org.feature4j.FeatureBundleProviderImpl.java Source code

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Here is the source code for org.feature4j.FeatureBundleProviderImpl.java

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/*
 * Copyright 2014 the original author or authors.
 *
 * 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 org.feature4j;

import com.google.common.base.Optional;
import com.google.common.collect.ImmutableMap;

import java.util.Collection;
import java.util.List;

/**
 * Provide a "bundle" of features based on...contextual input.
 */
public class FeatureBundleProviderImpl implements FeatureBundleProvider {

    private final Collection<Feature<?, ?>> features;

    public FeatureBundleProviderImpl(List<Feature<?, ?>> features) {
        this.features = features;
    }

    @Override
    public FeatureBundle getFeatures(FeaturesContext context) {
        final ImmutableMap.Builder<String, Object> featureMapBuilder = ImmutableMap.builder();
        for (Feature feature : features) {
            Object value = getValue(context, feature);
            featureMapBuilder.put(feature.key(), value);
        }
        return new FeatureBundle(featureMapBuilder.build());
    }

    public Object getValue(FeaturesContext context, Feature feature) {
        Iterable<FeatureOverride> overrides = feature.overrides();
        Optional<Object> optValue;
        for (FeatureOverride override : overrides) {
            optValue = override.extractFeatureValue(context);
            if (optValue != null && optValue.isPresent()) {
                return optValue.get();
            }
        }
        return feature.defaultValue();
    }
}