MVC metatdataprovider and html helpers - asp.net

Question

I have my own implementation of the metadataprovider, in it a check for my custom attribute and get the metadata from the database.
public class EntityPropertyMetadataAttribute: Attribute
{
[MaxLength(256)]
public string EntityFullName { get; set; }
[MaxLength(64)]
public string PropertyName { get; set; }
public string DisplayName { get; set; }
public string DisplayFormatString { get; set; }
public string EditFormatString { get; set; }
public object DefaultValue { get; set; }
}
Now I observed the following if I have a View like this:
<div class="editor-label">
#Html.LabelFor(model => model.Id)
</div>
<div class="editor-field">
#Html.EditorFor(model => model.Id)
#Html.ValidationMessageFor(model => model.Id)
</div>
The function
protected override ModelMetadata CreateMetadata(IEnumerable<Attribute> attributes, Type containerType, Func<object> modelAccessor, Type modelType, string propertyName)
gets called 3 times for property Id, if I remove one for example:
<div class="editor-field">
#Html.EditorFor(model => model.Id)
#Html.ValidationMessageFor(model => model.Id)
</div>
it gets called 2 times.
Now when I use this:
#using (Html.BeginForm()) {
#Html.ValidationSummary(true)
#Html.EditorForModel(Model)
<p>
<input type="submit" value="Create" />
</p>
}
CreateMetadata gets called a whopping 22 for each property in the model.
That's not really what you want performance wise. Probably I should hook up the DB code (currently inside CreateMetadata method) somewhere else.
any suggestion appreciated.
cheers

Answer 1

Ok finally on the right track with a bit of help from MVC extensions
http://mvcextensions.codeplex.com/SourceControl/changeset/view/f71bcadf0e76#Trunk%2fMvcExtensions%2fModelMetadata%2fModelMetadataRegistry.cs
In my case I shouldn't override
protected override ModelMetadata CreateMetadata(IEnumerable<Attribute> attributes, Type containerType,
Func<object> modelAccessor, Type modelType, string propertyName)
from DataAnnotationsModelMetadataProvider but override the Get methods from AssociatedMetadataProvider like this one:
public override IEnumerable<ModelMetadata> GetMetadataForProperties(object container, Type containerType)
And put hte database calls there.