/// <summary>
/// Takes an <see cref="IEnumerable{T}"/> of string arrays representing the raw data of the imported file.
/// Then using the specifications in the <see cref="MappingInfo"/> it translates this raw data into an
/// <see cref="IEnumerable{T}"/> of entities. Any problems will be added in the <see cref="ImportErrors"/> dictionary.
/// This function is the opposite of <see cref="DataComposer.Compose{TEntityForSave}(List{TEntityForSave}, MappingInfo)"/>.
/// </summary>
public async Task <IEnumerable <TEntityForSave> > ParseAsync <TEntityForSave>(IEnumerable <string[]> dataWithoutHeader, MappingInfo mapping, ImportErrors errors)
where TEntityForSave : Entity
{
// Load related entities from API
var relatedEntities = await LoadRelatedEntities(dataWithoutHeader, mapping, errors);
if (!errors.IsValid)
{
return(null);
}
// Clear all cached entities and lists, and create the root list
mapping.ClearEntitiesAndLists();
mapping.List = new List <TEntityForSave>(); // This root list will contain the final result
// Set some values on the root mapping infor for handling self referencing FKs
mapping.IsRoot = true;
int matchesIndex = 0;
foreach (var prop in mapping.SimpleProperties.OfType <ForeignKeyMappingInfo>().Where(p => p.IsSelfReferencing))
{
prop.EntityMetadataMatchesIndex = matchesIndex++;
}
int rowNumber = 2;
foreach (var dataRow in dataWithoutHeader) // Foreach row
{
bool keepGoing = ParseRow(dataRow, rowNumber, mapping, relatedEntities, errors, matchesIndex); // Recursive function
if (!keepGoing)
{
// This means the errors collection is full, no need to keep going
break;
}
rowNumber++;
}
// Grab the result from the root mapping
var result = mapping.List.Cast <TEntityForSave>();
// Hydrate self referencing FKs if any, these properties are not hydrated in ParseRow()
// Since they requires all the imported entities to be created and all their other
// properties already hydrated
HydrateSelfReferencingForeignKeys(result, mapping, errors);
// Return the result
return(result);
}
/// <summary>
/// Inspects the data and mapping and loads all related entities from the API, that are referenced by custom use keys like Code and Name.
/// The purpose is to use the Ids of these entities in the constructed Entity objects that are being imported
/// </summary>
private async Task <RelatedEntities> LoadRelatedEntities(IEnumerable <string[]> dataWithoutHeader, MappingInfo mapping, ImportErrors errors)
{
if (errors is null)
{
throw new ArgumentNullException(nameof(errors));
}
// Each set of foreign keys will result in an API query to retrieve the corresponding Ids for FK hydration
// So we group foreign keys by the target type, the target definition Id and the key property (e.g. Code or Name)
var queryInfos = new List <(Type navType, int?navDefId, PropertyMetadata keyPropMeta, HashSet <object> keysSet)>();
foreach (var g in mapping.GetForeignKeys().Where(p => p.NotUsingIdAsKey)
.GroupBy(fk => (fk.TargetType, fk.TargetDefId, fk.KeyPropertyMetadata)))
{
var(navType, navDefId, keyPropMetadata) = g.Key;
HashSet <object> keysSet = new HashSet <object>();
foreach (var fkMapping in g)
{
int rowNumber = 2;
foreach (var row in dataWithoutHeader)
{
string stringKey = row[fkMapping.Index];
if (string.IsNullOrEmpty(stringKey))
{
continue;
}
switch (fkMapping.KeyType)
{
case KeyType.String:
keysSet.Add(stringKey);
break;
case KeyType.Int:
if (int.TryParse(stringKey, out int intKey))
{
keysSet.Add(intKey);
}
else if (!errors.AddImportError(rowNumber, fkMapping.ColumnNumber, _localizer[$"Error_TheValue0IsNotAValidInteger", stringKey]))
{
// This means the validation errors are at maximum capacity, pointless to keep going.
