We're using Amazon SES to send our e-mails, which is why we send all e-mail that could be bulkish using DelayedJob. DelayedJob queues these e-mails to be sent with at least a second between them.
It generally works fine, but I've seen problems with variables appearing to be cached inside the ActionMailer templates and in the generated PDFs that are sent along with some of these e-mails. The PDFs are generated using Prawn.
Say, for instance, all our clients have an unique ID and I send an e-mail to two clients. The first client has ID 1234 and the second has ID 2345. What happens is that both clients receive an e-mail with the ID 1234 in it. Both e-mails go to the correct person though and some other variables will render properly.
I originally thought this problem to be related to the use of helpers in my e-mail template. I'll share an example:
<%- #extra_lines.each do |line|
if #interpolations
#interpolations.each do |key,value|
line = line.html_safe.sub "%{#{key}}", value.to_s
end
end %>
<p><%= line.html_safe %></p>
<%- end %>
I hope this makes sense, #extra_lines is a variable that contains some extra paragraphs for our e-mail that's generated based on a set of conditions. The value of each member of the #interpolations contains what's duplicated in the second e-mail. In the mentioned case #interpolations would look something like {user_id: 1234}.
Now, not all variables have this problem. If I simply render a variable that's passed on from the Mailer class, this doesn't happen. Which is why I'm worried the output of one of the helper methods I'm using is being cached. All the more because similar behaviour happens in my PDF classes.
So I've tried to reproduce this by generating a new Rails application with DelayedJob enabled and created this mailer:
class MyMailer < ActionMailer::Base
default from: "from#example.com"
def random_amount(arguments)
#extra_lines = arguments[:extra_lines]
#interpolations = arguments[:interpolations]
mail to: 'to#example.com'
end
end
This mailer template:
<%- #extra_lines.each do |line|
if #interpolations
#interpolations.each do |key,value|
line = line.html_safe.sub "%{#{key}}", value.to_s
end
end %>
<p><%= line.html_safe %></p>
<%- end %>
And this controller:
class RandomController < ApplicationController
def index
extra_lines = [
'Test line 1',
'Test line 2 with %{variable}',
'Test line 3'
]
10.times do
interpolations = {variable: rand(1..100)}
arguments = {extra_lines: extra_lines, interpolations: interpolations}
MyMailer.delay.random_amount(arguments)
end
render :text => "Master, I've scheduled mail for you."
end
end
This is as close as I could get to the "real" application and it results in 10 e-mails with unique random amounts being sent to me. So, basically, I'm not able to reproduce the problem and, even more confusingly, most of the time it just works.
Is there anyone out there to whom this rings any bells?
I think I've found the answer to my question and it's much simpler than I originally thought. The #extra_lines were built from an I18n array. I'm doing this because these texts are used in e-mail, PDF and on a webpage and because they are multilingual, I wanted to store these texts in one central place, for which I feel I18n is perfect, but it doesn't support interpolation in arrays, which meant I had to roll that myself.
So, long story short, in the PDF class, I was looping through the resulting array and interpolating using line.sub! "%{#{key}}", value.to_s (as opposed to line = line.sub(..)) which also updates the #extra_lines variable, which updates the (cached) result of the I18n.t('get.specific.extra.lines') query. When it tries to interpolate these strings again, it runs the interpolations on the already interpolated (cached) strings and thus, there are no interpolations taking place. This explains why e-mails were working fine in my tests: if I had generated a PDF before sending an e-mail it would have worked.
Related
In my rails application I've created a business daily report. There is some non-trivial logic for showing it (all kind of customizable parameters that are used for filtering in the model, a controller that calls that model and some non-trivial view for it, for example, some of the columns are row-spanning over several rows).
Now I wish to send this report nightly (with fixed parameters), in addition to the user ability to generate a customize report in my web site. Of course, I wish not to re-write/duplicate my work, including the view.
My question is how can I call the controller action from my mailer so that it will be as if the page was requested by a user (without sending a get request as a browser, which I wish to avoid, of course)?
In answer to your question is if you are generating some sort of pdf report then go with using the wicke_pdf gem does exactly that generates pdfs. To send a report on a nightly basis the best thing for this is to implement some sort of cron job that runs at a particular time which you can do using the whenever gem. You can do something like:
schedule.rb
every :day, :at => '12:00am'
runner User.send_report
end
With this at hand you can see that you call the send_report method sits inside the User model class as shown below:
User.rb
class User < ActiveRecord::Base
def self.send_report
ReportMailer.report_pdf(#user).deliver
end
end
Inside send_report we call the mailer being ReportMailer which is the name of the class for our mailer and the method being report_pdf and pass in the user. BUT remember this is an example I have here I am not sure the exact specified information you want in a report.
