Welcome!

You will be redirected in 30 seconds or close now.

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

Related Topics: ColdFusion, Microservices Expo, 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
China Unicom exhibit at the 19th International Cloud Expo, which took place at the Santa Clara Convention Center in Santa Clara, CA, in November 2016. China United Network Communications Group Co. Ltd ("China Unicom") was officially established in 2009 on the basis of the merger of former China Netcom and former China Unicom. China Unicom mainly operates a full range of telecommunications services including mobile broadband (GSM, WCDMA, LTE FDD, TD-LTE), fixed-line broadband, ICT, data communica...
My team embarked on building a data lake for our sales and marketing data to better understand customer journeys. This required building a hybrid data pipeline to connect our cloud CRM with the new Hadoop Data Lake. One challenge is that IT was not in a position to provide support until we proved value and marketing did not have the experience, so we embarked on the journey ourselves within the product marketing team for our line of business within Progress. In his session at @BigDataExpo, Sum...
With the introduction of IoT and Smart Living in every aspect of our lives, one question has become relevant: What are the security implications? To answer this, first we have to look and explore the security models of the technologies that IoT is founded upon. In his session at @ThingsExpo, Nevi Kaja, a Research Engineer at Ford Motor Company, will discuss some of the security challenges of the IoT infrastructure and relate how these aspects impact Smart Living. The material will be delivered i...
Apache Hadoop is emerging as a distributed platform for handling large and fast incoming streams of data. Predictive maintenance, supply chain optimization, and Internet-of-Things analysis are examples where Hadoop provides the scalable storage, processing, and analytics platform to gain meaningful insights from granular data that is typically only valuable from a large-scale, aggregate view. One architecture useful for capturing and analyzing streaming data is the Lambda Architecture, represent...
As organizations realize the scope of the Internet of Things, gaining key insights from Big Data, through the use of advanced analytics, becomes crucial. However, IoT also creates the need for petabyte scale storage of data from millions of devices. A new type of Storage is required which seamlessly integrates robust data analytics with massive scale. These storage systems will act as “smart systems” provide in-place analytics that speed discovery and enable businesses to quickly derive meaningf...
Your homes and cars can be automated and self-serviced. Why can't your storage? From simply asking questions to analyze and troubleshoot your infrastructure, to provisioning storage with snapshots, recovery and replication, your wildest sci-fi dream has come true. In his session at @DevOpsSummit at 20th Cloud Expo, Dan Florea, Director of Product Management at Tintri, will provide a ChatOps demo where you can talk to your storage and manage it from anywhere, through Slack and similar services ...
SYS-CON Events announced today that Ocean9will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Ocean9 provides cloud services for Backup, Disaster Recovery (DRaaS) and instant Innovation, and redefines enterprise infrastructure with its cloud native subscription offerings for mission critical SAP workloads.
The taxi industry never saw Uber coming. Startups are a threat to incumbents like never before, and a major enabler for startups is that they are instantly “cloud ready.” If innovation moves at the pace of IT, then your company is in trouble. Why? Because your data center will not keep up with frenetic pace AWS, Microsoft and Google are rolling out new capabilities In his session at 20th Cloud Expo, Don Browning, VP of Cloud Architecture at Turner, will posit that disruption is inevitable for c...
SYS-CON Events announced today that SoftLayer, an IBM Company, has been named “Gold Sponsor” of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2016, at the Javits Center in New York, New York. SoftLayer, an IBM Company, provides cloud infrastructure as a service from a growing number of data centers and network points of presence around the world. SoftLayer’s customers range from Web startups to global enterprises.
SYS-CON Events announced today that Conference Guru has been named “Media Sponsor” of SYS-CON's 20th International Cloud Expo, which will take place on June 6–8, 2017, at the Javits Center in New York City, NY. A valuable conference experience generates new contacts, sales leads, potential strategic partners and potential investors; helps gather competitive intelligence and even provides inspiration for new products and services. Conference Guru works with conference organizers to pass great dea...
SYS-CON Events announced today that Technologic Systems Inc., an embedded systems solutions company, will exhibit at SYS-CON's @ThingsExpo, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Technologic Systems is an embedded systems company with headquarters in Fountain Hills, Arizona. They have been in business for 32 years, helping more than 8,000 OEM customers and building over a hundred COTS products that have never been discontinued. Technologic Systems’ pr...
SYS-CON Events announced today that CA Technologies has been named “Platinum Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY, and the 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. CA Technologies helps customers succeed in a future where every business – from apparel to energy – is being rewritten by software. From ...
With major technology companies and startups seriously embracing Cloud strategies, now is the perfect time to attend @CloudExpo | @ThingsExpo, June 6-8, 2017, at the Javits Center in New York City, NY and October 31 - November 2, 2017, Santa Clara Convention Center, CA. Learn what is going on, contribute to the discussions, and ensure that your enterprise is on the right path to Digital Transformation.
SYS-CON Events announced today that Telecom Reseller has been named “Media Sponsor” of SYS-CON's 20th International Cloud Expo, which will take place on June 6–8, 2017, at the Javits Center in New York City, NY. Telecom Reseller reports on Unified Communications, UCaaS, BPaaS for enterprise and SMBs. They report extensively on both customer premises based solutions such as IP-PBX as well as cloud based and hosted platforms.
SYS-CON Events announced today that Loom Systems will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Founded in 2015, Loom Systems delivers an advanced AI solution to predict and prevent problems in the digital business. Loom stands alone in the industry as an AI analysis platform requiring no prior math knowledge from operators, leveraging the existing staff to succeed in the digital era. With offices in S...
SYS-CON Events announced today that Interoute, owner-operator of one of Europe's largest networks and a global cloud services platform, has been named “Bronze Sponsor” of SYS-CON's 20th Cloud Expo, which will take place on June 6-8, 2017 at the Javits Center in New York, New York. Interoute is the owner-operator of one of Europe's largest networks and a global cloud services platform which encompasses 12 data centers, 14 virtual data centers and 31 colocation centers, with connections to 195 add...
SYS-CON Events announced today that T-Mobile will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. As America's Un-carrier, T-Mobile US, Inc., is redefining the way consumers and businesses buy wireless services through leading product and service innovation. The Company's advanced nationwide 4G LTE network delivers outstanding wireless experiences to 67.4 million customers who are unwilling to compromise on ...
In his session at @ThingsExpo, Eric Lachapelle, CEO of the Professional Evaluation and Certification Board (PECB), will provide an overview of various initiatives to certifiy the security of connected devices and future trends in ensuring public trust of IoT. Eric Lachapelle is the Chief Executive Officer of the Professional Evaluation and Certification Board (PECB), an international certification body. His role is to help companies and individuals to achieve professional, accredited and worldw...
SYS-CON Events announced today that Infranics will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Since 2000, Infranics has developed SysMaster Suite, which is required for the stable and efficient management of ICT infrastructure. The ICT management solution developed and provided by Infranics continues to add intelligence to the ICT infrastructure through the IMC (Infra Management Cycle) based on mathemat...
SYS-CON Events announced today that SD Times | BZ Media has been named “Media Sponsor” of SYS-CON's 20th International Cloud Expo, which will take place on June 6–8, 2017, at the Javits Center in New York City, NY. BZ Media LLC is a high-tech media company that produces technical conferences and expositions, and publishes a magazine, newsletters and websites in the software development, SharePoint, mobile development and commercial UAV markets.