/// <summary>
/// Removes data from local storage. This does not affect the backend.
/// </summary>
/// <returns>Details of the clear operation, including the number of entities that were cleared.</returns>
/// <param name="query">Optional Query parameter.</param>
public KinveyDeleteResponse ClearCache(IQueryable <T> query = null)
{
if (this.storeType == DataStoreType.NETWORK)
{
throw new KinveyException(EnumErrorCategory.ERROR_DATASTORE_NETWORK, EnumErrorCode.ERROR_DATASTORE_INVALID_CLEAR_CACHE_OPERATION, "");
}
var ret = cache.Clear(query?.Expression);
if (ret?.IDs != null)
{
var pendings = ret.IDs.Select(entityId => syncQueue.GetByID(entityId));
syncQueue.Remove(pendings);
}
else
{
syncQueue.RemoveAll();
}
// Remove any associated entry from the QueryCache (for delta set sync)
string mongoQuery = null;
if (query != null)
{
StringQueryBuilder queryBuilder = new StringQueryBuilder();
KinveyQueryVisitor visitor = new KinveyQueryVisitor(queryBuilder, typeof(T), VisitorClause.Order | VisitorClause.SkipTake | VisitorClause.Where | VisitorClause.Select);
var queryModel = (query.Provider as KinveyQueryProvider)?.qm;
queryBuilder.Write("{");
queryModel?.Accept(visitor);
queryBuilder.Write("}");
mongoQuery = queryBuilder.BuildQueryString();
}
var qci = client.CacheManager.GetQueryCacheItem(CollectionName, mongoQuery, null);
if (qci != null)
{
client.CacheManager.DeleteQueryCacheItem(qci);
}
return(ret);
}
public KinveyDeleteResponse DeleteByQuery(IQueryable <object> query)
{
var kdr = new KinveyDeleteResponse();
try
{
var visitor = new KinveyQueryVisitor(typeof(T), VisitorClause.Where);
var queryModel = (query.Provider as KinveyQueryProvider)?.qm;
//We call it here to find unsupported LINQ where clauses.
queryModel?.Accept(visitor);
int skipNumber = 0;
int takeNumber = 0;
bool sortAscending = true;
LambdaExpression exprSort = null;
var lambdaExpr = ConvertQueryExpressionToFunction(query.Expression, ref skipNumber, ref takeNumber, ref sortAscending, ref exprSort);
var dataTable = dbConnectionSync.Table <T>();
if (lambdaExpr == null)
{
throw new KinveyException(EnumErrorCategory.ERROR_GENERAL, EnumErrorCode.ERROR_DATASTORE_WHERE_CLAUSE_IS_ABSENT_IN_QUERY, "'Where' clause is absent in query.");
}
dataTable = dataTable.Where(lambdaExpr);
var matchIDs = new List <string>();
foreach (var item in dataTable.ToList())
{
var entity = item as IPersistable;
matchIDs.Add(entity.ID);
}
kdr = this.DeleteByIDs(matchIDs);
}
catch (SQLiteException ex)
{
throw new KinveyException(EnumErrorCategory.ERROR_DATASTORE_CACHE, EnumErrorCode.ERROR_DATASTORE_CACHE_REMOVING_ENTITIES_ACCORDING_TO_QUERY, string.Empty, ex);
}
return(kdr);
}
/// <summary>
/// Builds the mongo-style query string to be run against the backend.
/// </summary>
/// <param name="query">LINQ-style query that can be used to filter delete results.</param>
/// <param name="visitorClause">Enum to filter LINQ clauses which should be used in a query for network request.</param>
/// <returns>The mongo-style query string.</returns>
private static string GetQuery <T>(IQueryable <object> query, VisitorClause visitorClause)
{
if (query != null)
{
StringQueryBuilder queryBuilder = new StringQueryBuilder();
KinveyQueryVisitor visitor = new KinveyQueryVisitor(queryBuilder, typeof(T), visitorClause);
QueryModel queryModel = (query.Provider as KinveyQueryProvider)?.qm;
queryBuilder.Write("{");
queryModel?.Accept(visitor);
queryBuilder.Write("}");
string mongoQuery = queryBuilder.BuildQueryString();
return(mongoQuery);
}
return(default(string));
}
