===Requirement===
Annotations are simply marks and notes created on top of a document in order to give users the possibility to interact with the document while preserving the original document. 

===Design===

The annotation is implemented using the Flexpaper viewer with annotations plugin.  The annotation plugin generates specifics events which can be captures using the javascript api provided by them. 

onMarkCreated - This javascript function would get called when a new note is created. 

onMarkChanged - This api would get called when a note's content gets changed. This event is used to add/update the node into the Database.  a 5sec delay in calling this api (as per the desing of the api).


Table name - annotations
^ Column_name       ^type       ^ Description   ^
| id | integer           | primary key   | 
| content | text           | content in the annotation   | 
| owner_id | integer           | who created this annotation   | 
| page_index | integer           | document page no where the annotation is  | 
| position_x | inter           | x cordinate value  | 
| postion_y | integer           | y cordinate value | 
| width |integer |width of the note  | 
| height |integer |height of the note   |
| created_at| date_time |created date |
| updated_at| date_time|updated date |
| asset_id |integer |foreign key to the assets table. |