Task 5: Adding BOM methods and mapping them to the XOM

You add BOM methods to a BOM class to help verbalize your rules. To keep the XOM synchronized with the BOM, you must map the new BOM methods to the XOM.

About this task

You use methods to specify conditions and actions in your rules. You create methods in Rule Designer.

When you add methods to the BOM, you create members in the BOM that are not defined in the XOM. This mismatch creates errors in your rule project. To avoid this mismatch, you map the new methods to the XOM by using the BOM Editor.

Note: You must not make any changes directly in the XOM.

In this task, you add the following methods, verbalize them, and then apply BOM-to-XOM mapping.

Class Method Description
Loan public void addMessage(String msg) Defines what is needed to pass information from the rules.
Loan public void reject Identifies whether the loan application was rejected.
Borrower public long computeIncomeAfterTax Computes the income of the borrower, after tax.

Procedure

To add BOM methods and map them to the XOM, start by adding the addMessage method:

  1. On the Class page of the BOM editor, in the Members section, click New.
  2. On the Member page of the New Member dialog, make the following entries.
    Field Data entry
    Type Select Method
    Name Type addMessage
    Method type Type void
  3. On the same page, click Add and then complete the Method Argument dialog as follows.
    Field Data entry
    Name Type msg
    Type Type java.lang.String
  4. Click OK to close the Method Argument dialog, and then click Finish.

    On the Class page of the BOM editor, the Members list now includes the addMessage method.

  5. Double-click the addMessage method, and in the Member Verbalization section of the BOM Editor, click Create to view the default verbalization:

    add {0} to the messages of {this}

    You are not going to change this verbalization.

  6. Scroll down to the BOM to XOM mapping section of the BOM Editor and then click the arrow next to the Body field to open the BOM-to-XOM Mapping editor.
  7. Type the following Java™ code: 
    this.messages.add(msg);
  8. Save your work.
  9. Add the reject method to the Loan class and then save it:

    On the Member page of the New Member dialog, make the following entries.

    Field Data entry
    Type Select Method
    Name Type reject
    Method type Type void

    You do not add parameters for this method.

    The following table shows you what to enter for the verbalization and the BOM-to-XOM mapping.

    Verbalization BOM-to-XOM mapping
    Accept the default verbalization, reject {this} this.approved = false;
  10. Add the computeIncomeAfterTax method to the Borrower class and then save it:

    On the Member page of the New Member dialog, make the following entries.

    Field Data entry
    Type Select Method
    Name Type computeIncomeAfterTax
    Method type Type float

    You do not add parameters to this method.

    The following table shows you what to enter for the verbalization and the BOM-to-XOM mapping.

    Verbalization BOM-to-XOM mapping
    Change the verbalization to the income after tax of {this} 
    if (this.yearlyIncome < 24000) {
  return this.yearlyIncome;
}
 else {
  return java.lang.Math.round(this.yearlyIncome * 0.9F);
}
  11. In the Outline view, in the model package, expand the Borrower class to view the computeIncomeAfterTax method, and then expand the Loan class to view the addMessage and reject methods you added.