Click here to close now.

Welcome!

You will be redirected in 30 seconds or close now.

ColdFusion Authors: Yakov Fain, Maureen O'Gara, Nancy Y. Nee, Tad Anderson, Daniel Kaar

Related Topics: ColdFusion, @MicroservicesE Blog, Microsoft Cloud

ColdFusion: Article

Crossing the .NET Divide: CFMX, Web Services, and .NET

ColdFusion Web service interoperability with .NET

Like it or not, .NET is proving a powerful force in the software industry. As a ColdFusion developer, you'll probably need to interact with it at some point in time.

One of the promises of .NET is that it can provide this interoperability through Web services. Although it's easy to send simple data to and from .NET Web services, a little bit of extra work on our end can make arrays, structures, and even queries work across the two platforms.

Quick Review: ColdFusion Web Services
This article is about ColdFusion Web service interoperability with .NET. It assumes a basic knowledge of how to create and consume Web services in ColdFusion. A brief review may help everyone get on the same page.

Web services use XML to provide remote procedure calls, or services, in a platform- and language-agnostic environment. By using the XML document Web Services Definition Language (WSDL), they describe how they work in a common, agreed-on format. When they communicate, data is sent in another XML format called Simple Object Access Protocol (SOAP).

Although WSDL and SOAP are both fairly complicated, creating and consuming Web services in ColdFusion couldn't be easier! To create a service, create a ColdFusion component (CFC) file in a Web-accessible directory. Give it at least one function (or method), being sure to specify its return type and that its access attribute is set to remote. If the method has arguments, you must also specify the data type of those arguments. The following code shows a very simple ColdFusion Web service that returns a simple string:


<cfcomponent>
  <cffunction name="getString"
    returntype="string"
    access="remote">
    <cfreturn "Hello, world!">
  </cffunction>
</cfcomponent>

After creating your CFC, it will be available as a Web service at http://<servername>/<path>/<filename>?WSDL. For example, if the code from the previous example was in "sampleService.cfc" under the root on your local machine, it would be available as a Web service at http://localhost/sampleService.cfc?WSDL.

Consuming a Web service from ColdFusion is just as simple. In fact, it only takes one line of code. The following code shows how to consume and then display the results of our CFC from the previous example. In this example, we use the CFInvoke tag to both instantiate and call a method of our sample Web service. We then output the result in a standard CFOutput block:


<cfinvoke
  webservice="http://localhost/
    sampleService.cfc?WSDL"
	method="getString"
	returnvariable="result">
<cfoutput>#result#</cfoutput>

Now that we've reviewed creating and consuming Web services in ColdFusion, let's move on to creating Web services that can be consumed by .NET clients.

Providing Data to .NET Through Web Services
When you build a Web service in ColdFusion, the "returnType" attribute of the CFFunction tag states what type of data the Web service will be returning. The language Web services uses to communicate (SOAP), describes these return types using XML. ColdFusion automatically creates this XML when your CFC is accessed as a Web service. It is up to the client software to interpret this XML and create variables it can "understand" from the data returned by your Web service.

Sending Simple Values to .NET
ColdFusion is considered a typeless language, and simple values are the variables that fall into this "typeless" category. An easy way to think of simple values is that they can be directly printed to a page using a CFOutput block. For example, you can directly output a date inside a CFOutput tag, but not a query: A date is a simple value, but a query is not.

Lucky for us, .NET understands all of the simple ColdFusion return types without a hitch. This means that any Web service method returning these types can be understood by .NET without any changes. Table 1 shows the .NET data types that the results of your ColdFusion Web services will be translated into.

You'll notice that three of the most powerful ColdFusion data types aren't listed in Table 1: arrays, structures, and queries. These are three of the complex data types available in ColdFusion. It's when we use ColdFusion Web services to send complex data types to .NET that we begin to encounter trouble.

