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ColdFusion 10: Returning Complex data from a REST service

There are various complex types in ColdFusion – Array, Struct, Query. When a REST service in ColdFusion returns one of these complex types, it has to be serialized to either JSON or XML format. As explained in my previous post, the HTTP protocol can be used in content type negotiation. You can specify the desired content type either by specifying it at the end of the URL or in the Accept header of HTTP request. In this post, I’ll explain the format in which the complex types are returned from a ColdFusion REST service.

JSON format:
Consider the following REST service:
<cfcomponent rest="true" restpath="/jsonSerialization" produces="application/JSON"> <cffunction name="structSerialization" access="remote" httpmethod="GET" returntype="Struct" restpath="serializeStruct"> <cfset myStruct = StructNew()> <cfset myStruct.productName = "ColdFusion"> <cfset myStruct.productVersion = 10> <cfset myStruct.codeName = "Zeus"> <cfreturn myStruct> </cffunction> <cffunction name="querySerialization" access="remote" httpmethod="GET" returntype="Query" restpath="serializeQuery"> <cfset myQuery = queryNew("productName,version,codeName", "Varchar,Integer,Varchar", [["ColdFusion", 9, "Centaur"], ["ColdFusion", 10, "Zeus"]])> <cfreturn myQuery> </cffunction> <cffunction name="arraySerialization" access="remote" httpmethod="GET" returntype="Array" restpath="serializeArray"> <cfset myArray = ArrayNew(2)> <cfset ArrayAppend(myArray, ["ColdFusion", 9, "Centaur"])> <cfset ArrayAppend(myArray, ["ColdFusion", 10, "Zeus"])> <cfreturn myArray> </cffunction> <cffunction name="cfcSerialization" access="remote" httpmethod="GET" returntype="TestComponent" restpath="serializeCFC"> <cfset obj = new TestComponent()> <cfset obj.prop1 = "CF"> <cfset obj.prop2 = "Zeus"> <cfreturn obj> </cffunction> </cfcomponent>
As you can see, the produces attribute is specified at the component level and not at the function level. This indicates that all the services in this component produce or return data in the specified format(application/json here). However, if the produces attribute is specified at both component and at the function level then the one specified at the function level would take precedence.
The complex types – Array, Struct, Query as well as a CFC can be serialized to a JSON format. The above REST service is invoked using CFHTTP with the URI: http://localhost:8500/rest/complexTypes/jsonSerialization/serializeQuery.json (to obtain query data) and then the result is de-serialized to obtain the below output:
Query_Serialized_JSON
The above struct contains the query data as well as the columns.

XML format:
Similar to the JSON format, if the produces attributes’ value is changed to application/XML then the complex data returned from a REST service is serialized to XML format. Here is the output obtained by invoking the REST service to obtain the CFC data serialized to XML format:

<COMPONENT ID="1" NAME="restapp.ComplexTypes.TestComponent">
<PROPERTY NAME="PROP1" TYPE="STRING">CF</PROPERTY>
<PROPERTY NAME="PROP2" TYPE="STRING">Zeus</PROPERTY>
</COMPONENT>

Similarly other complex data types can be serialized to JSON or XML format.
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Comments

  1. Andy PetersonApril 26, 2013 at 6:53 PM

    Thank you. Is the Service Mapping name in the example above complexTypes? Is the name of the component irrelevant because the component's restpath been declared?

    ReplyDelete
  2. Sagar GanatraApril 26, 2013 at 7:03 PM

    Here complexTypes is the mapping that you would provide when registering the directory containing RESTful CFCs. The other mapping 'jsonSerialization' is for this CFC. If you omit the restpath mapping in the cfcomponent tag then you can access it my providing the directory path to the CFC in the url. I have mentioned the details in this post: http://www.sagarganatra.com/2012/02/coldfusion-10-restful-webservices-in.html

    ReplyDelete
  3. Andy PetersonApril 26, 2013 at 8:05 PM

    Excellent. Learning so much. Thank you.

    ReplyDelete
  4. Sagar GanatraApril 26, 2013 at 8:18 PM

    Thanks Andy, you can also refer to my Adobe Developer Connect article on CF10's RESTful services here - http://www.adobe.com/devnet/coldfusion/articles/restful-web-services.html

    ReplyDelete
  5. LeptinellaMay 8, 2013 at 8:06 AM

    Have you tried produces="application/json;charset=utf-8" in the function? It seems to work for me.

    ReplyDelete
  6. JMRJune 2, 2013 at 9:09 PM

    What about an array of components that were built with ? This seems to not work with CF10, but DOES work with Railo. In CF10 it returns JSON data that has the proper keys, but null values. In Railo, the exact same code works perfectly -- both keys and values, one set for each array entry.

    ReplyDelete
  7. Sagar GanatraJune 2, 2013 at 10:59 PM

    Can you post the sample code on the Adobe CF forum. One of the engineers should be able to help you with this.

    ReplyDelete

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