ro.pippo.pebble.ClasspathResourceFunction Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of pippo-pebble Show documentation
Pebble template engine
The newest version!
/*
 * Copyright (C) 2014-present 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 ro.pippo.pebble;

import com.mitchellbosecke.pebble.extension.Function;
import com.mitchellbosecke.pebble.template.EvaluationContext;
import com.mitchellbosecke.pebble.template.PebbleTemplate;
import ro.pippo.core.PippoRuntimeException;
import ro.pippo.core.route.ClasspathResourceHandler;
import ro.pippo.core.route.Router;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.atomic.AtomicReference;

/**
 * Base class for handling classpath resource url generation from a Pebble template.
 *
 * @author James Moger
 */
abstract class ClasspathResourceFunction implements Function {

    final Router router;
    final Class resourceHandlerClass;
    final AtomicReference patternRef;

    protected ClasspathResourceFunction(Router router, Class resourceHandlerClass) {
        this.router = router;
        this.resourceHandlerClass = resourceHandlerClass;
        this.patternRef = new AtomicReference<>();
    }

    @Override
    public List getArgumentNames() {
        List names = new ArrayList<>();
        names.add(ClasspathResourceHandler.PATH_PARAMETER);

        return names;
    }

    @Override
    public Object execute(Map args, PebbleTemplate self, EvaluationContext context, int lineNumber) {
        if (patternRef.get() == null) {
            String pattern = router.uriPatternFor(resourceHandlerClass);
            if (pattern == null) {
                throw new PippoRuntimeException("You must register a route for {}", resourceHandlerClass.getSimpleName());
            }
            patternRef.set(pattern);
        }

        String path = (String) args.get(ClasspathResourceHandler.PATH_PARAMETER);
        Map parameters = new HashMap<>();
        parameters.put(ClasspathResourceHandler.PATH_PARAMETER, path);

        return router.uriFor(patternRef.get(), parameters);
    }

}