Re: [rules-users] Drools Flow, constraint parametrization

Ricardo, If you need to access process variables and have only simple constraint expressions, I suggest you use code constraints (Java or MVEL dialect), as they have direct access to variables (and globals). If you want to use rule constraints anyway (because your constraints can become rather complex), there are a few options: - You cannot use globals to pass information used in your constraints, because globals are considered immutable with respect to rule conditions - You can put your data you want to access in your working memory. Rule constraints can then access this info just like any normal rule. - You access the variable value using the special "processInstance" rule constraint (I just added a new section in the documentation to explain): Rule constraints do not have direct access to variables defined inside the process. It is however possible to refer to the current process instance inside a rule constraint, by adding the process instance to the working memory and matching to the process instance inside your rule constraint. We have added special logic to make sure that a variable "processInstance" of type WorkflowProcessInstance will only match to the current process instance and not to other process instances in the working memory. Note that you are however responsible yourself to insert (and possibly update) the process instance into the session (for example using Java code or an (on-entry or on-exit or explicit) action in your process). The following exampleof a rule constraint will search for a person with the same name as the value stored in the variable "name" of the process: processInstance: WorkflowProcessInstance() Person( name == ( processInstance.getVariable("name") ) ) # add more constraints here ... Kris Quoting Ricardo Gil Alcañiz <rgil(a)okode.com&gt;: