I have a mailer that checks for all users that meet a certain criteria.
If that criteria is true, I'm trying to do a do loop, and return the result into an array.
I'm then trying to use that to loop through that array and send an email to each email in the array.
I tried assigning the variable 'emails' to this array where I'm passing this code in
emails = [User.where(:state => 'Arizona').each]
Which isn't working because when I do the following.. the emails aren't sent
emails.each do |email|
new_request(email,row).deliver_now
end
Then I tried to do a loop and save those results to an variable
User.where(:state => 'Arizona').each do |u|
emails = u.email
end
Yet again, when I do this following code the emails aren't sent
emails.each do |email|
new_request(email,row).deliver_now
end
FYI - everything else is working just fine with the rest of my program, the emails are definitely going out fine when I don't use this code. For instance, if I do this:
emails = ['a#gmail.com','b#gmail.com']
the array works fine, and then I can do this..
emails.each do |email|
new_request(email,row).deliver_now
end
and the code email is sent to a#gmail.com and b#gmail.com. So again, the real question is, how do I loop through those users where that criteria is true, and save to an array like this so I can run this emails.each do code and get it work?
User.where(:state => 'Arizona').each do |u|
emails = u.email
end
In the above logic, in every iteration, the emails will be overwritten with the iteration email.
You have to insert the emails in an array to make the logic as expected.
emails = []
User.where(state: 'Arizona').each do |u|
emails << u.email # To insert the user email into the array
end
You can also try to debug the values in the array whenever you face issues in logic.
User.where(:state => 'Arizona').each do |u|
emails = u.email
p emails, "emails" # To check the value stored in the emails.
end
Just use pluck
User.where(:state => 'Arizona').pluck(:email)
=> ["a#gmail.com", "b#gmail.com"]
Related
I am currently working on a ticket where it asks me to filter out any inactive email to be sent to the recipient. Here is the method I am working on:
def self.delivering_email(message)
return if email_to_be_delivered?(message.subject)
email_list = message.to
if email_list.is_a?(String)
email_list = email_list.split(",").map(&:strip)
end
email_list.each { |email|
identity = Identity.find_by(email: email)
next if identity.nil?
# email_list.delete(email) unless identity.try(:preferred_user).active?
email_list.select(email) if identity.try(:preferred_user).active?
}
message.to = email_list
message.perform_deliveries = !email_list.empty?
end
the "# email_list.delete(email) unless identity.try(:preferred_user).active?" I commented out because the QA mentioned that ONLY one inactive email filters out and does not fully filter other inactive emails in the array. I assumed instead of .delete I have to use .select but don't know if it works because I don't have any way to test and reproduce the error on my end, or how to implement it the right way.
Any help will be appreciated.
You're trying to modify an array while you're iterating over it, that may lead to weird behavior. One option is to just use a separate array.
Since you are already iterating with email_list.each you can call next if the current email does not satisfy you, like you already do for identity.nil?.
So it may look smth like
valid_emails = []
email_list.each { |email|
identity = Identity.find_by(email: email)
next if identity.nil? || !identity.try(:preferred_user).active?
valid_emails << email
end
message.to = valid_emails
So I have app that has political candidates.
When a new political candidate is entered, I want to enter a notification into the notifications table for every user that's state is equal to the state of the new candidate being entered.
Ultimately, I want to enter in records to the notification table for every single user where that condition is met.
I know I'm way off, but here's where I'm at now. I'm trying to loop through each user and then enter this record when that condition is true.
def create
#candidate = Candidate.new(candidate_params)
if #candidate.save
User.each do |u|
if Candidate.state == User.state
#notification = Notification.new(:message => 'Message', :user_id => U.id)
#notification.save
else
end
end
else
render('new')
end
end
The candidate is created with this code, but the notifications aren't working. Basically I have two users where their state equals "Arizona" and I would expect if I create a new candidate where the state is "Arizona" that I should get two record into notifications, one with each user ID.
