FILTER.java
/*
* 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.Arrays;
import java.util.List;
import io.atlasmap.core.AtlasPath;
import io.atlasmap.core.BaseFunctionFactory;
import io.atlasmap.expression.Expression;
import io.atlasmap.expression.internal.BooleanExpression;
import io.atlasmap.expression.parser.ParseException;
import io.atlasmap.v2.AtlasModelFactory;
import io.atlasmap.v2.Field;
import io.atlasmap.v2.FieldGroup;
public class FILTER extends BaseFunctionFactory {
@Override
public Expression create(List<Expression> args) throws ParseException {
if (args.size() != 2) {
throw new ParseException("FILTER expects 2 arguments.");
}
Expression parentExpression = args.get(0);
BooleanExpression filterExpression = BooleanExpression.asBooleanExpression(args.get(1));
return (ctx) -> {
Field parent = (Field) parentExpression.evaluate(ctx);
List<Field> collection = parent instanceof FieldGroup ? ((FieldGroup)parent).getField() : Arrays.asList(parent);
FieldGroup filtered = AtlasModelFactory.createFieldGroupFrom(parent, true);
int index = 0;
for (Field f : collection) {
if (
filterExpression.matches((subCtx) -> {
return AtlasPath.extractChildren(f, subCtx);
})
) {
adjustRootCollectionIndex(f, index);
index++;
filtered.getField().add(f);
}
}
return filtered;
};
}
private void adjustRootCollectionIndex(Field f, int index) {
AtlasPath filteredPath = new AtlasPath(f.getPath());
Integer collectionSegmentIndex = null;
List<AtlasPath.SegmentContext> filteredSegments = filteredPath.getSegments(true);
if (filteredSegments.get(0).getCollectionIndex() != null) {
collectionSegmentIndex = 0;
} else if (filteredSegments.get(1).getCollectionIndex() != null) {
collectionSegmentIndex = 1;
}
if (collectionSegmentIndex != null) {
if (f instanceof FieldGroup) {
AtlasPath.setCollectionIndexRecursively((FieldGroup) f, collectionSegmentIndex, index);
} else {
filteredPath.setCollectionIndex(collectionSegmentIndex, index);
f.setPath(filteredPath.getOriginalPath());
}
}
}
}