ActionHandler


1   package za.co.csir.icomtek.workflow.handlers;
2   
3   import java.util.Vector  ;
4   import java.util.ArrayList  ;
5   import java.util.Iterator  ;
6   
7   import za.co.csir.icomtek.workflow.interfaces.WorkflowContext;
8   import za.co.csir.icomtek.workflow.model.Action;
9   import za.co.csir.icomtek.workflow.model.State;
10  import za.co.csir.icomtek.workflow.model.StateTransition;
11  
12  /**
13   * This class is used to execute actions from the project workflow
14   *
15   *   Actions consist of a clazz, method, name(optional), and any number of 
16   * parameters elements. Parameter elements can contain parameters which are
17   * simple static values or nested actions.
18   * If the action class tag names a module then the method will be invoked on the 
19   * module with all parameters being placed into the context. If the action class 
20   * contains non module class then this class will try to instantiate the named 
21   * class and invoke the method on it passing all parameters as method parameters 
22   * to the call.
23   *
24   *   The parameter blocks specify a value and a type or name. If the name is 
25   * specified then it is assumed that the value will be passed to a module call
26   * as a parameter in the context. If the type is specified then it is assumed
27   * that the value will be passed as a method parameter and it will be converted
28   * to an object of that type.
29   *   When specifying a hard-coded value the type field contains the java type.
30   * NOTE: always use the wrapper type for primatives
31   * 
32   */
33  public class ActionHandler extends BaseHandler {
34  
35      /**
36       * This method is used to fire off entry actions that have been specified
37       * in a state
38       *
39       * @param ctx is the context on who's behalf we are firing the actions
40       * @param state is the state containing entry actions that will be fired
41       */
42      public static void performActions (WorkflowContext ctx, 
43                                         State state) 
44          throws Exception   
45      {
46          if (state.getEntryStateActions() != null && 
47              state.getEntryStateActions().getActionAsReference() != null) {
48              performActions(ctx, state.getEntryStateActions()
49                             .getActionAsReference());
50          }
51      }
52  
53      /**
54       * This method is used to fire off exit actions that have been specified in
55       * a state transition
56       *
57       * @param ctx is the context on who's behalf we are firing the actions
58       * @param st is the state transtion containing exit actions that will be 
59       *           fired
60       */
61      public static void performActions (WorkflowContext ctx, 
62                                         StateTransition st) 
63          throws Exception   
64      {
65          if (st.getExitStateActions() != null && 
66              st.getExitStateActions().getActionAsReference() != null) {
67              performActions(ctx, st.getExitStateActions()
68                             .getActionAsReference());
69          }
70      }
71  
72      private static void performActions (WorkflowContext ctx, 
73                                          Vector   actions) 
74          throws Exception   
75      {
76          // Setup any workflow context for actions
77          try {
78              ctx.beginWorkflowAction();
79              for (Iterator   it = actions.iterator(); it.hasNext(); ) {
80                  Action action = (Action)it.next();
81                  ArrayList   reqAttVals = new ArrayList  ();
82                  try {
83                      Object   [] paramVals = populateParameterValues(action.getParameterElementAsReference(), ctx, reqAttVals);            
84                      executeAction(ctx, action, paramVals);
85                      clearRequestAttributes(ctx, reqAttVals);
86                  } catch (Exception   e) {
87                      e.printStackTrace();
88                      // It is ok if an action fails
89                  }
90              }
91          } finally {
92              ctx.endWorkflowAction();
93          }
94      }
95  }
96
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