Sending Simple Arrays to .NET
ColdFusion arrays and .NET arrays are very different, and the technical details of these differences are beyond the scope of this article. What is relevant, however, is that .NET does not translate a ColdFusion array sent over a Web service back into a native .NET array. Instead, .NET interprets them as its generic "object" type.

As long as your array contains simple values, you're in the clear. A .NET developer can easily loop over your result in the .NET equivalent of a collection-based CFLoop to extract the data. The following example shows the VB.NET code to do this:


For Each i In CFArrayResult
	Response.Write("i: " & i)
Next

We'll tackle complex arrays, such as arrays of structures, after we've first taken a look at how a structure can be sent to .NET

Sending Structures to .NET
Presently, ColdFusion structures do not translate to .NET. If you send a structure to .NET through a ColdFusion Web service, the .NET developer receives nothing but an empty object. However, Macromedia has provided a solution to this through CFCs.

To return a structure to .NET, you create a "definition" CFC that will represent the structure and its data. Each member of the structure needs a corresponding CFProperty tag in the definition CFC.

Instead of returning a structure, you first create an instance of the CFC. Then, use CFSet tags to set its properties to their corresponding values in your structure. Last, you return the instance of the CFC instead of your structure. It's important to note that you need to change the returntype of your CFFunction tag from "structure" to the (package) name of the CFC you're returning.

In Listing 1, we take a look at how to do this. It first shows our definition CFC (employee.cfc) that represents an "employee" structure. Then, we have a Web service (employeeService.cfc) that creates the structure, translates it into the employee CFC, and returns the CFC.

When the definition CFC is returned to .NET, .NET sees it as a type named after the interface component. In other words, the employee CFC returned in Listing 1 would be seen as an "Employee" object having directly accessible properties named EmployeeId, Firstname, and Lastname. On the .NET side, if the result was stored in a variable called "myEmployee," the employee's first name would be accessible as "myEmployee.Firstname." This is exactly as it would be in a ColdFusion structure.

Combining Arrays and Structures
By combining what we've seen of sending arrays and structures to .NET, it's simple to send more complex arrays or structures to .NET. For example, if you want to send an array of structures back to .NET, you first create an array and then populate it with CFC instances that hold the structure data. In Listing 2, an array named "result" is created, and each member of this array is an instance of our employee CFC. We then return the entire array.

On the .NET side, we first store the result in an object named "employees." Then, we loop over the members of the employee object with each being an instance of an employee. Knowing that the individual employee's data is stored in directly accessible properties, we can then print it out using simple "dot-syntax."

Queries: XML to the Rescue!
After covering arrays and structures, it should be easy enough to send queries to .NET. We could represent the entire query as an array, with each row using a facade CFC. Believe it or not, we can do better by returning ColdFusion queries in a format .NET already understands.

First, let me give you some background. The .NET equivalent of a ColdFusion query is called a DataSet. It's part of ADO.NET, which is the portion of .NET that deals with databases. DataSets are XML representations of database schemas. They can hold multiple queries, maintain relationships between the queries, and perform a slew of automated database tasks.

From a ColdFusion perspective, what's great about DataSets is that we can easily create XML that a .NET client can turn into a DataSet. Listing 3 shows an example of XML that can be used to create a .NET data set. You'll see that it's fairly simple. A root-level tag defines a "table" named books, with each "book" node describing a row in that table. Inside each book node, we describe each column. In this case, the columns are the "author" and "title" nodes.

Using ColdFusion MX's XML support, we can easily turn a query into this type of XML and return it to .NET as a string. To help out, I've created a user-defined function (UDF) that transforms queries into exactly this format of XML. This UDF is part of a utility CFC I've created called QueryTool, available on www.CFCZone.org or my site at: www.clearsoftware.net/client/queryTool.cfm. Listing 4 shows an entire solution for creating a query, transforming it to XML using this UDF, returning the XML, and finally the VB.NET client code for creating a DataSet from the result.

