org.springframework.boot.autoconfigure.mustache.MustacheEnvironmentCollector.java Source code

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Here is the source code for org.springframework.boot.autoconfigure.mustache.MustacheEnvironmentCollector.java

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/*
 * Copyright 2012-2019 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
 *
 *      https://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.springframework.boot.autoconfigure.mustache;

import com.samskivert.mustache.DefaultCollector;
import com.samskivert.mustache.Mustache.Collector;
import com.samskivert.mustache.Mustache.VariableFetcher;

import org.springframework.context.EnvironmentAware;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.Environment;

/**
 * Mustache {@link Collector} to expose properties from the Spring {@link Environment}.
 *
 * @author Dave Syer
 * @author Madhura Bhave
 * @since 1.2.2
 */
public class MustacheEnvironmentCollector extends DefaultCollector implements EnvironmentAware {

    private ConfigurableEnvironment environment;

    private final VariableFetcher propertyFetcher = new PropertyVariableFetcher();

    @Override
    public void setEnvironment(Environment environment) {
        this.environment = (ConfigurableEnvironment) environment;
    }

    @Override
    public VariableFetcher createFetcher(Object ctx, String name) {
        VariableFetcher fetcher = super.createFetcher(ctx, name);
        if (fetcher != null) {
            return fetcher;
        }
        if (this.environment.containsProperty(name)) {
            return this.propertyFetcher;
        }
        return null;
    }

    private class PropertyVariableFetcher implements VariableFetcher {

        @Override
        public Object get(Object ctx, String name) {
            return MustacheEnvironmentCollector.this.environment.getProperty(name);
        }

    }

}