/**
* Normalizes a value using the given context.
*
* @param ctx the context.
* @param value the value to normalize.
* @param type the expected RDF type, use RDF_TYPE_UNKNOWN if not known.
* @param predicate an optional predicate for the value (used to look up
* type coercion info).
* @param usedCtx a context to update if a value was used from "ctx".
*
* @return the normalized string.
*/
static string _normalizeValue(
DynamicObject& ctx, DynamicObject value,
RdfType type, const char* predicate, DynamicObject* usedCtx)
{
string rval;
// "@" or "a"/RDF_TYPE predicates have values that are IRIs or CURIEs
if(predicate != NULL &&
(strcmp(predicate, "@") == 0 || strcmp(predicate, "a") == 0 ||
strcmp(predicate, RDF_TYPE_NORM) == 0))
{
type = RDF_TYPE_IRI;
}
// IRI "@" is already normalized
if(type == RDF_TYPE_IRI && strcmp(value, "@") == 0)
{
rval.assign(value);
}
// IRI "a" is special rdf type
else if(type == RDF_TYPE_IRI && strcmp(value, "a") == 0)
{
rval.assign(RDF_TYPE_NORM);
}
else
{
string datatype;
// look for type coercion info
if(type == RDF_TYPE_UNKNOWN && predicate != NULL &&
!ctx.isNull() && ctx->hasMember("#types") &&
ctx["#types"]->hasMember(predicate))
{
DynamicObject& tci = ctx["#types"][predicate];
if(usedCtx != NULL)
{
(*usedCtx)["#types"][predicate] = tci.clone();
}
// handle specific type
if(tci->getType() == String)
{
rval = value->getString();
datatype = _normalizeValue(ctx, tci, RDF_TYPE_IRI, NULL, usedCtx);
type = (strcmp(datatype.c_str(), XSD_ANY_URI_NORM) == 0) ?
RDF_TYPE_IRI : RDF_TYPE_TYPED_LITERAL;
}
// handle type preferences in order
else
{
DynamicObjectIterator ti = tci.getIterator();
while(type == RDF_TYPE_UNKNOWN && ti->hasNext())
{
// FIXME: if value works w/type, set value, datatype, type
//type = RDF_TYPE_TYPED_LITERAL;
}
}
}
// determine type from DynamicObjectType
else if(type == RDF_TYPE_UNKNOWN && value->getType() != String)
{
type = RDF_TYPE_TYPED_LITERAL;
rval = value->getString();
// handle native xsd types
if(value->isNumber())
{
datatype = value->isInteger() ? XSD_INTEGER : XSD_DOUBLE;
}
else if(value->getType() == Boolean)
{
datatype = XSD_BOOLEAN;
}
else
{
// FIXME: this should never happen?
datatype = XSD_ANY_TYPE;
}
}
else
{
// JSON-LD decode
RdfType t = type;
_decode(value, type, rval, datatype);
if(type == RDF_TYPE_TYPED_LITERAL)
{
_expandCurie(ctx, datatype.c_str(), datatype, usedCtx);
}
// preserve expected type
if(t != RDF_TYPE_UNKNOWN)
{
type = t;
}
}
// expand CURIE
if(type == RDF_TYPE_IRI)
{
_expandCurie(ctx, rval.c_str(), rval, usedCtx);
}
// JSON-LD encode
rval = _encode(type, rval.c_str(), datatype.c_str());
}
return rval;
}
