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>

Defined Under Namespace

Classes: ParseTreeVisitor

Constant Summary collapse

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

Instance Attribute Summary collapse

Attributes inherited from Tag

#line_number, #nodelist, #parse_context, #tag_name

Instance Method Summary collapse

Methods inherited from Tag

#blank?, disable_tags, #name, parse, #parse, #raw, #render

Methods included from ParserSwitching

#parse_with_selected_parser, #strict_parse_with_error_mode_fallback

Constructor Details

#initialize(tag_name, markup, options) ⇒ Cycle

Returns a new instance of Cycle.



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# File 'lib/liquid/tags/cycle.rb', line 22

def initialize(tag_name, markup, options)
  super
  case markup
  when NamedSyntax
    @variables = variables_from_string(Regexp.last_match(2))
    @name      = parse_expression(Regexp.last_match(1))
  when SimpleSyntax
    @variables = variables_from_string(markup)
    @name      = @variables.to_s
  else
    raise SyntaxError, options[:locale].t("errors.syntax.cycle")
  end
end

Instance Attribute Details

#variables ⇒ Object (readonly)

Returns the value of attribute variables.



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# File 'lib/liquid/tags/cycle.rb', line 20

def variables
  @variables
end

Instance Method Details

#render_to_output_buffer(context, output) ⇒ Object 



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# File 'lib/liquid/tags/cycle.rb', line 36

def render_to_output_buffer(context, output)
  context.registers[:cycle] ||= {}

  key       = context.evaluate(@name)
  iteration = context.registers[:cycle][key].to_i

  val = context.evaluate(@variables[iteration])

  if val.is_a?(Array)
    val = val.join
  elsif !val.is_a?(String)
    val = val.to_s
  end

  output << val

  iteration += 1
  iteration = 0 if iteration >= @variables.size

  context.registers[:cycle][key] = iteration
  output
end