Mailer
class ReportMailer< ActionMailer::Base
default :from => DEFAULT_FROM
def report_pdf(user)
#user = user
mail(:subject => "Overtime", :to => user.email) do |format|
format.text # renders report.text.erb for body of email
format.pdf do
attachments["report.pdf"] = WickedPdf.new.pdf_from_string(
render_to_string(:pdf => "report",:template => 'report/index.pdf.erb',
:layouts => "pdf.html"))
end
end
end
end
Inside the mailer there are a variety of things going on but the most important part is inside the format.pdf block that uses a variety of wicked_pdf methods (this is assuming that you are using wicked_pdf btw. Inside the block you create a new WickedPDF pdf object and render it to a string. Then provide it with the name of the report, the template and the layout. It is important that you create a template. This usually will where the report will be displaying from. The file type is a .pdf.erb this means that when this view or report is generated in the view the embedded ruby tags are being parsed in and the output is going to be a pdf format.
UserController
def report
#user = User.scoped
if params[:format] == 'pdf'
#Do some stuff here
User.send_report(#users)
end
respond_to do |format|
format.html
format.pdf do
render :pdf => "#{Date.today.strftime('%B')} Report",
:header => {:html => {:template => 'layouts/pdf.html.erb'}}
end
end
end
The key thing you asked that I picked up on.
how can I call the controller action from my mailer
In the controller simply collate a scope of Users, then check the format is a pdf, providing it is do some stuff. Then it will run the method send_report which I earlier highlighted in the user model class (Btw in your words this is the controller calling the model). Then inside the respond block for this there is a format.pdf so that you can generate the pdf. Once again note that you need a template for the core design of the pdf, which is similar to how rails generates an application.html.erb in the layouts. However here we have a pdf.html.erb defined. So that this can be called anywhere again in your application should you want to generate another pdf in your application somewhere else.
Think I've provided a substantial amount of information to set you off in the right direction.
I have a controller action that calls a model method which generates a serialized list of data pulled from another model database. I need this to be uncached because the SQL queries should be random data pulls.
Here's a general idea of my code (Note that User has_one Foo, Bar is an arbitrary model of data, :data_list is of type text, and the database is SQLite):
# app/models/foo.rb
class Foo < ActiveRecord::Base
serialize :data_list
def generate_data
list = []
for i in 1..4
data = Bar.find(:first, :order => "Random()")
list << data
end
self.data_list = list
end
end
# app/controllers/users_controller.rb
class UsersController < ApplicationController
def generate_action
...
uncached do
#user.foo.generate_data
end
#user.foo.save
end
end
# app/views/user/show.html.erb
...
<% #user.foo.data_list.each do |data| %>
<%= data %><br />
<% end %>
Whenever uncached do ... end is removed, everything works fine and the show view prints out each set of Bar objects in #user.foo.data_list. Unfortunately, because of Rails' SQL caching, it ends up look like this:
RandomDataPoint8
RandomDataPoint8
RandomDataPoint8
RandomDataPoint8
When I need to look like this:
RandomDataPoint7
RandomDataPoint13
RandomDataPoint2
RandomDataPoint21
It should be noted that running user.foo.generate_data from Rails command line works perfectly with the randomization. It is only when being called from the controller that caching starts to occur.
My research suggested I use uncached in the controller to remove caching, however it seems to destroy my data serialization and I receive the error:
undefined method 'each' for #<String:0x007ff49008dc70>
In fact, it does this even if I retroactively add in uncached (having successfully generated a data_plan without uncached prior) and save the controller, but don't call generate_action.
EDIT
I believe this problem is actually related to the fact that I was storing an object in the hash. Switching to the object id fixed this problem. Another SO question of mine regarding this can be found here:
Rails - Accessing serialized data from console
The following has been preserved just because the syntax may still help people, but I don't believe it was the actual cause of the problem.
I solved this by moving uncached to the model. For reference, the source I was using to originally solve this problem was this link: http://railspikes.com/2008/8/18/disabling-activerecord-query-caching-when-needed
What I overlooked is that he puts uncached in the model, not the controller. Also, the syntax needed to be a little different:
# app/models/foo.rb
self.class.uncached do
...
end
instead of
uncached do
...
end
The source for the syntax correction is this SO response: https://stackoverflow.com/a/967690/337903
Lets say you have a post with comments on the same page, and you render a form for capturing a new comment also on the same page as you are displaying the post/comments. A post has_many comments. Code as follows:
class PostsController < ApplicationController
...
def show
#post = Post.find(:params[id])
#comment = Post.comments.new
end
...
end
Now when you call <%= #post.comments.count %> in your views it gives the number of comments that have been saved, but if you call <%= render #post.comments %> it returns all the saved comments PLUS the newly created (but not yet saved and therefore still invalid) comment. Why is this? This has really taken me time to find this and I can't imagine that this would be useful, why not just render all the valid database records?
Has anyone else ran into this? Easy to fix but puzzling..
Well, #post.comments.count actually does a database query and can therefore only return the number of saved records. (Use #post.comments.size or .length) for the number of objects in your collection.
The render call, AFAIK, only loops over the objects in the collection.
The thing to know here is the difference between when you do actual queries with the association, and when active record is using the cached objects. It is perhaps easy to assume that the comments in #post.comments is just an Array. It actually is a fancy proxy object that, depending on method called and state of the cached collection, acts like an Array or as an interface to the Model's query methods.
