Rails: Calling render() outside your Controllers

I found myself needing to render a .rxml template from my Model today (Ok, stop the MVC preach already...) anyways.. found a few deadends, but finally got down to use method_missing to see what's needed by ActionViewer::Base. Not sure if there's an easier way...

 

# 
# lib/render_anywhere.rb
# 
# Render templates outside of a controller or view.
# 
# Simply mixin this module to your existing class, for example:
# 
#   class MyTemplater < ActiveRecord::Base
#     include RenderAnywhere
# 
# And you can use render() method that works the same as ActionView::Base#render
# 
#   obj = MyTemplater.new
#   obj.html = obj.render :file => '/shared/header'
# 
# 
module RenderAnywhere
    
    class DummyController
        def logger
            RAILS_DEFAULT_LOGGER
        end
        def headers
            {}
        end
    end
    
    def render(options, assigns = {})
        viewer = ActionView::Base.new(Rails::Configuration.new.view_path, assigns, DummyController.new)
        viewer.render options
    end
    
    def template_exists?(path, assigns = {})
        viewer = ActionView::Base.new(Rails::Configuration.new.view_path, assigns, DummyController.new)
        viewer.pick_template_extension(path) rescue false
    end
end

Hope this is helpful to someone 

Comments

[Matias]

Great, but... How to pass variables to the template?? I've tried with :locals=>{:somevar=>'value'} and doesn't works.

Thanks

[choonkeat]

Yea, I haven't figured that out yet. maybe when I need it - my problem that day was to render a rxml file with variables from elsewhere.

Sure would love to hear any solution. Can probably tweak DummyController, but I'm not very sure.

[willc]

You can actually render a template with a one liner, .eg:

ActionView::Base.new(Rails::Configuration.new.view_path).render(:partial => 'foo/bar', :locals => {:foo => 'bar'})

[choonkeat]

@willc: much better! thanks :-)

[Dave Troy]

This has come up often for me and I wanted a more elegant solution. So I put together ActsAsRenderer to give models a simple and elegant way to render output to strings or files.

Please see:
http://davetroy.blogspot.com/2008/02/actsasrenderer-brings-output-to-models.html

[Adam]

Setting instance variables for the templates is easy: just add the name and value to the ActionView instance's @assigns hash, like this:

av = ActionView::Base.new(Rails::Configuration.new.view_path)
av.assigns[:foo] = "bar"
av.render "some/template/here"

[Jeff]

Thanks for sharing this. I've got it mostly working but need to use UrlHelpers.

In other words, I'd like to include things like this in my templates (bad example):

Suggestions on how to do this?

Thanks
Jeff

[Jeff]

Er, looks like it stripped out the rhtml which is the following wrapped correctly:
link_to 'Edit', edit_user_path(@user)

[Olivier]

You could use:

result = ERB.new(template_content).result(binding)

Olivier

[eric]

Adam's suggestion worked for me. The RenderAnywhere did not! Rails 2.3.3.