smcphpgenerator.java

SMC takes a state machine stored in a .sm file and generates a State pattern in twelve programming l

            }
            else
            {
                // This is not the first transition and it has
                // no condition.
                _source.println("else {");
            }
        }
        // There is only one guard. Does this guard have
        // a condition?
        else if (condition.length() == 0)
        {
            // No. This is a plain, old. vanilla transition.
            indent2 = _indent;
        }
        else
        {
            // Yes there is a condition.
            indent2 = _indent + "    ";

            _source.print(_indent);
            _source.print("if (");
            _source.print(condition);
            _source.println(") {");
        }

        // Now that the necessary conditions are in place, it's
        // time to dump out the transition's actions. First, do
        // the proper handling of the state change. If this
        // transition has no actions, then set the end state
        // immediately. Otherwise, unset the current state so
        // that if an action tries to issue a transition, it will
        // fail.
        if (actions.size() == 0 && endStateName.length() != 0)
        {
            fqEndStateName = endStateName;
        }
        else if (actions.size() > 0)
        {
            // Save away the current state if this is a loopback
            // transition. Storing current state allows the
            // current state to be cleared before any actions are
            // executed. Remember: actions are not allowed to
            // issue transitions and clearing the current state
            // prevents them from doing do.
            if (loopbackFlag == true)
            {
                fqEndStateName = "$endState";

                _source.print(indent2);
                _source.print(fqEndStateName);
                _source.println(" = $fsm->getState();");
            }
            else
            {
                fqEndStateName = endStateName;
            }
        }

        // Decide if runtime loopback checking must be done.
        if (defaultFlag == true &&
            transType != Smc.TRANS_POP &&
            loopbackFlag == false)
        {
            _source.print(indent2);
            _source.print(
                "$loopbackFlag = $fsm->getState()->getName() == ");
            _source.print(fqEndStateName);
            _source.println("->getName();");
        }

        // Dump out the exit actions - but only for the first
        // guard.
        // v. 1.0, beta 3: Not any more. The exit actions are
        // executed only if 1) this is a standard, non-loopback
        // transition or a pop transition.
        if (transType == Smc.TRANS_POP || loopbackFlag == false)
        {
            indent4 = indent2;

            // If this is a non-loopback, generic transition,
            // do runtime loopback checking.
            if (transType == Smc.TRANS_SET &&
                defaultFlag == true)
            {
                indent4 = indent2 + "    ";

                _source.print(indent2);
                _source.println("if ($loopbackFlag == false) {");
            }

            _source.print(indent4);
            _source.println("$fsm->getState()->Exit_($fsm);");
            if (transType == Smc.TRANS_SET &&
                defaultFlag == true)
            {
                _source.print(indent2);
                _source.println("}");
            }
        }

        // Dump out this transition's actions.
        if (actions.isEmpty() == true)
        {
            List<SmcAction> entryActions =
                state.getEntryActions();
            List<SmcAction> exitActions = state.getExitActions();

            // If this is an if or else body, then give it a
            // pass.
            if (condition.length() > 0 ||
                _guardCount > 1)
            {
                _source.print(indent2);
                _source.println("# No actions.");
            }
            // If there are:
            // 1. No entry actions,
            // 2. No exit actions,
            // 3. Only one guard,
            // 4. No condition,
            // 5. No actions,
            // 6. Not a loopback, push or pop transition and
            // 7. No debug code being generated.
            // then give this transition a pass.
            else if (_guardCount == 1 &&
                     (entryActions == null ||
                      entryActions.isEmpty() == true) &&
                     (exitActions == null ||
                      exitActions.isEmpty() == true) &&
                     transType != Smc.TRANS_PUSH &&
                     transType != Smc.TRANS_POP &&
                     loopbackFlag == true &&
                     Smc.isDebug() == false)
            {
                _source.print(indent2);
                _source.println("# No actions.");
                _source.print(indent2);
            }

            indent3 = indent2;
        }
        else
        {
            // Now that we are in the transition, clear the
            // current state.
            _source.print(indent2);
            _source.println("$fsm->clearState();");

            // v. 2.0.0: Place the actions inside a try/finally
            // block. This way the state will be set before an
            // exception leaves the transition method.
            // v. 2.2.0: Check if the user has turned off this
            // feature first.
            if (Smc.isNoCatch() == false)
            {
                _source.print(indent2);
                _source.println("$exception = NULL;");
                _source.print(indent2);
                _source.println("try {");

                indent3 = indent2 + "    ";
            }
            else
            {
                indent3 = indent2;
            }

            indent4 = _indent;
            _indent = indent3;

            for (SmcAction action: actions)
            {
                action.accept(this);
            }

            _indent = indent4;

            // v. 2.2.0: Check if the user has turned off this
            // feature first.
            // PHP has no 'finally', thus emulate it with catch
            // and rethrow at the end.
            // http://bugs.php.net/bug.php?id=32100
            if (Smc.isNoCatch() == false)
            {
                _source.print(indent2);
                _source.println("}");
                _source.print(indent2);
                _source.println("catch (Exception $exception) {}");
            }
        }

