List of BPEL Activities1

        List of BPEL Activities1

Assign Actitivity: This Activity provide a method for manipulation, such as copying the contents of one variable to another. Copy operation enables you to transfer information between variables, expressions, end points& other elements

Wait Activity: This Activity allows a process to specify a delay for a certain period or until a certain deadline is reached. A typical use of this activity is to invoke an operation at a certain time.
                           The wait activity is a Asynchronous process because it gives response after some period of time. In BPEL 2.0, the Wait dialog includes a Documentation tab & doesn't include a skip condition tab.


Terminate Activity: A Terminate Activity enables you to end the task of an Activity. This Activity is replaced by the exit activity in BPEL 2.0
         (For example: if a clients bad credit history or social history number is identified invalid, a loan application process is terminated, & the clients loan application is never submitted to the service loan provider.)


 Empty Activity: This Activity only used for representation purpose, it does nothing. This Activity enables you to insert a no operation instruction into a process, This Activity is useful when you must use an Activity that does nothing. In BPEL 2.0 the empty dialog includes a Documentation tab & doesn't include a skip condition tab.


 Invoke Activity: An Invoke Activity directs a web service to perform an operation. Or with an invoke activity a process can call another web service that has been defined as a partner. The Invoke can be either Synchronous or Asynchronous


 Receive Activity: This activity specifies the partner link from which to receive information and the port type and operation for the partner link to invoke. This activity waits for an asynchronous callback response message from a service, such as a leave approval service,while the BPEL Process is waiting, it is dehydrated(compressed and stored) until the callback message arrives. The receive activity plays an important role in the life cycle of a business process.


Reply Activity: A reply activity is used for sending a response after receive activity has been called. A replay is only useful in a synchronous interaction. An asynchronous reaction always has to be use of an invoke.
The combination of a receive and a reply activity forms a request-response operation on the WSDL port type for the process.


Pick Activity: The Pick will wait for the specified time (or) The Pick Activity waits till one event in a set of events occurs.When an event occurs the activities associated event are executed. Generally it is used for Leave Process, Loan Process. The two branches of Pick Activity are OnMessage & OnAlarm.


 Switch Activity: This activity consists of an ordered list of one or more conditional branches defined in a case branch, followed optionally by an otherwise branch. The branches are considered   in the order in which they appear. 
             The first branch whose condition is true is taken and provides the activity performed for the switch. If no branch with a condition is taken, then the otherwise branch is taken. If the otherwise branch is not explicitly specified, then an otherwise branch with an empty activity is assumed to be available.
            The switch activity is complete when the activity of the selected branch completes. A Switch Activity is differs in functionality from a flow activity. This Activity is replaced by the if activity in BPEL 2.0


  While Activity: In BPEL, whenever you think of a loop, think of a while. There is no for loop or do while.
            This activity supports repeated performance of a specified iterative activity. The iterative activity is repeated until the given while condition is no longer true. In BPEL 2.0, the While dialog includes a Documentation tab & doesn't include a skip condition tab.


Scope Activity: In a Programming language Scope is a group of variables and statements. In BPEL a Scope is a group of Variables and activities.
            A Scope Activity is a structured activity & it's also container activity, in that it contain other activities. A Parent scope contain child scopes, each with the possibility of creating their own variables. The Primary or parent scope variables are visible from within the whole process, while variables of the child scope are not visible to the parent.
            You can use a scope to contain a unit of work, making it easy to manage and execute, and if necessary reverse. For example, if a customer cancels a paid ticket order, the money must be returned & the ticket cancelled, without affecting orders. you can use a scope to manage these activities as a unit. Each scope offers a compensation handler, a fault handler & an event handler, variables.     



 Sequence Activity: The Sequence activity arranges and executes a collection of activities sequentially in an ordered list. In a Sequence, the first activity in a sequence executes, and when it finishes, the second activity begins.  The activity is complete when the last activity in the Sequence is finished. In a Scope more than one activity & those activities should be kept in a sequence.

o      Validate Activity: Validate variables in the list against their XML schema.