Using dynamic class with TableEntityAdapter for Azure Table Storage

Question

I have the following line of code:

var entity = new TableEntityAdapter<object>(obj, partitionKey, id);

The object obj contains properties and when I save to Table Storage, then those properties are not saved. I understand why, because they are not defined in the class object.

How do I define a class to be used by TableEntityAdapter at runtime?

UPDATE

Yes, I solved it with ElasticTableEntity as mentioned below - however, I also discovered that there is now a built-in DynamicTableEntity which is the default table result. It serves the same purpose.

Answer 1

UPDATE:

The newest version of Microsoft.Azure.Cosmos.Table has a built in class ElasticTableEntity which serves this exact purpose.

OLD SOLUTION:

I solved it using this ElasticTableEntity

http://pascallaurin42.blogspot.com/2013/03/using-azure-table-storage-with-dynamic.html

public class ElasticTableEntity : DynamicObject, ITableEntity,
    ICustomMemberProvider // For LinqPad's Dump
{
    public ElasticTableEntity()
    {
        this.Properties = new Dictionary<string, EntityProperty>();
    }
    
    public IDictionary<string, EntityProperty> Properties { get; private set; }
 
    public object this[string key] 
    { 
        get
        {
            if (!this.Properties.ContainsKey(key))
                this.Properties.Add(key, this.GetEntityProperty(key, null));
 
            return this.Properties[key];
        }
        set
        {
            var property = this.GetEntityProperty(key, value);
            
            if (this.Properties.ContainsKey(key))
                this.Properties[key] = property;
            else
                this.Properties.Add(key, property);
        }
    }
    
    #region DynamicObject overrides
 
    public override bool TryGetMember(GetMemberBinder binder, out object result)
    {
        result = this[binder.Name];
        return true;
    }
 
    public override bool TrySetMember(SetMemberBinder binder, object value)
    {
        this[binder.Name] = value;
        return true;
    }
    
    #endregion
    
    #region ITableEntity implementation
    
    public string PartitionKey { get; set; }
 
    public string RowKey { get; set; }
 
    public DateTimeOffset Timestamp { get; set; }
 
    public string ETag { get; set; }
    
    public void ReadEntity(IDictionary<string, EntityProperty> properties, OperationContext operationContext)
    {
        this.Properties = properties;
    }
 
    public IDictionary<string, EntityProperty> WriteEntity(OperationContext operationContext)
    {
        return this.Properties;
    }
    
    #endregion
    
    #region ICustomMemberProvider implementation for LinqPad's Dump
    
    public IEnumerable<string> GetNames()
    {
        return new[] { "PartitionKey", "RowKey", "Timestamp", "ETag" }
            .Union(this.Properties.Keys);
    }
    
    public IEnumerable<Type> GetTypes()
    {
        return new[] { typeof(string), typeof(string), typeof(DateTimeOffset), typeof(string) }
            .Union(this.Properties.Values.Select(x => this.GetType(x.PropertyType)));
    }
    
    public IEnumerable<object> GetValues()
    {
        return new object[] { this.PartitionKey, this.RowKey, this.Timestamp, this.ETag }
            .Union(this.Properties.Values.Select(x => this.GetValue(x)));
    }
    
    #endregion
    
    private EntityProperty GetEntityProperty(string key, object value)
    {
        if (value == null) return new EntityProperty((string)null);
        if (value.GetType() == typeof(byte[])) return new EntityProperty((byte[])value);
        if (value.GetType() == typeof(bool)) return new EntityProperty((bool)value);
        if (value.GetType() == typeof(DateTimeOffset)) return new EntityProperty((DateTimeOffset)value);
        if (value.GetType() == typeof(DateTime)) return new EntityProperty((DateTime)value);
        if (value.GetType() == typeof(double)) return new EntityProperty((double)value);
        if (value.GetType() == typeof(Guid)) return new EntityProperty((Guid)value);
        if (value.GetType() == typeof(int)) return new EntityProperty((int)value);
        if (value.GetType() == typeof(long)) return new EntityProperty((long)value);
        if (value.GetType() == typeof(string)) return new EntityProperty((string)value);
        throw new Exception("not supported " + value.GetType() + " for " + key);
    }
    
    private Type GetType(EdmType edmType)
    {
        switch (edmType)
        {
            case EdmType.Binary : return typeof(byte[]);
            case EdmType.Boolean : return typeof(bool);
            case EdmType.DateTime : return typeof(DateTime);
            case EdmType.Double : return typeof(double);
            case EdmType.Guid : return typeof(Guid);
            case EdmType.Int32 : return typeof(int);
            case EdmType.Int64 : return typeof(long);
            case EdmType.String : return typeof(string);
            default: throw new Exception("not supported " + edmType);
        }
    }
 
    private object GetValue(EntityProperty property)
    {
        switch (property.PropertyType)
        {
            case EdmType.Binary : return property.BinaryValue;
            case EdmType.Boolean : return property.BooleanValue;
            case EdmType.DateTime : return property.DateTimeOffsetValue;
            case EdmType.Double : return property.DoubleValue;
            case EdmType.Guid : return property.GuidValue;
            case EdmType.Int32 : return property.Int32Value;
            case EdmType.Int64 : return property.Int64Value;
            case EdmType.String : return property.StringValue;
            default: throw new Exception("not supported " + property.PropertyType);
        }
    }
}