Module: ActionView::Helpers::PrototypeHelper::JavaScriptGenerator::GeneratorMethods

Defined in:
lib/action_view/helpers/prototype_helper.rb,
lib/action_view/helpers/scriptaculous_helper.rb

Overview

JavaScriptGenerator generates blocks of JavaScript code that allow you to change the content and presentation of multiple DOM elements. Use this in your Ajax response bodies, either in a <script> tag or as plain JavaScript sent with a Content-type of “text/javascript”.

Create new instances with PrototypeHelper#update_page or with ActionController::Base#render, then call insert_html, replace_html, remove, show, hide, visual_effect, or any other of the built-in methods on the yielded generator in any order you like to modify the content and appearance of the current page.

Example:

# Generates:
#     new Element.insert("list", { bottom: "<li>Some item</li>" });
#     new Effect.Highlight("list");
#     ["status-indicator", "cancel-link"].each(Element.hide);
update_page do |page|
  page.insert_html :bottom, 'list', "<li>#{@item.name}</li>"
  page.visual_effect :highlight, 'list'
  page.hide 'status-indicator', 'cancel-link'
end

Helper methods can be used in conjunction with JavaScriptGenerator. When a helper method is called inside an update block on the page object, that method will also have access to a page object.

Example:

module ApplicationHelper
  def update_time
    page.replace_html 'time', Time.now.to_s(:db)
    page.visual_effect :highlight, 'time'
  end
end

# Controller action
def poll
  render(:update) { |page| page.update_time }
end

Calls to JavaScriptGenerator not matching a helper method below generate a proxy to the JavaScript Class named by the method called.

Examples:

# Generates:
#     Foo.init();
update_page do |page|
  page.foo.init
end

# Generates:
#     Event.observe('one', 'click', function () {
#       $('two').show();
#     });
update_page do |page|
  page.event.observe('one', 'click') do |p|
   p[:two].show
  end
end

You can also use PrototypeHelper#update_page_tag instead of PrototypeHelper#update_page to wrap the generated JavaScript in a <script> tag.

Instance Method Summary collapse

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method, *arguments) ⇒ Object (private)


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# File 'lib/action_view/helpers/prototype_helper.rb', line 566

def method_missing(method, *arguments)
  JavaScriptProxy.new(self, method.to_s.camelize)
end

Instance Method Details

#<<(javascript) ⇒ Object

Writes raw JavaScript to the page.

Example:

page << "alert('JavaScript with Prototype.');"

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# File 'lib/action_view/helpers/prototype_helper.rb', line 500

def <<(javascript)
  @lines << javascript
end

#[](id) ⇒ Object

Returns a element reference by finding it through id in the DOM. This element can then be used for further method calls. Examples:

page['blank_slate']                  # => $('blank_slate');
page['blank_slate'].show             # => $('blank_slate').show();
page['blank_slate'].show('first').up # => $('blank_slate').show('first').up();

You can also pass in a record, which will use ActionController::RecordIdentifier.dom_id to lookup the correct id:

page[@post]     # => $('post_45')
page[Post.new]  # => $('new_post')

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# File 'lib/action_view/helpers/prototype_helper.rb', line 251

def [](id)
  case id
    when String, Symbol, NilClass
      JavaScriptElementProxy.new(self, id)
    else
      JavaScriptElementProxy.new(self, ActionController::RecordIdentifier.dom_id(id))
  end
end

#alert(message) ⇒ Object

Displays an alert dialog with the given message.

Example:

# Generates: alert('This message is from Rails!')
page.alert('This message is from Rails!')

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# File 'lib/action_view/helpers/prototype_helper.rb', line 423

def alert(message)
  call 'alert', message
end

#assign(variable, value) ⇒ Object

Assigns the JavaScript variable the given value.

Examples:

# Generates: my_string = "This is mine!";
page.assign 'my_string', 'This is mine!'

# Generates: record_count = 33;
page.assign 'record_count', 33

# Generates: tabulated_total = 47
page.assign 'tabulated_total', @total_from_cart

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# File 'lib/action_view/helpers/prototype_helper.rb', line 491

def assign(variable, value)
  record "#{variable} = #{javascript_object_for(value)}"
end

#call(function, *arguments, &block) ⇒ Object

Calls the JavaScript function, optionally with the given arguments.

If a block is given, the block will be passed to a new JavaScriptGenerator; the resulting JavaScript code will then be wrapped inside function() { ... } and passed as the called function's final argument.

Examples:

# Generates: Element.replace(my_element, "My content to replace with.")
page.call 'Element.replace', 'my_element', "My content to replace with."

