Check from razor view if derived System.ComponentModel.DataAnnotations.ValidationAttribute exists

Question

I'm implementing Html.EditorForModel() so that it's Bootstrap friendly. I have editor templates for all the data types, and one, Object.cshtml, that wraps each editor template with <div class="form-control"></div> etc.

The issue is that when I have a property on a model that is marked as [ComplexType], I want to then list each property of the child class. This works fine, however, for [DataType(DataType.Upload)], which is an HttpPostedFileBase data type, prop.IsComplexType sees that as a complex data type and ends up listing its properties rather than rendering <input type="file" />

Here's Object.cshtml:

@model dynamic

@{
    var modelMetaData = ViewData.ModelMetadata;
    var properties = modelMetaData.Properties;
}

@foreach (var prop in properties.Where(p => p.ShowForEdit))
{
string propertyName = prop.PropertyName;

if (prop.TemplateHint == "HiddenInput")
{
    @Html.Hidden(propertyName)
}
else
{
    if (prop.IsComplexType)
    {
        <fieldset>
            <legend>@propertyName</legend>
            <div class="mt-ml-2em">
                @foreach (var subProp in prop.Properties)
                {
                    var propertyName1 = subProp.PropertyName;
                    string fullname = propertyName + "." + propertyName1;

                    <div class="form-group">
                        @Html.BootstrapLabel(propertyName1)
                        @Html.Editor(fullname, MyHelpers.TemplateHelpers.GetTemplateForProperty(subProp))
                        <p class="help-block">@subProp.Description</p>
                        @Html.ValidationMessage(fullname, new { @class = "color-red" })
                    </div>
                }
            </div>
        </fieldset>
    }
    else
    {
        <div class="form-group">
            @Html.BootstrapLabel(propertyName)
            @Html.Editor(propertyName, MyHelpers.TemplateHelpers.GetTemplateForProperty(prop))
            <p class="help-block">@prop.Description</p>
            @Html.ValidationMessage(propertyName, new { @class = "color-red" })
        </div>
    }
}

}

My razor view:

@model MyMvc45Template.Areas.SampleTests.Models.Product
@{
    ViewBag.Title = "ForModel";
}

@*<h2>BsFormGroupFor</h2>
@Html.BsFormGroupFor(m => m.ProductName)*@

<h2>For Model Test</h2>
@using (Html.BeginForm("ForModel", "FormTests", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
    @Html.EditorForModel()

    <div class="form-group">
        <input type="submit" value="Save" class="btn btn-success" />
    </div>
}

And my sample classes:

public class Product
{
    public int Id { get; set; }

    [DataType(DataType.EmailAddress)]
    public string Email { get; set; }

    [HasChildProperties] //I am thinking I can use this custom ValidationAttribute as a flag in Object.cshtml
    public Address Address { get; set; }

    [DataType(DataType.PhoneNumber)]
    public string Phone { get; set; }

    [DataType(DataType.Upload)]
    public HttpPostedFileBase File { get; set; }

    [DataType(DataType.Url)]
    public string Url { get; set; }
}

Address class:

[ComplexType]
public class Address
{
    [Display(Description = "This is the help block text")]
    public string Line1 { get; set; }
    public string Line2 { get; set; }
    public string City { get; set; }
}

And what the output looks like:

As the image shows, my File property ends up having its members listed rather than rendering my Upload.cshtml:

@model dynamic
@Html.TextBox("", ViewData.TemplateInfo.FormattedModelValue,
new { @class = "form-control", placeholder = ViewData.ModelMetadata.Watermark, 
type = "file" })

I was thinking I could use this ValidationAttribute as a flag in Object.cshtml:

/// <summary>
/// This will make the editor template for Object.cshtml list any child properties in an edit form
/// </summary>
public class HasChildProperties : ValidationAttribute
{

}

But I can't find my custom ValidationAttribute in the metadata. How can I access this attribute? Is there a more elegant solution?

Answer 1

I ended up using UIHint:

[UIHint("HasChildProperties")]
public Address Address { get; set; }

if (prop.TemplateHint == "HasChildProperties") {...}