Developing client applications

You can invoke a deployed ruleset from a client application through a SOAP or a REST web service.

Execution components
Execution components are components that enable the execution of a ruleset by the execution unit (XU). You choose between execution components depending on the ruleset deployment and execution platform, and on the execution pattern.
Execution patterns
Rule Execution Server supports synchronous execution patterns and asynchronous messaging through the Java™ Message Service (JMS) API.
Rule sessions
A rule session is a runtime connection between a client and a rule engine. Rule sessions use rule engine resources.
Setting up ruleset execution traces
You can activate traces of ruleset execution by using a specific application programming interface (API). You can start from the provided code sample to write your own code.
Ruleset interceptors
You can implement a ruleset interceptor on rule sessions to make ruleset selection depend on certain events that involve modified RuleApp or ruleset properties.
Ruleset parsing and the ruleset cache
Rulesets are parsed synchronously or asynchronously. With asynchronous parsing, which is set by default, execution of a new deployed version of a ruleset is not delayed by parsing. You can use a property to set ruleset parsing to synchronous.
RuleApp execution code generators
To call a ruleset on Rule Execution Server, you must write execution code to locate a deployed RuleApp that contains the ruleset on an application server. Decision Server includes a set of generators for you to create execution code, together with the necessary configuration parameters and resources for a new client project. You can use the code generators to create ruleset execution code for your Eclipse client projects.
Creating a client for Rule Execution Server
To execute rulesets in Rule Execution Server, you must create session-type-specific client projects. In Rule Designer, you can either create client projects for decision service, or client projects for RuleApps. You can modify the provided execution code generators and create your own.
Executing rules by using the REST service
Decision Server provides a Representational State Transfer (REST) service for ruleset execution. You can use it to execute rulesets through the HTTP protocol by using the XML or the JSON format.
JNDI bindings
Rule Execution Server supports local and remote JNDI bindings.
Cascading ruleset execution
Cascading ruleset execution is an execution of a ruleset from rules of another ruleset in a different instance of an execution unit (XU).
Usage of Java date and time types in HTDS
You have a ruleset based on a Java XOM model that contains some fields with date and time types from the Java SE 8 java.time package (also known as JSR 310). You must annotate your Java XOM model for the date and time types if you plan to execute SOAP, REST XML, and REST JSON requests or generate sample requests with a hosted transparent decision service (HTDS).