/// <summary>
/// Prints the string representation of a SPARQL SELECT query
/// </summary>
internal static String PrintSelectQuery(RDFSelectQuery selectQuery, Double indentLevel, Boolean fromUnion)
{
StringBuilder sb = new StringBuilder();
if (selectQuery != null)
{
#region INDENT
Int32 subqueryHeaderSpacesFunc(Double indLevel)
{
return(subqueryBodySpacesFunc(indentLevel) - 2 < 0 ? 0 : subqueryBodySpacesFunc(indentLevel) - 2);
}
Int32 subqueryBodySpacesFunc(Double indLevel)
{
return(Convert.ToInt32(4 * indentLevel));
}
Int32 subqueryUnionSpacesFunc(Boolean union)
{
return(union ? 2 : 0);
}
String subquerySpaces = new String(' ', subqueryHeaderSpacesFunc(indentLevel) + subqueryUnionSpacesFunc(fromUnion));
String subqueryBodySpaces = new String(' ', subqueryBodySpacesFunc(indentLevel) + subqueryUnionSpacesFunc(fromUnion));
#endregion
#region PREFIX
if (!selectQuery.IsSubQuery)
{
if (selectQuery.Prefixes.Any())
{
selectQuery.Prefixes.ForEach(pf =>
{
sb.Append("PREFIX " + pf.NamespacePrefix + ": <" + pf.NamespaceUri + ">\n");
});
sb.Append("\n");
}
}
#endregion
#region HEADER
#region BEGINSELECT
if (selectQuery.IsSubQuery)
{
if (selectQuery.IsOptional && !fromUnion)
{
sb.Append(subquerySpaces + "OPTIONAL {\n");
}
else
{
sb.Append(subquerySpaces + "{\n");
}
}
sb.Append(subqueryBodySpaces + "SELECT");
#endregion
#region DISTINCT
selectQuery.GetModifiers()
.Where(mod => mod is RDFDistinctModifier)
.ToList()
.ForEach(dm => sb.Append(" " + dm));
#endregion
#region VARIABLES
if (selectQuery.ProjectionVars.Any())
{
selectQuery.ProjectionVars.OrderBy(x => x.Value)
.ToList()
.ForEach(v => sb.Append(" " + v.Key));
}
else
{
sb.Append(" *");
}
sb.Append("\n");
#endregion
#endregion
#region BODY
sb.Append(subqueryBodySpaces + "WHERE {\n");
#region MEMBERS
Boolean printingUnion = false;
List <RDFQueryMember> evaluableQueryMembers = selectQuery.GetEvaluableQueryMembers().ToList();
RDFQueryMember lastQueryMbr = evaluableQueryMembers.LastOrDefault();
foreach (var queryMember in evaluableQueryMembers)
{
#region PATTERNGROUPS
if (queryMember is RDFPatternGroup)
{
//Current pattern group is set as UNION with the next one
if (((RDFPatternGroup)queryMember).JoinAsUnion)
{
//Current pattern group IS NOT the last of the query
//(so UNION keyword must be appended at last)
if (!queryMember.Equals(lastQueryMbr))
{
//Begin a new Union block
if (!printingUnion)
{
printingUnion = true;
sb.Append(subqueryBodySpaces + " {\n");
}
sb.Append(PrintPatternGroup((RDFPatternGroup)queryMember, subqueryBodySpaces.Length + 2, true, selectQuery.Prefixes));
sb.Append(subqueryBodySpaces + " UNION\n");
}
//Current pattern group IS the last of the query
//(so UNION keyword must not be appended at last)
else
{
//End the Union block
if (printingUnion)
{
printingUnion = false;
sb.Append(PrintPatternGroup((RDFPatternGroup)queryMember, subqueryBodySpaces.Length + 2, true, selectQuery.Prefixes));
sb.Append(subqueryBodySpaces + " }\n");
}
else
{
