Many of my model object inherit from a class called AuditedEntity that tracks the changes to the object. I would like to have my model objects that inherit from AuditedEntity automatically have the appropriate fields populated when constructed during the model binding process. I have been looking into sub-classing the default model binder, but wit开发者_如何转开发hout much luck.
Can anyone point me in the correct direction?
Are these properties are populated with known values, or values from a good source. Or are these properties populated with values dependant on values from form/route/query etc?
Subclassing the DefaultModelBinder should be fine, e.g.:
public class MyModel
{
public string Forename { get; set }
public string SomeSpecialProperty { get; set; }
}
public MyModelBinder : DefaultModelBinder
{
public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
var model = (MyModel)base.BindModel(controllerContext, bindingContext);
model.SomeSpecialProperty = // Do something here...
return model;
}
}
ModelBinder.Binders[typeof(MyModel)] = new MyModelBinder();
What have you found so far?
I ended up having to rely on all the data having been bound. This was the solution I ended up using. placing the code in OnModelUpdated allowed me to rely on the other properties having been set.
public class AuditedEntityModelBinder : DefaultModelBinder
{
protected override void OnModelUpdated(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
if (bindingContext.ModelType.IsSubclassOfGeneric(typeof(AuditedEntity<>)))
{
string name = controllerContext.HttpContext.User.Identity.Name;
if(!name.IsNullOrEmpty())
{
if((bool) bindingContext.ModelType.GetProperty("IsNew").GetValue(bindingContext.Model, null))
{
bindingContext.ModelType.GetProperty("CreatedBy").SetValue(bindingContext.Model, name, null);
bindingContext.ModelType.GetProperty("Created").SetValue(bindingContext.Model, DateTime.Now, null);
}
else
{
bindingContext.ModelType.GetProperty("ModifiedBy").SetValue(bindingContext.Model, name, null);
bindingContext.ModelType.GetProperty("Modified").SetValue(bindingContext.Model, DateTime.Now, null);
}
}
}
base.OnModelUpdated(controllerContext, bindingContext);
}
}
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