Class: BuildingBlocks::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/building_blocks/base.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(m, *args, &block) ⇒ Object (protected)

If a method is missing, we’ll assume the user is starting a new block group by that missing method name



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# File 'lib/building_blocks/base.rb', line 408

def method_missing(m, *args, &block)
  options = args.extract_options!

  # If the specified block group has already been defined, it is simply returned here for iteration.
  #  It will consist of all the blocks used in this block group that have yet to be rendered,
  #   as the call for their use occurred before the template was rendered (where their definitions likely occurred)
  return self.block_groups[m] unless self.block_groups[m].nil?

  # Allows for nested block groups, store the current block positions array and start a new one
  original_queued_blocks = self.queued_blocks
  self.queued_blocks = []
  self.block_groups[m] = self.queued_blocks

  # Capture the contents of the block group (this will only capture block definitions and block renders; it will ignore anything else)
  view.capture(global_options.merge(options), &block) if block_given?

  # restore the original block positions array
  self.queued_blocks = original_queued_blocks
  nil
end

Instance Attribute Details

#anonymous_block_number ⇒ Object

counter, used to give unnamed blocks a unique name



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# File 'lib/building_blocks/base.rb', line 13

def anonymous_block_number
  @anonymous_block_number
end

#block_groups ⇒ Object

A Hash of queued_blocks arrays; a new array is started when method_missing is invoked



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# File 'lib/building_blocks/base.rb', line 16

def block_groups
  @block_groups
end

#blocks ⇒ Object

Hash of block names to BuildingBlocks::Container objects



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# File 'lib/building_blocks/base.rb', line 7

def blocks
  @blocks
end

#global_options ⇒ Object

These are the options that are passed into the initalize method



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# File 'lib/building_blocks/base.rb', line 19

def global_options
  @global_options
end

#queued_blocks ⇒ Object

Array of BuildingBlocks::Container objects, storing the order of blocks as they were queued



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# File 'lib/building_blocks/base.rb', line 10

def queued_blocks
  @queued_blocks
end

#surrounding_tag_surrounds_before_and_after_blocks ⇒ Object

Boolean variable for whether BuildingBlocks should render before and after blocks inside or outside of a collections’ elements’ surrounding tags



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# File 'lib/building_blocks/base.rb', line 31

def surrounding_tag_surrounds_before_and_after_blocks
  @surrounding_tag_surrounds_before_and_after_blocks
end

#template_folder ⇒ Object

The default folder to look in for global partials



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# File 'lib/building_blocks/base.rb', line 22

def template_folder
  @template_folder
end

#use_partials ⇒ Object

Boolean variable for whether BuildingBlocks should attempt to render blocks as partials if a defined block cannot be found



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# File 'lib/building_blocks/base.rb', line 28

def use_partials
  @use_partials
end

#variable ⇒ Object

The variable to use when rendering the partial for the templating feature (by default, “blocks”)



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# File 'lib/building_blocks/base.rb', line 25

def variable
  @variable
end

#view ⇒ Object

a pointer to the ActionView that called BuildingBlocks



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# File 'lib/building_blocks/base.rb', line 4

def view
  @view
end

Instance Method Details

#after(name, options = {}, &block) ⇒ Object Also known as: append, for

Add a block to render after another block. This after block will be put into an array so that multiple

after blocks may be queued. They will render in the order in which they are declared when the
"blocks#render" method is called. Any options specified to the after block will override any options
specified in the block definition.
 <% blocks.define :wizard, :option1 => 1, :option2 => 2 do |options| %>
   Step 2 (:option1 => <%= options[option1] %>, :option2 => <%= options[option2] %>)<br />
 <% end %>

 <% blocks.after :wizard, :option1 => 3 do
   Step 3 (:option1 => <%= options[option1] %>, :option2 => <%= options[option2] %>)<br />
 <% end %>

 <% blocks.after :wizard, :option2 => 4 do
   Step 4 (:option1 => <%= options[option1] %>, :option2 => <%= options[option2] %>)<br />
 <% end %>

