XmlBlob.java

/* Copyright (c) 2008 Google Inc.
 *
 * 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 com.google.gdata.model;

import com.google.gdata.util.common.base.Charsets;
import com.google.gdata.util.ParseException;
import com.google.gdata.wireformats.ContentCreationException;
import com.google.gdata.wireformats.ContentValidationException;
import com.google.gdata.wireformats.WireFormat;
import com.google.gdata.wireformats.WireFormatGenerator;
import com.google.gdata.wireformats.WireFormatParser;
import com.google.gdata.wireformats.input.InputProperties;
import com.google.gdata.wireformats.input.InputPropertiesBuilder;
import com.google.gdata.wireformats.output.OutputProperties;
import com.google.gdata.wireformats.output.OutputPropertiesBuilder;

import java.io.IOException;
import java.io.StringReader;
import java.io.StringWriter;
import java.nio.charset.Charset;

/**
 * Arbitrary self-contained block of XML.
 * <p>
 * Need to support multi-rooted content e.g. {@code <a/><b/>}.
 */
public class XmlBlob extends Element {

  /**
   * The id-less key for XmlBlob, a real name must be set before being used.
   */
  public static final ElementKey<Void, XmlBlob> KEY = ElementKey.of(
      null, XmlBlob.class);

  /**
   * Registers the metadata for this element.
   */
  public static void registerMetadata(MetadataRegistry registry) {
    if (registry.isRegistered(KEY)) {
      return;
    }

    ElementCreator builder = registry.build(KEY);
  }

  /**
   * Constructs a new instance using the specified element key.
   *
   * @param key the element key for this element.
   */
  public XmlBlob(ElementKey<?, ? extends XmlBlob> key) {
    super(key);
  }

  /**
   * Initial {@code xml:lang} value. This value is typically inherited through
   * the XML tree. The blob itself may contain overrides.
   * <p>
   *
   * See http://www.w3.org/TR/REC-xml/#sec-lang-tag for more information.
   */
  public String getLang() {
    throw new UnsupportedOperationException("Not supported yet");
  }
  public void setLang(String v) {
    throw new UnsupportedOperationException("Not supported yet");
  }

  /**
   * Initial {@code xml:base} value. This value is typically inherited through
   * the XML tree. The blob itself may contain overrides.
   * <p>
   *
   * See http://www.cafeconleche.org/books/xmljava/chapters/ch03s03.html for
   * more information.
   */
  public String getBase() {
    throw new UnsupportedOperationException("Not supported yet");
  }
  public void setBase(String v) {
    throw new UnsupportedOperationException("Not supported yet");
  }

  // Uncomment and replace with new data model code. Need to update
  // {@link XmlParser} also.
//  /**
//   * Namespace declarations inherited when this blob was parsed but used
//   * within it.
//   */
//  protected LinkedList<XmlNamespace> namespaces =
//    new LinkedList<XmlNamespace>();
//
//  public List<XmlNamespace> getNamespaces() {
//    return namespaces;
//  }
//
//  public boolean addNamespace(XmlNamespace namespace) {
//    return namespaces.add(namespace);
//  }

  /**
   * Get blob content. Depending on how the blob was parsed, it may contain
   * top-level text() nodes mixed together with child elements.
   *
   * @return blob content
   */
  public String getBlob() {
    StringWriter sw = new StringWriter();
    // formatting model should be aligned with the broader context, and its
    // context and registry should come from the other content too.
    OutputProperties outProps = new OutputPropertiesBuilder()
        .build();
    WireFormatGenerator generator = WireFormat.XML.createGenerator(
        outProps, sw, Charsets.UTF_8, false);
    try {
      generator.generate(this);
    } catch (ContentValidationException e) {
      throw new RuntimeException(e);
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
    return sw.toString();
  }

  /**
   * Set blob content.
   *
   * @param v blob content
   */
  public void setBlob(String v) {
    clear();

    InputProperties inProps = new InputPropertiesBuilder()
        .build();

    WireFormatParser parser = WireFormat.XML.createParser(
        inProps, new StringReader(v), Charset.forName("utf-8"));
    try {
      parser.parse(this);
    } catch (ParseException e) {
      throw new RuntimeException(e);
    } catch (ContentCreationException e) {
      throw new RuntimeException(e);
    } catch (ContentValidationException e) {
      throw new RuntimeException(e);
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }

  /**
   * Get blob content full-text indexing.
   */
  public String getFullText() {
    throw new UnsupportedOperationException("Not supported yet");
  }

  /**
   * Set blob content full-text indexing.
   */
  public void setFullText(String v) {
    throw new UnsupportedOperationException("Not supported yet");
  }

}