How to mark a property as required in Swagger, without ASP.NET model validation?

Question

I am creating a public API that uses multiple private APIs (can not be accessed from outside). Business validations have been written for the private APIs and I do not want to re-write them for the public API. But I do want the swagger documentation to be the same.

That is why I wonder if I can mark property as mandatory, without using the Required attribute of ASP.NET. But that the swagger documentation indicates that it is mandatory. Is this possible?

Answer 1

Thanks to Mohsin, I solved my problem. The following I came up with, I created an attribute called SwaggerRequired. This attribute can be placed on any model. The AddSwaggerRequiredSchemaFilter then ensures that the Swagger documentation is modified. See below the code I wrote for this

A random model:

public class Foo
{
    [SwaggerRequired]
    public string FooBar{ get; set; }
}

The SwaggerRequiredAttribute:

[AttributeUsage(AttributeTargets.Property)] 
public class SwaggerRequiredAttribute : Attribute
{
}

And the AddSwaggerRequiredSchemaFilter to get it working:

public class AddSwaggerRequiredSchemaFilter : ISchemaFilter
{
    public void Apply(Swashbuckle.Swagger.Schema schema, SchemaRegistry schemaRegistry, Type type)
    {
        PropertyInfo[] properties = type.GetProperties();
        foreach (PropertyInfo property in properties)
        {
            var attribute = property.GetCustomAttribute(typeof(SwaggerRequiredAttribute));

            if (attribute != null)
            {
                var propertyNameInCamelCasing = char.ToLowerInvariant(property.Name[0]) + property.Name.Substring(1);

                if (schema.required == null)
                {
                    schema.required = new List<string>()
                    {
                        propertyNameInCamelCasing
                    };
                }
                else
                {
                    schema.required.Add(propertyNameInCamelCasing);
                }
            }
        }
    }
}