Surveys On Rails

Surveyor is a developer tool that brings surveys into Rails applications. Surveys are written in the Surveyor DSL (Domain Specific Language). Internally, Surveyor is a Rails engine distributed as a ruby gem, meaning it is straightforward to override or extend its behaviors in your Rails app without maintaining a fork.

Why you might want to use Surveyor

If your Rails app needs to asks users questions as part of a survey, quiz, or questionnaire then you should consider using Surveyor. This gem was designed to deliver clinical research surveys to large populations, but it can be used for any type of survey.

The Surveyor DSL defines questions, answers, question groups, survey sections, dependencies (e.g. if response to question 4 is A, then show question 5), and validations. Answers are the options available for each question - user input is called "responses" and are grouped into "response sets". A DSL makes it significantly easier to import long surveys (no more click/copy/paste). It also enables non-programmers to write out, edit, re-edit... any number of surveys.

DSL example

The Surveyor DSL supports a wide range of question types (too many to list here) and complex dependency logic. Here are the first few questions of the "kitchen sink" survey which should give you and idea of how it works. The full example with all the types of questions available if you follow the installation instructions below.

survey "Kitchen Sink survey" do

  section "Basic questions" do
    # A label is a question that accepts no answers
    label "These questions are examples of the basic supported input types"

    # A basic question with radio buttons
    question_1 "What is your favorite color?", :pick => :one
    answer "red"
    answer "blue"
    answer "green"
    answer "yellow"
    answer :other

    # A basic question with checkboxes
    # "question" and "answer" may be abbreviated as "q" and "a"
    q_2 "Choose the colors you don't like", :pick => :any
    a_1 "red"
    a_2 "blue"
    a_3 "green"
    a_4 "yellow"
    a :omit

    # A dependent question, with conditions and rule to logically join them
    # the question's reference identifier is "2a", and the answer's reference_identifier is "1"
    # question reference identifiers used in conditions need to be unique on a survey for the lookups to work
    q_2a "Please explain why you don't like this color?"
    a_1 "explanation", :text
    dependency :rule => "A or B or C or D"
    condition_A :q_2, "==", :a_1
    condition_B :q_2, "==", :a_2
    condition_C :q_2, "==", :a_3
    condition_D :q_2, "==", :a_4

    # ... other question, sections and such. See surveys/kitchen_sink_survey.rb for more.


The first question is "pick one" (radio buttons) with "other". The second question is "pick any" (checkboxes) with the option to "omit". It also features a dependency with a follow up question. Notice the dependency rule is defined as a string. We support complex dependency such as "A and (B or C) and D" or "A or ((B and C) or D)". The conditions are evaluated separately using the operators "==","!=","<>", ">=","<" the substituted by letter into to the dependency rule and evaluated.


Add surveyor to your Gemfile:

gem "surveyor"

Then run:

bundle install

Generate assets, run migrations:

script/rails generate surveyor:install
bundle exec rake db:migrate

Try out the "kitchen sink" survey. The rake task above generates surveys from our custom survey DSL (a good format for end users and stakeholders).

bundle exec rake surveyor FILE=surveys/kitchen_sink_survey.rb

Start up your app and visit http://localhost:3000/surveys

Try taking the survey and compare it to the contents of the DSL file kitchen_sink_survey.rb. See how the DSL maps to what you see.

There are two other useful rake tasks:

  • surveyor:remove removes all unused surveys.
  • rake surveyor:unparse exports a survey from the application into a file in the surveyor DSL.


When you are ready to update to the latest version of Surveyor, just do

bundle update surveyor

and you'll get the latest version that bundler thinks you can use based on the constraints in your Gemfile.

After you've installed a new version, you should always re-run the surveyor generator:

script/rails generate surveyor:install

This will copy over any new or updated assets and new migrations. Use your VCS' utilities to review what's changed, then commit the new versions.

git status
git diff
git add -A
git commit

If there were new migrations, you'll want to be sure to run them before the next time you start your app:

bundle exec rake db:migrate

Finally, review the changelog entries corresponding to the versions between your original version and the version you've updated to. There may be changes which will affect your customizations. There should be hints in the changelog or the referenced issues for what to update when necessary.

