Developing a REST API in ABAPIn two recent blogs, I demonstrated how to write web clients of REST APIs with XML demo application here or JSON demo application here as data transfer format. In this blog, I will focus on the server side How to implement a REST API as ABAP request handler. You can inspect all the code I am discussing here on the MIGROS BSP website Its all in Class ZCLJOBDATA. The ICF Tree. Request handlers are classes implementing the interface IFHTTPEXTENSION, which consists of one single method HANDLEREQUEST. Reference how to interact with the Calendar REST API that provides access to events, calendars, and calendar groups in Exchange Online. Below is the simple task I want to do 1 Create a simple form employee details form and use SharePoint list to save the data. You have to complete. REST API. For POST and PUT calls, pass request parameters as a JSON payload in the request body, not as URL parameters. Endpoints API calls with access token. Rest_api_explorer.png/600px-Rest_api_explorer.png' alt='Update List Item Rest Api Best' title='Update List Item Rest Api Best' />A request handler class can be attached to a path in transaction SICF. An incoming HTTP request will be analyzed by the Internet Communication Framework, trying to match the request path against the SICF path. The match process is stopped as soon as a node with an attached request handler is found. If this is the case, an instance of the handler class will be created, and the method HANDLEREQUEST will be called. Our example service is attached to the path jobattributes. The class ZCLJOBDATA is declared to be responsible for all incoming requests where the request path starts with jobattributes First Strategy HTTP Request Method. The implementation of the interface method ifhttpextensionhandlerequest forms the uppermost level of processing. Therefore, the implementation only gives the rough processing skeleton An instance for database operations, as well as an instance for the processing of the REST operation are created, the request handling is delegated to that instance, and there is a catch block for error processing in case that no instance could be determined for processing the request. Such a situation should result in an HTTP response with status code 4. Bad Request. At this place, we are using the Strategy design pattern Depending on the HTTP method GET, PUT, POST, DELETE, OPTIONS, a specific instance is created. Each possible instance corresponds to a specific strategy. Object for database operations. Get the correct rest handler instance, depending on the verb GET, PUT, POST, OPTIONS, DELETE. Do the operation. Bad Request. reason lvreason. We are using a naming convention for the instance determination The class LCLRESTGET will be associated with HTTP verb GET, LCLRESTPUT with PUT, and so on. All these classes implement the interface LIFREST. This way, we can use dynamic instance creation. Alternatively, we could have written a large CASE statement with many WHENs. The advantage of the CASE would be that the create object statement could be statically checked for syntactical correctness. I have chosen the dynamical variant since I find it clearer and more readable than a bunch of WHEN branches. Update List Item Rest Api Best' title='Update List Item Rest Api Best' />Such a good post I had a requirement to expose a REST API about 16 months ago. This wouldve come in very helpful. Grade A development Foundations and Concepts Updated Information Using the Goal Navigator Introducing vRealize Automation Service Catalog Overview Infrastructure as a Service. In addition to utilizing the HTTP verbs appropriately, resource naming is arguably the most debated and most important concept to grasp when creating an. Again, this will select almost all columns that are available to the list. Royal Caribbean Mariner Seas Wifi. Note that I said almost, because SharePoints REST API doesnt really bring. Can anyone explain or point me to a link with samples of doing Update, Delete using Jquery with the SharePoint 2010 Rest API I have the insert working and of course. Observe that the HTTP request method GET, PUT, POST, is available as pseudo header field with the name requestmethod method getrest. LCLREST lvmethod into lvclassname. Method not supported0. Second Strategy Data Transfer Format. Now we have different handler classes for the different HTTP request methods. But for all these handlers, there are some common tasks. One of these common tasks is to determine the current data transfer format, and to convert the input if available into ABAP data, and vice versa to convert the ABAP result data into the output with the desired data transfer format XML or JSON. Now, some request methods like GET do not require any  request content. So the conversion of incoming data is performed by those method handlers that know they require content data. On the other hand, there will always be a result of the following data type types. There may not always be entries in the job table. But not every component of this structure will be initial. If there is no job table, then usually there will be a message. So the conversion of the result can always be performed. Update List Item Rest Api Best' title='Update List Item Rest Api Best' />It makes sense to work with an abstract converter class, the specific subclasses containing the conversion algorithms per content type. This is the second application of the Strategy pattern. DEFINITIONThe static method LCLCONVERTER GETINSTANCE makes the distinction, depending on the Accept header field of the HTTP request class lclconverter implementation. IMPLEMENTATIONThe Common Plot for All Requests. We can extract common tasks into a superclass lclrest of all specific method handlers, implementing the interface lifresthandlerequest once for all subclasses. The common code in the superclasse needs to be mixed with specific code, implemented in the subclass and defining the specific behaviour of that subclass. To achieve this, we call at the desired point of time in lifresthandlerequest, an abstract method do, which has to be redefined in the subclasses. This do method will contain the specific action. Now, the common implementation lifresthandle in the superclass only defines the flow of the processing, leaving the concrete actions to the subclasses or to delegates like goconverter Execute the specific action by calling do,Error handling, with HTTP error code 4. Bad Request in case of conversion error wrong incoming data, or setting response data for an error message in case of an application error,The result structure is mapped to the response data structure XML or JSON, using the corresponding converter instance,Finally, the response data is placed into the body of the HTTP response, and also the appropriate response type is set applicationjson, or textxml. This is the general sketch the response processing that is valid for all HTTP request methods and for all content types XML as well as JSON. The details are contained in the called methods. Execute the specific operation. Bad request. reason   loex gettext. E. Convert result structure into JSON or XML, respectively. Place the result in the response body. A Specific Task the PUT Request. Lets look at a specific task for illustration The PUT request which always is a task to update or insert job attributes for a given ID on the database. As follows from the design, there is an own local class LCLRESTPUT handling PUT requests. Actually, for this request handler, there was only the do method itself to implement which is the absolute minimum for a specific task class to implement do is abstract in the parent class. Without an implementation, no instances could be built. DEFINITIONThe implementation goes as follows The job with the specified ID is read from the database if an ID was specified for new jobs, this is not the case,The entered data will be parsed into an lsjob structure, using the appropriate goconverter instance,And finally, the save method is called. It is implemented in the superclass, since other request methods use it, too. Job has been saved0. S.   success message. IMPLEMENTATIONNote that the implementation of this task doesnt care about the HTTP data structure, the format actually in use, nor about the details of the transfer data format. It simply works with ABAP data structures lsjob for the input and esresult for the output. Session, Identity and Locking. In the test applications neither in the JSON app nor in the XML app, there is neither login nor enqueue of the data. Since the applications are open for everybody, this works only since I dont really operate on a database table ZJOBS.