Compatibility and Performance
I imagine some of you are wondering how these changes to your ColdFusion Web services affect both performance and compatibility with existing ColdFusion-based clients. Tasks such as translating queries to XML are costly, and they should be performed only when necessary.

In my own applications, I'm using a two-tier approach to provide data to both ColdFusion and .NET clients. The first tier consists of a CFC with no modifications for .NET compatibility. ColdFusion applications can then call this component and its Web services with no changes. The second tier is also a CFC, used solely to provide data to .NET. It does this by instantiating the first-tier CFC as a component, calling the appropriate method, and then performing any necessary .NET-specific translations on the result. This way, any performance drains such as translating queries to XML only impact .NET clients, and I maintain compatibility with existing ColdFusion clients.

Consuming Data from .NET Web Services
Similar to ColdFusion, .NET makes it very easy to create Web services. Also similar to ColdFusion, it has no reservations about returning data in its own proprietary formats, like the DataSet.

Because of these differences in architecture, consuming .NET Web services is more difficult than consuming native ColdFusion Web services. In this section, we'll take a look at how to consume the various types of data returned by .NET Web services.

Consuming Simple Types
Again, ColdFusion and .NET see eye to eye on simple data types. The .NET string type, its various numeric types, and its date type all translate to their ColdFusion equivalents automatically. This means that consuming a .NET Web service that returns a simple value is no different than consuming an equivalent ColdFusion Web service.

Consuming .NET Arrays
When dealing with arrays, things get a little more complicated. Before we look at how to consume a .NET array, we need to understand a fundamental difference between .NET and ColdFusion. ColdFusion is typeless, whereas .NET is a typed, object oriented environment. This means that every .NET variable is of a specific type, and all of those types inherit from a root "object" class.

For ColdFusion, this means that any complex data type sent over a .NET Web service will not be automatically translated into its ColdFusion equivalent. Instead, it will be translated into a Java object. This Java object will have various properties and methods, just like a CFC or COM object. You can CFDump the resultant object at any time to get a list of its properties and methods. If any of you have ever returned a CFC from a Web service, this should look very familiar.

Now that you know this, if you're calling a .NET Web service that you think returns an array, don't be surprised when your result is an object. Unlike ColdFusion arrays, .NET arrays are of a specific type, meaning that each element of the array is of the same type. Simple arrays can be arrays of strings, numbers, or even raw bytes. Elements in more complex arrays can contain any type of object.

If you CFDump the result of a .NET Web service returning an array, the object you receive will contain a method called "Get<type>()." In this, "<type>" is replaced by the name of the type of array you're expecting, such as "GetString()." If you call this method, the result is the native ColdFusion array you'd expect from a ColdFusion-based Web service. For a more complex example, if you expected a .NET Web service to return an array of our employee structures/objects, you'd look for a method called "GetEmployee()." This is because you're looking for an array of the employee type.

Consuming .NET Structures
Now that we know that complex data returned by .NET will be represented as Java objects, we can explore how to consume .NET's equivalent of a structure. It's actually very easy. If you've ever used a ColdFusion Web service that returns a CFC, it should be familiar territory. When you CFDump the result of a .NET Web service that returns an enumeration or other similar class, you'll see a number of "get" and "set" methods. These work like their equivalents in a ColdFusion Web service returning a CFC instance. As we're concerned with consuming, it's the "get" methods we're interested in.

If we consume the .NET equivalent of our ColdFusion GetEmployee Web service, we'd see a Java object with methods named "GetFirstname," "GetLastname," and "GetEmployeeId." Calling these would then return the Firstname, Lastname, and EmployeeId values or "properties" of this object. If we stored our result in a variable named "employee" and wanted to print out the employee's first name, we could reference it as #employee.GetFirstname()#.

Consuming .NET DataSets
.NET's database interaction library, ADO.NET, uses what is called a DataSet. A DataSet is more than a query. It's an in-memory representation of a database schema. A DataSet can contain multiple tables and maintain relations between those tables. Each one of those tables can be thought of as an individual query.

