How to use org.drools.workbench.models.datamodel.rule

public static Collection<InterpolationVariable> extractInterpolationVariables(final String text) {
  if (text == null || text.length() == 0) {
    return Collections.emptyList();
  }
  List<InterpolationVariable> interpolationVariableList = new ArrayList<>();
  int pos = 0;
  while ((pos = text.indexOf("@{",
                pos)) != -1) {
    int end = text.indexOf('}',
                pos + 2);
    if (end != -1) {
      String varName = text.substring(pos + 2,
                      end);
      pos = end + 1;
      InterpolationVariable var = new InterpolationVariable(varName,
                                 DataType.TYPE_OBJECT);
      interpolationVariableList.add(var);
    } else {
      break;
    }
  }
  return interpolationVariableList;
}

static String extractFieldName(final BaseSingleFieldConstraint con) {
  if (con instanceof SingleFieldConstraintEBLeftSide) {
    return ((SingleFieldConstraintEBLeftSide) con).getExpressionLeftSide().getFieldName();
  } else if (con instanceof SingleFieldConstraint) {
    return ((SingleFieldConstraint) con).getFieldName();
  } else if (con instanceof ConnectiveConstraint) {
    return ((ConnectiveConstraint) con).getFieldName();
  }
  return null;
}

static String extractFactType(final FactPattern factPattern,
               final BaseSingleFieldConstraint con) {
  if (con instanceof SingleFieldConstraintEBLeftSide) {
    return ((SingleFieldConstraintEBLeftSide) con).getExpressionLeftSide().getPreviousClassType();
  }
  return factPattern.getFactType();
}

private void fixConnectiveConstraints(SingleFieldConstraint sfc) {
  if (sfc.getConnectives() == null) {
    return;
  }
  for (ConnectiveConstraint cc : sfc.getConnectives()) {
    if (cc.getFieldName() == null) {
      cc.setFieldName(sfc.getFieldName());
      cc.setFieldType(sfc.getFieldType());
    }
  }
}

  private void addModify(String itemText,
              int position) {
    this.model.addRhsItem(new ActionUpdateField(itemText),
               position);
  }
}

private void setUpSingleFieldConstraintEBLeftSide(SingleFieldConstraintEBLeftSide sfexp) {
  this.factType = sfexp.getExpressionLeftSide().getPreviousClassType();
  if (this.factType == null) {
    this.factType = sfexp.getExpressionLeftSide().getClassType();
  }
  this.fieldName = sfexp.getExpressionLeftSide().getFieldName();
  this.fieldType = sfexp.getExpressionLeftSide().getGenericType();
}

private static ExpressionFormLine buildExpressionFormLine() {
  ExpressionFormLine efl = new ExpressionFormLine();
  efl.setBinding( "eflBinding" );
  efl.appendPart( new ExpressionText( "text" ) );
  efl.appendPart( new ExpressionCollectionIndex( "collectionIndex", "CT", "GT" ) );
  return efl;
}

private void addActionSetField(String itemText,
                int position) {
  this.model.addRhsItem(new ActionSetField(itemText),
             position);
}

private void addNewFact(String itemText,
            int position) {
  this.model.addLhsItem(new FactPattern(itemText),
             position);
}

private void addNewCE(String s,
           int position) {
  this.model.addLhsItem(new CompositeFactPattern(s),
             position);
}

private void addCallMethod(String itemText,
              int position) {
  this.model.addRhsItem(new ActionCallMethod(itemText),
             position);
}

private void addNewDSLRhs(DSLSentence sentence,
             int position) {
  this.model.addRhsItem(sentence.copy(),
             position);
}

private void addNewDSLLhs(final DSLSentence sentence,
             int position) {
  model.addLhsItem(sentence.copy(),
           position);
}

  @Override
  public int hashCode() {
    int result = super.hashCode();
    result = ~~result;
    result = 31 * result + (expLeftSide != null ? expLeftSide.hashCode() : 0);
    result = ~~result;
    return result;
  }
}

