Hi I have something like the folowing:
class TrialRequest
attr_accessor :trial_email
def initialize(email)
#trial_email = email
puts "Trial_email: #{trial_email}"
end
def create
#email = ::Gmail.connect!(gmail_name, gmail_password) do |gmail|
email = gmail.compose do
to 'trial#domain.com'
from trial_email
subject trial_email
text_part do
content_type 'text/html; charset=UTF-8'
body 'Sign me up.'
end
end
#binding.pry
gmail.deliver!(email)
end
end
end
The problem is that inside the compose block trial_email is not defined:
NameError: undefined local variable or method `trial_email' for #<Mail::Message:0x0000000431b830>
Is this a Ruby 1.9 issue or a gmail gem issue?
How should I go about making this method 'visible'/within the scope of the compose block?
Update:
This is an issue/feature of the gmail gem - ruby 1.9 blocks have changed but not this much!
In addition to the accepted answer, another workaround is to pass the data in as a method parameter:
def create(trial_email)
...
end
Looks like a GMail issue to me. Inside the blocks, self will be some object from the GMail gem so that you can have to, from, and similar DSL niceties available. You should be able to put self.trial_email into a local variable and then access that inside the blocks:
email_address = self.trial_email
#email = ::Gmail.connect!(gmail_name, gmail_password) do |gmail|
email = gmail.compose do
to 'trial#domain.com'
from email_address
subject email_address
#...
You're expecting (as you're entitled to) that the block should preserve the value of self, as it usually does. It looks like the gmail gem is using instance_exec here which allows it to change the value of self for the block to an instance of Mail::Message (which is why you can call to and from in that block even though you define no such methods)
While instance_exec is handy for producing nice DSLs, it is not without its downsides. Local variable scope isn't affected so you could store either trial_email or self in a local variable prior to the block and then use that local variable inside the block
The problem is that the block you pass to compose method is later passed to Mail.new and finally to Message.new (if I traced the chain correctly) and then this block is evaluated like that here:
instance_eval(&block)
As it's performed inside initialize method of a different object (instance of Message class) you do not have access to attributes of your TrialRequest object.
You can do the same thing without having any troubles like that:
email = gmail.compose
email.to = 'trial#domain.com'
email.from = trial_email
email.subject = trial_email
email.text_part do
content_type 'text/html; charset=UTF-8'
body 'Sign me up.'
end
Related
I am using the iex exchange api for grabbing info about stocks. It's working great but my code is very ugly was wondering how to refactor the code.
stock = IEX::Api::Client.new(
publishable_token: token,
endpoint: 'https://sandbox.iexapis.com/v1'
)
This is what is needed to grab the info. The problem is that I have to put the code above in every method that utilizes the api. For instance,
def self.stock_price(ticker)
stock = IEX::Api::Client.new(
publishable_token: token,
endpoint: 'https://sandbox.iexapis.com/v1'
)
company = stock.company(ticker)
quote = stock.quote(ticker.upcase)
puts "#{company.company_name}: #{quote.latest_price}"
end
def self.week_52_high(ticker)
stock = IEX::Api::Client.new(
publishable_token: token,
endpoint: 'https://sandbox.iexapis.com/v1'
)
key_stats = stock.key_stats(ticker)
puts "52-week high: #{key_stats.week_52_high}"
end
def self.week_52_low(ticker)
stock = IEX::Api::Client.new(
publishable_token: token,
endpoint: 'https://sandbox.iexapis.com/v1'
)
key_stats = stock.key_stats(ticker)
puts "52-week low: #{key_stats.week_52_low}"
end
Is there any way to factor that call out to a different file and call the method that way? The code is very repetitive as is. The "stock" variable is what i need to actually work with, should I made that a global variable? I've heard that's a no-no but is this case an exception? Also, where i have
publishable_token: token,
that token variable is actually my actual, hard-coded token, not the "token" variable you see, I simply changed it for security issues. What should I do instead of hard-coding it? The documentation says to turn it into an environment variable but i dont know what that means. Thanks in advance!
What should I do instead of hard-coding it? The documentation says to
turn it into an environment variable but i dont know what that means.
An environment variable is a variable whose value is set outside the the application, typically through functionality built into the operating system or shell. You need to check the documentation for your setup to see how to set env vars.
You can get env vars in Ruby through the ENV hash.