 <%= blocks.render :wizard %>

 <!-- Will render:
   Step 2 (:option1 => 1, :option2 => 2)<br />
   Step 3 (:option1 => 3, :option2 => 2)<br />
   Step 4 (:option1 => 1, :option2 => 4)<br />
 -->

 <%= blocks.render :wizard, :step => @step %>

Options:

name

The name of the block to render this code after when that block is rendered

options

Any options to specify to the after block when it renders. These will override any options specified when the block was defined.

block

The block of code to render after another block



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# File 'lib/building_blocks/base.rb', line 338

def after(name, options={}, &block)
  self.queue_block_container("after_#{name.to_s}", options, &block)
  nil
end

#around(name, options = {}, &block) ⇒ Object

Add a block to render around another block. This around block will be put into an array so that multiple

around blocks may be queued. They will render in the order in which they are declared when the
"blocks#render" method is called, with the last declared around block being rendered as the outer-most code, and
the first declared around block rendered as the inner-most code. Any options specified to the after block will override any options
specified in the block definition. The user of an around block must declare a block with at least one parameter and
should invoke the #call method on that argument.

 <% blocks.define :my_block do %>
   test
 <% end %>

 <% blocks.around :my_block do |content_block| %>
   <h1>
     <%= content_block.call %>
   </h1>
 <% end %>

 <% blocks.around :my_block do |content_block| %>
   <span style="color:red">
     <%= content_block.call %>
   </span>
 <% end %>

 <%= blocks.render :my_block %>

 <!-- Will render:
 <h1>
   <span style="color:red">
     test
   </span>
 </h1>

Options:

name

The name of the block to render this code around when that block is rendered

options

Any options to specify to the around block when it renders. These will override any options specified when the block was defined.

block

The block of code to render after another block



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# File 'lib/building_blocks/base.rb', line 385

def around(name, options={}, &block)
  self.queue_block_container("around_#{name.to_s}", options, &block)
  nil
end

#before(name, options = {}, &block) ⇒ Object Also known as: prepend

Add a block to render before another block. This before block will be put into an array so that multiple

before blocks may be queued. They will render in the order in which they are declared when the
"blocks#render" method is called. Any options specified to the before block will override any options
specified in the block definition.
 <% blocks.define :wizard, :option1 => 1, :option2 => 2 do |options| %>
   Step 2 (:option1 => <%= options[option1] %>, :option2 => <%= options[option2] %>)<br />
 <% end %>

 <% blocks.before :wizard, :option1 => 3 do
   Step 0 (:option1 => <%= options[option1] %>, :option2 => <%= options[option2] %>)<br />
 <% end %>

 <% blocks.before :wizard, :option2 => 4 do
   Step 1 (:option1 => <%= options[option1] %>, :option2 => <%= options[option2] %>)<br />
 <% end %>

 <%= blocks.render :wizard %>

 <!-- Will render:
   Step 0 (:option1 => 3, :option2 => 2)<br />
   Step 1 (:option1 => 1, :option2 => 4)<br />
   Step 2 (:option1 => 1, :option2 => 2)<br />
 -->

 <%= blocks.render :wizard, :step => @step %>

Options:

name

The name of the block to render this code before when that block is rendered

options

Any options to specify to the before block when it renders. These will override any options specified when the block was defined.

block

The block of code to render before another block



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# File 'lib/building_blocks/base.rb', line 299

def before(name, options={}, &block)
  self.queue_block_container("before_#{name.to_s}", options, &block)
  nil
end

#define(name, options = {}, &block) ⇒ Object

Define a block, unless a block by the same name is already defined.

<%= blocks.define :some_block_name, :parameter1 => "1", :parameter2 => "2" do |options| %>
  <%= options[:parameter1] %> and <%= options[:parameter2] %>
<% end %>

Options:

name

The name of the block being defined (either a string or a symbol)

options

The default options for the block definition. Any or all of these options may be overrideen by whomever calls “blocks.render” on this block.

block

The block that is to be rendered when “blocks.render” is called for this block.



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# File 'lib/building_blocks/base.rb', line 55

def define(name, options={}, &block)
  collection = options.delete(:collection)

  if collection
    collection.each do |object|
      define(evaluated_proc(name, object, options), options, &block)
    end
  else
    self.define_block_container(name, options, &block)
  end

  nil
end

#defined?(name) ⇒ Boolean

Checks if a particular block has been defined within the current block scope.

