How can I call a controller/view action from a mailer? - ruby-on-rails-3

Question

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)?

Answer 1

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.