com.google.template.soy.shared.internal.FunctionAdapters.java Source code

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Here is the source code for com.google.template.soy.shared.internal.FunctionAdapters.java

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/*
 * Copyright 2015 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.shared.internal;

import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Sets;
import com.google.template.soy.shared.restricted.SoyFunction;
import com.google.template.soy.shared.restricted.SoyJavaFunction;
import com.google.template.soy.shared.restricted.SoyPrintDirective;

import java.util.Set;

/**
 * Functions for adapting the legacy Java {@link SoyFunction} implementations
 * ({@link SoyJavaRuntimeFunction}
 * and {@link com.google.template.soy.tofu.restricted.SoyTofuFunction}) to the canonical
 * implementation ({@link SoyJavaFunction}).
 *
 * <p>TODO(user): migrate the legacy impls and remove this class.
 */
public final class FunctionAdapters {

    /**
     * Given the set of all Soy function implementations and a specific Soy function type (subtype
     * of SoyFunction) to look for, finds the Soy functions that implement the specific type
     * and returns them in the form of a map from function name to function.
     *
     * @param <T> The specific Soy function type to look for.
     * @param soyFunctionsSet The set of all Soy functions.
     * @param specificSoyFunctionType The class of the specific Soy function type to look for.
     * @return A map of the relevant specific Soy functions (name to function).
     */
    public static <T extends SoyFunction> ImmutableMap<String, T> buildSpecificSoyFunctionsMap(
            Set<SoyFunction> soyFunctionsSet, Class<T> specificSoyFunctionType) {

        ImmutableMap.Builder<String, T> mapBuilder = ImmutableMap.builder();

        Set<String> seenFnNames = Sets.newHashSetWithExpectedSize(soyFunctionsSet.size());

        for (SoyFunction fn : soyFunctionsSet) {
            if (specificSoyFunctionType.isAssignableFrom(fn.getClass())) {
                String fnName = fn.getName();

                if (seenFnNames.contains(fnName) || BuiltinFunction.forFunctionName(fnName) != null) {
                    throw new IllegalStateException(
                            "Found two implementations of " + specificSoyFunctionType.getSimpleName()
                                    + " with the same function name '" + fnName + "'.");
                }
                seenFnNames.add(fnName);

                mapBuilder.put(fnName, specificSoyFunctionType.cast(fn));
            }
        }

        return mapBuilder.build();
    }

    /**
     * Given the set of all Soy directive implementations and a specific Soy directive type (subtype
     * of SoyPrintDirective) to look for, finds the Soy directives that implement the specific type
     * and returns them in the form of a map from directive name to directive.
     *
     * @param <T> The specific Soy directive type to look for.
     * @param soyDirectivesSet The set of all Soy directives.
     * @param specificSoyDirectiveType The class of the specific Soy directive type to look for.
     * @return A map of the relevant specific Soy directives (name to directive).
     */
    public static <T extends SoyPrintDirective> ImmutableMap<String, T> buildSpecificSoyDirectivesMap(
            Set<SoyPrintDirective> soyDirectivesSet, Class<T> specificSoyDirectiveType) {

        ImmutableMap.Builder<String, T> mapBuilder = ImmutableMap.builder();

        Set<String> seenDirectiveNames = Sets.newHashSetWithExpectedSize(soyDirectivesSet.size());

        for (SoyPrintDirective directive : soyDirectivesSet) {
            if (specificSoyDirectiveType.isAssignableFrom(directive.getClass())) {
                String directiveName = directive.getName();

                if (seenDirectiveNames.contains(directiveName)) {
                    throw new IllegalStateException(
                            "Found two implementations of " + specificSoyDirectiveType.getSimpleName()
                                    + " with the same directive name '" + directiveName + "'.");
                }
                seenDirectiveNames.add(directiveName);

                mapBuilder.put(directiveName, specificSoyDirectiveType.cast(directive));
            }
        }

        return mapBuilder.build();
    }
}