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

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package com.google.sitebricks.rendering.control;

import com.google.sitebricks.Evaluator;
import com.google.sitebricks.Renderable;
import com.google.sitebricks.Respond;
import com.google.sitebricks.compiler.Parsing;
import com.google.sitebricks.rendering.EmbedAs;
import net.jcip.annotations.Immutable;

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

/**
 * @author Dhanji R. Prasanna ([email protected])
 */
@Immutable
@EmbedAs("Repeat")
class RepeatWidget implements Renderable {
    private final WidgetChain widgetChain;
    private final String items;
    private final String var;
    private final String pageVar;
    private final Evaluator evaluator;

    private static final String DEFAULT_PAGEVAR = "__page";
    private static final String DEFAULT_VAR = "__this";

    public RepeatWidget(WidgetChain widgetChain, String expression, Evaluator evaluator) {
        this.widgetChain = widgetChain;

        final Map map = Parsing.toBindMap(expression);
        this.items = map.get("items");
        String var = map.get("var");

        if (null != var)
            this.var = Parsing.stripQuotes(var);
        else
            this.var = DEFAULT_VAR;

        //by default the page comes in as __page
        String pageVar = map.get("pageVar");
        if (null == pageVar)
            pageVar = DEFAULT_PAGEVAR;
        else
            pageVar = Parsing.stripQuotes(pageVar);

        this.pageVar = pageVar;
        this.evaluator = evaluator;
    }

    public void render(Object bound, Respond respond) {
        Collection things = (Collection) evaluator.evaluate(items, bound);

        //do nothing if the collection is unavailable for some reason
        if (null == things)
            return;

        Map context = new HashMap();

        //set up context variables
        int i = 0;
        for (Object thing : things) {

            //decorate with some context
            context.put(var, thing);
            context.put(pageVar, bound);
            context.put("index", i++);
            context.put("isLast", i == things.size());
            widgetChain.render(context, respond);
        }

    }


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