Apache Authors: Liz McMillan, Pat Romanski, John Mertic, Elizabeth White, Janakiram MSV

Related Topics: @CloudExpo, Mobile IoT, Microservices Expo, Microsoft Cloud, Silverlight, Apache

@CloudExpo: Article

Windows Azure Mobile Services

Windows Azure Mobile Services is the bomb, but how can we work with enum values?

Now, in order to do this, it makes some assumptions.  It looks at the JSON object, and if it sees a certain type of data, it creates a certain type of column to support the data.  The easiest thing that it could have done would be to just create text columns in the underlying SQL database, since any type of data can be stored as a string.  Instead, it does something quite a bit smarter, and creates data types that are quite a bit more “appropriate”.  Here’s the strategy that it uses:

JSON / CLR Data Type T-SQL Type in underlying SQL Azure database table
Numeric values (integer, decimal, floating point) float(53) – this is the maximum precision float.
Boolean bit
DateTime DateTimeOffset(3)
String nvarchar(max)

OK, so this is great.  Dynamic schema is pretty cool.  However…

When I work on a database schema, I often run into a case where I want to create a “code/decode” style table.  In my world, a “code/decode” table is typically a two column table, where the primary key is the “code” and the other column is a textual description.  The canonical example is a “States” table (in the US).  Like this:

Code Decode
AL Alabama
AK Alaska
AZ Arizona
IL Illinois
WY Wyoming

Then, with this table defined, I’ll just use it anywhere I need a State… like this:

Column DataType Notes
FirstName nvarchar(50)
LastName nvarchar(50)
Address1 nvarchar(100)
Address2 nvarchar(100)
City nvarchar(100)
State char(2) Foreign Key to State Code
ZIPCode char(5)

Now, in my current project, it wasn’t a state code that I needed, it was a “CurrencyType”.  And moreover, I wanted to be able to have an “enum” value of CurrencyTypes to be able to work with in my application.  This led me to wonder how WAMS could handle storing and retrieving an “enum” in the database.  It’s not immediately clear that it would know what to do with it as a JSON type.  The JavaScriptSerializer seems to turn enum values into an integer value, which would probably work, but I really wanted my underlying SQL table to store “IL” for Illinois, and not the number 14 as a 53 bits of precision float.  So, how can I turn my enum values into the underlying state codes as a 2 character string on the way in, and reconvert them back to my enum values on the way out?

To start with, here’s the (truncated) version of my enum for my CurrencyType.

public enum CurrencyType

Next, the secret sauce turns out to be an IDataMemberJsonConverter .  This interface exists within the Microsoft.WindowsAzure.MobileServices assembly, and has 2 methods that you need to implement – ConvertFromJson and ConvertToJson.  Here’s the type converter that I created to massage my enum into a string going in, and from a string back to the enum on the way back out…

First, the ConvertToJson method:

public IJsonValue ConvertToJson(object instance)
	if (instance is Types.CurrencyType)
		switch ((Types.CurrencyType)instance)
			case Types.CurrencyType.UnitedArabEmiratesDirham:
				return JsonValue.CreateStringValue("AED");
			case Types.CurrencyType.AfghanistanAfghani:
				return JsonValue.CreateStringValue("AFN");
			case Types.CurrencyType.AlbaniaLek:
				return JsonValue.CreateStringValue("ALL");
			case Types.CurrencyType.UnitedStatesDollar:
				return JsonValue.CreateStringValue("USD");
				return JsonValue.CreateStringValue("XXX");
		return JsonValue.Parse("null");

Next, the ConvertFromJson method:

public object ConvertFromJson(IJsonValue value)
	CurrencyType result = Types.CurrencyType.Unknown; 
	if (value != null && value.ValueType == JsonValueType.String) 
		switch (value.GetString()) 
			case "AED": 
				return Types.CurrencyType.UnitedArabEmiratesDirham; 
			case "AFN": 
				return Types.CurrencyType.AfghanistanAfghani; 
			case "ALL": 
				return Types.CurrencyType.AlbaniaLek;
// SNIP 
			case "USD": 
				return Types.CurrencyType.UnitedStatesDollar;
// SNIP 
			case "ZWD": 
				return Types.CurrencyType.ZimbabweDollar; 
			case "XXX": 
				return Types.CurrencyType.Unknown; 
				return Types.CurrencyType.Unknown; 
	return result;

Now, the only thing remaining is to decorate the CLR class that we’re using to hold our object with enough information to get the serializer to use our type converter as necessary.  In my case, the column for CurrencyType is contained in a class called FamilyGroup.  Here’s that implementation:

public class FamilyGroup
	public long Id { get; set; } 
	public string Name { get; set; }

 	[DataMemberJsonConverter(ConverterType = typeof(CurrencyTypeConverter))] 
	public CurrencyType CurrencyType { get; set; }

And that’s it.  We have our enum to work with in our code, we’re able to store and retrieve our values to WAMS and the data in the tables is readable to boot.

