How to use EntityResolver with Azure Storage?

Question

I am writing below code to retrieve all entities from Azure table. But I am kind of stuck up in passing entity resolver delegate. I could not find much reference on MSDN.

Can some one please point out, how to use EntityResover in below code?

public class ATSHelper<T> where T : ITableEntity, new()
{
    CloudStorageAccount storageAccount;
    public ATSHelper(CloudStorageAccount storageAccount)
    {
        this.storageAccount = storageAccount;
    }
    public async Task<IEnumerable<T>> FetchAllEntities(string tableName)
    {
        List<T> allEntities = new List<T>();
        CloudTable table = storageAccount.CreateCloudTableClient().GetTableReference(tableName);
        TableContinuationToken contToken = new TableContinuationToken();
        TableQuery query = new TableQuery();
        CancellationToken cancelToken = new CancellationToken();            

        do
        {
            var qryResp = await table.ExecuteQuerySegmentedAsync<T>(query, ???? EntityResolver ???? ,contToken, cancelToken);
            contToken = qryResp.ContinuationToken;
            allEntities.AddRange(qryResp.Results);
        }
        while (contToken != null);
        return allEntities;
    }
}

Answer 1

Here is a nice article describing the Table Storage in deep. It also includes couple of samples for EntityResolver.

Ideal would be to have one Generic Resolver, that produces the desired result. Then you can include it in your call. I will just quote here one example from the provided article:

EntityResolver<ShapeEntity> shapeResolver = (pk, rk, ts, props, etag) =>
{
    ShapeEntity resolvedEntity = null;
    string shapeType = props["ShapeType"].StringValue;

    if (shapeType == "Rectangle") { resolvedEntity = new RectangleEntity(); }
    else if (shapeType == "Ellipse") { resolvedEntity = new EllipseEntity(); }
    else if (shapeType == "Line") { resolvedEntity = new LineEntity(); }    
    // Potentially throw here if an unknown shape is detected 

    resolvedEntity.PartitionKey = pk;
    resolvedEntity.RowKey = rk;
    resolvedEntity.Timestamp = ts;
    resolvedEntity.ETag = etag;
    resolvedEntity.ReadEntity(props, null);

    return resolvedEntity;
};

    currentSegment = await drawingTable.ExecuteQuerySegmentedAsync(drawingQuery, shapeResolver, currentSegment != null ? currentSegment.ContinuationToken : null);

Read the full article to better understand the deal with resolvers.