Prevent Azure TableEntity property from being serialized in MVC 4 WebAPI

Question

So I have a Model Subscription which inherits from Azure's TableEntity class for use in a WebApi Get method as follows:

[HttpGet]
public IEnumerable<Subscription> Subscribers()

In this method, I do a Select query on my subscribers table to find all subscribers, but I only want to return a few of the columns (properties) as follows:

var query = new TableQuery<Subscription>().Select(new string[] {
    "PartitionKey", 
    "RowKey", 
    "Description", 
    "Verified"
    });

The definition for the model is below:

public class Subscription : TableEntity
{
    [Required]
    [RegularExpression(@"[\w]+",
     ErrorMessage = @"Only alphanumeric characters and underscore (_) are allowed.")]
    [Display(Name = "Application Name")]
    public string ApplicationName
    {
        get
        {
            return this.PartitionKey;
        }
        set
        {
            this.PartitionKey = value;
        }
    }

    [Required]
    [RegularExpression(@"[\w]+",
     ErrorMessage = @"Only alphanumeric characters and underscore (_) are allowed.")]
    [Display(Name = "Log Name")]
    public string LogName
    {
        get
        {
            return this.RowKey;
        }
        set
        {
            this.RowKey = value;
        }
    }

    [Required]
    [EmailAddressAttribute]
    [Display(Name = "Email Address")]
    public string EmailAddress { get; set; }

    public string Description { get; set; }

    public string SubscriberGUID { get; set; }

    public bool? Verified { get; set; }
}

The following is the XML response of the API query:

<ArrayOfSubscription>
    <Subscription>
        <ETag>W/"datetime'2013-03-18T08%3A54%3A32.483Z'"</ETag>
        <PartitionKey>AppName1</PartitionKey><RowKey>Log1</RowKey>
        <Timestamp>
            <d3p1:DateTime>2013-03-18T08:54:32.483Z</d3p1:DateTime>
            <d3p1:OffsetMinutes>0</d3p1:OffsetMinutes>
        </Timestamp>
        <ApplicationName>AppName1</ApplicationName>
        <Description>Desc</Description>
        <EmailAddress i:nil="true"/>
        <LogName>Log1</LogName>
        <SubscriberGUID i:nil="true"/>
        <Verified>false</Verified>
    </Subscription>
</ArrayOfSubscription>

As you can see, the model not only has a few additional properties such as SubscriberGUID which I do not want to be serialized in the response (and since they are not in the select query, they are null anyway), but TableEntity itself has fields such as PartitionKey, RowKey, Etag, and Timestamp which are also being serialized.

How do I continue to use Azure tables but avoid serializing in the response these undesired fields I do not want the user to see.

Answer 1

Not disagreeing with the answer of using a specific DTO, but the Microsoft.WindowsAzure.Storage assembly now provides an attribute, the IgnorePropertyAttribute, that you can decorate your public property with to avoid serialization.

I haven't actually tried it yet but there is a method on TableEntity called ShouldSkipProperty() that checks a number of things before returning false (i.e. don't skip):

• Is the Property Name one of "PartitionKey", "RowKey", "Timestamp" or "ETag" -> skip
• Are EITHER of the getter and setter non-public -> skip
• Is it static -> skip
• Does the property have the attribute IgnorePropertyAttribute -> skip

Looks like it'll do the trick.