Hint: Ruby methods use def ...; ...; end syntax [OK]
Common Mistakes:
Using curly braces instead of def/end
Using arrow syntax which is invalid in Ruby
Omitting colons in keyword arguments
3. Given this mailer method in Rails:
def alert_email(user)
mail(to: user.email, subject: 'Alert')
end
What will happen when alert_email(user).deliver_now is called?
medium
A. An email is sent immediately to the user's email
B. The email is saved but not sent
C. A syntax error occurs
D. The method returns nil without sending email
Solution
Step 1: Understand deliver_now in Rails mailers
Calling deliver_now sends the email immediately instead of queuing it.
Step 2: Analyze the method behavior
The method returns a Mail::Message object, and deliver_now triggers sending the email to the specified address.
Final Answer:
An email is sent immediately to the user's email -> Option A
Quick Check:
deliver_now sends email immediately [OK]
Hint: deliver_now sends email immediately [OK]
Common Mistakes:
Confusing deliver_now with deliver_later
Thinking email is only saved, not sent
Assuming method returns nil
4. Identify the error in this Rails mailer method:
def notify_user(user)
mail(to user.email, subject: 'Notification')
end
medium
A. Using parentheses incorrectly
B. Incorrect method name 'notify_user'
C. Missing 'end' keyword for method
D. Missing colon after 'to' keyword argument
Solution
Step 1: Check syntax of mail method arguments
Keyword arguments require a colon after the key, so it should be to: user.email.
Step 2: Verify method structure
The method name and 'end' keyword are correct; parentheses are optional but not incorrect here.
Final Answer:
Missing colon after 'to' keyword argument -> Option D
Quick Check:
Keyword args need colon = Missing colon after 'to' keyword argument [OK]
Hint: Keyword args need colon after key [OK]
Common Mistakes:
Omitting colon after keyword argument
Assuming method name causes error
Forgetting 'end' keyword
5. You want to send a confirmation email only if the user's email is verified. Which code snippet correctly integrates this condition in a Rails mailer?
hard
A. def confirmation_email(user)
if user.email_verified?
mail(to: user.email, subject: 'Confirm')
end
end
B. def confirmation_email(user)
mail(to: user.email, subject: 'Confirm') if !user.email_verified?
end
C. def confirmation_email(user)
mail(to: user.email, subject: 'Confirm') unless user.email_verified?
end
D. def confirmation_email(user)
mail(to: user.email, subject: 'Confirm')
end
Solution
Step 1: Understand conditional email sending
The email should be sent only if user.email_verified? returns true.
Step 2: Analyze each code snippet
def confirmation_email(user)
mail(to: user.email, subject: 'Confirm') if user.email_verified?
end uses inline if but returns nil if condition false, which may cause unexpected behavior. def confirmation_email(user)
if user.email_verified?
mail(to: user.email, subject: 'Confirm')
end
end clearly wraps mail call inside if block, ensuring mail is sent only when verified. def confirmation_email(user)
mail(to: user.email, subject: 'Confirm') unless user.email_verified?
end sends mail unless verified, which is opposite logic. def confirmation_email(user)
mail(to: user.email, subject: 'Confirm')
end sends mail unconditionally.
Final Answer:
def confirmation_email(user)
if user.email_verified?
mail(to: user.email, subject: 'Confirm')
end
end -> Option A
Quick Check:
Use if block for conditional mail sending = def confirmation_email(user)
if user.email_verified?
mail(to: user.email, subject: 'Confirm')
end
end [OK]
Hint: Use if block to conditionally send email [OK]
Common Mistakes:
Using unless instead of if for condition
Placing mail call outside condition
Using inline if that returns nil unexpectedly
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