How can I "pretty" format my JSON output in Ruby on Rails?
I would like my JSON output in Ruby on Rails to be "pretty" or nicely formatted.
Right now, I call to_json and my JSON is all on one line. At times this can be difficult to see if there is a problem in the JSON output stream.
Is there way to configure or a method to make my JSON "pretty" or nicely formatted in Rails?
Use the pretty_generate() function, built into later versions of JSON. For example:
require 'json'
my_object = { :array => [1, 2, 3, { :sample => "hash"} ], :foo => "bar" }
puts JSON.pretty_generate(my_object)
Which gets you:
{
"array": [
1,
2,
3,
{
"sample": "hash"
}
],
"foo": "bar"
}
Thanks to Rack Middleware and Rails 3 you can output pretty JSON for every request without changing any controller of your app. I have written such middleware snippet and I get nicely printed JSON in browser and curl output.
class PrettyJsonResponse
def initialize(app)
@app = app
end
def call(env)
status, headers, response = @app.call(env)
if headers["Content-Type"] =~ /^application/json/
obj = JSON.parse(response.body)
pretty_str = JSON.pretty_unparse(obj)
response = [pretty_str]
headers["Content-Length"] = pretty_str.bytesize.to_s
end
[status, headers, response]
end
end
The above code should be placed in app/middleware/pretty_json_response.rb of your Rails project. And the final step is to register the middleware in config/environments/development.rb :
config.middleware.use PrettyJsonResponse
I don't recommend to use it in production.rb . The JSON reparsing may degrade response time and throughput of your production app. Eventually extra logic such as 'X-Pretty-Json: true' header may be introduced to trigger formatting for manual curl requests on demand.
(Tested with Rails 3.2.8-5.0.0, Ruby 1.9.3-2.2.0, Linux)
The <pre> tag in HTML, used with JSON.pretty_generate , will render the JSON pretty in your view. I was so happy when my illustrious boss showed me this:
<% if !@data.blank? %>
<pre><%= JSON.pretty_generate(@data) %></pre>
<% end %>
上一篇: 使用grep