Design Pattern - Creational - Builder

Scenario:

Create a custom CheckBox.

Solution:

Creational Pattern to separate the construction from representation, so same process to construct can give us different representation. 

Example: Create a custom checkbox, with additional attributes and enable/disable based on permissions for the user

1. Take the label of checkbox, attributes and claim (permission) as input and then build the checkbox using builder pattern based on conditions:
   



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public static MvcHtmlString CheckBox(this HtmlHelper helper, string label, string claim, string httpMethod,
            object htmlAttributes)
{
            var builder = new TagBuilder("input");

            builder.MergeAttributes(new RouteValueDictionary(htmlAttributes));
            builder.MergeAttribute("type", HtmlHelper.GetInputTypeString(InputType.CheckBox));
            if (IsAuthorized(claim, httpMethod) &&
                !htmlAttributes.ToString().Contains("disabled"))
            {
                builder.Attributes.Add("disabled", "disabled");
            }

            builder.InnerHtml = label;
            return MvcHtmlString.Create(builder.ToString(TagRenderMode.Normal));
}



2. Below is cshtml caller to render the checkbox using the above helper class



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<tr>
    <td class="">
        @Html.CheckBox("Delete User", "DeleteUser", "POST", new { name = "selectedDeleteUser", value = "1" })
    </td>
</tr>