Happy coding.

More Stories By Adam Hoffman

Adam is an technical evangelist working for Microsoft. By day, you can likely find him somewhere in the Midwest, driving to somewhere, ready to figure out how the cloud can save your family from certain doom, and make you rich and successful in the process. Before he started evangelizing, Adam was a Senior Developer Lead for Microsoft in Redmond, working on Office 365, BPOS, and Office Live. He misses Redmond, and the excitement of the mother ship, but the call of bitter cold and lots of snow in Chicago was too much for him, and he had to return.

Prior that that he developed software and ran teams for Thomson Reuters, Method Engine (which he co-founded), VSA Partners, Navigant Consulting, Andersen Consulting, and a couple of CASE tool companies way back in the day. His favorite possession is a clone of the original Altair computer, running BillG's 8K BASIC, which he's still intending to hook up to the cloud, someday, somehow.

You can read his Windows Azure Blog at http://stratospher.es, and tweeter-er him at http://twitter.com/stratospher_es.

Additionally, if you'd like to keep track of his cloud connected car, you can follow it on Twitter at http://twitter.com/cloudcar1.

@ThingsExpo Stories
@ThingsExpo has been named the Top 5 Most Influential Internet of Things Brand by Onalytica in the ‘The Internet of Things Landscape 2015: Top 100 Individuals and Brands.' Onalytica analyzed Twitter conversations around the #IoT debate to uncover the most influential brands and individuals driving the conversation. Onalytica captured data from 56,224 users. The PageRank based methodology they use to extract influencers on a particular topic (tweets mentioning #InternetofThings or #IoT in this ...
@ThingsExpo has been named the Top 5 Most Influential M2M Brand by Onalytica in the ‘Machine to Machine: Top 100 Influencers and Brands.' Onalytica analyzed the online debate on M2M by looking at over 85,000 tweets to provide the most influential individuals and brands that drive the discussion. According to Onalytica the "analysis showed a very engaged community with a lot of interactive tweets. The M2M discussion seems to be more fragmented and driven by some of the major brands present in the...
In the next forty months – just over three years – businesses will undergo extraordinary changes. The exponential growth of digitization and machine learning will see a step function change in how businesses create value, satisfy customers, and outperform their competition. In the next forty months companies will take the actions that will see them get to the next level of the game called Capitalism. Or they won’t – game over. The winners of today and tomorrow think differently, follow different...
In an era of historic innovation fueled by unprecedented access to data and technology, the low cost and risk of entering new markets has leveled the playing field for business. Today, any ambitious innovator can easily introduce a new application or product that can reinvent business models and transform the client experience. In their Day 2 Keynote at 19th Cloud Expo, Mercer Rowe, IBM Vice President of Strategic Alliances, and Raejeanne Skillern, Intel Vice President of Data Center Group and ...
The Internet of Things (IoT), in all its myriad manifestations, has great potential. Much of that potential comes from the evolving data management and analytic (DMA) technologies and processes that allow us to gain insight from all of the IoT data that can be generated and gathered. This potential may never be met as those data sets are tied to specific industry verticals and single markets, with no clear way to use IoT data and sensor analytics to fulfill the hype being given the IoT today.
More and more brands have jumped on the IoT bandwagon. We have an excess of wearables – activity trackers, smartwatches, smart glasses and sneakers, and more that track seemingly endless datapoints. However, most consumers have no idea what “IoT” means. Creating more wearables that track data shouldn't be the aim of brands; delivering meaningful, tangible relevance to their users should be. We're in a period in which the IoT pendulum is still swinging. Initially, it swung toward "smart for smar...
Virgil consists of an open-source encryption library, which implements Cryptographic Message Syntax (CMS) and Elliptic Curve Integrated Encryption Scheme (ECIES) (including RSA schema), a Key Management API, and a cloud-based Key Management Service (Virgil Keys). The Virgil Keys Service consists of a public key service and a private key escrow service. 

