ToLiquid PropertyResolverAdapter

ToLiquid.java

package liqp;

/**
 * Provide alternative to :to_liquid
 * Used in some liquid transformation.
 */
public interface ToLiquid {
    Object toLiquid();
}

ToLiquidPropertyResolverAdapter.java

package liqp.filters.where;

import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;
import liqp.LValue;
import liqp.ToLiquid;

import java.util.Map;
import java.util.regex.Pattern;

public class ToLiquidPropertyResolverAdapter extends LValue implements PropertyResolverAdapter {

    @Override
    public Object getItemProperty(ObjectMapper mapper, Object input, Object property) {
        Object startValue = ((ToLiquid) input).toLiquid();
        String[] parts = asString(property).split(Pattern.quote("."));
        return reduceByDigging(mapper, parts, startValue);
    }

    @Override
    public boolean support(Object target) {
        return target instanceof ToLiquid;
    }

    private Object reduceByDigging(ObjectMapper mapper, String[] path, Object target) {
        Object topProperty = getRawProperty(mapper, target, path[0]);
        if (path.length == 1) {
            return topProperty;
        } else {
            path = shiftArray(path);
            return reduceByDigging(mapper, path, topProperty);
        }
    }


    /* package */ String[] shiftArray(String[] in) {
        String[] res = new String[in.length - 1];
        System.arraycopy(in, 1, res, 0, res.length);
        return res;
    }

    private Object getRawProperty(ObjectMapper mapper, Object target, String property) {
        Map<String, Object> mapRepresentation = mapper.convertValue(target, new TypeReference<Map<String, Object>>() {
        });
        return mapRepresentation.get(property);
    }

}