com.google.sitebricks.rendering.control.ChooseWidget Maven / Gradle / Ivy

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package com.google.sitebricks.rendering.control;

import com.google.inject.Inject;
import com.google.inject.Provider;
import com.google.sitebricks.Evaluator;
import com.google.sitebricks.Renderable;
import com.google.sitebricks.Respond;
import com.google.sitebricks.binding.FlashCache;
import com.google.sitebricks.compiler.Parsing;
import com.google.sitebricks.rendering.SelfRendering;
import net.jcip.annotations.Immutable;

import java.util.Collection;
import java.util.Map;
import java.util.Set;

/**
 * @author Dhanji R. Prasanna ([email protected])
 */
@Immutable @SelfRendering
class ChooseWidget implements Renderable {
    private final WidgetChain widgetChain;
    private final Map map;
    private final Evaluator evaluator;

    private volatile Provider cache;

    public ChooseWidget(WidgetChain widgetChain, String expression, Evaluator evaluator) {
        this.evaluator = evaluator;
        this.map = Parsing.toBindMap(expression);
        this.widgetChain = widgetChain;

        //TODO validate expression
    }

    public void render(Object bound, Respond respond) {
        final String from = map.get("from");

        Object o = evaluator.read(from, bound);

        if (!(o instanceof Collection))
            throw new IllegalArgumentException("@Choose widget's from argument MUST be of type java.util.Collection " +
                    "but was: " + (null == o ? "null" : o.getClass()));

        respond.write("");

        //store for later retrieval during binding
        cache.get().put(from, collection);
    }

    public  Set collect(Class clazz) {
        return widgetChain.collect(clazz);
    }

    @Inject
    public void setCache(Provider cache) {
        this.cache = cache;
    }
}