Ok so i have this helper
def current_company_title
(Company.find_by_id(params["company_id"]).name rescue nil) || (#companies.first.name rescue nil) current_user.company.name
end
Basically what I am achieving with this is the following ...
If the param["company_id"] exists then try to get the company and if not then
if #companies exists grab the first company name and if not then get the current users company name
This works but the rescues seem like a hack...any idea on another way to achieve this
Indeed rescue is kind of a hack, id' probably split it up into two methods and then use try to fetch the name if available: http://api.rubyonrails.org/classes/Object.html#method-i-try
def current_company
#current_company ||= Company.find_by_id(params[:company_id]) || #companies.try(:first) || current_user.try(:company)
end
def current_company_name
current_company.try(:name)
end
Company.find_by_id(params["company_id"]).name`
find and its derivates are meant to be used when you're sure-ish you'll have a positive result, and only in some cases (row was deleted, etc) errors. That's why it raises an exception. In your case, you're assuming it's gonna fail, so a regular where, which would return nil if no rows was found, would do better, and remove the first rescue
#companies.first.name rescue nil
could be replaced by
#companies.first.try(:name)
I'll let you check the api for more on the topic of try. It's not regular ruby, it's a Rails addition.
Less "magic", simple code, simple to read:
def current_company_title
company = Company.where(id: params["company_id"]).presence
company ||= #companies.try(:first)
company ||= current_user.company
company.name
end
Ps. Not a big fan of Rails' try method, but it solves the problem.
def current_company_title
if params["company_id"]
return Company.find_by_id(params["company_id"]).name
elsif #companies
return #companies.first.name
else
return current_user.company.name
end
end
The rescues are a hack, and will obscure other errors if they occur.
Try this:
(Company.find_by_id(params["company_id"].name if Company.exists?(params["company_id"]) ||
(#companies.first.name if #companies && #companies.first) ||
current_user.company.name
then you can extract each of the bracketed conditions to their own methods to make it more readable, and easier to tweak the conditions:
company_name_from_id(params["company_id"]) || name_from_first_in_collection(#companies) || current_user_company_name
def company_name_from_id(company_id)
company=Company.find_by_id(company_id)
company.name if company
end
def name_from_first_in_collection(companies)
companies.first.name if companies && companies.first
end
def current_user_company_name
current_user.company.name if current_user.company
end
[Company.find_by_id(params["company_id"]),
#companies.to_a.first,
current_user.company
].compact.first.name
Related
In my app that I am building to learn Rails and Ruby, I have below iteration/loop which is not functioning as it should.
What am I trying to achieve?
I am trying to find the business partner (within only the active once (uses a scope)) where the value of the field business_partner.bank_account is contained in the field self_extracted_data and then set the business partner found as self.sender (self here is a Document).
So once a match is found, I want to end the loop. A case exists where no match is found and sender = nil so a user needs to set it manually.
What happens now, is that on which ever record of the object I save (it is called as a callback before_save), it uses the last identified business partner as sender and the method does not execute again.
Current code:
def set_sender
BusinessPartner.active.where.not(id: self.receiver_id).each do |business_partner|
bp_bank_account = business_partner.bank_account.gsub(/\s+/, '')
rgx = /(?<!\w)(#{Regexp.escape(bp_bank_account)})?(?!\w)/
if self.extracted_data.gsub(/\s+/, '') =~ rgx
self.sender = business_partner
else
self.sender = nil
end
end
end
Thanks for helping me understand how to do this kind of case.
p.s. have the pickaxe book here yet this is so much that some help / guidance would be great. The regex works.