I think you got a bit mixed up between classes and instances. Here's the relevant bit:
#candidate = Candidate.new(candidate_params)
...
User.each do |u|
if Candidate.state == User.state
...
end
end
In your code Candidate is a class, and #candidate holds the recently created instance of a Candidate. Likewise, User is a class and u holds a User instance (on each loop iteration). Your comparison should actually use the instances rather than the classes:
if #candidate.state == u.state
Having sorted that, it's worth noting that your code has a couple of other errors -- User.each won't work. You need to specify a selector to get a list of User objects to loop through. One way would be to call User.all.each (which looking at your code is probably what you were trying). That pulls all User objects. But, since users can be from anywhere, if you do that you will cycle through a lot of users you don't need to.
Since all you need is users whose state matches the new candidate, you can use the where() method to pre-filter the list you are looping through. That way you don't need the if at all.
#candidate = Candidate.new(candidate_params)
...
User.where(state: #candidate.state).each do |u|
#notification = Notification.new(message: 'Message', user: u)
#notification.save
end
The other problem in your code is in the line to create a notification. You use U.id but the loop variable is lower case u. As an added tip, you don't need to set the object ID specifically. If you just pass the User object (as in the code above), Rails is smart enough to figure out the rest.
For performance don't iterate all users, you can search users that match the candidate's state then create notification for each user.
def create
#candidate = Candidate.new(candidate_params)
if #candidate.save
users = User.where(state: #condidate.state)
users.each { |user| #notification = Notification.create(:message => 'Message', :user_id =user.id } if users
else
render 'new'
end
end
I am trying to allow users to upload csv files, however I am having some issues trying to figure out how to handle errors from the file itself.
My controller method:
def create
Product.import_csv(file)
redirect_to products_path, :flash => { :notice => "Items Added!" }
end
My model method to import the file:
def self.import_csv(file)
csv = CSV.read(file.path), :headers => true)
csv.each do |row|
item_id = row[0]
start_date = Date.parse(row[1])
order_date = Date.parse(row[2])
new_rec = where(item_id:item_id, order_date:order_date).first_or_initialize
new_rec.save!
end
end
All this works well when the file is properly formatted, however Im confused as to how to handle exceptions. Once such exception is when start_date or order_date are missing; I get an no implicit conversion of nil into String because I'm attempting to parse the date of an empty cell. Even though I have validations in my model for presence, they only get fired on the save action.
I don't want to silently ignore these errors with a rescue block, but instead redirect back, and notify the user.
How can I handle such exceptions, so that the jobs fails, and the user gets notified of the error, not specifically solely the error given above, but including errors we can't account for? Another example would be a empty line or something we cant even account for. How can I handle such errors, and notify the user with, for example, a generic "Bad data" message?
Should I handle this in my model or my controller?
If you have presence validations for the dates, you can simply assign them only if they exist, and let your model do the rest:
def self.import_csv(file)
csv = CSV.read(file.path), :headers => true)
csv.each do |row|
item_id = row[0]
start_date = row[1].nil? ? nil : Date.parse(row[1])
order_date = row[2].nil? ? nil : Date.parse(row[2])
new_rec = where(item_id:item_id, order_date:order_date).first_or_initialize
new_rec.save!
end
end
I have a record and I want to inset it inside and array and later access it.
users = User.all
results = []
users.each do |user|
results << {:name => user.name, :email => user.email}
end
is results variable still an array ? If yes how can I get all the names alongwith email?
Your example would create an array results filled with hashes containing each users name and email.
You could access it in several ways, the easiest of which is a simple loop:
results.each do |result|
name = result[:name]
email = result[:email]
end
You can also access individual items directly like so:
first_result_name = results[0][:name]
but be careful of trying to access results that may not be there.
Arrays
Hashes
But I have to ask, why do you want to do this? There's no gain from assigning all the Users name and emails to an array, User.all is no different really in functionality.
