first round of documenation for ujs

1 files changed, 401 insertions, 3 deletions

diff --git a/actionpack/lib/action_view/helpers/ajax_helper.rb b/actionpack/lib/action_view/helpers/ajax_helper.rb
index 02b2588c42..54915e3c89 100644
--- a/actionpack/lib/action_view/helpers/ajax_helper.rb
+++ b/actionpack/lib/action_view/helpers/ajax_helper.rb
@@ -5,6 +5,55 @@ module ActionView
       # Rails classes should not be aware of individual JS frameworks
       include PrototypeHelper 
 
+      # 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:
+      #
+      #   # Generates:
+      #   #     <form class='edit_post' 
+      #   #           id='edit_post_1' 
+      #   #           action='/posts/1/edit' 
+      #   #           method='post'
+      #   #           data-remote='true'>...</div>
+      #   #
+      #   <% 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:
+      #   # Generates:
+      #   #     <form class='edit_post_comment' 
+      #   #           id='edit_comment_1' 
+      #   #           action='/posts/1/comments/1/edit' 
+      #   #           method='post' 
+      #   #           data-remote='true'>...</div>
+      #   #
+      #   <% 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!
         object_name = extract_object_name_for_form!(args, options, record_or_name_or_array)
@@ -15,6 +64,46 @@ module ActionView
       end
       alias_method :form_remote_for, :remote_form_for
 
