Render html partial in JSON JBuilder

Question

I am rendering JSON of some students using JBuilder in Rails 4. I want each student to have a "html" attribute that contains the HTML partial for a given student:

[
  { html: "<b>I was rendered from a partial</b>" }
]

I have tried the following:

json.array! @students do |student|
  json.html render partial: 'students/_student', locals: { student: student }
end

But this gives me:

Missing partial students/_student with {:locale=>[:en], :formats=>[:json], :handlers=>[:erb, :builder, :raw, :ruby, :jbuilder, :coffee, :haml]}.

Answer 1

You have to specify the partial format as Rails will look for partial with current format (json) by default. For example:

render partial: 'students/student.html.erb'

Answer 2

You need to specify the partial format:

json.array! @students do |student|
  json.html render(student, formats: [:html])
end

Answer 3

Here's what worked for me:

# students/index.json.jbuilder
json.array! @students do |student|
  json.html render partial: 'student.html.erb', locals: { student: student }
end

# students/_student.html.erb
<h4><%= student.name %></h4>

Answer 4

Rails partials use an underscore in the filename but not in the code when referenced as a string (depending on how you are loading them of course). Usually a partial called posts/_post.html.haml will be referenced in code as render :partial => 'posts/post'