Rails helpers cheatsheet

Date

distance_of_time_in_words(Time.now, project.end_date) #=> 3 hours
distance_of_time_in_words_to_now(project.end_date)    #=> 3 hours

time_ago_in_words 3.minutes.ago #=> "3 minutes"

Numbers

number_to_currency 20.33
number_to_currency 20.33, precision: 0
number_with_precision 3.14159, precision: 2
number_to_percentage 32       #=> "32%"
number_with_delimiter 2048    #=> "2,048"
number_to_human 12000000      #=> "12 million"
number_to_human_size 12000000 #=> "12 MB"
number_to_phone "5551234"     #=> "555-1234"

Cache

<% cache project do %>
<% cache [project, current_user] do %>

<% cache_if admin?, project do %>
<% cache_unless admin?, project do %>

Tags

tag("br")
tag("img", src: "image.jpg")
content_tag(:p, "Hello")

Time select

# Creates a time select tag that, when POSTed, will be stored in the article
# variable in the sunrise attribute.
time_select "article", "start_time"

# All options are optional
time_select "article", "start_time", \
  include_seconds: true,
  minute_step: 15,
  prompt: true,
  prompt: { hour: "Choose hr", minute: "Choose min", second: "Choose sec" },
  ampm: true

# For dates (all options are optional)
date_select "article", "written_on", \
  start_year: 1995,
  use_month_numbers: true,
  discard_day: true,
  include_blank: true,
  order: [:day, :month, :year],
  default: 3.days.from_now,
  default: { day: 20 },
  prompt: { day: 'Select day', month: 'Select month', year: 'Select year' }

Time tag

time_tag Date.today 
#=> '<time datetime="2010-11-04">November 04, 2010<%rtime>'

time_tag Time.now
#=> '<time datetime="2010-11-04T17:55:45+01:00">November 04, 2010 17:55</time>'

time_tag Date.yesterday, 'Yesterday'
#=> '<time datetime="2010-11-03">Yesterday<%rtime>'

time_tag Date.today, pubdate: true
#=> '<time datetime="2010-11-04" pubdate="pubdate">November 04, 2010</time>'

time_tag Date.today, \
  format: :short_date # (en.time.formats.short_date)

Files

= form_for @post, multipart: true do |f|
  = f.file_field :picture

i18n

t('folders')
t('folders.save')

l(Time.now)

t('x_files', count: files.count)
# files:
#    one: 'one file'
#    other: '%{count} files'

References

* http://api.rubyonrails.org/classes/ActionView/Helpers.html