Use the Invoke system function to request a Web Service. See About Web Services for information about using Web Services in workflows.
NOTE Prior to defining the Invoke system function, you must specify the Partner Links in the Workflow Properties.
To specify the general properties for the Invoke system function
See About system steps for information about including multiple system functions in a single step.
See the note at the end of this topic for information regarding partner links that are modified after the parameters are defined for an Invoke system function.
Parameters - use workflow data fields and attachments for input and output. This option is available for simple parameters and for schemas up to two levels deep.
Choose one of the following options to specify the expression.
NOTE If the <Create parameter_name> option is not available, a field with the parameter name might already exist, or the parameter name might result in an invalid field name, such as a reserved word.
NOTE Parameter names must not contain numbers, special characters, or spaces.
XML - use XML messages for input and output. This option must be used for nested parameters more than two levels deep.
NOTE All fields in the outgoing message must be strings, so you must convert other types, such as float or integer, to strings. For example, to use data field MyFloatData, you can use convert(MyFloatData, string) in the message. This restriction applies only when using XML; in the Parameter format, Process Designer handles data conversions for the messages.
You can specify a timeout expression that will provide alternative processing after a specified amount of time.
For example, you can enter a time function such as
addminutes(systemtime(), 30)
This allows the step to wait 30 minutes before it goes to the specified timeout map.
You can use WS-ReliableMessaging technology to provide assurance that an Invoke message that is sent will be received by the target Web Service. To achieve the reliability, a standardized series of messages is exchanged between the sender and the receiver. In addition, each message is sent repeatedly until the expected acknowledgement message is received. See About WS-ReliableMessaging for information about FileNet's implementation of this technology.
NOTE WS-ReliableMessaging results in a minimum of five messages for every request, plus additional messages if retransmissions are necessary. Therefore, FileNet recommends that you use WS-ReliableMessaging only for requests that warrant this type of handling.
To specify WS-Reliable Messaging for the Invoke function
NOTE
TIP If the message is not delivered in the specified time limit, a fault will be returned in the same manner as for standard requests. For a reliable messaging request, the fault message includes the current state of the reliable message invocation, which helps to identify where the problems is occurring. Therefore, to realize the benefit of this technology, FileNet recommends that you use the fault handling options (described below) to handle any faults in an appropriate manner.
On the Faults tab, you can specify string fields or XML data fields to hold a fault message, and submaps to execute for faults specified by the Web Service, or for other faults.
NOTE The fault message returned will not include Process Engine exception codes, only the exception message.
For unexpected problems with an invokation using WS-ReliableMessaging, the status message will be appended to this fault message.
If no submap is specified and a fault occurs, the work item will go to the Malfunction queue.
In XML mode, you can specify one or more properties that will be used to identify a runtime conversation between two processes. For example, with Web Services involving purchase orders, there might be several exchanges of messages between the buyer and the seller, so you need to ensure that each message stays with the appropriate conversation. (If you are using Parameter mode, the Correlation Set tab is available for Receive, but not for Invoke.)
When you specify a correlation set for Invoke, the F_Corr<Correlation_Set_Name> field is set to the value specified by the XPath query.
See Using Web Services in FileNet workflows for examples of invoking and receiving Web Services requests.
NOTE If a partner link's endpoint is changed (for example, if you update the partner link by selecting a different version of a workflow with the corresponding Receive system function), Process Designer inspects each Invoke system function in the current workflow and updates them as follows: