# EPUB Content

1. OPS (xhtml arcticles)
2. OPF (packaging)
   - .opf (manifest, items, metadata)
   - .ncx (chapters)
3. OCF (container/zip)
   - mimetype file
   - container.xml (point to .opf file)

# Abstract Book Description

Book has:
  - Unique ID
  - Name
  - Author
  - List of Item

Item is:
  - (FileName/Content/MediaType)
  - Maybe Metadata

Metadata can be:
  - ChapterMetadata
        - Title

# Structure of the Book

   +-------------------------------------+
   | Book with Name/Title/Id             |
   |                                     |
   |                                     |
   |+----------------------------------+ |
   || Item 1                           | |
   ||                                  | |
   ||                                  | |
   |+----------------------------------+ |
   |                                     |
   |+----------------------------------+ |
   || Item 2                           | |
   ||                                  | |
   |+----------------------------------+ |
   |                                     |
   +-------------------------------------+


# Book Construction

1. Create Abstract Book and fill it with
   content.

2. Serialize Abstract Book to file (zip)

But in step 2 there are following
hidden operations:

1. From the Book the following files are 
   created:
   - OPF with proper data filled
   - For each Item the file is Created
   - NCX with chapters 

2. The OCF is constructed with all files
   above and OPF File set as Root item.
  

# Autogenerated Data

Following data are automatically generated from the
Abstract book:

- Identifier of Chapter
- Sequence number of Chapter according the order in 
  the list of items.