ENV['FOO']
ENV.fetch('FOO') # will raise a KeyError if it is not set instead of just returning nil
Rails 5.2 and up have secure credentials that can be used instead. It stores your credentials in an encrypted YAML file that can be checked into source control.
How do I refactor this?
One way to refactor this would be to use delegation instead of bunch of largely static methods:
require 'forwardable'
class MyClient
extend Forwardable
TOKEN = ENV.fetch('IEX_API_TOKEN')
ENDPOINT = ENV.fetch('IEX_API_ENDPOINT', 'https://sandbox.iexapis.com/v1')
def_delegators :#client, :company, :quote, :key_stats
def initialize(publishable_token: TOKEN, endpoint: ENDPOINT, client: nil)
# This is know as constructor injection and makes it easy to mock out
# the dependency in tests
#client = client || IEX::Api::Client.new(publishable_token: TOKEN, endpoint: ENDPOINT)
end
def stock_price(ticker)
company_name = company(ticker).company_name
price = quote(ticker.upcase).latest_price
puts "#{company_name}: #{price}"
end
def week_52_high(ticker)
puts "52-week high: #{key_stats(ticker).week_52_high}"
end
def week_52_low(ticker)
puts "52-week low: #{key_stats(ticker).week_52_low}"
end
end
#client = MyClient.new
#client.week_52_low(ticker)
My goal is to set an instance variable using AFMotion's AFMotion::HTTP.get method.
I've set up a Post model. I would like to have something like:
class Post
...
def self.all
response = AFMotion::HTTP.get("localhost/posts.json")
objects = JSON.parse(response)
results = objects.map{|x| Post.new(x)}
end
end
But according to the docs, AFMotion requires some sort of block syntax that looks and seems to behave like an async javascript callback. I am unsure how to use that.
I would like to be able to call
#posts = Post.all in the ViewController. Is this just a Rails dream? Thanks!
yeah, the base syntax is async, so you don't have to block the UI while you're waiting for the network to respond. The syntax is simple, place all the code you want to load in your block.
class Post
...
def self.all
AFMotion::HTTP.get("localhost/posts.json") do |response|
if result.success?
p "You got JSON data"
# feel free to parse this data into an instance var
objects = JSON.parse(response)
#results = objects.map{|x| Post.new(x)}
elsif result.failure?
p result.error.localizedDescription
end
end
end
end
Since you mentioned Rails, yeah, this is a lil different logic. You'll need to place the code you want to run (on completion) inside the async block. If it's going to change often, or has nothing to do with your Model, then pass in a &block to yoru method and use that to call back when it's done.
I hope that helps!
I'm using devise and the bitbucket api gem and I have a method in my ApplicationController which creates an instance so I can make API calls. To do that, it tries to read the token and secret from the current_user.
This works fine with hardcoded token and secret strings, I'm also able to do puts current_user.inspect before the do block, and that all works fine. I'm also sure that bb_token and bb_secret exist (I'm able to call puts on them individually).
But once I try to create my bitbucket instance, it can't read current_user anymore. Any ideas?
class ApplicationController < ActionController::Base
protect_from_forgery
helper_method :current_user
def bitbucket
puts "token----------"
puts current_user
#bitbucket = BitBucket.new do |config|
config.oauth_token = current_user.bb_token # replaceing this with hardcoded string works
config.oauth_secret = current_user.bb_secret # replaceing this with hardcoded string works
config.client_id = 'xx'
config.client_secret = 'yy'
config.adapter = :net_http
end
end
end
And the error:
NameError (undefined local variable or method `current_user' for #<BitBucket::Client:0x007fbebc92f540>):
app/controllers/application_controller.rb:12:in `block in bitbucket'
app/controllers/application_controller.rb:11:in `bitbucket'
It seems block passed to BitBucket.new is executed in context of new BitBucket::Client instance (BitBucket.new is really BitBucket::Client.new, according to this).
A glance to the source confirms this supposition.
If you want to pass current_user, you can recall that the blocks are closures, so they keep the context in which they are defined. So you can do something like this:
def bitbucket
# (...)
user = current_user # local variable assignment
#bitbucket = BitBucket.new do |config|
config.oauth_token = user.bb_token # it works because user is local variable and the block is closure
# (...)
end
end
Inside BitBucket.new do..end block,self is set to config. But current_user is not a instance method of BitBucket class. Thus a valid error is thrown.
