$ command line ruby cheat sheets

INTRODUCTION

  ERB provides an easy to use but powerful templating system for Ruby.
  Rails/RoR, the web application framework, uses ERB to create views.

EDITORIAL NOTE:

  Shamelessly compiled and copied from:
  
  http://ruby-doc.org/stdlib/libdoc/erb/rdoc/classes/ERB.html

RECOGNIZED TAGS

  ERB recognizes certain tags in the provided template and converts 
  them based on the rules below:

    <% Ruby code -- inline with output %>
    
    <%= Ruby expression -- replace with result %>
    
    <%# comment -- ignored -- useful in testing %>
    
    % a line of Ruby code -- treated as <% line %> (optional -- see ERB.new)
    
    %% replaced with % if first thing on a line and % processing is used
    
    <%% or %%> -- replace with <% or %> respectively

    <%- and -%> suppress leading and trailing whitespace, including the trailing newline, and can be used interchangeably with <% and %>.

  All other text is passed through ERB filtering unchanged. 

ALTERNATIVES

  There are a variety of templating solutions available in various Ruby projects:

    * ERB‘s big brother, eRuby, works the same but is written in C for speed;
    * Erubis is a fast, secure, and very extensible implementation of eRuby
    * Amrita (smart at producing HTML/XML);
    * cs/Template (written in C for speed);
    * RDoc uses its own template engine, which can be reused elsewhere;
    * and others; search the RAA.
cheat sheets.