<%= blocks.defined? :some_block_name %>

Options:

name

The name of the block to check

Returns:

  • (Boolean) 


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# File 'lib/building_blocks/base.rb', line 38

def defined?(name)
  !blocks[name.to_sym].nil?
end

#evaluated_proc(*args) ⇒ Object 



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# File 'lib/building_blocks/base.rb', line 399

def evaluated_proc(*args)
  return nil unless args.present?
  v = args.shift
  v.is_a?(Proc) ? v.call(*(args[0, v.arity])) : v
end

#evaluated_procs(*args) ⇒ Object 



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# File 'lib/building_blocks/base.rb', line 390

def evaluated_procs(*args)
  options = args.shift.presence || {}
  if options.is_a?(Proc)
    evaluated_proc(options, *args)
  else
    options.inject({}) { |hash, (k, v)| hash[k] = evaluated_proc(v, *args); hash}
  end
end

#queue(*args, &block) ⇒ Object

Queue a block for later rendering, such as within a template.

<%= BuildingBlocks::Base.new(self).render_template("shared/wizard") do |blocks| %>
  <% blocks.queue :step1 %>
  <% blocks.queue :step2 do %>
    My overridden Step 2 |
  <% end %>
  <% blocks.queue :step3 %>
  <% blocks.queue do %>
    | Anonymous Step 4
  <% end %>
<% end %>

<!-- In /app/views/shared/wizard -->
<% blocks.define :step1 do %>
  Step 1 |
<% end %>

<% blocks.define :step2 do %>
  Step 2 |
<% end %>

<% blocks.define :step3 do %>
  Step 3
<% end %>

<% blocks.queued_blocks.each do |block| %>
  <%= blocks.render block %>
<% end %>

<!-- Will render: Step 1 | My overridden Step 2 | Step 3 | Anonymous Step 4-->

Options:

*args

The options to pass in when this block is rendered. These will override any options provided to the actual block definition. Any or all of these options may be overriden by whoever calls “blocks.render” on this block. Usually the first of these args will be the name of the block being queued (either a string or a symbol)

block

The optional block definition to render when the queued block is rendered



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# File 'lib/building_blocks/base.rb', line 218

def queue(*args, &block)
  self.queued_blocks << self.define_block_container(*args, &block)
  nil
end

#render(name_or_container, *args, &block) ⇒ Object Also known as: use

Render a block, first rendering any “before” blocks, then rendering the block itself, then rendering any “after” blocks. Additionally, a collection may also be passed in, and BuildingBlocks will render an the block, along with corresponding before and after blocks for each element of the collection. BuildingBlocks will make four different attempts to render block:

1) Look for a block that has been defined inline elsewhere, using the blocks.define method:
   <% blocks.define :wizard do |options| %>
     Inline Block Step#<%= options[:step] %>.
   <% end %>

   <%= blocks.render :wizard, :step => @step %>
2) Look for a partial within the current controller's view directory:
   <%= blocks.render :wizard, :step => @step %>

   <!-- In /app/views/pages/_wizard.html.erb (assuming it is the pages controller running): -->
   Controller-specific Block Step# <%= step %>.
3) Look for a partial with the global blocks view directory (by default /app/views/blocks/):
   <%= blocks.render :wizard, :step => @step %>

   <!-- In /app/views/blocks/_wizard.html.erb: -->
   Global Block Step#<%= step %>.
4) Render the default implementation for the block if provided to the blocks.render call:
   <%= blocks.render :wizard, :step => @step do |options| do %>
     Default Implementation Block Step#<%= options %>.
   <% end %>

Options:

name

The name of the block to render (either a string or a symbol)

*args

Any arguments to pass to the block to be rendered (and also to be passed to any “before” and “after” blocks). The last argument in the list can be a hash and can include the following special options:

[:collection]
  The collection of elements to render blocks for
[:as]
  The variable name to assign the current element in the collection being rendered over
[:surrounding_tag]
  The content tag to render around a block, which might be particularly useful when rendering a collection of blocks,
  such as for a list or table
[:surrounding_tag_html]
  The attributes to be applied to the HTML content tag, such as styling or special properties. Please note, any Procs passed
  in will automatically be evaluated (For example: :class => lambda { cycle("even", "odd") })
block

The default block to render if no such block block that is to be rendered when “blocks.render” is called for this block.



