From 21940d1edf1604f192957691e99677d191380543 Mon Sep 17 00:00:00 2001 From: Yorick Peterse Date: Mon, 8 Oct 2018 16:24:40 +0200 Subject: Support pushing of feature flags to the frontend This adds a method to Gitlab::GonHelper called `push_frontend_feature_flag`. This method can be used to easily expose the state of a feature flag to Javascript code. For example, using this method we may write the following controller code: before_action do push_frontend_feature_flag(:vim_bindings) end def index # ... end def edit # ... end In Javascript we can then check the state of the flag as follows: if ( gon.features.vimBindings ) { // ... } Fixes https://gitlab.com/gitlab-org/release/framework/issues/17 --- doc/development/feature_flags.md | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) (limited to 'doc') diff --git a/doc/development/feature_flags.md b/doc/development/feature_flags.md index 417298205f5..0f1f079bdb4 100644 --- a/doc/development/feature_flags.md +++ b/doc/development/feature_flags.md @@ -69,6 +69,37 @@ For more information about rolling out changes using feature flags, refer to the [Rolling out changes using feature flags](rolling_out_changes_using_feature_flags.md) guide. +### Frontend + +For frontend code you can use the method `push_frontend_feature_flag`, which is +available to all controllers that inherit from `ApplicationController`. Using +this method you can expose the state of a feature flag as follows: + +```ruby +before_action do + push_frontend_feature_flag(:vim_bindings) +end + +def index + # ... +end + +def edit + # ... +end +``` + +You can then check for the state of the feature flag in JavaScript as follows: + +```javascript +if ( gon.features.vimBindings ) { + // ... +} +``` + +The name of the feature flag in JavaScript will always be camelCased, meaning +that checking for `gon.features.vim_bindings` would not work. + ### Specs In the test environment `Feature.enabled?` is stubbed to always respond to `true`, -- cgit v1.2.1