What makes DataSets interoperable is that .NET uses XML to represent them. When calling a .NET Web service that returns a DataSet, exploration of the result leads to the discovery of a getAny() method. This method returns an array of objects representing the schema and data contained in a DataSet. These objects, in turn, have methods that expose their underlying XML. With a little bit of work, we can use ColdFusion MX's native XML support to translate this XML into ColdFusion queries.

Again, I've created a UDF for dealing with .NET DataSets. Listing 5 shows both the UDF and an example of its use. This UDF can be downloaded from my Web site: www.clearsoftware.net/client/convertDotNetDataset.cfm. Because DataSets can contain multiple queries, my implementation returns a structure. Each member of the structure is a query named after the table's name in the .NET DataSet.

Conclusion
As more software development moves toward Service-Oriented Architecture (SOA), it's important to ensure that ColdFusion is interoperable with other development platforms. Although some things are out of our control (e.g., the changing Web service standards), I hope this article has shown you that it's fairly easy to move data between ColdFusion and .NET via Web services. ColdFusion can be an important player in your service-oriented application, both as a client and service provider.

Supplemental Code
A complete example of interoperable ColdFusion MX and .NET Web services, along with client code, is available at: www.sys-con.com/coldfusion/sourcec.cfm

More Stories By Joe Rinehart

Joe Rinehart is a Flex, ColdFusion, and J2EE developer. You can find his blog at Firemoss.com.

Comments (6) View Comments

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


Most Recent Comments
AR 08/23/05 08:54:01 PM EDT

Joe,

Interesting read. Though Ive been using coldfusion for quite some time, I am now in a situation where I have to deal with web services created in .NET. I am working with a web service created in .NET that takes in a query as input and outputs a dataset. Needless to say, it's been a nightmare until I found your article. Your article is by far the most straightforward and most promising...if only I can get it to work! :(

I used your UDF dataset converter but I keep getting an error saying "Complex object types cannot be converted to simple values." Shouldnt it convert it to a complex object such as a query? Any idea of what is happening? Much appreciated.

ColdFusion Developer's Journal 08/04/05 09:35:02 AM EDT

Crossing the .NET Divide: CFMX, Web Services, and .NET. Like it or not, .NET is proving a powerful force in the software industry. As a ColdFusion developer, you'll probably need to interact with it at some point in time. One of the promises of .NET is that it can provide this interoperability through Web services.

petemeat 02/16/05 05:11:53 PM EST

by converting queries to xml strings, we lose the ability to truly describe the data in the WSDL file -- is there a work around for that?

Also, when the author states he has a 2 tiered approach, does this mean he has a .net and CF version of all CFCs? If not, does the author maintain one cfc for .NET that then calls the appropriate CFC and relays arguments? If so, how does the WSDL file look to .NET consukers?

Joe 02/05/05 05:15:27 PM EST

I got by this problem but now experience the following problem that I see many mentions to on the Macromedia forum but no solutions. Did you get you example code to ork?

{http://schemas.xmlsoap.org/soap/envelope/}Server.userException faultSubcode: faultString: org.xml.sax.SAXException: No deserializer for {http://ws.Services}employee faultActor:

Joe 02/05/05 05:01:39 PM EST

I keep getting the following error on the listing 2 example when I try to call the web service from a Cold fusion page. Any ideas?

[java.lang.IncompatibleClassChangeError : Dependent CFC type(s) have been modified. Please refresh your web service client.]

