io.atlasmap.functions.SELECT Maven / Gradle / Ivy
/**
* Copyright (C) 2017 Red Hat, Inc.
*
* Licensed 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 io.atlasmap.functions;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import io.atlasmap.core.AtlasPath;
import io.atlasmap.core.BaseFunctionFactory;
import io.atlasmap.expression.Expression;
import io.atlasmap.expression.parser.ParseException;
import io.atlasmap.v2.AtlasModelFactory;
import io.atlasmap.v2.Field;
import io.atlasmap.v2.FieldGroup;
public class SELECT extends BaseFunctionFactory {
@Override
public Expression create(List args) throws ParseException {
if (args.size() != 2) {
throw new ParseException("SELECT expects 2 arguments.");
}
Expression parentExpression = args.get(0);
Expression selectExpression =args.get(1);
return (ctx) -> {
Field parent = parentExpression.evaluate(ctx);
List collection = parent instanceof FieldGroup ? ((FieldGroup)parent).getField() : Arrays.asList(parent);
List selected = new ArrayList<>();
final FieldGroup answer = AtlasModelFactory.createFieldGroupFrom(parent, true);
answer.setPath(AtlasModelFactory.GENERATED_PATH);
for (Field f : collection) {
Field fs = (Field) selectExpression.evaluate((subCtx) -> {
if (subCtx != null && AtlasModelFactory.GENERATED_PATH.equals(answer.getPath())) {
answer.setPath(parent.getPath() +
(subCtx.startsWith(AtlasPath.PATH_SEPARATOR) ? subCtx : (AtlasPath.PATH_SEPARATOR + subCtx)));
}
return AtlasPath.extractChildren(f, subCtx);
});
selected.add(fs);
}
if (selected.size() == 1) {
return selected.get(0);
}
answer.getField().addAll(selected);
return answer;
};
}
}