Using feedback from #moveson, this code works:
def match_with_extracted_data?(rgx_to_match)
extracted_data.gsub(/\s+/, '') =~ rgx_to_match
end
def set_sender
self.sender_id = matching_business_partner.try(:id) #unless self.sender.id.present? # Returns nil if no matching_business_partner exists
end
def matching_business_partner
BusinessPartner.active.excluding_receiver(receiver_id).find { |business_partner| sender_matches?(business_partner) }
end
def sender_matches?(business_partner)
rgx_registrations = /(#{Regexp.escape(business_partner.bank_account.gsub(/\s+/, ''))})|(#{Regexp.escape(business_partner.registration.gsub(/\s+/, ''))})|(#{Regexp.escape(business_partner.vat_id.gsub(/\s+/, ''))})/
match_with_extracted_data?(rgx_registrations)
end
In Ruby you generally want to avoid loops and #each and long, procedural methods in favor of Enumerable iterators like #map, #find, and #select, and short, descriptive methods that each do a single job. Without knowing more about your project I can't be sure exactly what will work, but I think you want something like this:
# /models/document.rb
class Document < ActiveRecord::Base
def set_sender
self.sender = matching_business_partner.try(:id) || BusinessPartner.active.default.id
end
def matching_business_partners
other_business_partners.select { |business_partner| account_matches?(business_partner) }
end
def matching_business_partner
matching_business_partners.first
end
def other_business_partners
BusinessPartner.excluding_receiver_id(receiver_id)
end
def account_matches?(business_partner)
rgx = /(?<!\w)(#{Regexp.escape(business_partner.stripped_bank_account)})?(?!\w)/
data_matches_bank_account?(rgx)
end
def data_matches_bank_account?(rgx)
extracted_data.gsub(/\s+/, '') =~ rgx
end
end
# /models/business_partner.rb
class BusinessPartner < ActiveRecord::Base
scope :excluding_receiver_id, -> (receiver_id) { where.not(id: receiver_id) }
def stripped_bank_account
bank_account.gsub(/\s+/, '')
end
end
Note that I am assigning an integer id, rather than an ActiveRecord object, to self.sender. I think that's what you want.
I didn't try to mess with the database relations here, but it does seem like Document could include a belongs_to :business_partner, which would give you the benefit of Rails methods to help you find one from the other.
EDIT: Added Document#matching_business_partners method and changed Document#set_sender method to return nil if no matching_business_partner exists.
EDIT: Added BusinessPartner.active.default.id as the return value if no matching_business_partner exists.
I have approx 11 functions that look like this:
def pending_acceptance(order_fulfillments)
order_fulfillments.each do |order_fulfillment|
next unless order_fulfillment.fulfillment_time_calculator.
pending_acceptance?; collect_fulfillments(
order_fulfillment.status,
order_fulfillment
)
end
end
def pending_start(order_fulfillments)
order_fulfillments.each do |order_fulfillment|
next unless order_fulfillment.fulfillment_time_calculator.
pending_start?; collect_fulfillments(
order_fulfillment.status,
order_fulfillment
)
end
end
The iteration is always the same, but next unless conditions are different. In case you wonder: it's next unless and ; in it because RuboCop was complaining about it. Is there a solution to implement it better? I hate this spaghetti code. Something like passing the condition into "iterate_it" function or so...
edit: Cannot just pass another parameter because the conditions are double sometimes:
def picked_up(order_fulfillments)
order_fulfillments.each do |order_fulfillment|
next unless
order_fulfillment.handed_over_late? && order_fulfillment.
fulfillment_time_calculator.pending_handover?
collect_fulfillments(
order_fulfillment.status,
order_fulfillment
)
end
end
edit2: One question yet: how could I slice a symbol, to get a user role from a status? Something like:
:deliverer_started => :deliverer or 'deliverer'?
You can pass another parameter when you use that parameter to decide what condition to check. Just store all possible conditions as lambdas in a hash:
FULFILLMENT_ACTIONS = {
pending_acceptance: lambda { |fulfillment| fulfillment.fulfillment_time_calculator.pending_acceptance? },
pending_start: lambda { |fulfillment| fulfillment.fulfillment_time_calculator.pending_acceptance? },
picked_up: lambda { |fulfillment| fulfillment.handed_over_late? && fulfillment.fulfillment_time_calculator.pending_handover? }
}
def process_fulfillments(type, order_fulfillments)
condition = FULFILLMENT_ACTIONS.fetch(type)
order_fulfillments.each do |order_fulfillment|
next unless condition.call(order_fulfillment)
collect_fulfillments(order_fulfillment.status, order_fulfillment)
end
end
To be called like:
process_fulfillments(:pending_acceptance, order_fulfillments)
process_fulfillments(:pending_start, order_fulfillments)
process_fulfillments(:picked_up, order_fulfillments)
you can make array of strings
arr = ['acceptance','start', ...]
in next step:
arr.each do |method|
define_method ( 'pending_#{method}'.to_sym ) do |order_fulfillments|
order_fulfillments.each do |order_fulfillment|
next unless order_fulfillment.fulfillment_time_calculator.
send('pending_#{method}?'); collect_fulfillments(
order_fulfillment.status,
order_fulfillment
)
end
end
end
for more information about define_method
While next is handy it comes late(r) in the code and is thus a bit more difficult to grasp. I would first select on the list, then do the action. (Note that this is only possible if your 'check' does not have side effects like in order_fullfillment.send_email_and_return_false_if_fails).