Yes, it's still an array. You can have what you want later for example with:
results.each do |result|
result[:name] # access to name
result[:email] # access to email
end
You just need one line to do it
results = users.collect{|user| {:name => user.name, :email => user.email}}
In a kind of unrelated way, your initial code could be rewritten as:
results = User.all.inject([]) do |array, user|
array << {:name => user.name, :email => user.email}
end
Given that "results" now contains this collection of hashes, if you want to print every user name and email you would do:
results.each do |user|
puts "#{user[:name]} #{user[:email]}"
end
I'd like some advice on how I should synchronize a list of email addresses on 11k users against an external mailing list program, in this case Mailchimp.
Normally the way I'd do this is simply to have an :after_save callback, to send a single update to the external api.
But already each hour, a rake task is run to update a property on every user in the database. If I simply did that, every hour, the the poor mailchimp API would get be hit 11,000 times.
What's the most efficient, simple way to do this, to check only if a single attribute you're watching has changed from what it was before the save?
If there's a variable that persists across the transaction lifecycle I would simply do something like this, where I check if the value has changed, and if it's different execute come other code.
class User
:before_save :store_old_email
:after_save :sync_with_chimp
def store_old_email
$ugly_of_global_variable_to_store_email = user.email
end
:sync_with_chimp
if $ugly_of_global_variable_to_store_email != user.email
//update_mail_chimp_api
end
end
end
I've checked the rails api here, and I'm still slightly unclear on how I should be doing this.
Would you use the dirty? class here to do this?
This is the way I went with in the end.
It turns out Rails gives you loads of handy callbacks in the dirty to do this.
Any suggestions on how to make this code less repetitive wold be gratefully received.
def update_mailchimp(optin)
# Create a Hominid object (A wrapper to the mailchimp api), and pass in a hash from the yaml file
# telling which mailing list id to update with subscribe/unsubscribe notifications)
#hominid = Hominid.new
client_site_list_id = YAML.load(File.read(RAILS_ROOT + "/config/mailchimp.yml"))
case optin
when 'subscribe_newsletter'
logger.debug("subscribing to newsletter...")
"success!" if #hominid.subscribe(client_site_list_id['client_site_to_mailchimp_API_link'], email, {:FNAME => first_name, :LNAME => last_name}, 'html')
when 'unsubscribe_newsletter'
logger.debug("unsubscribing from newsletter...")
"success!" if #hominid.subscribe(client_site_list_id['client_site_to_mailchimp_API_link'], email, {:FNAME => first_name, :LNAME => last_name}, 'html')
when 'subscribe_monthly_update'
logger.debug("subscribing to monthly update...")
"success!" if #hominid.subscribe(client_site_list_id['monthly_update'], email, {:FNAME => first_name, :LNAME => last_name}, 'html')
when 'unsubscribe_monthly_update'
logger.debug("unsubscribing from monthly update...")
"success!" if #hominid.unsubscribe(client_site_list_id['monthly_update'], email, {:FNAME => first_name, :LNAME => last_name}, 'html')
end
end
# Keep the users in sync with mailchimp's own records - by only firing requests to the API if details on a user have changed after saving.
def check_against_mailchimp
logger.info("Checking if changes need to be sent to mailchimp...")
if newsletter_changed?
logger.info("Newsletter changed...")
newsletter ? update_mailchimp('subscribe_newsletter') : update_mailchimp('unsubscribe_newsletter')
end
if monthly_update_changed?
logger.info("update preferences changed...")
monthly_update ? update_mailchimp('subscribe_monthly_update') : update_mailchimp('unsubscribe_monthly_update')
end
end
you could change your users model to an active resource instead of active record and just use mailchimps api as your db for users
this is an older post about active resource but might get you started down the right path
http://www.therailsway.com/2007/9/3/using-activeresource-to-consume-web-services