# Generates: alert('My message!')
page.call 'alert', 'My message!'

# Generates:
#     my_method(function() {
#       $("one").show();
#       $("two").hide();
#    });
page.call(:my_method) do |p|
   p[:one].show
   p[:two].hide
end

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# File 'lib/action_view/helpers/prototype_helper.rb', line 474

def call(function, *arguments, &block)
  record "#{function}(#{arguments_for_call(arguments, block)})"
end

#delay(seconds = 1) ⇒ Object

Executes the content of the block after a delay of seconds. Example:

# Generates:
#     setTimeout(function() {
#     ;
#     new Effect.Fade("notice",{});
#     }, 20000);
page.delay(20) do
  page.visual_effect :fade, 'notice'
end

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# File 'lib/action_view/helpers/prototype_helper.rb', line 514

def delay(seconds = 1)
  record "setTimeout(function() {\n\n"
  yield
  record "}, #{(seconds * 1000).to_i})"
end

#draggable(id, options = {}) ⇒ Object

Creates a script.aculo.us draggable element. See ActionView::Helpers::ScriptaculousHelper for more information.


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# File 'lib/action_view/helpers/scriptaculous_helper.rb', line 250

def draggable(id, options = {})
  record @context.send(:draggable_element_js, id, options)
end

#drop_receiving(id, options = {}) ⇒ Object

Creates a script.aculo.us drop receiving element. See ActionView::Helpers::ScriptaculousHelper for more information.


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# File 'lib/action_view/helpers/scriptaculous_helper.rb', line 256

def drop_receiving(id, options = {})
  record @context.send(:drop_receiving_element_js, id, options)
end

#hide(*ids) ⇒ Object

Hides the visible DOM elements with the given ids.

Example:

# Hide a few people
# Generates: ["person_29", "person_9", "person_0"].each(Element.hide);
page.hide 'person_29', 'person_9', 'person_0'

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# File 'lib/action_view/helpers/prototype_helper.rb', line 401

def hide(*ids)
  loop_on_multiple_args 'Element.hide', ids
end

#insert_html(position, id, *options_for_render) ⇒ Object

Inserts HTML at the specified position relative to the DOM element identified by the given id.

position may be one of:

:top

HTML is inserted inside the element, before the element's existing content.

:bottom

HTML is inserted inside the element, after the element's existing content.

:before

HTML is inserted immediately preceding the element.

:after

HTML is inserted immediately following the element.

options_for_render may be either a string of HTML to insert, or a hash of options to be passed to ActionView::Base#render. For example:

# Insert the rendered 'navigation' partial just before the DOM
# element with ID 'content'.
# Generates: Element.insert("content", { before: "-- Contents of 'navigation' partial --" });
page.insert_html :before, 'content', :partial => 'navigation'

# Add a list item to the bottom of the <ul> with ID 'list'.
# Generates: Element.insert("list", { bottom: "<li>Last item</li>" });
page.insert_html :bottom, 'list', '<li>Last item</li>'

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# File 'lib/action_view/helpers/prototype_helper.rb', line 316

def insert_html(position, id, *options_for_render)
  content = javascript_object_for(render(*options_for_render))
  record "Element.insert(\"#{id}\", { #{position.to_s.downcase}: #{content} });"
end

#literal(code) ⇒ Object

Returns an object whose to_json evaluates to code. Use this to pass a literal JavaScript expression as an argument to another JavaScriptGenerator method.


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# File 'lib/action_view/helpers/prototype_helper.rb', line 262

def literal(code)
  ::ActiveSupport::JSON::Variable.new(code.to_s)
end

#redirect_to(location) ⇒ Object

Redirects the browser to the given location using JavaScript, in the same form as url_for.

Examples:

# Generates: window.location.href = "/mycontroller";
page.redirect_to(:action => 'index')

# Generates: window.location.href = "/account/signup";
page.redirect_to(:controller => 'account', :action => 'signup')

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# File 'lib/action_view/helpers/prototype_helper.rb', line 436

def redirect_to(location)
  url = location.is_a?(String) ? location : @context.url_for(location)
  record "window.location.href = #{url.inspect}"
end

#reloadObject

Reloads the browser's current location using JavaScript

Examples:

# Generates: window.location.reload();
page.reload

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# File 'lib/action_view/helpers/prototype_helper.rb', line 447

def reload
  record 'window.location.reload()'
end

#remove(*ids) ⇒ Object

Removes the DOM elements with the given ids from the page.

Example:

# Remove a few people
# Generates: ["person_23", "person_9", "person_2"].each(Element.remove);
page.remove 'person_23', 'person_9', 'person_2'

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# File 'lib/action_view/helpers/prototype_helper.rb', line 377

def remove(*ids)
  loop_on_multiple_args 'Element.remove', ids
end

#replace(id, *options_for_render) ⇒ Object

Replaces the “outer HTML” (i.e., the entire element, not just its contents) of the DOM element with the given id.

options_for_render may be either a string of HTML to insert, or a hash of options to be passed to ActionView::Base#render. For example:

# Replace the DOM element having ID 'person-45' with the
# 'person' partial for the appropriate object.
page.replace 'person-45', :partial => 'person', :object => @person

This allows the same partial that is used for the insert_html to be also used for the input to replace without resorting to the use of wrapper elements.

