How to pass variables to render_to_string?

Question

Trying to do the following

@message = render_to_string ( :sender => sender, :template => "template" )

But when accessing @sender in template it turns out to be nil:NilClass. Double checked if I pass the right variable and it's totally fine. Maybe there are other way to pass variables to render_to_string?

score 55 · Accepted Answer · edited Jun 09 '16 at 13:47

55

It might be the syntax you're using. Try using the :locals argument:

@m = render_to_string :template => "template", :locals => {:sender => sender}

Then you just need to access sender (without an @) as a local variable inside the template.

edited Jun 09 '16 at 13:47

mwfearnley

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answered Sep 15 '10 at 02:24

Peter Brown

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6

Just noticed you were trying to access sender as `@sender` in your view. Not sure about your original code, but if you use the locals syntax, it will be a local variable (not an instance variable) and will be accessed without the `@` – Peter Brown Sep 15 '10 at 12:53
Your solution actually work. You can pass locals as you said and access them as local variables, not instance variables. – MrYoshiji Dec 04 '12 at 15:48
11

I've been trying to use `render_to_string` from model. In order to use with as instance variable, I had to do `ActionController::Base.new.render_to_string(:template => "template", :locals => {:@sender => sender})` – Jason Kim May 15 '13 at 02:08

score 21 · Answer 2 · edited May 23 '17 at 12:25

21

Here's Jason Kim's solution he wrote in a comment which worked for me:

ActionController::Base.new.render_to_string(
  "user_mailer/welcome_email.html.erb", locals: { :@user => user}
)

Please mind the :@user => value bit.

In Rails 5 (atm in beta):

ApplicationController.render(
  file: 'path',
  assigns: { foo: 'bar' }
)

More here

edited May 23 '17 at 12:25

Community

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answered Jun 11 '16 at 12:02

Adit Saxena

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Doesn't work in the latest 4-2-stable https://github.com/rails/rails/commit/4c46a15e0a7815ca9e4cd7c7fda042eb8c1b7724#commitcomment-41917002 – Sergey Alekseev Aug 31 '20 at 16:03

score 5 · Answer 3 · edited Jun 25 '15 at 08:38

5

Try this:

ac = ActionController::Base.new()  
ac.render_to_string(:partial => 'path to your partial',:locals => {:varable => your variables})

edited Jun 25 '15 at 08:38

dario

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answered Jun 25 '15 at 08:19

Manish Prajapat

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score 2 · Answer 4 · answered Feb 14 '14 at 10:08

2

In rails 4.0.2 this worked:

render_to_string(partial: 'path/to/partial', locals: { argument: 'value'}

answered Feb 14 '14 at 10:08

vladCovaliov

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score 2 · Answer 5 · answered Sep 10 '14 at 14:36

I was trying to render a different format of partial in render_to_string. The thing which really worked for me was:

render_to_string(:partial => 'partial_file.html', :locals => {:variable => variable}, :format => :html)

where the name of the file was _partial_file.html.erb.

How to pass variables to render_to_string?

5 Answers5

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