/// <summary>
/// Fetch metadata for a single calculated field.
/// </summary>
/// <param name="provider">The calculated field metadata provider being extended.</param>
/// <param name="fieldId">The field to load.</param>
/// <param name="settings">Additional settings.</param>
/// <returns>Calculation results.</returns>
public static CalculatedFieldMetadata GetCalculatedFieldMetadata(this ICalculatedFieldMetadataProvider provider, long fieldId, CalculatedFieldSettings settings)
{
if (provider == null)
{
throw new ArgumentNullException("provider"); // assert false
}
var fields = new[] { fieldId };
// Call provider
var metadatas = provider.GetCalculatedFieldMetadata(fields, settings);
// Extract results
CalculatedFieldMetadata metadata = metadatas.FirstOrDefault();
return(metadata);
}
/// <summary>
/// Get the calculated field value for the specified entities.
/// </summary>
/// <param name="fieldMetadata">The metadata for the calculated field.</param>
/// <param name="entityIDs">Entities</param>
/// <param name="evalSettings">Evaluation settings</param>
/// <returns>List of results.</returns>
private IReadOnlyCollection <CalculatedFieldSingleResult> GetSingleFieldValues(CalculatedFieldMetadata fieldMetadata, IReadOnlyCollection <long> entityIDs, EvaluationSettings evalSettings)
{
if (fieldMetadata == null)
{
throw new ArgumentNullException("fieldMetadata");
}
if (entityIDs == null)
{
throw new ArgumentNullException("entityIDs");
}
// Handle statically broken calculated-fields
// (may be null due to not being a calculated field, or the script failing to compile)
if (fieldMetadata.Expression == null)
{
// If the calculated field was somehow invalid, return null for values.
return(entityIDs.Select(id => new CalculatedFieldSingleResult(id, null)).ToArray());
}
// Load entities
IReadOnlyCollection <IEntity> entities;
entities = _entityRepository.Get(entityIDs);
var results = new List <CalculatedFieldSingleResult>(entities.Count);
// Perform calculations
foreach (IEntity entity in entities)
{
ExpressionRunResult runResult;
CalculatedFieldSingleResult singleResult;
evalSettings.ContextEntity = entity;
try
{
runResult = _expressionRunner.Run(fieldMetadata.Expression, evalSettings);
singleResult = new CalculatedFieldSingleResult(entity.Id, runResult.Value);
}
catch (EvaluationException ex)
{
singleResult = new CalculatedFieldSingleResult(entity.Id, ex);
}
results.Add(singleResult);
}
return(results);
}
/// <summary>
/// Creates the evaluator for a single calculated field.
/// </summary>
/// <param name="calculatedField">Entity for the calculated field.</param>
/// <param name="settings">Settings.</param>
/// <returns></returns>
private CalculatedFieldMetadata GetSingleCalculatedFieldMetadata(Field calculatedField, CalculatedFieldSettings settings)
{
string calculation = null;
IExpression expression = null;
ParseException exception = null;
BuilderSettings builderSettings;
try
{
// Get calculation
calculation = calculatedField.FieldCalculation;
if (string.IsNullOrEmpty(calculation))
{
throw new ArgumentException("The field has no calculation script. It may not be a calculated field.");
}
// Get settings
builderSettings = CreateBuilderSettingsForField(calculatedField, settings);
// Compile
expression = _expressionCompiler.Compile(calculation, builderSettings);
// Register cache invalidations
if (CacheContext.IsSet())
{
CalculationDependencies dependencies = _expressionCompiler.GetCalculationDependencies(expression);
using (CacheContext cacheContext = CacheContext.GetContext())
{
cacheContext.Entities.Add(calculatedField.Id);
cacheContext.Entities.Add(dependencies.IdentifiedEntities);
cacheContext.Entities.Add(builderSettings.RootContextType.EntityTypeId);
}
}
}
catch (InvalidMemberParseException ex)
{
exception = ex;
// If a parse-exception resulted from being unable to look up a member name, then it may be corrected by renaming some arbitrary field or relationship
// that could not be otherwise detected by dependencies.IdentifiedEntities. So invalidate parse exceptions if any field/relationship changes.
if (CacheContext.IsSet())
{
using (CacheContext cacheContext = CacheContext.GetContext())
{
cacheContext.Entities.Add(ex.TypeId);
// TODO: ideally just listen for all fields/relationships attached to type
var fieldTypes = PerTenantEntityTypeCache.Instance.GetDescendantsAndSelf(new EntityRef("core:field").Id);
cacheContext.EntityTypes.Add(fieldTypes);
cacheContext.EntityTypes.Add(new EntityRef("core:relationship").Id);
}
}
}
catch (ParseException ex)
{
exception = ex;
}
// Build metadata
CalculatedFieldMetadata metadata = new CalculatedFieldMetadata(calculatedField.Id, calculation, expression, exception);
return(metadata);
}
