Class: Liquid::Cycle

Inherits:
Tag
  • Object
show all
Defined in:
lib/liquid/tags/cycle.rb

Overview

Cycle is usually used within a loop to alternate between values, like colors or DOM classes.

{% for item in items %}
  <div class="{% cycle 'red', 'green', 'blue' %}"> {{ item }} </div>
{% end %}

 <div class="red"> Item one </div>
 <div class="green"> Item two </div>
 <div class="blue"> Item three </div>
 <div class="red"> Item four </div>
 <div class="green"> Item five</div>

Constant Summary collapse

SimpleSyntax = 
/^#{QuotedFragment}+/o
NamedSyntax = 
/^(#{QuotedFragment})\s*\:\s*(.*)/o

Instance Attribute Summary

Attributes inherited from Tag

#context, #nodelist

Instance Method Summary collapse

Methods inherited from Tag

#name, #parse

Constructor Details

#initialize(tag_name, markup, tokens, context) ⇒ Cycle

Returns a new instance of Cycle.



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# File 'lib/liquid/tags/cycle.rb', line 19

def initialize(tag_name, markup, tokens, context)
  case markup
  when NamedSyntax
    @variables = variables_from_string($2)
    @name = $1
  when SimpleSyntax
    @variables = variables_from_string(markup)
    @name = "'#{@variables.to_s}'"
  else
    raise SyntaxError.new("Syntax Error in 'cycle' - Valid syntax: cycle [name :] var [, var2, var3 ...]")
  end
  super
end

Instance Method Details

#render(context) ⇒ Object 



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# File 'lib/liquid/tags/cycle.rb', line 33

def render(context)
  context.registers[:cycle] ||= Hash.new(0)

  context.stack do
    key = context[@name]
    iteration = context.registers[:cycle][key]
    result = context[@variables[iteration]]
    iteration += 1
    iteration  = 0  if iteration >= @variables.size
    context.registers[:cycle][key] = iteration
    result
  end
end