TemplateInfo.GetFullHtmlFieldName("DeviceComponentName" } })

UPDATE:

After reviewing the updated code, and re-reading the question, here is what I would suggest - which is similar to your first idea.

<td class="editableValue" id="<%= ViewData.TemplateInfo.GetFullHtmlFieldName("DeviceComponentName") %>">
  <%= Html.DisplayFor(model => model.DeviceComponentName)%>
  <button type="button" id="ComponentTreeButton" class="nestedDialogButton">...</button>
</td>

You shouldn't need to add an extra div inside the TD, because you can modify the value within the td directly via the jQuery. I believe the following should accomplish this:

$('#DeviceComponentName').html('newValue');