PaginationProcessor.java

package com.github.aesteve.vertx.nubes.handlers.impl;

import com.github.aesteve.vertx.nubes.context.PaginationContext;
import com.github.aesteve.vertx.nubes.handlers.Processor;
import com.google.common.net.HttpHeaders;
import io.vertx.core.logging.Logger;
import io.vertx.core.logging.LoggerFactory;
import io.vertx.ext.web.RoutingContext;

public class PaginationProcessor extends NoopAfterAllProcessor implements Processor {

  private static final Logger LOG = LoggerFactory.getLogger(PaginationProcessor.class);

  @Override
  public void preHandle(RoutingContext context) {
    context.data().put(PaginationContext.DATA_ATTR, PaginationContext.fromContext(context));
    context.next();
  }

  @Override
  public void postHandle(RoutingContext context) {
    PaginationContext pageContext = (PaginationContext) context.data().get(PaginationContext.DATA_ATTR);
    String linkHeader = pageContext.buildLinkHeader(context.request());
    if (linkHeader != null) {
      context.response().headers().add(HttpHeaders.LINK, linkHeader);
    } else {
      LOG.warn("You did not set the total count on PaginationContext, response won't be paginated");
    }
    context.next();
  }

}