So if tests can be complex I would start the refactoring by expressing the selection criteria and then pulling out the processing of these items (wich also matches more the method names you have given), somewhere in the middle it might look like this:
def pending_acceptance(order_fulfillments)
order_fulfillments.select do |o|
o.fulfillment_time_calculator.pending_acceptance?
end
end
def picked_up(order_fulfillments)
order_fulfillments.select do |order_fulfillment|
order_fulfillment.handed_over_late? && order_fulfillment.
fulfillment_time_calculator.pending_handover?
end
end
def calling_code
# order_fulfillments = OrderFulFillments.get_from_somewhere
# Now, filter
collect_fulfillments(pending_start order_fulfillments)
collect_fulfillments(picked_up order_fulfillments)
end
def collect_fullfillments order_fulfillments
order_fulfillments.each {|of| collect_fullfillment(of) }
end
You'll still have 11 (+1) methods, but imho you express more what you are up to - and your colleagues will grok what happens fast, too. Given your example and question I think you should aim for a simple, expressive solution. If you are more "hardcore", use the more functional lambda approach given in the other solutions. Also, note that these approaches could be combined (by passing an iterator).
You could use something like method_missing.
At the bottom of your class, put something like this:
def order_fulfillment_check(method, order_fulfillment)
case method
when "picked_up" then return order_fulfillment.handed_over_late? && order_fulfillment.fulfillment_time_calculator.pending_handover?
...
... [more case statements] ...
...
else return order_fulfillment.fulfillment_time_calculator.send(method + "?")
end
end
def method_missing(method_name, args*, &block)
args[0].each do |order_fulfillment|
next unless order_fulfillment_check(method_name, order_fulfillment);
collect_fulfillments(
order_fulfillment.status,
order_fulfillment
)
end
end
Depending on your requirements, you could check if the method_name starts with "pending_".
Please note, this code is untested, but it should be somewhere along the line.
Also, as a sidenote, order_fulfillment.fulfillment_time_calculator.some_random_method is actually a violation of the law of demeter. You might want to adress this.
I'm using Rails 4 and have an Article model that has answer, side_effects, and benefits as attributes.
I am trying to create a before_save method that automatically looks at the side effects and benefits and creates links corresponding to another article on the site.
Instead of writing two virtually identical methods, one for side effects and one for benefits, I would like to use the same method and check to assure the attribute does not equal answer.
So far I have something like this:
before_save :link_to_article
private
def link_to_article
self.attributes.each do |key, value|
unless key == "answer"
linked_attrs = []
self.key.split(';').each do |i|
a = Article.where('lower(specific) = ?', i.downcase.strip).first
if a && a.approved?
linked_attrs.push("<a href='/questions/#{a.slug}' target=_blank>#{i.strip}</a>")
else
linked_attrs.push(i.strip)
end
end
self.key = linked_attrs.join('; ')
end
end
end
but chaining on the key like that gives me an undefined method 'key'.
How can I go about interpolating in the attribute?
in this bit: self.key you are asking for it to literally call a method called key, but what you want, is to call the method-name that is stored in the variable key.
you can use: self.send(key) instead, but it can be a little dangerous.
If somebody hacks up a new form on their browser to send you the attribute called delete! you don't want it accidentally called using send, so it might be better to use read_attribute and write_attribute.
Example below:
def link_to_article
self.attributes.each do |key, value|
unless key == "answer"
linked_attrs = []
self.read_attribute(key).split(';').each do |i|
a = Article.where('lower(specific) = ?', i.downcase.strip).first
if a && a.approved?
linked_attrs.push("<a href='/questions/#{a.slug}' target=_blank>#{i.strip}</a>")
else
linked_attrs.push(i.strip)
end
end
self.write_attribute(key, linked_attrs.join('; '))
end
end
end
I'd also recommend using strong attributes in the controller to make sure you're only permitting the allowed set of attributes.
OLD (before I knew this was to be used on all attributes)
That said... why do you go through every single attribute and only do something if the attribute is called answer? why not just not bother with going through the attributes and look directly at answer?
eg:
def link_to_article
linked_attrs = []
self.answer.split(';').each do |i|
a = Article.where('lower(specific) = ?', i.downcase.strip).first
if a && a.approved?
linked_attrs.push("<a href='/questions/#{a.slug}' target=_blank>#{i.strip}</a>")
else
linked_attrs.push(i.strip)
end
end
self.answer = linked_attrs.join('; ')
end
I have a before_action method like this:
def current_user
#current_user ||= User.find(:id => session[:id])
end
And I call a method like this:
def get_food user
food = Food.find(:id => user.id)
end
This is fine, but I want to add exception handling.
