/** Returns the root schema. */
public static Schema root(Schema schema) {
for (Schema s = schema; ; ) {
Schema previous = s;
s = s.getParentSchema();
if (s == null) {
return previous;
}
}
}
/** Returns the path of a schema, appending the name of a table if not null. */
public static List<String> path(Schema schema, String name) {
final List<String> list = new ArrayList<String>();
if (name != null) {
list.add(name);
}
for (Schema s = schema; s != null; s = s.getParentSchema()) {
if (s.getParentSchema() != null || !s.getName().equals("")) {
// Omit the root schema's name from the path if it's the empty string,
// which it usually is.
list.add(s.getName());
}
}
return ImmutableList.copyOf(Lists.reverse(list));
}
/** Returns the expression to access a table within a schema. */
public static Expression tableExpression(
Schema schema, Type elementType, String tableName, Class clazz) {
final MethodCallExpression expression;
if (Table.class.isAssignableFrom(clazz)) {
expression =
Expressions.call(
schema.getExpression(),
BuiltinMethod.SCHEMA_GET_TABLE.method,
Expressions.constant(tableName));
} else {
expression =
Expressions.call(
BuiltinMethod.SCHEMAS_QUERYABLE.method,
DataContext.ROOT,
schema.getExpression(),
Expressions.constant(elementType),
Expressions.constant(tableName));
}
return Types.castIfNecessary(clazz, expression);
}
/** Returns the expression for a sub-schema. */
public static Expression subSchemaExpression(Schema schema, String name, Class type) {
// (Type) schemaExpression.getSubSchema("name")
Expression call =
Expressions.call(
schema.getExpression(),
BuiltinMethod.SCHEMA_GET_SUB_SCHEMA.method,
Expressions.constant(name));
// CHECKSTYLE: IGNORE 2
//noinspection unchecked
if (false && type != null && !type.isAssignableFrom(Schema.class)) {
return unwrap(call, type);
}
return call;
}