class Liquid::Cycle

@liquid_public_docs @liquid_type tag @liquid_category iteration @liquid_name cycle @liquid_summary

Loops through a group of strings and outputs them one at a time for each iteration of a [`for` loop](/docs/api/liquid/tags/for).

@liquid_description

The `cycle` tag must be used inside a `for` loop.

> Tip:
> Use the `cycle` tag to output text in a predictable pattern. For example, to apply odd/even classes to rows in a table.

@liquid_syntax

{% cycle string, string, ... %}

Constants

NamedSyntax
SimpleSyntax

Attributes

variables[R]

Public Class Methods

new(tag_name, markup, options) click to toggle source
Calls superclass method Liquid::Tag::new
# File lib/liquid/tags/cycle.rb, line 23
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))
    @is_named = true
  when SimpleSyntax
    @variables = variables_from_string(markup)
    @name      = @variables.to_s
    @is_named = !@name.match?(/\w+:0x\h{8}/)
  else
    raise SyntaxError, options[:locale].t("errors.syntax.cycle")
  end
end

Public Instance Methods

named?() click to toggle source
# File lib/liquid/tags/cycle.rb, line 39
def named?
  @is_named
end
render_to_output_buffer(context, output) click to toggle source
# File lib/liquid/tags/cycle.rb, line 43
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

Private Instance Methods

variables_from_string(markup) click to toggle source
# File lib/liquid/tags/cycle.rb, line 68
def variables_from_string(markup)
  markup.split(',').collect do |var|
    var =~ /\s*(#{QuotedFragment})\s*/o
    Regexp.last_match(1) ? parse_expression(Regexp.last_match(1)) : nil
  end.compact
end