Abstract:
A system and method for parameter-driven value conversion in a client/server architecture is presented. A request is received from a client computer for an application service. The request includes a parameter defining a data field for a conversion and a conversion ID that specifies the conversion. A lookup is performed of a converter in a conversion registry based on the conversion ID, and the converter is then called to perform the conversion of the data field defined by the parameter in the request, to generate a converted data field. Finally, the converted data field is returned to the protocol handler.

Description:
TECHNICAL FIELD 
     The subject matter described herein relates to client/server computing, and more particularly to a parameter-driven value conversion framework in client/server architectures. 
     BACKGROUND 
     In a client server architecture there is often the demand to convert business data values from an internal server side representation into an external client side representation and inversely. A simple example of such data is a date like 08/17/2011, which could have an internal format 20110817 and multiple possible external formats such as 17.08.2011 (or others that are not based on the Gregorian calendar). Note that the representation could depend on the region from which the service is called. Other examples include timestamps, status codes, etc. 
     Current server applications expose the data values of structured business data in a fixed representation, often even in an internal but non-human readable format. A common solution to this problem is to implement some logic in the client to adjust this data representation to a desired format. In the emerging technology of mobile business scenarios, there are more and more clients that will be used “out of the box” and where the consumer of a service has no control over the client implementation. Thus there is a growing need to shift the control over the data values into the service calls and to enable the clients to be configured differently for the client side value representation. 
     Accordingly, what is needed is a solution to have client side control over the data values exposed by a consumed service. 
     SUMMARY 
     In one aspect, a computer-implemented method is disclosed. The method includes receiving, by a protocol handler of a server computer, a request from a client computer for an application service. The request includes a parameter defining a data field for a conversion and a conversion ID that specifies the conversion. The method further includes performing, by a conversion handler associated with the protocol handler, a lookup of a converter in a conversion registry based on the conversion ID. The method further includes calling, by the conversion handler, the converter to perform the conversion of the data field defined by the parameter in the request, to generate a converted data field, returning the converted data field to the protocol handler. 
     Implementations of the current subject matter can include, but are not limited to, systems and methods consistent including one or more features are described as well as articles that comprise a tangibly embodied machine-readable medium operable to cause one or more machines (e.g., computers, etc.) to result in operations described herein. Similarly, computer systems are also described that may include one or more processors and one or more memories coupled to the one or more processors. A memory, which can include a computer-readable storage medium, may include, encode, store, or the like one or more programs that cause one or more processors to perform one or more of the operations described herein. Computer implemented methods consistent with one or more implementations of the current subject matter can be implemented by one or more data processors residing in a single computing system or multiple computing systems. Such multiple computing systems can be connected and can exchange data and/or commands or other instructions or the like via one or more connections, including but not limited to a connection over a network (e.g. the Internet, a wireless wide area network, a local area network, a wide area network, a wired network, or the like), via a direct connection between one or more of the multiple computing systems, etc. 
     Implementations of the current subject matter can provide one or more advantages. For example, the system and method described herein allows further using out of the box clients and supports better decoupling of service and client applications. 
     The details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features and advantages of the subject matter described herein will be apparent from the description and drawings, and from the claims. While certain features of the currently disclosed subject matter are described for illustrative purposes in relation to an enterprise resource software system or other business software solution or architecture, it should be readily understood that such features are not intended to be limiting. The claims that follow this disclosure are intended to define the scope of the protected subject matter. 
    
    
     
       DESCRIPTION OF DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, show certain aspects of the subject matter disclosed herein and, together with the description, help explain some of the principles associated with the disclosed implementations. In the drawings, 
         FIG. 1  is a diagram illustrating aspects of a system showing features consistent with implementations of the current subject matter; and 
         FIG. 2  is a process flow diagram illustrating aspects of a method having one or more features consistent with implementations of the current subject matter; and 
         FIG. 3  is a process flow diagram illustrating other aspects of a method having one or more features consistent with implementations of the current subject matter; 
     
    
    