Derek 12/08/04 06:43:45 AM EST

I get a
"Element NewDataSet is undefined in a Java object of type class coldfusion.xml.XmlNodeList referenced as" error when I try to convert a Java Object using the function provided - any ideas?
Thanks
Derek

@ThingsExpo Stories
"We have a tagline - "Power in the API Economy." What that means is everything that is built in applications and connected applications is done through APIs," explained Roberto Medrano, Executive Vice President at Akana, in this SYS-CON.tv interview at 16th Cloud Expo, held June 9-11, 2015, at the Javits Center in New York City.
The Internet of Things is not only adding billions of sensors and billions of terabytes to the Internet. It is also forcing a fundamental change in the way we envision Information Technology. For the first time, more data is being created by devices at the edge of the Internet rather than from centralized systems. What does this mean for today's IT professional? In this Power Panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists addressed this very serious issue of profound change in the industry.
Explosive growth in connected devices. Enormous amounts of data for collection and analysis. Critical use of data for split-second decision making and actionable information. All three are factors in making the Internet of Things a reality. Yet, any one factor would have an IT organization pondering its infrastructure strategy. How should your organization enhance its IT framework to enable an Internet of Things implementation? In his session at @ThingsExpo, James Kirkland, Red Hat's Chief Architect for the Internet of Things and Intelligent Systems, described how to revolutionize your archit...
It is one thing to build single industrial IoT applications, but what will it take to build the Smart Cities and truly society-changing applications of the future? The technology won’t be the problem, it will be the number of parties that need to work together and be aligned in their motivation to succeed. In his session at @ThingsExpo, Jason Mondanaro, Director, Product Management at Metanga, discussed how you can plan to cooperate, partner, and form lasting all-star teams to change the world and it starts with business models and monetization strategies.
To many people, IoT is a buzzword whose value is not understood. Many people think IoT is all about wearables and home automation. In his session at @ThingsExpo, Mike Kavis, Vice President & Principal Cloud Architect at Cloud Technology Partners, discussed some incredible game-changing use cases and how they are transforming industries like agriculture, manufacturing, health care, and smart cities. He will discuss cool technologies like smart dust, robotics, smart labels, and much more. Prepare to be blown away with a glimpse of the future.
Internet of Things is moving from being a hype to a reality. Experts estimate that internet connected cars will grow to 152 million, while over 100 million internet connected wireless light bulbs and lamps will be operational by 2020. These and many other intriguing statistics highlight the importance of Internet powered devices and how market penetration is going to multiply many times over in the next few years.
Internet of Things (IoT) will be a hybrid ecosystem of diverse devices and sensors collaborating with operational and enterprise systems to create the next big application. In their session at @ThingsExpo, Bramh Gupta, founder and CEO of robomq.io, and Fred Yatzeck, principal architect leading product development at robomq.io, discussed how choosing the right middleware and integration strategy from the get-go will enable IoT solution developers to adapt and grow with the industry, while at the same time reduce Time to Market (TTM) by using plug and play capabilities offered by a robust IoT ...
Today air travel is a minefield of delays, hassles and customer disappointment. Airlines struggle to revitalize the experience. GE and M2Mi will demonstrate practical examples of how IoT solutions are helping airlines bring back personalization, reduce trip time and improve reliability. In their session at @ThingsExpo, Shyam Varan Nath, Principal Architect with GE, and Dr. Sarah Cooper, M2Mi’s VP Business Development and Engineering, will explore the IoT cloud-based platform technologies driving this change including privacy controls, data transparency and integration of real time context wi...
SYS-CON Events announced today that BMC will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. BMC delivers software solutions that help IT transform digital enterprises for the ultimate competitive business advantage. BMC has worked with thousands of leading companies to create and deliver powerful IT management services. From mainframe to cloud to mobile, BMC pairs high-speed digital innovation with robust IT industrialization – allowing customers to provide amazing user experiences with optimized IT per...
There will be 150 billion connected devices by 2020. New digital businesses have already disrupted value chains across every industry. APIs are at the center of the digital business. You need to understand what assets you have that can be exposed digitally, what their digital value chain is, and how to create an effective business model around that value chain to compete in this economy. No enterprise can be complacent and not engage in the digital economy. Learn how to be the disruptor and not the disruptee.