Data is the fuel that drives the machine learning algorithmic engines and ultimately provides the business value. In his session at Cloud Expo, Ed Featherston, a director and senior enterprise architect at Collaborative Consulting, will discuss the key considerations around quality, volume, timeliness, and pedigree that must be dealt with in order to properly fuel that engine.
What happens when the different parts of a vehicle become smarter than the vehicle itself? As we move toward the era of smart everything, hundreds of entities in a vehicle that communicate with each other, the vehicle and external systems create a need for identity orchestration so that all entities work as a conglomerate. Much like an orchestra without a conductor, without the ability to secure, control, and connect the link between a vehicle’s head unit, devices, and systems and to manage the ...
The best way to leverage your Cloud Expo presence as a sponsor and exhibitor is to plan your news announcements around our events. The press covering Cloud Expo and @ThingsExpo will have access to these releases and will amplify your news announcements. More than two dozen Cloud companies either set deals at our shows or have announced their mergers and acquisitions at Cloud Expo. Product announcements during our show provide your company with the most reach through our targeted audiences.
Machine Learning helps make complex systems more efficient. By applying advanced Machine Learning techniques such as Cognitive Fingerprinting, wind project operators can utilize these tools to learn from collected data, detect regular patterns, and optimize their own operations. In his session at 18th Cloud Expo, Stuart Gillen, Director of Business Development at SparkCognition, discussed how research has demonstrated the value of Machine Learning in delivering next generation analytics to impr...
For basic one-to-one voice or video calling solutions, WebRTC has proven to be a very powerful technology. Although WebRTC’s core functionality is to provide secure, real-time p2p media streaming, leveraging native platform features and server-side components brings up new communication capabilities for web and native mobile applications, allowing for advanced multi-user use cases such as video broadcasting, conferencing, and media recording.
Amazon has gradually rolled out parts of its IoT offerings, but these are just the tip of the iceberg. In addition to optimizing their backend AWS offerings, Amazon is laying the ground work to be a major force in IoT - especially in the connected home and office. In his session at @ThingsExpo, Chris Kocher, founder and managing director of Grey Heron, explained how Amazon is extending its reach to become a major force in IoT by building on its dominant cloud IoT platform, its Dash Button strat...
SYS-CON Events announced today that SoftNet Solutions will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. SoftNet Solutions specializes in Enterprise Solutions for Hadoop and Big Data. It offers customers the most open, robust, and value-conscious portfolio of solutions, services, and tools for the shortest route to success with Big Data. The unique differentiator is the ability to architect and ...
A critical component of any IoT project is what to do with all the data being generated. This data needs to be captured, processed, structured, and stored in a way to facilitate different kinds of queries. Traditional data warehouse and analytical systems are mature technologies that can be used to handle certain kinds of queries, but they are not always well suited to many problems, particularly when there is a need for real-time insights.
DevOps is being widely accepted (if not fully adopted) as essential in enterprise IT. But as Enterprise DevOps gains maturity, expands scope, and increases velocity, the need for data-driven decisions across teams becomes more acute. DevOps teams in any modern business must wrangle the ‘digital exhaust’ from the delivery toolchain, "pervasive" and "cognitive" computing, APIs and services, mobile devices and applications, the Internet of Things, and now even blockchain. In this power panel at @...
One of biggest questions about Big Data is “How do we harness all that information for business use quickly and effectively?” Geographic Information Systems (GIS) or spatial technology is about more than making maps, but adding critical context and meaning to data of all types, coming from all different channels – even sensors. In his session at @ThingsExpo, William (Bill) Meehan, director of utility solutions for Esri, will take a closer look at the current state of spatial technology and ar...
Everyone knows that truly innovative companies learn as they go along, pushing boundaries in response to market changes and demands. What's more of a mystery is how to balance innovation on a fresh platform built from scratch with the legacy tech stack, product suite and customers that continue to serve as the business' foundation. In his General Session at 19th Cloud Expo, Michael Chambliss, Head of Engineering at ReadyTalk, will discuss why and how ReadyTalk diverted from healthy revenue an...
SYS-CON Events announced today that Streamlyzer will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Streamlyzer is a powerful analytics for video streaming service that enables video streaming providers to monitor and analyze QoE (Quality-of-Experience) from end-user devices in real time.
You have great SaaS business app ideas. You want to turn your idea quickly into a functional and engaging proof of concept. You need to be able to modify it to meet customers' needs, and you need to deliver a complete and secure SaaS application. How could you achieve all the above and yet avoid unforeseen IT requirements that add unnecessary cost and complexity? You also want your app to be responsive in any device at any time. In his session at 19th Cloud Expo, Mark Allen, General Manager of...