Adds tracking for returning anonymous users #142

[arunkodati77]

Closes #142

Changes description

• Added new argument 'track_anonymous_user' (TRUE by default) to telemetry$start_session().
• if username is null and track_anonymous_user = TRUE then a cookie will be set in users browser.
• When there is no session user or Shiny_Proxy_User then we will first look for the shiny_user_cookie cookie in users browser (will make sure cookie is a hexa-decimal key generated using 'sha256' algorithm.
• if not found, cookie value is generated using :
  cookie_string <- paste0(session$request$HTTP_USER_AGENT, session$request$REMOTE_ADDR, Sys.time()) cookie_value <- digest::digest(cookie_string, algo = "sha256")
  Note:
• Cookie expires in 365 days.
• In the ShinyProxy environment, tracking anonymous users presents a challenge when the application.yml configuration file for ShinyProxy is set with authentication: none. Under this setting, ShinyProxy assigns a random hash to each session as a makeshift user identifier, which is accessible in Shiny applications via the Sys.getenv("SHINYPROXY_USERNAME") command. Refer Official Documentation. This could be easily resolved by adding a condition , if (Sys.getenv("SHINYPROXY_USERNAME") == <<random_hash>> ) then set the cookie. But what if shinyproxy user itself is a Random hash?

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 49 lines in your changes are missing coverage. Please review.

Project coverage is 30.48%. Comparing base (6136a33) to head (a813c33).

❗ Current head a813c33 differs from pull request most recent head 80407e8. Consider uploading reports for the commit 80407e8 to get more accurate results

Files	Patch %	Lines
R/telemetry.R	0.00%	32 Missing ⚠️
R/ui_elements.R	0.00%	17 Missing ⚠️

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Additional details and impacted files

@@            Coverage Diff             @@
##             main     #157      +/-   ##
==========================================
- Coverage   31.33%   30.48%   -0.85%     
==========================================
  Files          16       16              
  Lines        1436     1476      +40     
==========================================
  Hits          450      450              
- Misses        986     1026      +40     

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[averissimo]

The functionality works great! I've tested it locally.

I've found some improvements on the code, let's discuss them 😄

ps. can you assign yourself to the original issue? (this flags that you're working on it)

[averissimo]

I see that you preferred to implement the changes here directly instead of using #159

Good job on using htmltools::htmlDependency, but it seemed like you overlooked some of the other aspects of the PR:

• LICENSE file (this needs to be distributed with js-cookie.min.js, otherwise we might be in breach of the license)

Optional (but I think they can be included here):

• Use of shiny::singleton to prevent injection of repeated <script> tags
• Minor optimization of ID using shiny::NS instead of glue::glue

[averissimo]

Looks good.

Tested it out again and works like it should.

I left one last optional suggestion. Feel free to accept it or not.