require 'set'
module ActionView
module Helpers
# Provides a set of helpers for calling Prototype JavaScript functions,
# including functionality to call remote methods using
# Ajax[http://www.adaptivepath.com/publications/essays/archives/000385.php].
# This means that you can call actions in your controllers without
# reloading the page, but still update certain parts of it using
# injections into the DOM. The common use case is having a form that adds
# a new element to a list without reloading the page.
#
# To be able to use these helpers, you must include the Prototype
# JavaScript framework in your pages. See the documentation for
# ActionView::Helpers::JavaScriptHelper for more information on including
# the necessary JavaScript.
#
# See link_to_remote for documentation of options common to all Ajax
# helpers.
#
# See also ActionView::Helpers::ScriptaculousHelper for helpers which work
# with the Scriptaculous controls and visual effects library.
#
# See JavaScriptGenerator for information on updating multiple elements
# on the page in an Ajax response.
module PrototypeHelper
unless const_defined? :CALLBACKS
CALLBACKS = Set.new([ :uninitialized, :loading, :loaded,
:interactive, :complete, :failure, :success ] +
(100..599).to_a)
AJAX_OPTIONS = Set.new([ :before, :after, :condition, :url,
:asynchronous, :method, :insertion, :position,
:form, :with, :update, :script ]).merge(CALLBACKS)
