[emph]History display concept[/emph]

The history needs to provide the user the ability to show the changes
made on an item in a easy and clear way without producing innumerable
rows and information.

[emph]Item History tab[/emph]

Every item will have avalable a fixed tab named 'History' where last changes 
will be loaded. The content of the tab will be requested to server when user
enters th tab, minimizing the size of the original request of the item detail.

This tab has to be enabled enabled on the configuration file.

The history tab will have all the changes produced on the last 30 days
(by default, configurable) on all fields of an item. The information
will be included into the json answer array (jsonDetail action) with
the key 'history'.

On 'History' tab the user will be able to get all history referred to
that specific item. The json request will be:

[code]
/History/jsonList/moduleId/<ModuleId>/itemId/<itemId>/
[/code]

Additional filters could be added:

startDate and endDate to limit the start and end date of the report.

FieldName to filter the report for only one field.

UserName to show the changes made for one specific user.

The information to be shown on the report will be:
username, modification datetime, field name, new value.

The count and offset values will be also applied on this report to
enable further pagination.


[emph]Each field changes[/emph]

On the item detail form it could be possible to get all changes for an
item asking for the field history on the context menu. The json
message to get the field changes history will be:

[code]
/History/jsonList/moduleId/<moduleId>/itemId/<itemId>/fieldName/<fieldName>
[/code]


[emph]Configuration values for history[/emph]

The configuration file will have the following values related to
history log and display:

history.enabled boolean: Will enable and disable the history log of
item changes.

history.show boolean: will determine if the history tab will be
displayed or not.

history.days integer: Number of days shown by default on history tab.
