This actually has more to do with Rails and/or Sinatra than it does with Heroku. You have to enable IFrame support in your headers explicitly. With Rails you can add this to your config/application.rb file config.action_dispatch.default_headers = ...

AppEngine is nice, but it's a little limiting. No cron jobs, filesystem use nor customization with third party libraries, software, databases, languages, etc. You can't deploy PHP, Ruby and or your 'other' favorite web development tools. You can only use ...

Here is the one liner. ls -lhtTr It will output something like total 24152 -rw-rw-r-- 1 sean staff 1.0M May 4 14:31:42 2019 4c2caf52cb084ea39a6a65a0e68ee382 -rw-rw-r-- 1 sean staff 1.0M May 4 14:31:44 2019 76eeeea5d...

TinyMCE is a nice little WYSIWYG for text processing online. It uses iFrames and Javascript callbacks to manipulate textarea form fields. Using it with Rails can be somewhat problematic if you want to set up an observer on a field that TinyMCE is managing...

This may not be the ideal solution. This just manages request.referers in a session variable, then looping over each unique path prints a link to the screen. It's more of a "history" than a hierarchy for resources in an application. It is however, pretty ...