For developers: Hierarchical types API

Sitefinity CMS provides you with an API for managing hierarchical items that uses the DynamicContentExtensions public class.

The API consists of extension methods over DynamicContent items:

• To set the parentItem as parent of the current dynamic content item, use the following method:
  void SetParent(this DynamicContent dynamicContent, DynamicContent parentItem)
• To set the parent of the current dynamic, use the following method:
  void SetParent(this DynamicContent dynamicContent, Guid parentId, string systemParentType)
  The parent item is described with Id and type.
• To sets the childItem as child of the current dynamic content item, use the following method:
  void AddChildItem(this DynamicContent parnetItem, DynamicContent childItem)
• To return all child items from specified type, use one of the following methods. The first method specifies child item type as type, the second as string:
  
  IQueryable<DynamicContent> GetChildItems(this DynamicContent dynamicContent, Type childItemsType)
  IQueryable<DynamicContent> GetChildItems(this DynamicContent dynamicContent, string childItemsType)
  If the method is invoked for a Live item, it returns Live child items only, otherwise, it returns items in status Master. If the chidlItemsType is missing, the method returns all child types from type DynamicContent.
• To returns all the successor items of specified type for specific parent, use one of the following methods:
  IQueryable<DynamicContent> GetSuccessors(this DynamicContent dynamicContent, string childItemsType)
  IQueryable<DynamicContent> GetSuccessors(this DynamicContent dynamicContent, Type childItemsType)

  The child type does not need to be a direct child of the current parent item.  If the method is invoked for a Live item, it returns Live child items only, otherwise, it returns items in status Master.

• To return all child items from specified type, filtered by specific filter expression, use one of the following methods. The first method specifies child item type as type, the second as string:
  IEnumerable<DynamicContent> GetChildItems(this DynamicContent dynamicContent, Type childItemsType, string filterExpression, string orderExpression, int? skip, int? take, ref int? totalCount)
  IEnumerable<DynamicContent> GetChildItems(this DynamicContent dynamicContent, string childItemsType, string filterExpression, string orderExpression, int? skip, int? take, ref int? totalCount)

  The method can be used from a custom pager, since it return the total count of the items and accepts skip and take as parameters. If the method is invoked for a Live item, it returns Live child items only, otherwise, it returns items in status Master. If the chidlItemsType is missing, the method returns all child types from type DynamicContent.

• To return the count of child items from specified type, use one of the following methods. The first method specifies child item type as type, the second as string:
  int GetChildItemsCount(this DynamicContent parentItem, Type childItemsType)
  int GetChildItemsCount(this DynamicContent parentItem, string childItemsType)
  If the chidlItemsType is missing, the method returns the count of all child types from type DynamicContent.
• To check whether a parent type is valid parent type for this particular item, use one of the following methods. The first method specifies child item type as type, the second as string:
  bool IsValidParent(this DynamicContent childItem, Type systemParentType)
  bool IsValidParent(this DynamicContent childItem, string systemParentType)
• To checks whether the parent type is valid predecessor type for this specific item, use the following methods. The first method specifies child item type as type, the second as string:
  bool IsValidPredecessor(this DynamicContent childItem, Type systemParentType)
  bool IsValidPredecessor(this DynamicContent childItem, string systemParentType)