I wrote a very simple User class. The instance variable email has a reader accessor and my own writer accessor that validates the email address with a regex.
class User
attr_reader :email
def email=(value)
if (value =~ /^[a-z\d\-\_\+\.]+#([a-z\d\-]+\.)+[a-z]+$/)
#email = value
else
# bonus question: is ArgumentError the right error type to use here?
raise ArgumentError, "#{value} is not a valid email address."
end
end
end
I wrote the following test:
require 'test/unit'
require_relative '../lib/user'
class TC_UserTest < Test::Unit::TestCase
def setup
#user = User.new()
end
def test_email
# using the writer accessor
#user.email = 'user#example.com'
# bypassing the writer accessor. evil.
#user.email[4] = '#'
assert_equal('user#example.com', #user.email)
end
end
By using the reference given to me by the reader accessor, I am able to manipulate the email instance variable without going through the writer accessor.
The same principe would apply to any data type that allows manipulation without outright assigning a new value with =
Am I being overzealous? I just want to write robust code. Is there a way to ensure that my email address can only be set using the writer accessor?
I'm new to the language and I'm trying to get a feel for the best practices.
An option to make the test pass (and protect the #email variable) is to expose a duplicate.
def email
#email.dup
end
To do what you're trying to do, my advice is to move the regexp into its own validation method.
Better still, don't write an email regexp unless you really want to do it right.
Use a gem instead: https://github.com/SixArm/sixarm_ruby_email_address_validation
After you set the email, freeze it with http://ruby-doc.org/core-1.9.3/Object.html#method-i-freeze
Bonus answer: yes, ArgumentError is the right error type in general. If you're using Rails, consider using the Rails validation methods.
You can freeze value in writer, that way you'll be able to assign new one via writer, but already assigned would be immutable:
class User
attr_reader :email
def email=(value)
if (value =~ /^[a-z\d\-\_\+\.]+#([a-z\d\-]+\.)+[a-z]+$/)
# make email immutable:
#email = value.freeze
else
# bonus question: is ArgumentError the right error type to use here?
raise ArgumentError, "#{value} is not a valid email address."
end
end
end
RuNubie here. I've got a class Login that logs into gmail using the net/IMAP library. What is happening is that I create a new instance of that class, such as:
a = Login.new("username", "gmail.com", "passw")
Then, I'm working on other classes that will do some "stuff" with the mailbox. The problem is that the #imap variable I've defined in Login seems to have disappeared (due to scoping I assume).
This is how #imap is declared in Login class:
#imap = Net::IMAP.new('imap.gmail.com',993,true,nil,false)
So this:
#today = Date.today
#received_today = imap.search(["SINCE", #today.strftime("%d-%b-%Y")]).count.to_s
...returns an error. These are the two errors I've gotten while playing around with this. The first one is when I use imap, the second one is when I try #imap:
NameError: undefined local variable or method `imap' for #<Object:0x10718d2a8>
NoMethodError: undefined method `search' for nil:NilClass
What are the best practices for dealing with a situation like this? Is the only solution to define my methods that do "stuff" in the same class where I'm creating the new instance of Net::IMAP? Is declaring #imap as a global variable $imap a bad practice? So confused, I bet the answer is very simple and obvious too, but I'm just not seeing it. Thanks!
This:
#received_today = imap.search(["SINCE", #today.strftime("%d-%b-%Y")]).count.to_s
won't work because, well, there is no imap in scope at that point and so you get a NameError. When you try it like this:
#received_today = #imap.search(["SINCE", #today.strftime("%d-%b-%Y")]).count.to_s
You get a NoMethodError because instance variables, such as #imap, are automatically created at first use and initialized as nil. Your real #imap is in another object so you can't refer to it as #imap anywhere else.
I think you want a structure more like this:
class User
def imap
if(!#imap)
#imap = Net::IMAP.new('imap.gmail.com', 993, true, nil, false)
# and presumably an #imap.authenticate too...
end
#imap
end
end
class OtherOne
def some_method(user)
#today = Date.today
#received_today = user.imap.search(["SINCE", #today.strftime("%d-%b-%Y")]).count.to_s
end
end
Keep your Net::IMAP localized inside your User and let other objects use it by providing a simple accessor method.
Oh and that global $imap idea, I'll just pretend I didn't see that as globals are almost always a really bad idea.
a shorter way to define the imap variable in the User class, which is pretty much the same as what mu posted:
class User
def imap
#imap ||= Net::IMAP.new...
end
end