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# File 'lib/building_blocks/base.rb', line 133

def render(name_or_container, *args, &block)
  options = args.extract_options!
  collection = options.delete(:collection)

  buffer = ActiveSupport::SafeBuffer.new

  if collection
    as = options.delete(:as)

    collection.each do |object|
      cloned_args = args.clone
      cloned_args.unshift(object)
      cloned_options = options.clone
      cloned_options = cloned_options.merge(object.options) if object.is_a?(BuildingBlocks::Container)
      cloned_args.push(cloned_options)

      block_name = evaluated_proc(name_or_container, *cloned_args)
      as_name = (as.presence || block_name).to_sym
      cloned_options[as_name] = object

      buffer << render(block_name, *cloned_args, &block)
    end
  else
    surrounding_tag = options.delete(:surrounding_tag)
    surrounding_tag_html = options.delete(:surrounding_tag_html)

    args.push(options)

    if surrounding_tag_surrounds_before_and_after_blocks
      buffer << content_tag(surrounding_tag, surrounding_tag_html, *args) do
        temp_buffer = ActiveSupport::SafeBuffer.new
        temp_buffer << render_before_blocks(name_or_container, *args)
        temp_buffer << render_block_with_around_blocks(name_or_container, *args, &block)
        temp_buffer << render_after_blocks(name_or_container, *args)
      end
    else
      buffer << render_before_blocks(name_or_container, *args)
      buffer << content_tag(surrounding_tag, surrounding_tag_html, *args) do
        render_block_with_around_blocks(name_or_container, *args, &block)
      end
      buffer << render_after_blocks(name_or_container, *args)
    end
  end

  buffer
end

#render_template(partial, &block) ⇒ Object

Render a partial, treating it as a template, and any code in the block argument will impact how the template renders

<%= BuildingBlocks::Base.new(self).render_template("shared/wizard") do |blocks| %>
  <% blocks.queue :step1 %>
  <% blocks.queue :step2 do %>
    My overridden Step 2 |
  <% end %>
  <% blocks.queue :step3 %>
  <% blocks.queue do %>
    | Anonymous Step 4
  <% end %>
<% end %>

<!-- In /app/views/shared/wizard -->
<% blocks.define :step1 do %>
  Step 1 |
<% end %>

<% blocks.define :step2 do %>
  Step 2 |
<% end %>

<% blocks.define :step3 do %>
  Step 3
<% end %>

<% blocks.queued_blocks.each do |block| %>
  <%= blocks.render block %>
<% end %>

<!-- Will render: Step 1 | My overridden Step 2 | Step 3 | Anonymous Step 4-->

Options:

partial

The partial to render as a template

block

An optional block with code that affects how the template renders



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# File 'lib/building_blocks/base.rb', line 258

def render_template(partial, &block)
  render_options = global_options.clone
  render_options[self.variable] = self
  render_options[:captured_block] = view.capture(self, &block) if block_given?

  view.render partial, render_options
end

#replace(name, options = {}, &block) ⇒ Object

Define a block, replacing an existing block by the same name if it is already defined.

<%= blocks.define :some_block_name, :parameter1 => "1", :parameter2 => "2" do |options| %>
  <%= options[:parameter1] %> and <%= options[:parameter2] %>
<% end %>

<%= blocks.replace :some_block_name, :parameter3 => "3", :parameter4 => "4" do |options| %>
  <%= options[:parameter3] %> and <%= options[:parameter4] %>
<% end %>

Options:

name

The name of the block being defined (either a string or a symbol)

options

The default options for the block definition. Any or all of these options may be overrideen by whomever calls “blocks.render” on this block.

block

The block that is to be rendered when “blocks.render” is called for this block.



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# File 'lib/building_blocks/base.rb', line 85

def replace(name, options={}, &block)
  blocks[name.to_sym] = nil
  self.define_block_container(name, options, &block)
  nil
end