LinksUtil.java

/**
 *
 * Copyright 2009-2011 Rickard Öberg AB
 *
 * 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 org.qi4j.library.rest.common.link;

import org.qi4j.functional.Function;
import org.qi4j.functional.Iterables;
import org.qi4j.functional.Specification;

/**
 * Helper methods for links
 */
public final class LinksUtil
{
   public static Specification<Link> withId(final String id)
   {
      return new Specification<Link>()
      {
         @Override
         public boolean satisfiedBy(Link link )
         {
            return link.id().get().equals(id);
         }
      };
   }

   public static Specification<Link> withText(final String text)
   {
      return new Specification<Link>()
      {
         @Override
         public boolean satisfiedBy(Link link )
         {
            return link.text().get().equals(text);
         }
      };
   }

   public static Specification<Link> withRel(final String rel)
   {
      return new Specification<Link>()
      {
         @Override
         public boolean satisfiedBy(Link link )
         {
            return link.rel().get().equals(rel);
         }
      };
   }

   public static Specification<Link> withClass(final String clazz)
   {
      return new Specification<Link>()
      {
         @Override
         public boolean satisfiedBy(Link link )
         {
             String classes = link.classes().get();
             return classes != null && classes.contains( clazz );
         }
      };
   }

    public static Link withRel(String rel, Links links)
    {
        return Iterables.single( Iterables.filter( withRel( rel ), links.links().get() ) );
    }

    public static Link withId(String id, Links links)
    {
        return Iterables.single( Iterables.filter( withId( id ), links.links().get() ) );
    }

   public static Function<Link, String> toRel()
   {
      return new Function<Link, String>()
      {
         @Override
         public String map(Link link )
         {
            return link.rel().get();
         }
      };
   }
}