return(null);
}
break;
default:
throw new InvalidOperationException("Bug: Only int and string IDs are supported");
}
rowNumber++;
}
}
if (keysSet.Any())
{
// Actual API calls are delayed till the end in case there are any errors
queryInfos.Add((navType, navDefId, keyPropMetadata, keysSet));
}
}
if (!errors.IsValid)
{
return(null);
}
using var _1 = _instrumentation.Block("Loading Related Entities");
using var _2 = _instrumentation.Disable();
var result = new RelatedEntities();
if (queryInfos.Any())
{
// Load all related entities in parallel
// If they're the same type we load them in sequence because it will be the same controller instance and it might cause issues
await Task.WhenAll(queryInfos.GroupBy(e => e.navType).Select(async g =>
{
var navType = g.Key;
foreach (var queryInfo in g)
{
var(_, navDefId, keyPropMeta, keysSet) = queryInfo; // Deconstruct the queryInfo
var service = _sp.FactWithIdServiceByEntityType(navType.Name, navDefId);
var keyPropDesc = keyPropMeta.Descriptor;
var keyPropName = keyPropDesc.Name;
var args = new SelectExpandArguments {
Select = keyPropName
};
var(data, _) = await service.GetByPropertyValues(keyPropName, keysSet, args, cancellation: default);
var grouped = data.GroupBy(e => keyPropDesc.GetValue(e)).ToDictionary(g => g.Key, g => (IEnumerable <EntityWithKey>)g);
result.TryAdd((navType, navDefId, keyPropName), grouped);
}
// The code above might override the definition Id of the service calling it, here we fix that
_sp.FactWithIdServiceByEntityType(navType.Name, mapping.MetadataForSave.DefinitionId);
}));
}
return(result);
}
/// <summary>
/// Recursive function that parses a single data row (string array) into 0 or more entities that are each
/// added in the correct list in the <see cref="MappingInfo"/> tree. Any errors will be added to the <see cref="ImportErrors"/>.
/// Entities referenced by user keys should be loaded in advance and passed to this function as a <see cref="RelatedEntities"/> dictionary.
/// This function is the opposite of <see cref="DataComposer.ComposeDataRowsFromEntity(List{string[]}, EntityWithKey, MappingInfo, int, int)"/>
/// </summary>
/// <param name="dataRow">An array of strings representing a single row in a CSV or XSLX file</param>
/// <param name="rowNumber">The number of the current row, for the purpose of error reporting</param>
/// <param name="mapping">The <see cref="MappingInfo"/> to rely on for constructing the <see cref="Entity"/> objects</param>
/// <param name="entities">All related entities that are referenced by user keys in the raw data</param>
/// <param name="errors">Any validation errors are added to this collection</param>
/// <returns>False if the <see cref="ImportErrors"/> dictionary has been maxed out, true otherwise.</returns>
private bool ParseRow(string[] dataRow, int rowNumber, MappingInfo mapping, RelatedEntities entities, ImportErrors errors, int selfRefPropertiesCount = 0)
{
bool entityCreated = false;
foreach (var prop in mapping.SimpleProperties)
{
var stringField = dataRow[prop.Index];
if (!string.IsNullOrEmpty(stringField))
{
if (!entityCreated)
{
mapping.Entity = mapping.CreateBaseEntity(rowNumber);
mapping.List.Add(mapping.Entity);
entityCreated = true;
}
var entity = prop.GetTerminalEntityForSave(mapping.Entity);
// Hydrate the property
if (prop is ForeignKeyMappingInfo fkProp && fkProp.NotUsingIdAsKey)
{
// Get the user key value (usually the code or the name)
object userKeyValue = fkProp.KeyType switch
{
KeyType.String => stringField?.Trim(),
KeyType.Int => int.Parse(stringField),
_ => null
};
// Get the entity from the dictionary
var dic = entities[(fkProp.TargetType, fkProp.TargetDefId, fkProp.KeyPropertyMetadata.Descriptor.Name)];