code-dot-org/shared/middleware/helpers/experiments.rb at test · code-dot-org/code-dot-org

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# Sometimes we want to hide features behind dynamic configurations

# because they are not ready yet. To test these features, you might

# want to use a URL parameter or browser cookie to temporarily

# enable it for a single user. If you want to configure it for all

# users, you can use DCDO.

# If multiple configurations are available, this is the priority

# (from highest to lowest):

# 1. URL Parameter - https://code.org?my_experiment=1

# 2. Browser Cookie - document.cookie = 'my_experiment=1';

# 3. DCDO config - DCDO.set('my_experiment', 1)

# Note: To surface these experiment values to front-end code, make

# use of the `experiments` module in our JavaScript codebase found

# at apps/src/util/experiments.js instead of passing the value

# through via any Haml. Specifically:

# experiments.isEnabledAllowingQueryString("my_experiment")

# is the JavaScript equivalent for the Ruby side's:

# `experiment_value("my_experiment", request)`

# You will need to add the experiment tag to that `util/experiments.js`

# file along with allowing it to be pushed from DCDO to the frontend in

# `lib/dynamic_config/dcdo.rb` by adding the flag to the

# `frontend_config` function.

# @param name [String] the name of the experiment.

# @param request [ActionDispatch::Request] the web request being processed

# @param default [Object] the value to return if no configuration is found.

def experiment_value(name, request, default = nil)

return request.params[name] if request.params[name].present?

return request.cookies[name] if request.cookies[name].present?

DCDO.get(name, default)

end

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