br.com.objectos.html.io.SingleValue Maven / Gradle / Ivy

Go to download
/*
 * Copyright 2016 Objectos, Fábrica de Software LTDA.
 *
 * 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 br.com.objectos.html.io;

import java.util.NoSuchElementException;

import br.com.objectos.css.Selector;
import br.com.objectos.html.Tag;

/**
 * @author [email protected] (Marcio Endo)
 */
public abstract class SingleValue extends Value {

  private final Selector selector;
  private Tag result;

  SingleValue(Selector selector) {
    this.selector = selector;
  }

  @Override
  public boolean found() {
    return result != null;
  }

  @Override
  public Tag get() {
    if (result == null) {
      throw new NoSuchElementException("No value present");
    }
    return result;
  }

  public String textOrEmpty() {
    return result != null ? result.text() : "";
  }

  @Override
  final void consume(HtmlReader reader) {
    result = find(reader, selector);
  }

  @Override
  final void consumeTag(TagPojo tag) {
    result = selector.matches(tag) ? tag : null;
  }

  abstract Tag find(HtmlReader reader, Selector selector);

}