When the user is nil I want to use #current_user:
def get_food user
food = Food.find(if user is nil i want to use #current_user.id)
end
Of course, I can write it like this:
def get_food user
if user.nil?
food = Food.find(#current_user.id)
else
food = Food.find(user.id)
end
Or, is this the best way?
def get_food user
food = Food.find(user == nil? #current_user.id : user.id)
end
I'm curious is there a better way than adding a simple if statement inside the param?
The shortest one lines I can think of are something like this:
Food.find((user || current_user).id)
Food.find(user.try(:id) || current_user.id)
Food.find(user ? user.id : current_user.id)
Not sure if this is really an impovement in readability. I would prefer something like this:
def get_food(user)
user ||= current_user
Food.find(user.id)
end
You can use ternary operator to make it one line:
user ? Food.find(user.id) : Food.find(#current_user.id)
How about arrays
food = Food.where(id: [#current_user.try(:id),user.id]).first
You can try this:
food = Food.find(user.nil? ? #current_user.id : user.id)
What about default parameters?
def get_food(user = #current_user)
food = Food.find(user.id)
end
It will work if you call it without the parameter
something.get_food # notice the method is called with no params
If you want it working also if you pass nil, you should also add:
def get_food(user = #current_user)
food = Food.find((user || #current_user).id)
end
However is strange that foods and users have the same ids...
Maybe the correct query is:
food = Food.find_by_user_id((user || #current_user).id)
or, if users have more than just one food:
foods = Food.where(user: (user || #current_user)) # rails 4, :user => (user || #current_user) for rails 3
Food.find(user.id rescue #current_user.id)
To check if buyer.save is going to fail I use buyer.valid?:
def create
#buyer = Buyer.new(params[:buyer])
if #buyer.valid?
my_update_database_method
#buyer.save
else
...
end
end
How could I check if update_attributes is going to fail ?
def update
#buyer = Buyer.find(params[:id])
if <what should be here?>
my_update_database_method
#buyer.update_attributes(params[:buyer])
else
...
end
end
it returns false if it was not done, same with save. save! will throw exceptions if you like that better. I'm not sure if there is update_attributes!, but it would be logical.
just do
if #foo.update_attributes(params)
# life is good
else
# something is wrong
end
http://apidock.com/rails/ActiveRecord/Base/update_attributes
Edit
Then you want this method you have to write. If you want to pre check params sanitation.
def params_are_sanitary?
# return true if and only if all our checks are met
# else return false
end
Edit 2
Alternatively, depending on your constraints
if Foo.new(params).valid? # Only works on Creates, not Updates
#foo.update_attributes(params)
else
# it won't be valid.
end
The method update_attributes returns false if object is invalid. So just use this construction
def update
if #buyer.update_attributes(param[:buyer])
my_update_database_method
else
...
end
end
If your my_update_database_method has to be call only before update_attributes, then you shoud use merge way, probably like this:
def update
#buyer = Buyer.find(params[:id])
#buyer.merge(params[:buyer])
if #buyer.valid?
my_update_database_method
#buyer.save
else
...
end
end
This may not be the best answer, but it seems to answer your question.
def self.validate_before_update(buyer)#parameters AKA Buyer.validate_before_update(params[:buyer])
# creates temporary buyer which will be filled with parameters
# the temporary buyer is then check to see if valid, if valid returns fail.
temp_buyer = Buyer.new
# populate temporary buyer object with data from parameters
temp_buyer.name = buyer["name"]
# fill other required parameters with valid data
temp_buyer.description = "filler desc"
temp_buyer.id = 999999
# if the temp_buyer is not valid with the provided parameters, validation fails
if temp_buyer.valid? == false
temp_buyer.errors.full_messages.each do |msg|
logger.info msg
end
# Return false or temp_buyer.errors depending on your need.
return false
end
return true
end
you'd better check it in your model through a before_save
before_save :ensure_is_valid
private
def ensure_is_valid
if self.valid?
else
end
end
I've run into the same scenario - needed to know if record is valid and do some actions before update save. I've found out that there is assign_attributes(attributes) method which update method uses before save. So nowadays it's likely correct to do:
def update
#buyer = Buyer.find(params[:id])
#buyer.assign_attributes(params[:buyer])
if #buyer.valid?
my_update_database_method
#buyer.save
else
...
end
end