end
# Returns a link to a remote action defined by <tt>options[:url]</tt>
# (using the url_for format) that's called in the background using
# XMLHttpRequest. The result of that request can then be inserted into a
# DOM object whose id can be specified with <tt>options[:update]</tt>.
# Usually, the result would be a partial prepared by the controller with
# render :partial.
#
# Examples:
# link_to_remote "Delete this post", :update => "posts",
# :url => { :action => "destroy", :id => post.id }
# link_to_remote(image_tag("refresh"), :update => "emails",
# :url => { :action => "list_emails" })
#
# You can override the generated HTML options by specifying a hash in
# <tt>options[:html]</tt>.
#
# link_to_remote "Delete this post", :update => "posts",
# :url => post_url(@post), :method => :delete,
# :html => { :class => "destructive" }
#
# You can also specify a hash for <tt>options[:update]</tt> to allow for
# easy redirection of output to an other DOM element if a server-side
# error occurs:
#
# Example:
# link_to_remote "Delete this post",
# :url => { :action => "destroy", :id => post.id },
# :update => { :success => "posts", :failure => "error" }
#
# Optionally, you can use the <tt>options[:position]</tt> parameter to
# influence how the target DOM element is updated. It must be one of
# <tt>:before</tt>, <tt>:top</tt>, <tt>:bottom</tt>, or <tt>:after</tt>.
#
# The method used is by default POST. You can also specify GET or you
# can simulate PUT or DELETE over POST. All specified with <tt>options[:method]</tt>
#
# Example:
# link_to_remote "Destroy", :url => person_url(:id => person), :method => :delete
#
# By default, these remote requests are processed asynchronous during
# which various JavaScript callbacks can be triggered (for progress
# indicators and the likes). All callbacks get access to the
# <tt>request</tt> object, which holds the underlying XMLHttpRequest.
#
# To access the server response, use <tt>request.responseText</tt>, to
# find out the HTTP status, use <tt>request.status</tt>.
#
# Example:
# link_to_remote word,
# :url => { :action => "undo", :n => word_counter },
# :complete => "undoRequestCompleted(request)"
#
# The callbacks that may be specified are (in order):
#
# <tt>:loading</tt>:: Called when the remote document is being
# loaded with data by the browser.
# <tt>:loaded</tt>:: Called when the browser has finished loading
# the remote document.
# <tt>:interactive</tt>:: Called when the user can interact with the
# remote document, even though it has not
# finished loading.
# <tt>:success</tt>:: Called when the XMLHttpRequest is completed,
# and the HTTP status code is in the 2XX range.
# <tt>:failure</tt>:: Called when the XMLHttpRequest is completed,
# and the HTTP status code is not in the 2XX
# range.
# <tt>:complete</tt>:: Called when the XMLHttpRequest is complete
# (fires after success/failure if they are
# present).
#
# You can further refine <tt>:success</tt> and <tt>:failure</tt> by
# adding additional callbacks for specific status codes.
#
# Example:
# link_to_remote word,
# :url => { :action => "action" },
# 404 => "alert('Not found...? Wrong URL...?')",
# :failure => "alert('HTTP Error ' + request.status + '!')"
#
# A status code callback overrides the success/failure handlers if
# present.
#
# If you for some reason or another need synchronous processing (that'll
# block the browser while the request is happening), you can specify
# <tt>options[:type] = :synchronous</tt>.
#
# You can customize further browser side call logic by passing in
# JavaScript code snippets via some optional parameters. In their order
# of use these are:
#
# <tt>:confirm</tt>:: Adds confirmation dialog.
# <tt>:condition</tt>:: Perform remote request conditionally
# by this expression. Use this to
# describe browser-side conditions when
# request should not be initiated.
# <tt>:before</tt>:: Called before request is initiated.
# <tt>:after</tt>:: Called immediately after request was
# initiated and before <tt>:loading</tt>.
# <tt>:submit</tt>:: Specifies the DOM element ID that's used
# as the parent of the form elements. By
# default this is the current form, but
# it could just as well be the ID of a
# table row or any other DOM element.
def link_to_remote(name, options = {}, html_options = nil)
link_to_function(name, remote_function(options), html_options || options.delete(:html))
end
# Periodically calls the specified url (<tt>options[:url]</tt>) every
# <tt>options[:frequency]</tt> seconds (default is 10). Usually used to
# update a specified div (<tt>options[:update]</tt>) with the results
# of the remote call. The options for specifying the target with :url
# and defining callbacks is the same as link_to_remote.
def periodically_call_remote(options = {})
frequency = options[:frequency] || 10 # every ten seconds by default
code = "new PeriodicalExecuter(function() {#{remote_function(options)}}, #{frequency})"
javascript_tag(code)
end
# Returns a form tag that will submit using XMLHttpRequest in the
# background instead of the regular reloading POST arrangement. Even
# though it's using JavaScript to serialize the form elements, the form
# submission will work just like a regular submission as viewed by the
# receiving side (all elements available in <tt>params</tt>). The options for
# specifying the target with :url and defining callbacks is the same as
# link_to_remote.
#
# A "fall-through" target for browsers that doesn't do JavaScript can be
# specified with the :action/:method options on :html.
#
# Example:
# form_remote_tag :html => { :action =>
# url_for(:controller => "some", :action => "place") }
#
# The Hash passed to the :html key is equivalent to the options (2nd)
# argument in the FormTagHelper.form_tag method.
#
# By default the fall-through action is the same as the one specified in
# the :url (and the default method is :post).
#
# form_remote_tag also takes a block, like form_tag:
# <% form_remote_tag :url => '/posts' do -%>
# <div><%= submit_tag 'Save' %></div>
# <% end -%>
def form_remote_tag(options = {}, &block)
options[:form] = true
options[:html] ||= {}
options[:html][:onsubmit] =
(options[:html][:onsubmit] ? options[:html][:onsubmit] + "; " : "") +
"#{remote_function(options)}; return false;"
form_tag(options[:html].delete(:action) || url_for(options[:url]), options[:html], &block)
end
# Creates a form that will submit using XMLHttpRequest in the background
# instead of the regular reloading POST arrangement and a scope around a
# specific resource that is used as a base for questioning about
# values for the fields.
#
# === Resource
#
# Example:
# <% remote_form_for(@post) do |f| %>
# ...
# <% end %>
#
# This will expand to be the same as:
#
# <% remote_form_for :post, @post, :url => post_path(@post), :html => { :method => :put, :class => "edit_post", :id => "edit_post_45" } do |f| %>
# ...
# <% end %>
#
# === Nested Resource
#
# Example:
# <% remote_form_for([@post, @comment]) do |f| %>
# ...
# <% end %>
#
# This will expand to be the same as:
#
# <% remote_form_for :comment, @comment, :url => post_comment_path(@post, @comment), :html => { :method => :put, :class => "edit_comment", :id => "edit_comment_45" } do |f| %>
# ...
# <% end %>
#
# If you don't need to attach a form to a resource, then check out form_remote_tag.
#
# See FormHelper#form_for for additional semantics.
def remote_form_for(record_or_name_or_array, *args, &proc)
options = args.extract_options!