For certain models, I wish to provide functionality that allows a user to create a new record with default attributes based on copy of an existing record.
I'm wondering what would be the correct restful route for this.
My initial thinking is that it could be a parameter to the new action. I.e. to borrow from the the Rails Guides examples, instead of just:
GET : /photos/new
Also allow:
GET : /photos/new/:id
...where :id is the id of the record to use as a template. The response would be a new/edit form, same as with a plain old new but the values would be pre-filled with data from the existing record. The parameter (or absense of it) could be easily handled by the new controller method.
The alternative seems to be to create a new controller method, for example copy which would also accept an id of an existing record and response with the new form as above. This seems a little 'incorrect' to me, as the record is not actually being copied until the user saves the new record (after probably editig it somewhat).
TIA...
UPDATE: my question is not "how do I do this in rails?", it's "is it RESTful?"
my question is not "how do I do this in rails?", it's "is it RESTful?"
No, it isn't. For that matter, neither is GET /photos/new. Rails seems to be hopelessly mired in the past, where it was considered haute programme for a GET on a URI to return an HTML form which would then POST x-www-form-urlencoded data back to that same URI. The opacity of that POST forces them to invent new verbs-as-URI's like /photos/new, when you could be using PUT instead, or at least POST with the same media type.
The simplest way to make a copy of an HTTP resource RESTfully is:
GET /photos/{id}/ -> [representation of a photo resource]
...make modifications to that representation as desired...
POST /photos/ <- [modified representation]
If you're implementing this for browsers, you should be able to perform those actions via Ajax quite easily, using an HTML page sitting perhaps at /photos/manager.html/ to drive the interaction with the user.
You can try to use nested resources. I'm not exactly sure about structure of you application, but in general using nested photos will look somehow like this:
routes.rb
resources :photos do
resources :photos
end
photos_controller.rb
before_filter :find_parent_photo, :only => [:new, :create]
def create
#photo = Photo.new params[:photo]
if #parent_photo.present?
# fill some #photo fields from #parent_photo
end
#photo.save
respond_with #photo
end
def find_parent_photo
#parent_photo = Photo.find(params[:photo_id]) if params[:photo_id].present?
end
new.html.haml
= form_for [#parent_photo, #photo] do |f|
-# your form code
previously when you wanted to add a link to photo creation you wrote something like that
= link_to "new photo", [:new, :photo]
now if you want to add a link to photo creation based on foto #photo1
= link_to "new photo based on other one", [:new, #photo1, :photo]
You should be able to match a route like so:
match 'photos/new/:photo_id' => 'photos#new
or you could just pass a :photo_id parameter in the url and handle it in the controller:
'/photos/new?photo_id=17'
Example using helper method: new_photo_path(:photo_id => 17)
Edit: I don't know if this conforms to REST
It may be over the top, but you could do something like this:
class PhotoCopiesController < ApplicationController
def new
#photo = Photo.find(params[:photo_id]).dup
end
def create
end
end
and
resources :photo_copies, :only => [:new, :create]
and
= link_to 'Copy', photo_copy_path(:photo_id => #photo.id)
The context: creating a tripcode implementation (http://en.wikipedia.org/wiki/Tripcode) for a forum. Essentially, a weak hash for registrationless identification.
There is one model, 'Post'. Posts are arranged in parent/child format, new post creates parent, replies create child to parent. There is one form, right now has a field that posts to the controller/model, contains a content and password field.
require 'bcrypt'
class Shout
include DataMapper::Resource
include BCrypt
property :id, Serial # unique key
property :content, Text
property :password_hash, String
property :trip, String # trip for display
belongs_to :forum
is :tree, :order => [:created_at]
attr_accessor :password
#before :save do
def password
#password ||= Password.new(password_hash)
end
def password=(new_password)
#password = Password.create(new_password)
self.password_hash = #password
end
def trip
#trip = '!'<<self.password_hash.to_str[20..33]
self.trip = #trip
end
#end
end
DataMapper.finalize
The basic flow is this - post/reply, if there is a password in the password field, take that and run through bcrypt, store that result as password_hash for later comparison, create tripcode for display. But I'm getting errors I've been beating my head against
The primary error I'm getting is
undefined method `primitive?' for nil:NilClass
seemingly emanating from
lib/active_support/whiny_nil.rb:48:in `method_missing'
I don't know how to handle or work around this. I'm not doing something or checking something with the controller, but don't yet know what. The other error I'm getting stems from an invalid bcrypt hash, but not able to duplicate this immediately.
The hook methods are right off the bcrypt-ruby page.
Creating a BCryptHash field works (dm-types) -- but increases the time to process the form by a factor of 10, on a localhost server, and does it for every post so I need a way to tweak the cost of the bcrypt hash (eg. 1 instead of default 10) and only run it when there is a password present, which is why I'm doing this.
But this doesn't work right now, I've rammed my head against it enough and moving on to other problems and coming back to it if I can get some input. I'm working with rails, so I've added that tag although its not primarily a rails issue.
Feel free to review or contribute or use for errors here.
https://github.com/blueblank/Shout/tree/oneshout