Java tutorial
/* * Copyright 2013 Google 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 com.google.template.soy.data.internal; import com.google.common.base.Preconditions; import com.google.common.collect.Maps; import com.google.template.soy.data.SoyRecord; import com.google.template.soy.data.SoyValueProvider; import java.util.Map; import javax.annotation.Nonnull; import javax.annotation.Nullable; /** * Implementation of ParamStore that represents a backing store augmented with additional fields * (params). The additional fields may hide fields from the backing store. * * <p> Important: Do not use outside of Soy code (treat as superpackage-private). * */ public class AugmentedParamStore extends ParamStore { /** The backing store (can be any SoyRecord, not necessarily ParamStore) being augmented. */ private final SoyRecord backingStore; /** The internal map holding the additional fields (params). */ private final Map<String, SoyValueProvider> localStore; public AugmentedParamStore(@Nullable SoyRecord backingStore, int expectedKeys) { this.backingStore = backingStore; this.localStore = Maps.newHashMapWithExpectedSize(expectedKeys); } @Override public AugmentedParamStore setField(String name, @Nonnull SoyValueProvider valueProvider) { Preconditions.checkNotNull(valueProvider); localStore.put(name, valueProvider); return this; } @Override public boolean hasField(String name) { return localStore.containsKey(name) || backingStore.hasField(name); } @Override public SoyValueProvider getFieldProvider(String name) { SoyValueProvider val = localStore.get(name); return (val != null) ? val : backingStore.getFieldProvider(name); } }