case record_or_name_or_array
when String, Symbol
object_name = record_or_name_or_array
when Array
object = record_or_name_or_array.last
object_name = ActionController::RecordIdentifier.singular_class_name(object)
apply_form_for_options!(record_or_name_or_array, options)
args.unshift object
else
object = record_or_name_or_array
object_name = ActionController::RecordIdentifier.singular_class_name(record_or_name_or_array)
apply_form_for_options!(object, options)
args.unshift object
end
concat(form_remote_tag(options), proc.binding)
fields_for(object_name, *(args << options), &proc)
concat('</form>', proc.binding)
end
alias_method :form_remote_for, :remote_form_for
# Returns a button input tag that will submit form using XMLHttpRequest
# in the background instead of regular reloading POST arrangement.
# <tt>options</tt> argument is the same as in <tt>form_remote_tag</tt>.
def submit_to_remote(name, value, options = {})
options[:with] ||= 'Form.serialize(this.form)'
options[:html] ||= {}
options[:html][:type] = 'button'
options[:html][:onclick] = "#{remote_function(options)}; return false;"
options[:html][:name] = name
options[:html][:value] = value
tag("input", options[:html], false)
end
# Returns 'eval(request.responseText)' which is the JavaScript function
# that form_remote_tag can call in :complete to evaluate a multiple
# update return document using update_element_function calls.
def evaluate_remote_response
"eval(request.responseText)"
end
# Returns the JavaScript needed for a remote function.
# Takes the same arguments as link_to_remote.
#
# Example:
# <select id="options" onchange="<%= remote_function(:update => "options",
# :url => { :action => :update_options }) %>">
# <option value="0">Hello</option>
# <option value="1">World</option>
# </select>
def remote_function(options)
javascript_options = options_for_ajax(options)
update = ''
if options[:update] && options[:update].is_a?(Hash)
update = []
update << "success:'#{options[:update][:success]}'" if options[:update][:success]
update << "failure:'#{options[:update][:failure]}'" if options[:update][:failure]
update = '{' + update.join(',') + '}'
elsif options[:update]
update << "'#{options[:update]}'"
end
function = update.empty? ?
"new Ajax.Request(" :
"new Ajax.Updater(#{update}, "
url_options = options[:url]
url_options = url_options.merge(:escape => false) if url_options.is_a?(Hash)
function << "'#{url_for(url_options)}'"
function << ", #{javascript_options})"
function = "#{options[:before]}; #{function}" if options[:before]
function = "#{function}; #{options[:after]}" if options[:after]
function = "if (#{options[:condition]}) { #{function}; }" if options[:condition]
function = "if (confirm('#{escape_javascript(options[:confirm])}')) { #{function}; }" if options[:confirm]
