Github user xccui commented on a diff in the pull request:
https://github.com/apache/flink/pull/6090#discussion_r196994767
--- Diff:
flink-libraries/flink-sql-client/src/main/java/org/apache/flink/table/client/config/UDFDescriptor.java
---
@@ -0,0 +1,153 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.flink.table.client.config;
+
+import org.apache.flink.api.common.typeinfo.BasicTypeInfo;
+import org.apache.flink.api.common.typeinfo.TypeInformation;
+import org.apache.flink.table.client.SqlClientException;
+import org.apache.flink.table.descriptors.ClassTypeDescriptor;
+import org.apache.flink.table.descriptors.ClassTypeValidator;
+import org.apache.flink.table.descriptors.DescriptorProperties;
+import org.apache.flink.table.descriptors.FunctionDescriptor;
+import org.apache.flink.table.descriptors.FunctionValidator;
+import org.apache.flink.table.descriptors.PrimitiveTypeDescriptor;
+import org.apache.flink.table.descriptors.PrimitiveTypeValidator;
+import org.apache.flink.table.typeutils.TypeStringUtils;
+
+import java.util.List;
+import java.util.Map;
+
+import static
org.apache.flink.table.client.config.UDFDescriptor.From.CLASS;
+
+/**
+ * Descriptor for user-defined functions.
+ */
+public class UDFDescriptor extends FunctionDescriptor {
+
+ private static final String FROM = "from";
+
+ private From from;
+
+ private UDFDescriptor(String name, From from) {
+ super(name);
+ this.from = from;
+ }
+
+ public From getFrom() {
+ return from;
+ }
+
+ /**
+ * Create a UDF descriptor with the given config.
+ */
+ public static UDFDescriptor create(Map<String, Object> config) {
+ if (!config.containsKey(FunctionValidator.FUNCTION_NAME())) {
+ throw new SqlClientException("The 'name' attribute of a
function is missing.");
+ }
+
+ final Object name =
config.get(FunctionValidator.FUNCTION_NAME());
+ if (!(name instanceof String) || ((String) name).length() <= 0)
{
+ throw new SqlClientException("Invalid function name '"
+ name + "'.");
+ }
--- End diff --
At first, I did use `ConfigUtil.normalizeYaml` for that. But I found the
type information for some parameters was lost in this process, e.g., we could
not tell a `false` is a boolean or a string.
---
