How to use

getExpression

method

in

org.hisp.dhis.expression.Expression

@Override
public Set<DataElement> getDataElements( ValidationRule validationRule )
{
  Set<DataElement> elements = new HashSet<>();
  elements.addAll( expressionService.getDataElementsInExpression( validationRule.getLeftSide().getExpression() ) );
  elements.addAll( expressionService.getDataElementsInExpression( validationRule.getRightSide().getExpression() ) );
  return elements;
}

/**
 * Gets all DimensionalItemObjects from the expressions and skip test.
 *
 * @param expressions set of expressions.
 * @param skipTest the skip test expression (if any).
 * @return set of all dimensional item objects found in all expressions.
 */
private Set<DimensionalItemObject> getDimensionItems( Set<String> expressions, Expression skipTest )
{
  Set<DimensionalItemObject> operands = new HashSet<>();
  for ( String expression : expressions )
  {
    operands.addAll( expressionService.getDimensionalItemObjectsInExpression( expression ) );
  }
  if ( skipTest != null )
  {
    operands.addAll( expressionService.getDimensionalItemObjectsInExpression( skipTest.getExpression() ) );
  }
  return operands;
}

@Override
public Double getExpressionValue( Expression expression, Map<? extends DimensionalItemObject, Double> valueMap,
  Map<String, Double> constantMap, Map<String, Integer> orgUnitCountMap, Integer days,
  ListMap<String, Double> aggregateMap )
{
  String expressionString = generateExpression( expression.getExpression(),
    valueMap, constantMap, orgUnitCountMap, days, expression.getMissingValueStrategy(),
    aggregateMap );
  return expressionString != null ? calculateExpression( expressionString ) : null;
}

@Override
public Collection<ValidationRule> getValidationRulesForDataSet( DataSet dataSet )
{
  Set<String> elementsAndOptionCombos = new HashSet<>();
  for ( DataSetElement dataSetElement : dataSet.getDataSetElements() )
  {
    DataElement dataElement = dataSetElement.getDataElement();
    elementsAndOptionCombos.add( dataElement.getUid() );
    CategoryCombo catCombo = dataSetElement.hasCategoryCombo()
      ? dataSetElement.getCategoryCombo()
      : dataElement.getCategoryCombo();
    for ( CategoryOptionCombo optionCombo : catCombo.getOptionCombos() )
    {
      elementsAndOptionCombos.add( dataElement.getUid() + Expression.SEPARATOR + optionCombo.getUid() );
    }
  }
  Set<ValidationRule> rulesForDataSet = new HashSet<>();
  for ( ValidationRule rule : getAllFormValidationRules() )
  {
    if ( !Sets.intersection( expressionService.getElementsAndOptionCombosInExpression( rule.getLeftSide().getExpression() ), elementsAndOptionCombos ).isEmpty() ||
      !Sets.intersection( expressionService.getElementsAndOptionCombosInExpression( rule.getRightSide().getExpression() ), elementsAndOptionCombos ).isEmpty() )
    {
      rulesForDataSet.add( rule );
    }
  }
  return rulesForDataSet;
}

@Override
public SortedMap<ValidationRule, String> getInvalidValidationRuleLeftSideExpressions()
{
  SortedMap<ValidationRule, String> invalids = new TreeMap<>();
  I18n i18n = i18nManager.getI18n();
  for ( ValidationRule rule : validationRuleService.getAllValidationRules() )
  {
    ExpressionValidationOutcome result = expressionService.expressionIsValid( rule.getLeftSide().getExpression() );
    if ( !result.isValid() )
    {
      invalids.put( rule, i18n.getString(result.getKey()) );
    }
  }
  return invalids;
}

private void upgradeExpressions()
{
  Collection<Expression> expressions = expressionService.getAllExpressions();
  for ( Expression expression : expressions )
  {
    String expr = upgradeExpression( expression.getExpression() );
    if ( expr != null )
    {
      expression.setExpression( expr );
      expressionService.updateExpression( expression );
    }
  }
}

@Override
public SortedMap<ValidationRule, String> getInvalidValidationRuleRightSideExpressions()
{
  SortedMap<ValidationRule, String> invalids = new TreeMap<>();
  I18n i18n = i18nManager.getI18n();
  for ( ValidationRule rule : validationRuleService.getAllValidationRules() )
  {
    ExpressionValidationOutcome result = expressionService.expressionIsValid( rule.getRightSide().getExpression() );
    if ( !result.isValid() )
    {
      invalids.put( rule, i18n.getString(result.getKey()) );
    }
  }
  return invalids;
}

  .getDimensionalItemIdsInExpression( rule.getLeftSide().getExpression() );
dimensionItemIdentifiers.putValues(
  expressionService.getDimensionalItemIdsInExpression( rule.getRightSide().getExpression() ) );

expressionService.getAggregatesAndNonAggregatesInExpression( generator.getExpression(), aggregates, nonAggregates );
Map<String, Double> constantMap = constantService.getConstantMap();
Set<Period> outputPeriods = getPeriodsBetweenDates( predictor.getPeriodType(), startDate, endDate );