return function
end
# Observes the field with the DOM ID specified by +field_id+ and calls a
# callback when its contents have changed. The default callback is an
# Ajax call. By default the value of the observed field is sent as a
# parameter with the Ajax call.
#
# Required +options+ are either of:
# <tt>:url</tt>:: +url_for+-style options for the action to call
# when the field has changed.
# <tt>:function</tt>:: Instead of making a remote call to a URL, you
# can specify a function to be called instead.
#
# Additional options are:
# <tt>:frequency</tt>:: The frequency (in seconds) at which changes to
# this field will be detected. Not setting this
# option at all or to a value equal to or less than
# zero will use event based observation instead of
# time based observation.
# <tt>:update</tt>:: Specifies the DOM ID of the element whose
# innerHTML should be updated with the
# XMLHttpRequest response text.
# <tt>:with</tt>:: A JavaScript expression specifying the parameters
# for the XMLHttpRequest. The default is to send the
# key and value of the observed field. Any custom
# expressions should return a valid URL query string.
# The value of the field is stored in the JavaScript
# variable +value+.
#
# Examples
#
# :with => "'my_custom_key=' + value"
# :with => "'person[name]=' + prompt('New name')"
# :with => "Form.Element.serialize('other-field')"
#
# Finally
# :with => 'name'
# is shorthand for
# :with => "'name=' + value"
# This essentially just changes the key of the parameter.
# <tt>:on</tt>:: Specifies which event handler to observe. By default,
# it's set to "changed" for text fields and areas and
# "click" for radio buttons and checkboxes. With this,
# you can specify it instead to be "blur" or "focus" or
# any other event.
#
# Additionally, you may specify any of the options documented in
# link_to_remote.
def observe_field(field_id, options = {})
if options[:frequency] && options[:frequency] > 0
build_observer('Form.Element.Observer', field_id, options)
else
build_observer('Form.Element.EventObserver', field_id, options)
end
end
# Observes the form with the DOM ID specified by +form_id+ and calls a
# callback when its contents have changed. The default callback is an
# Ajax call. By default all fields of the observed field are sent as
# parameters with the Ajax call.
#
# The +options+ for +observe_form+ are the same as the options for
# +observe_field+. The JavaScript variable +value+ available to the
# <tt>:with</tt> option is set to the serialized form by default.
def observe_form(form_id, options = {})
if options[:frequency]
build_observer('Form.Observer', form_id, options)
else
build_observer('Form.EventObserver', form_id, options)
end
end
# All the methods were moved to GeneratorMethods so that
# #include_helpers_from_context has nothing to overwrite.
class JavaScriptGenerator #:nodoc:
def initialize(context, &block) #:nodoc:
@context, @lines = context, []
include_helpers_from_context
@context.instance_exec(self, &block)
end
private
def include_helpers_from_context
@context.extended_by.each do |mod|
extend mod unless mod.name =~ /^ActionView::Helpers/
end
extend GeneratorMethods
end
# 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:
#
# 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
#
# generates the following JavaScript:
#
# new Insertion.Bottom("list", "<li>Some item</li>");
# new Effect.Highlight("list");
# ["status-indicator", "cancel-link"].each(Element.hide);
#
# 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
#
# You can also use PrototypeHelper#update_page_tag instead of
# PrototypeHelper#update_page to wrap the generated JavaScript in a
# <script> tag.
module GeneratorMethods
def to_s #:nodoc:
returning javascript = @lines * $/ do
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
# 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')
def [](id)
case id
when String, Symbol, NilClass
JavaScriptElementProxy.new(self, id)
else
JavaScriptElementProxy.new(self, ActionController::RecordIdentifier.dom_id(id))
end
end
# Returns an object whose <tt>#to_json</tt> evaluates to +code+. Use this to pass a literal JavaScript
# expression as an argument to another JavaScriptGenerator method.
def literal(code)
ActiveSupport::JSON::Variable.new(code.to_s)
end
# 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 # => $$('p.welcome b').first().hide();
#
# You can also use prototype enumerations with the collection. Observe:
#
# page.select('#items li').each do |value|
# value.hide
# end
# # => $$('#items li').each(function(value) { value.hide(); });
#
# 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:
#
# page.select('#items li').collect('hidden') do |item|
# item.hide
# end
# # => var hidden = $$('#items li').collect(function(value, index) { return value.hide(); });
def select(pattern)
JavaScriptElementCollectionProxy.new(self, pattern)
end
# Inserts HTML at the specified +position+ relative to the DOM element
# identified by the given +id+.
#
# +position+ may be one of:
#
# <tt>:top</tt>:: HTML is inserted inside the element, before the
# element's existing content.
# <tt>:bottom</tt>:: HTML is inserted inside the element, after the
# element's existing content.
# <tt>:before</tt>:: HTML is inserted immediately preceeding the element.
# <tt>:after</tt>:: 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'.
# insert_html :before, 'content', :partial => 'navigation'
#
# # Add a list item to the bottom of the <ul> with ID 'list'.
# insert_html :bottom, 'list', '<li>Last item</li>'
#
def insert_html(position, id, *options_for_render)
insertion = position.to_s.camelize
call "new Insertion.#{insertion}", id, render(*options_for_render)