Following master

If you are following along with pre-release versions of Surveyor using a :git source in your Gemfile, be particularly careful about reviewing migrations after updating Surveyor and re-running the generator. We will never change a migration between two released versions of Surveyor. However, we may on rare occasions change a migration which has been merged into master. When this happens, you'll need to assess the differences and decide on an appropriate course of action for your app.

If you aren't sure what this means, we do not recommend that you deploy an app that's locked to surveyor master into production.

Customizing surveyor

Surveyor's controller, models, and views may be customized via classes in your app/models, app/helpers and app/controllers directories. To generate a sample custom controller and layout, run:

script/rails generate surveyor:custom

and read surveys/EXTENDING_SURVEYOR

The asset pipeline

Surveyor is now aware of the Rails asset pipeline ( With the asset pipeline enabled Rails.application.config.assets.enabled == true, then the surveyor:install generator will generate app/assets/stylesheets/surveyor_all.css and app/assets/javascripts/surveyor_all.js manifest files and link them from the surveyor_default layout. Assets remain in the gem and are picked up for inclusion and pre-compilation from there if config/environments/production.rb is set to include surveyor assets.

# Precompile additional assets (application.js, application.css, and all non-JS/CSS are already added)
config.assets.precompile += %w( surveyor_all.js surveyor_all.css )

The previous copy-to-application behavior still exists in the case where the asset pipeline is missing or disabled.

PDF support

  • Add the following lines to your Gemfile:

    gem 'pdfkit'
    gem 'wkhtmltopdf'

or on OSX:

    gem 'pdfkit'
    gem 'wkhtmltopdf-binary'
  • Add the following to your application.rb:

    config.middleware.use PDFKit::Middleware
  • Create links with :format => 'pdf' in them, for example:

    %li= link_to "PDF", view_my_survey_path(:survey_code => response_set.survey.access_code, :response_set_code => response_set.access_code, :format => 'pdf')


Surveyor works with:

  • Ruby 1.8.7, 1.9.2, and 1.9.3
  • Rails 3.0-3.2

Some key library dependencies are:

  • HAML
  • Sass
  • Formtastic

A more exhaustive list can be found in the gemspec.


For general discussion (e.g., "how do I do this?"), please send a message to the surveyor-dev group. This group is moderated to keep out spam; don't be surprised if your message isn't posted immediately.

For reproducible bugs, please file an issue on the GitHub issue tracker. Please include a minimal test case (a detailed description of how to trigger the bug in a clean rails application). If you aren't sure how to isolate the bug, send a message to surveyor-dev with what you know and we'll try to help.

Contributing, testing

To work on the code, fork this github project. Install bundler if you don't have it, then run

$ bundle update

to install all the necessary gems. Then

$ bundle exec rake testbed

to generate a test app in testbed. Now you can run

$ bundle exec rake spec

to run the specs and

$ bundle exec rake cucumber

to run the features and start writing tests!


Some of Surveyor's integration tests use Selenium WebDriver and Capybara. The WebDriver-based tests default to running in Chrome due to an unfortunate Firefox bug. For them to run, you'll either need:

  • Chrome and chromedriver installed, or
  • to switch to use Firefox instead

To use Firefox instead of Chrome, invoke one or more features with SELENIUM_BROWSER set in the environment:

$ SELENIUM_BROWSER=firefox bundle exec rake cucumber
$ SELENIUM_BROWSER=firefox bundle exec cucumber features/ajax_submissions.feature

Note that when running features in Firefox, you must allow the WebDriver-driven Firefox to retain focus, otherwise some tests will fail.

Copyright (c) 2008-2011 Brian Chamberlain and Mark Yoon, released under the MIT license