The Internet of Things is not only adding billions of sensors and billions of terabytes to the Internet. It is also forcing a fundamental change in the way we envision Information Technology. For the first time, more data is being created by devices at the edge of the Internet rather than from centralized systems. What does this mean for today's IT professional? In this Power Panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists will addresses this very serious issue of profound change in the industry.
Business as usual for IT is evolving into a "Make or Buy" decision on a service-by-service conversation with input from the LOBs. How does your organization move forward with cloud? In his general session at 16th Cloud Expo, Paul Maravei, Regional Sales Manager, Hybrid Cloud and Managed Services at Cisco, discusses how Cisco and its partners offer a market-leading portfolio and ecosystem of cloud infrastructure and application services that allow you to uniquely and securely combine cloud business applications and services across multiple cloud delivery models.
In his General Session at 16th Cloud Expo, David Shacochis, host of The Hybrid IT Files podcast and Vice President at CenturyLink, investigated three key trends of the “gigabit economy" though the story of a Fortune 500 communications company in transformation. Narrating how multi-modal hybrid IT, service automation, and agile delivery all intersect, he will cover the role of storytelling and empathy in achieving strategic alignment between the enterprise and its information technology.
Buzzword alert: Microservices and IoT at a DevOps conference? What could possibly go wrong? In this Power Panel at DevOps Summit, moderated by Jason Bloomberg, the leading expert on architecting agility for the enterprise and president of Intellyx, panelists peeled away the buzz and discuss the important architectural principles behind implementing IoT solutions for the enterprise. As remote IoT devices and sensors become increasingly intelligent, they become part of our distributed cloud environment, and we must architect and code accordingly. At the very least, you'll have no problem fillin...
Growth hacking is common for startups to make unheard-of progress in building their business. Career Hacks can help Geek Girls and those who support them (yes, that's you too, Dad!) to excel in this typically male-dominated world. Get ready to learn the facts: Is there a bias against women in the tech / developer communities? Why are women 50% of the workforce, but hold only 24% of the STEM or IT positions? Some beginnings of what to do about it! In her Opening Keynote at 16th Cloud Expo, Sandy Carter, IBM General Manager Cloud Ecosystem and Developers, and a Social Business Evangelist, d...
Converging digital disruptions is creating a major sea change - Cisco calls this the Internet of Everything (IoE). IoE is the network connection of People, Process, Data and Things, fueled by Cloud, Mobile, Social, Analytics and Security, and it represents a $19Trillion value-at-stake over the next 10 years. In her keynote at @ThingsExpo, Manjula Talreja, VP of Cisco Consulting Services, discussed IoE and the enormous opportunities it provides to public and private firms alike. She will share what businesses must do to thrive in the IoE economy, citing examples from several industry sectors.
In his keynote at 16th Cloud Expo, Rodney Rogers, CEO of Virtustream, discussed the evolution of the company from inception to its recent acquisition by EMC – including personal insights, lessons learned (and some WTF moments) along the way. Learn how Virtustream’s unique approach of combining the economics and elasticity of the consumer cloud model with proper performance, application automation and security into a platform became a breakout success with enterprise customers and a natural fit for the EMC Federation.
SYS-CON Events announced today that the "Second Containers & Microservices Conference" will take place November 3-5, 2015, at the Santa Clara Convention Center, Santa Clara, CA, and the “Third Containers & Microservices Conference” will take place June 7-9, 2016, at Javits Center in New York City. Containers and microservices have become topics of intense interest throughout the cloud developer and enterprise IT communities.
SYS-CON Events announced today that the "First Containers & Microservices Conference" will take place June 9-11, 2015, at the Javits Center in New York City. The “Second Containers & Microservices Conference” will take place November 3-5, 2015, at Santa Clara Convention Center, Santa Clara, CA. Containers and microservices have become topics of intense interest throughout the cloud developer and enterprise IT communities.
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo in Silicon Valley. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place Nov 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 17th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal an...