end
# 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.
# replace_html 'person-45', :partial => 'person', :object => @person
#
def replace_html(id, *options_for_render)
call 'Element.update', id, render(*options_for_render)
end
# 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.
# 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
# page.insert_html :bottom, :partial => 'person', :object => @person
#
# # Replace an existing person
# page.replace 'person_45', :partial => 'person', :object => @person
#
def replace(id, *options_for_render)
call 'Element.replace', id, render(*options_for_render)
end
# Removes the DOM elements with the given +ids+ from the page.
def remove(*ids)
loop_on_multiple_args 'Element.remove', ids
end
# Shows hidden DOM elements with the given +ids+.
def show(*ids)
loop_on_multiple_args 'Element.show', ids
end
# Hides the visible DOM elements with the given +ids+.
def hide(*ids)
loop_on_multiple_args 'Element.hide', ids
end
# Toggles the visibility of the DOM elements with the given +ids+.
def toggle(*ids)
loop_on_multiple_args 'Element.toggle', ids
end
# Displays an alert dialog with the given +message+.
def alert(message)
call 'alert', message
end
# Redirects the browser to the given +location+, in the same form as +url_for+.
def redirect_to(location)
assign 'window.location.href', @context.url_for(location)
end
# 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 <tt>function() { ... }</tt>
# and passed as the called function's final argument.
def call(function, *arguments, &block)
record "#{function}(#{arguments_for_call(arguments, block)})"
end
# Assigns the JavaScript +variable+ the given +value+.
def assign(variable, value)
record "#{variable} = #{javascript_object_for(value)}"
end
# Writes raw JavaScript to the page.
def <<(javascript)
@lines << javascript
end
# Executes the content of the block after a delay of +seconds+. Example:
#
# page.delay(20) do
# page.visual_effect :fade, 'notice'
# end
def delay(seconds = 1)
record "setTimeout(function() {\n\n"
yield
record "}, #{(seconds * 1000).to_i})"
end
# Starts a script.aculo.us visual effect. See
# ActionView::Helpers::ScriptaculousHelper for more information.
def visual_effect(name, id = nil, options = {})
record @context.send(:visual_effect, name, id, options)
end
# 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.
def sortable(id, options = {})
record @context.send(:sortable_element_js, id, options)
end
# Creates a script.aculo.us draggable element.
# See ActionView::Helpers::ScriptaculousHelper for more information.
def draggable(id, options = {})
record @context.send(:draggable_element_js, id, options)
end
# Creates a script.aculo.us drop receiving element.
# See ActionView::Helpers::ScriptaculousHelper for more information.
def drop_receiving(id, options = {})
record @context.send(:drop_receiving_element_js, id, options)
end
private
def loop_on_multiple_args(method, ids)
record(ids.size>1 ?
"#{javascript_object_for(ids)}.each(#{method})" :
"#{method}(#{ids.first.to_json})")
end
def page
self
end
def record(line)
returning line = "#{line.to_s.chomp.gsub(/\;\z/, '')};" do
self << line
end
end
def render(*options_for_render)
old_format = @context && @context.template_format
@context.template_format = :html if @context
Hash === options_for_render.first ?
@context.render(*options_for_render) :
options_for_render.first.to_s
ensure
@context.template_format = old_format if @context
end
def javascript_object_for(object)
object.respond_to?(:to_json) ? object.to_json : object.inspect
end
def arguments_for_call(arguments, block = nil)
arguments << block_to_function(block) if block
arguments.map { |argument| javascript_object_for(argument) }.join ', '
end
def block_to_function(block)
generator = self.class.new(@context, &block)
literal("function() { #{generator.to_s} }")
end
def method_missing(method, *arguments)
JavaScriptProxy.new(self, method.to_s.camelize)
end
end
end
# Yields a JavaScriptGenerator and returns the generated JavaScript code.
# Use this to update multiple elements on a page in an Ajax response.
# See JavaScriptGenerator for more information.
def update_page(&block)