Examples:

<div id="people">
  <%= render :partial => 'person', :collection => @people %>
</div>

# Insert a new person
#
# Generates: new Insertion.Bottom({object: "Matz", partial: "person"}, "");
page.insert_html :bottom, :partial => 'person', :object => @person

# Replace an existing person

# Generates: Element.replace("person_45", "-- Contents of partial --");
page.replace 'person_45', :partial => 'person', :object => @person

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# File 'lib/action_view/helpers/prototype_helper.rb', line 365

def replace(id, *options_for_render)
  call 'Element.replace', id, render(*options_for_render)
end

#replace_html(id, *options_for_render) ⇒ Object

Replaces the inner HTML of the DOM element with the given id.

options_for_render may be either a string of HTML to insert, or a hash of options to be passed to ActionView::Base#render. For example:

# Replace the HTML of the DOM element having ID 'person-45' with the
# 'person' partial for the appropriate object.
# Generates:  Element.update("person-45", "-- Contents of 'person' partial --");
page.replace_html 'person-45', :partial => 'person', :object => @person

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# File 'lib/action_view/helpers/prototype_helper.rb', line 331

def replace_html(id, *options_for_render)
  call 'Element.update', id, render(*options_for_render)
end

#select(pattern) ⇒ Object

Returns a collection reference by finding it through a CSS pattern in the DOM. This collection can then be used for further method calls. Examples:

page.select('p')                      # => $$('p');
page.select('p.welcome b').first      # => $$('p.welcome b').first();
page.select('p.welcome b').first.hide # => $$('p.welcome b').first().hide();

You can also use prototype enumerations with the collection. Observe:

# Generates: $$('#items li').each(function(value) { value.hide(); });
page.select('#items li').each do |value|
  value.hide
end

Though you can call the block param anything you want, they are always rendered in the javascript as 'value, index.' Other enumerations, like collect() return the last statement:

# Generates: var hidden = $$('#items li').collect(function(value, index) { return value.hide(); });
page.select('#items li').collect('hidden') do |item|
  item.hide
end

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# File 'lib/action_view/helpers/prototype_helper.rb', line 288

def select(pattern)
  JavaScriptElementCollectionProxy.new(self, pattern)
end

#show(*ids) ⇒ Object

Shows hidden DOM elements with the given ids.

Example:

# Show a few people
# Generates: ["person_6", "person_13", "person_223"].each(Element.show);
page.show 'person_6', 'person_13', 'person_223'

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# File 'lib/action_view/helpers/prototype_helper.rb', line 389

def show(*ids)
  loop_on_multiple_args 'Element.show', ids
end

#sortable(id, options = {}) ⇒ Object

Creates a script.aculo.us sortable element. Useful to recreate sortable elements after items get added or deleted. See ActionView::Helpers::ScriptaculousHelper for more information.


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# File 'lib/action_view/helpers/scriptaculous_helper.rb', line 244

def sortable(id, options = {})
  record @context.send(:sortable_element_js, id, options)
end

#to_sObject

:nodoc:


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# File 'lib/action_view/helpers/prototype_helper.rb', line 229

def to_s #:nodoc:
  (@lines * $/).tap do |javascript|
    if ActionView::Base.debug_rjs
      source = javascript.dup
      javascript.replace "try {\n#{source}\n} catch (e) "
      javascript << "{ alert('RJS error:\\n\\n' + e.toString()); alert('#{source.gsub('\\','\0\0').gsub(/\r\n|\n|\r/, "\\n").gsub(/["']/) { |m| "\\#{m}" }}'); throw e }"
    end
  end
end

#toggle(*ids) ⇒ Object

Toggles the visibility of the DOM elements with the given ids. Example:

# Show a few people
# Generates: ["person_14", "person_12", "person_23"].each(Element.toggle);
page.toggle 'person_14', 'person_12', 'person_23'      # Hides the elements
page.toggle 'person_14', 'person_12', 'person_23'      # Shows the previously hidden elements

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# File 'lib/action_view/helpers/prototype_helper.rb', line 413

def toggle(*ids)
  loop_on_multiple_args 'Element.toggle', ids
end

#visual_effect(name, id = nil, options = {}) ⇒ Object

Starts a script.aculo.us visual effect. See ActionView::Helpers::ScriptaculousHelper for more information.


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# File 'lib/action_view/helpers/scriptaculous_helper.rb', line 236

def visual_effect(name, id = nil, options = {})
  record @context.send(:visual_effect, name, id, options)
end