// internal extension methods - IIndexer is an internal interface
internal static bool TryGetIndex <TModel, TProperty>(this IIndexer indexer, Expression <Func <TModel, TProperty> > propExpr, out IIndex index)
{
index = null;
// we can get the name of the property
var member = propExpr.Body as MemberExpression;
var prop = member.Member;
return(indexer.TryGetIndex(new DataValue(typeof(TProperty), DataAttributes.Index).Value(prop.Name), out index));
}
/*
* If data does not have an ID then a key is generated on the fly.
* ***/
private bool CheckConstraints(IIndexer indexer, object[] data, out DataValue key)
{
var passConstraints = true;
key = new DataValue(DataType.Int, Attribs.PKey);
var idx = 0;
while (passConstraints && idx < data.Length)
{
var field = Fields[idx];
IIndex index;
if (field.Is(Attribs.PKey))
{
key = new DataValue(field.Type, field.Attributes);
if (field.Is(Attribs.AutoIncr))
{
// even if a real value is supplied, an AutoIncr attribute will
// overwrite with the appropriate value
if (data[idx] is DataValue)
{
key = ((DataValue)data[idx]).Value(mIndexer());
}
else
{
key = key.Value(mIndexer());
}
passConstraints = (data[idx] = key.Value()) != null;
// check indexer constraints - true if valid
if (indexer.TryGetIndex(key, out index))
{
passConstraints &= index.Add(mCache.NextRowId, key);
}
}
}
else if (field.Is(Attribs.AutoIncr))
{
// even if a real value is supplied, an AutoIncr attribute will
// overwrite with the appropriate value
if (data[idx] is DataValue)
{
key = ((DataValue)data[idx]).Value(mIndexer());
}
else
{
key = key.Value(mIndexer());
}
passConstraints = (data[idx] = key.Value()) != null;
// check indexer constraints - true if valid
if (indexer.TryGetIndex(key, out index))
{
passConstraints &= index.Add(mCache.NextRowId, key);
}
}
// check if assign default value
if (field.Is(Attribs.Default))
{
data[idx] = field.Data.Value();
}
// check add Index
if (!field.Is(Attribs.PKey) && field.Is(Attribs.Index))
{
key = new DataValue(field.Type, field.Attributes).Value(field.Name);
if (!indexer.TryGetIndex(key, out index))
{
// TODO: index error, missing index
passConstraints &= false;
break;
}
key = key.Value(data[idx]);
passConstraints &= index.Add(mCache.NextRowId, key);
}
++idx;
}
if (!passConstraints)
{
passConstraints = (key = key.Value(mIndexer())).Value() != null;
}
return(passConstraints);
}