JavaScriptGenerator.new(@template, &block).to_s
end
# Works like update_page but wraps the generated JavaScript in a <script>
# tag. Use this to include generated JavaScript in an ERb template.
# See JavaScriptGenerator for more information.
#
# +html_options+ may be a hash of <script> attributes to be passed
# to ActionView::Helpers::JavaScriptHelper#javascript_tag.
def update_page_tag(html_options = {}, &block)
javascript_tag update_page(&block), html_options
end
protected
def options_for_ajax(options)
js_options = build_callbacks(options)
js_options['asynchronous'] = options[:type] != :synchronous
js_options['method'] = method_option_to_s(options[:method]) if options[:method]
js_options['insertion'] = "Insertion.#{options[:position].to_s.camelize}" if options[:position]
js_options['evalScripts'] = options[:script].nil? || options[:script]
if options[:form]
js_options['parameters'] = 'Form.serialize(this)'
elsif options[:submit]
js_options['parameters'] = "Form.serialize('#{options[:submit]}')"
elsif options[:with]
js_options['parameters'] = options[:with]
end
if request_forgery_protection_token
if js_options['parameters']
js_options['parameters'] << " + '&"
else
js_options['parameters'] = "'"
end
js_options['parameters'] << "_token=' + encodeURIComponent('#{escape_javascript form_token}')"
end
options_for_javascript(js_options)
end
def method_option_to_s(method)
(method.is_a?(String) and !method.index("'").nil?) ? method : "'#{method}'"
end
def build_observer(klass, name, options = {})
if options[:with] && (options[:with] !~ /[\{=(.]/)
options[:with] = "'#{options[:with]}=' + value"
else
options[:with] ||= 'value' unless options[:function]
end
callback = options[:function] || remote_function(options)
javascript = "new #{klass}('#{name}', "
javascript << "#{options[:frequency]}, " if options[:frequency]
javascript << "function(element, value) {"
javascript << "#{callback}}"
javascript << ", '#{options[:on]}'" if options[:on]
javascript << ")"
javascript_tag(javascript)
end
def build_callbacks(options)
callbacks = {}
options.each do |callback, code|
if CALLBACKS.include?(callback)
name = 'on' + callback.to_s.capitalize
callbacks[name] = "function(request){#{code}}"
end
end
callbacks
end
end
# Converts chained method calls on DOM proxy elements into JavaScript chains
class JavaScriptProxy < Builder::BlankSlate #:nodoc:
def initialize(generator, root = nil)
@generator = generator
@generator << root if root
end
private
def method_missing(method, *arguments, &block)
if method.to_s =~ /(.*)=$/
assign($1, arguments.first)
else
call("#{method.to_s.camelize(:lower)}", *arguments, &block)
end
end
def call(function, *arguments, &block)
append_to_function_chain!("#{function}(#{@generator.send(:arguments_for_call, arguments, block)})")
self
end
def assign(variable, value)
append_to_function_chain!("#{variable} = #{@generator.send(:javascript_object_for, value)}")
end
def function_chain
@function_chain ||= @generator.instance_variable_get(:@lines)
end
def append_to_function_chain!(call)
function_chain[-1].chomp!(';')
function_chain[-1] += ".#{call};"
end
end
class JavaScriptElementProxy < JavaScriptProxy #:nodoc:
def initialize(generator, id)
@id = id
super(generator, "$(#{id.to_json})")
end
# Allows access of element attributes through +attribute+. Examples:
#
# page['foo']['style'] # => $('foo').style;
# page['foo']['style']['color'] # => $('blank_slate').style.color;
# page['foo']['style']['color'] = 'red' # => $('blank_slate').style.color = 'red';
# page['foo']['style'].color = 'red' # => $('blank_slate').style.color = 'red';
def [](attribute)
append_to_function_chain!(attribute)
self
end
def []=(variable, value)
assign(variable, value)
end
def replace_html(*options_for_render)
call 'update', @generator.send(:render, *options_for_render)
end
def replace(*options_for_render)
call 'replace', @generator.send(:render, *options_for_render)
end
def reload(options_for_replace = {})
replace(options_for_replace.merge({ :partial => @id.to_s }))
end
end
class JavaScriptVariableProxy < JavaScriptProxy #:nodoc:
def initialize(generator, variable)
@variable = variable
@empty = true # only record lines if we have to. gets rid of unnecessary linebreaks
super(generator)