+      # 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 <tt>:url</tt> 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 <tt>:action</tt>/<tt>:method</tt> options on <tt>:html</tt>.
+      #
+      # Example:
+      #
+      #   # Generates:
+      #   #      <form action='/some/place'
+      #   #            method='post'
+      #   #            data-remote='true'>...</div>
+      #   #
+      #   form_remote_tag :html => { :action =>
+      #     url_for(:controller => "some", :action => "place") }
+      #     < form data-remote action="/some/place" method="post" >
+      #
+      # The Hash passed to the <tt>:html</tt> 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 <tt>:url</tt> (and the default method is <tt>:post</tt>).
+      #
+      # form_remote_tag also takes a block, like form_tag:
+      #   # Generates:
+      #   #     <form action='/'
+      #   #           method='post'
+      #   #           data-remote='true'> 
+      #   #       <div><input name="commit" type="submit" value="Save" /></div>
+      #   #     </form>
+      #   #
+      #   <% form_remote_tag :url => '/posts' do -%>
+      #     <div><%= submit_tag 'Save' %></div>
+      #   <% end -%>
+
       def form_remote_tag(options = {}, &block)
         attributes = {}
         attributes.merge!(extract_remote_attributes!(options))
@@ -25,6 +114,179 @@ module ActionView
         form_tag(attributes.delete(:action) || url, attributes, &block)
       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:
+      #
+      #   # Generates: 
+      #   #     <a href='/blog/3'
+      #   #        rel='nofollow'
+      #   #        data-remote='true'
+      #   #        data-method='delete' >Delete this post</ a>
+      #   #
+      #   link_to_remote "Delete this post", :update => "posts",
+      #     :url => { :action => "destroy", :id => post.id }
+      #
+      #   # Generates:  
+      #   #   <a data-remote='true' href="/mail/list_emails" rel="nofollow" >
+      #   #     <img src='/images/refresh.png'/>
+      #   #   </ a>
+      #   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>.
+      #
+      #   # Generates:  
+      #   #     <a class='destructive' 
+      #   #        href='/mail/list_emails' 
+      #   #        rel="nofollow" 
+      #   #        data-remote='true'>Delete this post</a>
+      #   #
+      #   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:
+      #   # Generates: 
+      #   #     <a href='/blog/5' 
+      #   #        rel='nofollow'
+      #   #        data-remote='true' 
+      #   #        data-method='delete' 
+      #   #        data-success='posts' 
+      #   #        data-failure='error' >Delete this post</a>
+      #   #
+      #   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:
+      #   # Generates: 
+      #   #     <a href='/person/4' 
+      #   #        rel='nofollow' 
+      #   #        data-remote='true' 
+      #   #        data-method='delete'>Destroy</a>
+      #   #
+      #   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:
+      #   # Generates: 
+      #   #     <a href='/words/undo?n=33'
+      #   #        data-remote='true' >hello</a>
+      #   #
+      #   word = 'hello'
+      #   link_to_remote word,
+      #     :url => { :action => "undo", :n => word_counter },
+      #     :complete => "undoRequestCompleted(request)"
+      #
+      # The callbacks that may be specified are (in order): (deprecated)
+      #
+      # <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:
+      #
+      #   # Generates:  
+      #   #     <a href='/testing/action'
+      #   #        date-remote='true'
+      #   #        data-failure="function(request){alert('HTTP Error '+ request.status +'+!');return false}"
+      #   #        data-404="function(request){alert('Not found...? Wrong URL...?')}"> Hello</a>
+      #   #
+      #   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.
+      # <tt>:with</tt>::         A JavaScript expression specifying
+      #                          the parameters for the XMLHttpRequest.
+      #                          Any expressions should return a valid
+      #                          URL query string.
+      #
+      #                          Example:
+      #
+      #                            :with => "'name=' + $('name').value"
+      #
+      # You can generate a link that uses AJAX in the general case, while
+      # degrading gracefully to plain link behavior in the absence of
+      # JavaScript by setting <tt>html_options[:href]</tt> to an alternate URL.
+      # Note the extra curly braces around the <tt>options</tt> hash separate
+      # it as the second parameter from <tt>html_options</tt>, the third.
+      #
+      # Example:
+      #
+      #   # Generates:
+      #   #     <a href='/posts/1' 
+      #   #        rel='nofollow' 
+      #   #        data-remote='true' 
+      #   #        data-method='delete'> Delete this post</a>
+      #   #
+      #   link_to_remote "Delete this post",
+      #     { :update => "posts", :url => { :action => "destroy", :id => post.id } },
+      #     :href => url_for(:action => "destroy", :id => post.id)
       def link_to_remote(name, url, options = {})
         attributes = {}
         attributes.merge!(extract_remote_attributes!(options))
@@ -33,7 +295,11 @@ module ActionView
         url = url_for(url) if url.is_a?(Hash)
         content_tag(:a, name, attributes.merge(:href => url))
       end
-
+  
+      # Creates a button with an onclick event which calls a remote action
+      # via XMLHttpRequest
+      # The options for specifying the target with :url
+      # and defining callbacks is the same as link_to_remote.
       def button_to_remote(name, options = {}, html_options = {})
         attributes = html_options.merge!(:type => "button", :value => name)
         attributes.merge!(extract_remote_attributes!(options))
@@ -42,6 +308,37 @@ module ActionView
         tag(:input, attributes)
       end
 
