Usage

Let's start out by initializing our template:

require 'erb'
require 'superb'

# Create a plain ERB template    
erb = ERB.new("My friend <%= @name %> is <%= @age %> years old")

# Create a Superb::Template that is bound to the ERB
# template.  Initialize the 'name' and 'age' fields.
t   = Superb::Template.new(erb, name: "Bob", age: 22)

Calling Superb::Template#render without any arguments renders the template based upon its current state:

t.render
# Outcome: "My friend Bob is 22 years old"

Templates behave kind of like Javascript objects. That is, their fields can be reassigned via Hash syntax or via setters:

t[:name] = "Brian"
t.age    = 29
t.render
# Outcome: "My friend Brian is 29 years old"

You can overwrite several fields at once by invoking Superb::Template#merge! :

t.merge!(name: "Fred", age: 52)
t.render
# Outcome: "My friend Fred is 52 years old"

Sometimes, you only want to override a template's field temporarily. This can be achieved by passing a Hash of overrides to the Superb::Template#render method:

t.render(name: "Bert")
# Outcome: "My friend Bert is 52 years old" 

t.render
# Outcome: "My friend Fred is 52 years old"

Alternatively, you can create a copy of the template and modify the copy:

t2 = t.dup
t2.name = "Mike"
t2.render
# Outcome: "My friend Mike is 52 years old"