To install ri and rdoc of any gem,

gem install gemname

This command installs ri and rdoc with installation of gem.

To skip the installation of ri and rdoc of gem,

gem install gemname –no-ri –no-rdoc

This command will skip the installation of ri and rdoc when installing gem.

RESTful interface means clean URLs, less code, CRUD interface.

CRUD means Create-READ-UPDATE-DESTROY.

You might heard about HTTP verbs, GET, POST. In REST, they add 2 new verbs, i.e, PUT, DELETE.

There are 7 default actions, those are – index, show, new, create, edit, update, destroy

GET is used when you retrieve data from database. POST is used when you create new record in database. PUT is used when you are updating any existing record in database, and DELETE is used when you are destroying any record in database. Following table may clear the concept.

Action VERB

index                        GET

show                        GET

new                          GET

create                       POST

edit                          GET

update                      PUT

destroy                    DELETE

To display datetimes in different formats in Ruby On Rails application,

following may help,

Format meaning:
%a – The abbreviated weekday name (“Sun”)
%A – The full weekday name (“Sunday”)
%b – The abbreviated month name (“Jan”)
%B – The full month name (“January”)
%c – The preferred local date and time representation
%d – Day of the month (01..31)
%H – Hour of the day, 24-hour clock (00..23)
%I – Hour of the day, 12-hour clock (01..12)
%j – Day of the year (001..366)
%m – Month of the year (01..12)
%M – Minute of the hour (00..59)
%p – Meridian indicator (“AM” or “PM”)
%S – Second of the minute (00..60)
%U – Week number of the current year, starting with the first Sunday as the first day of the first week (00..53)
%W – Week number of the current year, starting with the first Monday as the first day of the first week (00..53)
%w – Day of the week (Sunday is 0, 0..6)
%x – Preferred representation for the date alone, no time
%X – Preferred representation for the time alone, no date
%y – Year without a century (00..99)
%Y – Year with century
%Z – Time zone name
%% – Literal “%” character

For example,

t = Time.now
t.strftime(“Printed on %m/%d/%Y”) #=> “Printed on 04/09/2003″
t.strftime(“at %I:%M%p”) #=> “at 08:56AM”