Passing an object to HTML attributes

Question

How to pass an object to HTML attributes? For example I have the following code:

var attrs = new { id = \"myid\", style = \"color: Red;\" };

<

Answer 1

You do not need to convert to a string. The last paramater for HTML Helpers is an Object. You just give it the object like you have written above:

For exmample

@Html.TextBoxFor(x => x.Foo, new { size = 10, maxlength = 10 }) 
@Html.TextAreaFor(x => x.Notes, new { @class = "additionalInfo" })
@Html.TextBoxFor(x=>x.Registration.Address.Postcode, new {type="number", @class="postcode numeric", size=5, maxlength=5})

on a side note you probably should not be setting styles directy inline with your HTML and use a CSS class/selector instead with a seperate style sheet. Also the ID of each DOM element should automatically be set when you use MVC HTML helpers

Answer 2

This functionality is, surprisingly enough, provided by the RouteValueDictionary class:

IDictionary<string, object> htmlAttributes = new RouteValueDictionary(attrs);

You can then use this dictionary in conjunction with a TagBuilder, which you will probably be using anyway:

var tagBuilder = new TagBuilder("input");
tagBuilder.MergeAttributes(htmlAttributes);
tagBuilder.ToString(TagRenderMode.Normal);

You can see this done in the ASP.NET MVC source code itself; one of the simpler examples is in TextAreaExtensions.cs.

EDIT:

In order to properly convert "data_attr" to "data-attr", use the AnonymousObjectToHtmlAttributes static method.

IDictionary<string, object> htmlAttributes = HtmlHelper.AnonymousObjectToHtmlAttributes(attrs);

Answer 3

Here's how to do this conversion :

var htmlAttributes = new { id="myid", @class="myclass" };

string string_htmlAttributes = "";
foreach (PropertyDescriptor property in TypeDescriptor.GetProperties(htmlAttributes))
{
  string_htmlAttributes += string.Format("{0}=\"{1}\" ", property.Name.Replace('_', '-'), property.GetValue(htmlAttributes));
}

PropertyDescriptor belong to the class System.ComponentModel