        // Print the setState() call, if necessary. Do NOT
        // generate the set state it:
        // 1. The transition has no actions AND is a loopback OR
        // 2. This is a push or pop transition.
        if (transType == Smc.TRANS_SET &&
            (actions.isEmpty() == false ||
             loopbackFlag == false))
        {
            _source.print(indent2);
            _source.print("$fsm->setState(");
            _source.print(fqEndStateName);
            _source.println(");");
        }
        else if (transType == Smc.TRANS_PUSH)
        {
            // Set the next state so this it can be pushed
            // onto the state stack. But only do so if a clear
            // state was done.
            if (loopbackFlag == false ||
                actions.isEmpty() == false)
            {
                _source.print(indent2);
                _source.print("$fsm->setState(");
                _source.print(fqEndStateName);
                _source.println(");");
            }

            // Before doing the push, execute the end state's
            // entry actions (if any) if this is not a loopback.
            if (loopbackFlag == false)
            {
                if (defaultFlag == true)
                {
                    indent4 = indent2 + "    ";
                    _source.print(indent2);
                    _source.println("if ($loopbackFlag == false) {");
                }
                else
                {
                    indent4 = indent2;
                }

                _source.print(indent4);
                _source.println("$fsm->getState()->Entry($fsm);");

                if (defaultFlag == true)
                {
                    _source.print(indent2);
                    _source.println("}");
                }
            }

            _source.print(indent2);
            _source.print("$fsm->pushState(");
            _source.print(pushStateName);
            _source.println(");");
        }
        else if (transType == Smc.TRANS_POP)
        {
            _source.print(indent2);
            _source.println("$fsm->popState();");
        }

        // Perform the new state's enty actions.
        // v. 1.0, beta 3: Not any more. The entry actions are
        // executed only if 1) this is a standard, non-loopback
        // transition or a push transition.
        if ((transType == Smc.TRANS_SET &&
             loopbackFlag == false) ||
             transType == Smc.TRANS_PUSH)
        {
            indent4 = indent2;

            // If this is a non-loopback, generic transition,
            // do runtime loopback checking.
            if (transType == Smc.TRANS_SET &&
                defaultFlag == true)
            {
                indent4 = indent2 + "    ";

                _source.print(indent2);
                _source.println("if ($loopbackFlag == false) {");
            }

            _source.print(indent4);
            _source.println("$fsm->getState()->Entry($fsm);");

            if (transType == Smc.TRANS_SET &&
                defaultFlag == true)
            {
                _source.print(indent2);
                _source.println("}");
            }
        }

        // If there was a try/finally, then put the closing
        // brace on the finally block.
        // v. 2.2.0: Check if the user has turned off this
        // feature first.
        // PHP: rethrow the exception to emulate finally.
        if (actions.size() > 0 && Smc.isNoCatch() == false)
        {
            _source.print(indent2);
            _source.println("if ($exception != NULL) {");
            _source.print(indent2);
            _source.println("    throw $exception;");
            _source.print(indent2);
            _source.println("}");
        }

        // If there is a transition associated with the pop, then
        // issue that transition here.
        if (transType == Smc.TRANS_POP &&
            endStateName.equals(NIL_STATE) == false &&
            endStateName.length() > 0)
        {
            String popArgs = guard.getPopArgs();

            _source.print(indent2);
            _source.print("$fsm->");
            _source.print(endStateName);
            _source.print("(");

            // Output any and all pop arguments.
            if (popArgs.length() > 0)
            {
                _source.print(popArgs);
                _source.println();
                _source.print(indent2);
                _source.println(");");
            }
            else 
            {
                _source.println(");");
            }
        }

        // If this is a guarded transition, it will be necessary
        // to close off the "if" body. DON'T PRINT A NEW LINE!
        // Why? Because an "else" or "else if" may follow and we
        // won't know until we go back to the transition source
        // generator whether all clauses have been done.
        if (_guardCount > 1)
        {
            _source.print(_indent);
            _source.print("}");
        }

        return;
    } // end of visit(SmcGuard)

    public void visit(SmcAction action)
    {
        String name = action.getName();
        Iterator<String> it;
        String sep;

        // Need to distinguish between FSMContext actions and
        // application class actions. If the action is
        // "emptyStateStack", then pass it to the context.
        // Otherwise, let the application class handle it.
        _source.print(_indent);
        if (name.equals("emptyStateStack") == true)
        {
            _source.print("$fsm->");
        }
        else
        {
            _source.print("$ctxt->");
        }
        _source.print(name);
        _source.print("(");

        for (it = action.getArguments().iterator(), sep = "";
             it.hasNext() == true;
             sep = ", ")
        {
            _source.print(sep);
            _source.print(it.next());
        }

        _source.println(");");

        return;
    } // end of visit(SmcAction)

    public void visit(SmcParameter parameter)
    {
        String type = parameter.getType();

        if (type.equals(""))
        {
            _source.print(parameter.getName());
        }
        else
        {
            _source.print(type);
            _source.print(" ");
            _source.print(parameter.getName());
        }

        return;
    } // end of visit(SmcParameter)

//---------------------------------------------------------------
// Member data
//
} // end of class SmcPhpGenerator

//
// CHANGE LOG
// $Log: SmcPhpGenerator.java,v $
// Revision 1.1  2008/04/22 16:05:24  fperrad
// - add PHP language (patch from Toni Arnold)
//
//