In your Gemfile:
gem 'tap_if'
Then run:
$ bundle install
Before you use it:
require 'tap_if'
require 'tap_unless'
##Usage
Yields to the block if the caller
is truthy or given the method name + args
evaluate to
a truthy value.
Useful for clarity - always return the caller but only
execute the block when the condition passes.
# Update the user's account token if the user is an admin of the account.
User.find(user_id).tap_if(:admin?, account) do |user|
user.update_token(account)
end
# Only update twitter/facebook if the post actually updates/publishes.
def publish
(post.pending? && post.update_attributes(:published => true)).tap_if do
the_update = "New blog post: #{post.title[0..100]}... #{post.link}"
Twitter.update(the_update)
Facebook.update(the_update)
end
end
# Only add a user to an account if the user is not a member.
AccountUser.where(:account_id => account.id, :user_id => user.id).tap_if(:empty?) do |user|
account.users << user
end
# OR
AccountUser.where(:account_id => account.id, :user_id => user.id).tap_unless(:any?) do |user|
account.users << user
end
##The Motivation
I found myself assigning a variable and doing something to it if a condition passed.
This pattern leaves dangling ifs
on the end of lines and is simply less clear than
code that will execute if the line is reached.
# I found myself doing (a contrived version):
user = User.where(:email => email).first
user.update_attributes(:status => "active") if user.present? && user.admin?
#But now I can do:
User.where(:email => email).first.tap_if(:admin?) do |user|
user.update_attributes(:status => "active")
end
# In essence we always update the user assuming we get there.
License: MIT-LICENSE (LICENSE.md)