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.
Writes raw JavaScript to the page.
Example:
page << "alert('JavaScript with Prototype.');"
# File lib/action_view/helpers/prototype_helper.rb, line 500 500: def <<(javascript) 501: @lines << javascript 502: 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')
# File lib/action_view/helpers/prototype_helper.rb, line 251 251: def [](id) 252: case id 253: when String, Symbol, NilClass 254: JavaScriptElementProxy.new(self, id) 255: else 256: JavaScriptElementProxy.new(self, ActionController::RecordIdentifier.dom_id(id)) 257: end 258: end
Displays an alert dialog with the given message.
Example:
# Generates: alert('This message is from Rails!') page.alert('This message is from Rails!')
# File lib/action_view/helpers/prototype_helper.rb, line 423 423: def alert(message) 424: call 'alert', message 425: end
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
# File lib/action_view/helpers/prototype_helper.rb, line 491 491: def assign(variable, value) 492: record "#{variable} = #{javascript_object_for(value)}" 493: 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 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
# File lib/action_view/helpers/prototype_helper.rb, line 474 474: def call(function, *arguments, &block) 475: record "#{function}(#{arguments_for_call(arguments, block)})" 476: end
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
# File lib/action_view/helpers/prototype_helper.rb, line 514 514: def delay(seconds = 1) 515: record "setTimeout(function() {\n\n" 516: yield 517: record "}, #{(seconds * 1000).to_i})" 518: end
Creates a script.aculo.us draggable element. See ActionView::Helpers::ScriptaculousHelper for more information.
# File lib/action_view/helpers/scriptaculous_helper.rb, line 250 250: def draggable(id, options = {}) 251: record @context.send(:draggable_element_js, id, options) 252: end
Creates a script.aculo.us drop receiving element. See ActionView::Helpers::ScriptaculousHelper for more information.
# File lib/action_view/helpers/scriptaculous_helper.rb, line 256 256: def drop_receiving(id, options = {}) 257: record @context.send(:drop_receiving_element_js, id, options) 258: end
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'
# File lib/action_view/helpers/prototype_helper.rb, line 401 401: def hide(*ids) 402: loop_on_multiple_args 'Element.hide', ids 403: end
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>'
# File lib/action_view/helpers/prototype_helper.rb, line 316 316: def insert_html(position, id, *options_for_render) 317: content = javascript_object_for(render(*options_for_render)) 318: record "Element.insert(\"#{id}\", { #{position.to_s.downcase}: #{content} });" 319: end
Returns an object whose to_json evaluates to code. Use this to pass a literal JavaScript expression as an argument to another JavaScriptGenerator method.
# File lib/action_view/helpers/prototype_helper.rb, line 262 262: def literal(code) 263: ::ActiveSupport::JSON::Variable.new(code.to_s) 264: end
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')
# File lib/action_view/helpers/prototype_helper.rb, line 436 436: def redirect_to(location) 437: url = location.is_a?(String) ? location : @context.url_for(location) 438: record "window.location.href = #{url.inspect}" 439: end
Reloads the browser’s current location using JavaScript
Examples:
# Generates: window.location.reload(); page.reload
# File lib/action_view/helpers/prototype_helper.rb, line 447 447: def reload 448: record 'window.location.reload()' 449: end
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'
# File lib/action_view/helpers/prototype_helper.rb, line 377 377: def remove(*ids) 378: loop_on_multiple_args 'Element.remove', ids 379: 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. 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
# File lib/action_view/helpers/prototype_helper.rb, line 365 365: def replace(id, *options_for_render) 366: call 'Element.replace', id, render(*options_for_render) 367: 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. # Generates: Element.update("person-45", "-- Contents of 'person' partial --"); page.replace_html 'person-45', :partial => 'person', :object => @person
# File lib/action_view/helpers/prototype_helper.rb, line 331 331: def replace_html(id, *options_for_render) 332: call 'Element.update', id, render(*options_for_render) 333: 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 # => $$('p.welcome b').first().hide();
You can also use prototype enumerations with the collection. Observe:
# Generates: $$('#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
# File lib/action_view/helpers/prototype_helper.rb, line 288 288: def select(pattern) 289: JavaScriptElementCollectionProxy.new(self, pattern) 290: end
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'
# File lib/action_view/helpers/prototype_helper.rb, line 389 389: def show(*ids) 390: loop_on_multiple_args 'Element.show', ids 391: 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.
# File lib/action_view/helpers/scriptaculous_helper.rb, line 244 244: def sortable(id, options = {}) 245: record @context.send(:sortable_element_js, id, options) 246: end
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
# File lib/action_view/helpers/prototype_helper.rb, line 413 413: def toggle(*ids) 414: loop_on_multiple_args 'Element.toggle', ids 415: end
Starts a script.aculo.us visual effect. See ActionView::Helpers::ScriptaculousHelper for more information.
# File lib/action_view/helpers/scriptaculous_helper.rb, line 236 236: def visual_effect(name, id = nil, options = {}) 237: record @context.send(:visual_effect, name, id, options) 238: end
# File lib/action_view/helpers/prototype_helper.rb, line 556 556: def arguments_for_call(arguments, block = nil) 557: arguments << block_to_function(block) if block 558: arguments.map { |argument| javascript_object_for(argument) }.join ', ' 559: end
# File lib/action_view/helpers/prototype_helper.rb, line 561 561: def block_to_function(block) 562: generator = self.class.new(@context, &block) 563: literal("function() { #{generator.to_s} }") 564: end
# File lib/action_view/helpers/prototype_helper.rb, line 552 552: def javascript_object_for(object) 553: ::ActiveSupport::JSON.encode(object) 554: end
# File lib/action_view/helpers/prototype_helper.rb, line 521 521: def loop_on_multiple_args(method, ids) 522: record(ids.size>1 ? 523: "#{javascript_object_for(ids)}.each(#{method})" : 524: "#{method}(#{javascript_object_for(ids.first)})") 525: end
# File lib/action_view/helpers/prototype_helper.rb, line 566 566: def method_missing(method, *arguments) 567: JavaScriptProxy.new(self, method.to_s.camelize) 568: end
# File lib/action_view/helpers/prototype_helper.rb, line 527 527: def page 528: self 529: end
# File lib/action_view/helpers/prototype_helper.rb, line 531 531: def record(line) 532: line = "#{line.to_s.chomp.gsub(/\;\z/, '')};" 533: self << line 534: line 535: end
Disabled; run with --debug to generate this.
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