Rails render_to_string

Question

I am having difficulty with the rails render_to_string function. I have created an app using the --api flag, so i think this may be the issue as i have tested in 'full' rails apps and its works just fine.

Essentially i am calling:

body_html = render_to_string(template: 'reservations/print')

I have also tried

body_html = render_to_string('reservations/print')
body_html = render_to_string(partial: 'reservations/print')
body_html = render_to_string(partial: 'reservations/print.html.erb')

which should return the html for that template. The filename is print.html.erb and just has basic data i.e.

<p> Hello world. </p>

When i output the body_html it is empty.

I referenced this SO question What is the correct way to render_to_string in wicked pdf? and am also going to use Wicked PDF to generate a pdf file.

Many thanks

Bohannan

Referencing, the stack overflow question. Did you try passing just reservations/print without the template keyword? – Coulombe

I don't think the --api flag is the problem. According to the documentaiton on Rails Api, AbstractController::Rendering comes in default and this Module contains the render_to_string method. – Coulombe

Hi Dan, thank you for taking the time to answer. I have that and a few more. I will update the question. – Bohannan

sorry to add another comment, just wanted some fresh eyes if possible – Bohannan

Answer 1

Whilst I do not think this is the best solution doing the following worked.

ac = ActionController::Base.new  

html_string = ac.render_to_string(template: 'path_to_file') # e.g. 'posts/show'

The Application Controller file in Rails API mode inherits from ActionController::API, so I guess the functionality to render is in ActionController::Base.

Bohannan

This should no longer be required (but I haven't tested). See module ActionController::Renderers::ClassMethods: "Both ActionController::Base and ActionController::API include ActionController::Renderers::All, making all renderers available in the controller." – Dissension

Answer 2

Try the following snippet code:

ActionController::Base.new.render_to_string("mailer/your-html-file", locals: { data: your-json-data-that-you-wanna-add-to-your-html-file })

Symbolize

Answer 3

You can do something like this inside your action:

     respond_to do |format|
       format.html { render layout: 'your_layout' } # this is for your html responses if you need to respond with html
       format.json { # this block will execute for your json requests

        html = render_to_string action: :index, layout: false, :formats => [:html]
        render json: {data: html}
     }

Begga

Answer 4

This is the solution that work fine for me:

render_to_string partial: 'participant_data.html.erb'

The file must be named like this:

tickets/_participant_data.html.erb

Locust