AddEclMetadataIntoPackageAndComponentTbb.cs

[TcmTemplateTitle("Add ECL Metadata into Package and Component")]
public class AddEclMetadataIntoPackageAndComponent : Base.TemplateBase
{
  // ecl metadata fieldname
  const string SkuField = "sku";

  public override void Transform(Engine engine, Package package)
  {
    Initialize(engine, package);

    if (IsPageTemplate)
    {
      // log error
      Logger.Error("This Template Building Block is only supposed to be used on a Component Template.");
      return;
    }

    // get component xml from package
    Item componentItem = package.GetByType(ContentType.Component);
    string componentUri = componentItem.GetAsSource().GetValue("ID");
    XmlDocument doc = componentItem.GetAsXmlDocument();

    // get value from ecl metadata
    string sku = GetEclMetadata(componentUri, SkuField);

    // create a namespace manager to resolve the namespaces
    XmlNamespaceManager nsmgr = new XmlNamespaceManager(doc.NameTable);
    nsmgr.AddNamespace("tcm", Tridion.Constants.TcmNamespace);
    Component component = (Component)engine.GetObject(componentUri);
    nsmgr.AddNamespace("custom", component.MetadataSchema.NamespaceUri);

    // add sku field to component metadata (field must be defined in ecl stub schema)
    XmlNode metadata = doc.DocumentElement.SelectSingleNode("/tcm:Component/tcm:Data/tcm:Metadata/custom:Metadata", nsmgr);
    XmlNode skuNode = metadata.SelectSingleNode("custom:" + SkuField, nsmgr);
    if (skuNode == null)
    {
      skuNode = doc.CreateNode(XmlNodeType.Element, SkuField, component.MetadataSchema.NamespaceUri);
      skuNode.InnerText = sku;
      metadata.AppendChild(skuNode);

      // update component xml in package (updates are not saved to cms)
      componentItem.SetAsXmlDocument(doc);

      // add to actual component
      UpdateComponentMetadataField(component, SkuField, sku);

      Logger.Info(string.Format("'{0}' field added with value: {1}", SkuField, sku));
    }
    else if (!skuNode.InnerText.Equals(sku))
    {
      skuNode.InnerText = sku;

      // update component xml in package (updates are not saved to cms)
      componentItem.SetAsXmlDocument(doc);

      // update actual component
      UpdateComponentMetadataField(component, SkuField, sku);

      Logger.Info(string.Format("'{0}' field updated to value: {1}", SkuField, sku));
    }
  }

  // this method requires allowWriteOperationsInTemplates to be set to: true 
  // see http://sdllivecontent.sdl.com/LiveContent/content/en-US/SDL_Tridion_2013/concept_547C3E9D9A684B00BB8CB498B8AF7BBD
  // (requires login - http://docportal.sdl.com/sdltridion)
  private void UpdateComponentMetadataField(Component component, string field, string value)
  {
    if (component.IsShared)
    {
      TcmUri parentUri = new TcmUri(component.Id.ItemId, component.Id.ItemType, component.OwningRepository.Id.ItemId);
      CheckInitialized();
      component = (Component)m_Engine.GetObject(parentUri);
    }
    ItemFields metadataFields = new ItemFields(component.Metadata, component.MetadataSchema);
    component.CheckOut();
    ((SingleLineTextField)metadataFields[field]).Value = value;
    component.Metadata = metadataFields.ToXml();
    component.Save(true);
  }

  private string GetEclMetadata(string eclOrTcmUri, string name)
  {
    CheckInitialized();
    using (IEclSession eclSession = SessionFactory.CreateEclSession(m_Engine.GetSession()))
    {
      IEclUri eclUri = eclOrTcmUri.StartsWith("tcm:") ? eclSession.TryGetEclUriFromTcmUri(eclOrTcmUri) : eclSession.HostServices.CreateEclUri(eclOrTcmUri);
      if (eclUri != null)
      {
        using (IContentLibraryContext context = eclSession.GetContentLibrary(eclUri))
        {
          IContentLibraryMultimediaItem eclItem = (IContentLibraryMultimediaItem)context.GetItem(eclUri);
          if (!string.IsNullOrEmpty(eclItem.MetadataXml))
          {
            XNamespace ns = GetNamespace(eclItem.MetadataXml);
            XDocument metadata = XDocument.Parse(eclItem.MetadataXml);

            XElement property = (from xml in metadata.Descendants(ns + name) select xml).FirstOrDefault();
            if (property != null)
            {
              return property.Value;
            }
          }
        }
      }
    }

    return string.Empty;
  }

  private static string GetNamespace(string xml)
  {
    // ecl metadata string looks like <Metadata xmlns="..">..</Metadata>
    const string nsAttribute = "xmlns=\"";
    int start = xml.IndexOf(nsAttribute);
    int end = xml.IndexOf('\"', start + nsAttribute.Length);
    return xml.Substring(start + nsAttribute.Length, end - start - nsAttribute.Length);
  }
}