+      # Returns a button input tag with the element name of +name+ and a value (i.e., display text) of +value+
+      # that will submit form using XMLHttpRequest in the background instead of a regular POST request that
+      # reloads the page.
+      #
+      #  # Create a button that submits to the create action
+      #  #
+      #  # Generates: 
+      #  #      <input name='create_btn' 
+      #  #             type='button'
+      #  #             value='Create'
+      #  #             data-remote='true' 
+      #  #             data-url='/testing/create' />
+      #  #
+      #  <%= submit_to_remote 'create_btn', 'Create', :url => { :action => 'create' } %>
+      #
+      #  # Submit to the remote action update and update the DIV succeed or fail based
+      #  # on the success or failure of the request
+      #  #
+      #  # Generates: 
+      #  #    <input name='update_btn'
+      #  #           type='button'
+      #  #           value='Update'
+      #  #           date-remote='true' 
+      #  #           data-url='/testing/update' 
+      #  #           data-success='succeed' 
+      #  #           data-failure='fail' />
+      #  #
+      #  <%= submit_to_remote 'update_btn', 'Update', :url => { :action => 'update' },
+      #     :update => { :success => "succeed", :failure => "fail" }
+      #
+      # <tt>options</tt> argument is the same as in form_remote_tag.
       def submit_to_remote(name, value, options = {})
         html_options = options.delete(:html) || {}
         html_options.merge!(:name => name, :value => value, :type => "submit")
@@ -52,6 +349,31 @@ module ActionView
         tag(:input, attributes)
       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 <tt>:url</tt>
+      # and defining callbacks is the same as link_to_remote.
+      # Examples:
+      #  # Call get_averages and put its results in 'avg' every 10 seconds
+      #  # Generates:
+      #  #      new PeriodicalExecuter(function() {new Ajax.Updater('avg', '/grades/get_averages',
+      #  #      {asynchronous:true, evalScripts:true})}, 10)
+      #  periodically_call_remote(:url => { :action => 'get_averages' }, :update => 'avg')
+      #
+      #  # Call invoice every 10 seconds with the id of the customer
+      #  # If it succeeds, update the invoice DIV; if it fails, update the error DIV
+      #  # Generates:
+      #  #      new PeriodicalExecuter(function() {new Ajax.Updater({success:'invoice',failure:'error'},
+      #  #      '/testing/invoice/16', {asynchronous:true, evalScripts:true})}, 10)
+      #  periodically_call_remote(:url => { :action => 'invoice', :id => customer.id },
+      #     :update => { :success => "invoice", :failure => "error" }
+      #
+      #  # Call update every 20 seconds and update the new_block DIV
+      #  # Generates:
+      #  # new PeriodicalExecuter(function() {new Ajax.Updater('news_block', 'update', {asynchronous:true, evalScripts:true})}, 20)
+      #  periodically_call_remote(:url => 'update', :frequency => '20', :update => 'news_block')
+      #
       def periodically_call_remote(options = {})
         attributes = extract_observer_attributes!(options)
         attributes["data-js-type"] = "periodical_executer"
@@ -59,14 +381,90 @@ module ActionView
         script_decorator(attributes)
       end
 
-      #TODO: Should name change to a css query? - BR
+      # 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.
+      #
+      # Example:
+      #  # Generates: new Form.Element.Observer('suggest', 0.25, function(element, value) {new Ajax.Updater('suggest',
+      #  #         '/testing/find_suggestion', {asynchronous:true, evalScripts:true, parameters:'q=' + value})})
+      #  <%= observe_field :suggest, :url => { :action => :find_suggestion },
+      #       :frequency => 0.25,
+      #       :update => :suggest,
+      #       :with => 'q'
+      #       %>
+      #
+      # 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 javascript code to be called instead.
+      #                       Note that the value of this option is used as the
+      #                       *body* of the javascript function, a function definition
+      #                       with parameters named element and value will be generated for you
+      #                       for example:
+      #                         observe_field("glass", :frequency => 1, :function => "alert('Element changed')")
+      #                       will generate:
+      #                         new Form.Element.Observer('glass', 1, function(element, value) {alert('Element changed')})
+      #                       The element parameter is the DOM element being observed, and the value is its value at the
+      #                       time the observer is triggered.
+      #
+      # 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.
+      #
+      # Additionally, you may specify any of the options documented in the
+      # <em>Common options</em> section at the top of this document.
+      #
+      # Example:
+      #
+      #   # Sends params: {:title => 'Title of the book'} when the book_title input
+      #   # field is changed.
+      #   observe_field 'book_title',
+      #     :url => 'http://example.com/books/edit/1',
+      #     :with => 'title'
+      #
+      #
       def observe_field(name, options = {})
         options[:observed] = name
         attributes = extract_observer_attributes!(options)
 
         script_decorator(attributes)
       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(name, options = {})
         options[:observed] = name
         attributes = extract_observer_attributes!(options)