  @Override
  public int hashCode() {
    int result = factPattern != null ? factPattern.hashCode() : 0;
    result = ~~result;
    result = 31 * result + (expression != null ? expression.hashCode() : 0);
    result = ~~result;
    return result;
  }
}

private void extractInterpolationVariablesAbstractActionMultiConstraintBendableMatch(final AbstractActionMultiConstraintBendableMatch constraintMatch) {
  Collection<InterpolationVariable> interpolationVariables = constraintMatch.extractInterpolationVariables();
  assertEquals(2,
         interpolationVariables.size());
  assertTrue(interpolationVariables.contains(new InterpolationVariable("var1",
                                     DataType.TYPE_OBJECT)));
  assertTrue(interpolationVariables.contains(new InterpolationVariable("var2",
                                     DataType.TYPE_OBJECT)));
}

private void extractInterpolationVariablesAbstractActionConstraintMatch(final AbstractActionConstraintMatch constraintMatch) {
  Collection<InterpolationVariable> interpolationVariables = constraintMatch.extractInterpolationVariables();
  assertEquals(1,
         interpolationVariables.size());
  assertTrue(interpolationVariables.contains(new InterpolationVariable("var1",
                                     DataType.TYPE_OBJECT)));
}

@Test
public void extractInterpolationVariablesContainsVariables() {
  String string = "foo bar @{var1} baz @{var2}";
  Collection<InterpolationVariable> interpolationVariables = TemplateUtils.extractInterpolationVariables(string);
  assertEquals(2,
         interpolationVariables.size());
  assertTrue(interpolationVariables.contains(new InterpolationVariable("var1",
                                     DataType.TYPE_OBJECT)));
  assertTrue(interpolationVariables.contains(new InterpolationVariable("var2",
                                     DataType.TYPE_OBJECT)));
}

@Test
public void extractInterpolationVariablesActionMultiConstraintHardSoftMatch() {
  ActionHardConstraintMatch hardConstraintMatch = new ActionHardConstraintMatch("foo bar @{var1}");
  ActionSoftConstraintMatch softConstraintMatch = new ActionSoftConstraintMatch("foo bar @{var2}");
  ActionMultiConstraintHardSoftMatch multiConstraintHardSoftMatch = new ActionMultiConstraintHardSoftMatch(hardConstraintMatch,
                                                       softConstraintMatch);
  Collection<InterpolationVariable> interpolationVariables = multiConstraintHardSoftMatch.extractInterpolationVariables();
  assertEquals(2,
         interpolationVariables.size());
  assertTrue(interpolationVariables.contains(new InterpolationVariable("var1",
                                     DataType.TYPE_OBJECT)));
  assertTrue(interpolationVariables.contains(new InterpolationVariable("var2",
                                     DataType.TYPE_OBJECT)));
}

@Test
public void extractInterpolationVariablesActionMultiConstraintHardMediumSoftMatch() {
  ActionHardConstraintMatch hardConstraintMatch = new ActionHardConstraintMatch("foo bar @{var1}");
  ActionMediumConstraintMatch mediumConstraintMatch = new ActionMediumConstraintMatch("foo bar @{var2}");
  ActionSoftConstraintMatch softConstraintMatch = new ActionSoftConstraintMatch("foo bar @{var3}");
  ActionMultiConstraintHardMediumSoftMatch multiConstraintHardSoftMatch = new ActionMultiConstraintHardMediumSoftMatch(hardConstraintMatch,
                                                             mediumConstraintMatch,
                                                             softConstraintMatch);
  Collection<InterpolationVariable> interpolationVariables = multiConstraintHardSoftMatch.extractInterpolationVariables();
  assertEquals(3,
         interpolationVariables.size());
  assertTrue(interpolationVariables.contains(new InterpolationVariable("var1",
                                     DataType.TYPE_OBJECT)));
  assertTrue(interpolationVariables.contains(new InterpolationVariable("var2",
                                     DataType.TYPE_OBJECT)));
  assertTrue(interpolationVariables.contains(new InterpolationVariable("var3",
                                     DataType.TYPE_OBJECT)));
}