JSXM Maven Plugin

Adding memory to the model

Let’s say that we want to count the number of times that the machine received the input on at the OFF state.

We first introduce a memory variable in the memory section of the specification:

<memory>
  <declaration>
    int counter;
  </declaration>
  <initial >
    counter = 0;
  </initial>
  <display >
    "On_Counter :" + counter
  </display>
</memory>

The text within the <declaration>, <initial> and <display> XML tags is in-line Java code. You declare the variables you wish to use, you initialize them and you provide a way to be displayed. Notice that within the display you enter code that will render as a string.

Adding effects to processing functions

Let us now change the functions that handle the message on. We will add an <effect> tag with in-line Java code that will increase the counter memory variable.

<function name="SwitchOn" input="on" output="onOut" xsi:type="OutputFunction" >
  <effect>
    counter++;
  </effect>
</function>

Animate the model and notice the value of the memory changing as you send the message on at the OFF state:

[INFO ] [....] ------------------------------------------------------------
[INFO ] [....] STATE  : ON
[INFO ] [....] MEMORY : On_Counter :3
[INFO ] [....] ------------------------------------------------------------

Adding preconditions (guards) to processing functions

We can add a condition under which the function will trigger with the specific input. The condition can depend on the memory variable. We will add an <precondition> tag with in-line Java code (evaluating to a boolean value) that will check if the counter memory variable is less than 2:

<function name="SwitchOn" input="on" output="onOut" xsi:type="OutputFunction" >
  <precondition>
    counter &lt; 2
  </precondition>
  <effect>
    counter++;
  </effect>
</function>

NOTE: Within the in-line Java code you cannot use the symbols <, > and &. Instead you should type &lt;, &gt; and &amp;.

Definition of Complex Inputs and Outputs

The input and the output messages can carry typed values as arguments. Let us add to the inputs a complex input setCounter(x) where x is an integer argument:

<inputs>
...
  <input name="setCounter">
    <arg name="newCounterValue" type="xs:int" />
  </input>
...
</inputs>

There can be many arg elements within each input.

Similarly we can add a complex output:

<outputs>
...
  <output name="setCounterOut">
    <result name="outValue" type="xs:int" />
  </output>
...
</outputs>

There can be many arg elements within each input and many result elements within each output.

JSXM supports most of the XSD types such as xs:int, xs:byte, xs:decimal, xs:string, xs:boolean and xs:char.

Handling of Complex Inputs and Outputs in functions

We will add a new processing function SetCounter that will process the complex input and will produce the complex output.

<function name="SetCounter" input="setCounter" output="setCounterOut" xsi:type="OutputFunction" >
  <effect>
    counter = setCounter.get_newCounterValue();
    setCounterOut.outValue = counter;
  </effect>
</function>

Notice the syntax for accessing the arguments of an input: inputName.get_argName(). inputName in this case is setCounter and argName is newCounterValue as defined in the definition of the input.

The syntax for setting the results of the outputs is easier: outputName.resultName. outputName in this case is setCounterOut and resultName is outValue as defined in the definition of the output. We add the transition with the new processing function in both states as a self-transition.

<transitions>
...
  <transition from="OFF" function="SetCounter" to="OFF" />
  <transition from="ON" function="SetCounter" to="ON" />
...
</transitions>

Animate the model and notice what when you send the message setCounter an input window pops up in which you enter the number for the newCounterValue argument. Notice also the log screen of the animation. If you enter 2 then the input is setCounter(2) and the output is setCounterOut_2. Also notice how the memory variable is changing:

[INFO ] [22:55:47.492] Input  :
[INFO ] [22:55:47.494] Input argument: [newCounterValue]
[INFO ] [22:55:47.494] Type: xs:int value :2
[INFO ] [22:55:47.496] ---org.jsxm.jsxmcore.types.CounterSXM@14adde7
[INFO ] [22:55:47.497] ---org.jsxm.jsxmcore.types.CounterSXM@14adde7   STATE : OFF
[INFO ] [22:55:47.498] ---org.jsxm.jsxmcore.types.CounterSXM@14adde7  MEMORY : On_Counter :0
[INFO ] [22:55:47.498] ---org.jsxm.jsxmcore.types.CounterSXM@14adde7   INPUT : setCounter(2)
[INFO ] [22:55:47.504] ---org.jsxm.jsxmcore.types.CounterSXM@14adde7  OUTPUT : setCounterOut_2
[INFO ] [22:55:47.504] ---
[INFO ] [22:55:47.505] Output : setCounterOut_2
[INFO ] [22:55:47.505] ------------------------------------------------------------
[INFO ] [22:55:47.506] STATE  : OFF
[INFO ] [22:55:47.506] MEMORY : On_Counter :2
[INFO ] [22:55:47.506] ------------------------------------------------------------
[INFO ] [22:55:47.507] Input  :