     When practical, similar reference numbers denote similar structures, features, or elements. 
     DETAILED DESCRIPTION 
     To address these and potentially other issues with currently available solutions, methods, systems, articles of manufacture, and the like consistent with one or more implementations of the current subject matter can, among other possible advantages, provide a parameter-driven value conversion framework in client/server architectures. 
     In accordance with various implementations, introduces a new parameter is introduced to control data value conversions in the protocol layer between the client and server. In this parameter, names of various fields to be converted and a unique conversion ID are passed in tuples from client to server. These parameter values are evaluated on the server, and the conversion routines defined by the conversion Id are processed for the field values defined by the passed field names. 
       FIG. 1  illustrates a conversion framework  100  of a client/server architecture of one or more servers  101  communicating with one or more clients  103 . The conversion framework  100  includes a conversion registry  102 , a converter interface  104 , a conversion handler  106 , and a data converter  108 . Conversion IDs are stored together in the conversion registry  102  with the corresponding conversion modules that execute a conversion from an internal server-side value representation into external client-side representation, and conversely. Calculation of the conversions is performed by the converter interface  104 , which defines the modules and signature for the conversions. Accordingly, the framework is extensible for new conversions that can be registered under a unique conversion ID in the conversion registry  102 . 
     The conversion handler  106  communicates with a central protocol handler  110 , which is the central point of the server  101  where incoming requests from, and outgoing responses of the protocol to the client  103  are processed. Incoming parameters and values are passed to the protocol handler  110 , which passes the request to a service implementation  112 , which implements the requested service to generate outgoing result data. The outgoing data is centrally passed by the protocol handler  110  to the conversion handler  106 . The conversion handler  106  looks up the conversion modules in the conversion registry  102  with the passed conversion IDs, and triggers these converter modules  108  for the converter interface  104  to calculate the converted values for the past field names. 
       FIG. 2  illustrates a read access process  200  of a conversion framework, e.g., when requested application service is performed before data values are converted to an external representation. At  202 , the protocol handler of a server receives a request from a client for an application service. The request includes a conversion parameter. At  204 , the protocol handler passes the request to a service implementation of the application, which implements the service requested by the request. At  206 , the service implementation of the application passes the result of the requested service to the protocol handler. 
     At  208 , the protocol handler passes the result and associated parameters to a conversion layer or framework associated with the server, and in particular to a conversion handler associated with the protocol handler. At  210 , the conversion handler executes a lookup for conversion modules stored in a conversion registry, using a conversion ID as part of the parameters associated with the result. At  212 , one or more converters, or conversion modules, are called, preferably by the conversion handler and based on the lookup in the conversion registry. At  214 , each of the one or more converters converts a value associated with the result to a value corresponding to an external representation, i.e., a representation used by the client or client environment. 
     At  216 , the conversion handler updates the result with the converted value(s), and at  218 , returns the updated result to the protocol handler, preferably that handled the initial request. At  220 , the protocol handler sends the result, with the updated and converted value(s), to the client to fulfill the request and provide the requested result using a representation for at least some data values that are specific to the client or the client environment. 
       FIG. 3  illustrates a write access process  300  of a conversion framework, e.g., when requested application service is performed after data values are converted from an external representation to an internal representation. At  302 , a client sends a request to a protocol handler. The request includes a parameter and values in an external representation, i.e. a representation used by the client or in the client environment. At  304 , the protocol handler passes the request to a conversion handler of a conversion layer. 
     At  306 , the conversion handler performs a lookup of one or more converters, or conversion modules, in a conversion registry, based at least in part on conversion IDs associated with the parameters. At  308 , the conversion handler calls the converters for filed name conversion ID tuples, to execute a conversion routine on the associated data values. By  310 , each of the called converters returns values converted into an internal representation, i.e. a representation used by the server or server environment. 
     At  312 , the conversion handler updates the request with the converted values, and passes the updated request to the protocol handler. At  314 , the protocol handler passes the updated request to the service implementation to execute the service requested by the request from the client. At  316 , the requested application service is processed with the internal values, or the converted values from the external representation of the data values in the initial request from the client. 
     One or more aspects or features of the subject matter described herein can be realized in digital electronic circuitry, integrated circuitry, specially designed application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) computer hardware, firmware, software, and/or combinations thereof. These various aspects or features can include implementation in one or more computer programs that are executable and/or interpretable on a programmable system including at least one programmable processor, which can be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device. The programmable system or computing system may include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. 
     These computer programs, which can also be referred to as programs, software, software applications, applications, components, or code, include machine instructions for a programmable processor, and can be implemented in a high-level procedural and/or object-oriented programming language, and/or in assembly/machine language. As used herein, the term “machine-readable medium” refers to any computer program product, apparatus and/or device, such as for example magnetic discs, optical disks, memory, and Programmable Logic Devices (PLDs), used to provide machine instructions and/or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term “machine-readable signal” refers to any signal used to provide machine instructions and/or data to a programmable processor. The machine-readable medium can store such machine instructions non-transitorily, such as for example as would a non-transient solid-state memory or a magnetic hard drive or any equivalent storage medium. The machine-readable medium can alternatively or additionally store such machine instructions in a transient manner, such as for example as would a processor cache or other random access memory associated with one or more physical processor cores. 
     To provide for interaction with a user, one or more aspects or features of the subject matter described herein can be implemented on a computer having a display device, such as for example a cathode ray tube (CRT) or a liquid crystal display (LCD) or a light emitting diode (LED) monitor for displaying information to the user and a keyboard and a pointing device, such as for example a mouse or a trackball, by which the user may provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well. For example, feedback provided to the user can be any form of sensory feedback, such as for example visual feedback, auditory feedback, or tactile feedback; and input from the user may be received in any form, including, but not limited to, acoustic, speech, or tactile input. Other possible input devices include, but are not limited to, touch screens or other touch-sensitive devices such as single or multi-point resistive or capacitive trackpads, voice recognition hardware and software, optical scanners, optical pointers, digital image capture devices and associated interpretation software, and the like. 
     The subject matter described herein can be embodied in systems, apparatus, methods, and/or articles depending on the desired configuration. The implementations set forth in the foregoing description do not represent all implementations consistent with the subject matter described herein. Instead, they are merely some examples consistent with aspects related to the described subject matter. Although a few variations have been described in detail above, other modifications or additions are possible. In particular, further features and/or variations can be provided in addition to those set forth herein. For example, the implementations described above can be directed to various combinations and subcombinations of the disclosed features and/or combinations and subcombinations of several further features disclosed above. In addition, the logic flows depicted in the accompanying figures and/or described herein do not necessarily require the particular order shown, or sequential order, to achieve desirable results. Other implementations may be within the scope of the following claims.