sb.Append(PrintPatternGroup((RDFPatternGroup)queryMember, subqueryBodySpaces.Length, false, selectQuery.Prefixes));
}
}
}
//Current pattern group is set as INTERSECT with the next one
else
{
//End the Union block
if (printingUnion)
{
printingUnion = false;
sb.Append(PrintPatternGroup((RDFPatternGroup)queryMember, subqueryBodySpaces.Length + 2, true, selectQuery.Prefixes));
sb.Append(subqueryBodySpaces + " }\n");
}
else
{
sb.Append(PrintPatternGroup((RDFPatternGroup)queryMember, subqueryBodySpaces.Length, false, selectQuery.Prefixes));
}
}
}
#endregion
#region SUBQUERY
else if (queryMember is RDFQuery)
{
//Merge main query prefixes
selectQuery.Prefixes.ForEach(pf1 => {
if (!((RDFSelectQuery)queryMember).Prefixes.Any(pf2 => pf2.Equals(pf1)))
{
((RDFSelectQuery)queryMember).AddPrefix(pf1);
}
});
//Current subquery is set as UNION with the next one
if (((RDFSelectQuery)queryMember).JoinAsUnion)
{
//Current subquery IS NOT the last of the query
//(so UNION keyword must be appended at last)
if (!queryMember.Equals(lastQueryMbr))
{
//Begin a new Union block
if (!printingUnion)
{
printingUnion = true;
sb.Append(subqueryBodySpaces + " {\n");
}
sb.Append(PrintSelectQuery((RDFSelectQuery)queryMember, indentLevel + 1 + (fromUnion ? 0.5 : 0), true));
sb.Append(subqueryBodySpaces + " UNION\n");
}
//Current query IS the last of the query
//(so UNION keyword must not be appended at last)
else
{
//End the Union block
if (printingUnion)
{
printingUnion = false;
sb.Append(PrintSelectQuery((RDFSelectQuery)queryMember, indentLevel + 1 + (fromUnion ? 0.5 : 0), true));
sb.Append(subqueryBodySpaces + " }\n");
}
else
{
sb.Append(PrintSelectQuery((RDFSelectQuery)queryMember, indentLevel + 1 + (fromUnion ? 0.5 : 0), false));
}
}
}
//Current query is set as INTERSECT with the next one
else
{
//End the Union block
if (printingUnion)
{
printingUnion = false;
sb.Append(PrintSelectQuery((RDFSelectQuery)queryMember, indentLevel + 1 + (fromUnion ? 0.5 : 0), true));
sb.Append(subqueryBodySpaces + " }\n");
}
else
{
sb.Append(PrintSelectQuery((RDFSelectQuery)queryMember, indentLevel + 1 + (fromUnion ? 0.5 : 0), false));
}
}
}
#endregion
}
#endregion
sb.Append(subqueryBodySpaces + "}");
#endregion
#region FOOTER
#region MODIFIERS
List <RDFModifier> modifiers = selectQuery.GetModifiers().ToList();
// ORDER BY
if (modifiers.Any(mod => mod is RDFOrderByModifier))
{
sb.Append("\n");
sb.Append(subqueryBodySpaces + "ORDER BY");
modifiers.Where(mod => mod is RDFOrderByModifier)
.ToList()
.ForEach(om => sb.Append(" " + om));
}
// LIMIT/OFFSET
if (modifiers.Any(mod => mod is RDFLimitModifier || mod is RDFOffsetModifier))
{
modifiers.Where(mod => mod is RDFLimitModifier)
.ToList()
.ForEach(lim => { sb.Append("\n"); sb.Append(subqueryBodySpaces + lim); });
modifiers.Where(mod => mod is RDFOffsetModifier)
.ToList()
.ForEach(off => { sb.Append("\n"); sb.Append(subqueryBodySpaces + off); });
}
#endregion
#region ENDSELECT
sb.Append("\n");
if (selectQuery.IsSubQuery)
{
sb.Append(subquerySpaces + "}\n");
}
#endregion
#endregion
}
return(sb.ToString());
}