end
# The JSON Encoder calls this to check for the #to_json method
# Since it's a blank slate object, I suppose it responds to anything.
def respond_to?(method)
true
end
def to_json
@variable
end
private
def append_to_function_chain!(call)
@generator << @variable if @empty
@empty = false
super
end
end
class JavaScriptCollectionProxy < JavaScriptProxy #:nodoc:
ENUMERABLE_METHODS_WITH_RETURN = [:all, :any, :collect, :map, :detect, :find, :find_all, :select, :max, :min, :partition, :reject, :sort_by, :in_groups_of, :each_slice] unless defined? ENUMERABLE_METHODS_WITH_RETURN
ENUMERABLE_METHODS = ENUMERABLE_METHODS_WITH_RETURN + [:each] unless defined? ENUMERABLE_METHODS
attr_reader :generator
delegate :arguments_for_call, :to => :generator
def initialize(generator, pattern)
super(generator, @pattern = pattern)
end
def each_slice(variable, number, &block)
if block
enumerate :eachSlice, :variable => variable, :method_args => [number], :yield_args => %w(value index), :return => true, &block
else
add_variable_assignment!(variable)
append_enumerable_function!("eachSlice(#{number.to_json});")
end
end
def grep(variable, pattern, &block)
enumerate :grep, :variable => variable, :return => true, :method_args => [pattern], :yield_args => %w(value index), &block
end
def in_groups_of(variable, number, fill_with = nil)
arguments = [number]
arguments << fill_with unless fill_with.nil?
add_variable_assignment!(variable)
append_enumerable_function!("inGroupsOf(#{arguments_for_call arguments});")
end
def inject(variable, memo, &block)
enumerate :inject, :variable => variable, :method_args => [memo], :yield_args => %w(memo value index), :return => true, &block
end
def pluck(variable, property)
add_variable_assignment!(variable)
append_enumerable_function!("pluck(#{property.to_json});")
end
def zip(variable, *arguments, &block)
add_variable_assignment!(variable)
append_enumerable_function!("zip(#{arguments_for_call arguments}")
if block
function_chain[-1] += ", function(array) {"
yield ActiveSupport::JSON::Variable.new('array')
add_return_statement!
@generator << '});'
else
function_chain[-1] += ');'
end
end
private
def method_missing(method, *arguments, &block)
if ENUMERABLE_METHODS.include?(method)
returnable = ENUMERABLE_METHODS_WITH_RETURN.include?(method)
variable = arguments.first if returnable
enumerate(method, {:variable => (arguments.first if returnable), :return => returnable, :yield_args => %w(value index)}, &block)
else
super
end
end
# Options
# * variable - name of the variable to set the result of the enumeration to
# * method_args - array of the javascript enumeration method args that occur before the function
# * yield_args - array of the javascript yield args
# * return - true if the enumeration should return the last statement
def enumerate(enumerable, options = {}, &block)
options[:method_args] ||= []
options[:yield_args] ||= []
yield_args = options[:yield_args] * ', '
method_args = arguments_for_call options[:method_args] # foo, bar, function
method_args << ', ' unless method_args.blank?
add_variable_assignment!(options[:variable]) if options[:variable]
append_enumerable_function!("#{enumerable.to_s.camelize(:lower)}(#{method_args}function(#{yield_args}) {")
# only yield as many params as were passed in the block
yield(*options[:yield_args].collect { |p| JavaScriptVariableProxy.new(@generator, p) }[0..block.arity-1])
add_return_statement! if options[:return]
@generator << '});'
end
def add_variable_assignment!(variable)
function_chain.push("var #{variable} = #{function_chain.pop}")
end
def add_return_statement!
unless function_chain.last =~ /return/
function_chain.push("return #{function_chain.pop.chomp(';')};")
end
end
def append_enumerable_function!(call)
function_chain[-1].chomp!(';')
function_chain[-1] += ".#{call}"
end
end
class JavaScriptElementCollectionProxy < JavaScriptCollectionProxy #:nodoc:\
def initialize(generator, pattern)
super(generator, "$$(#{pattern.to_json})")
end
end
end
end
require 'action_view/helpers/javascript_helper'