Ruby on Rails[c] Up and Running

2017-07-07 02:10:07

5.7. Ajax

Be sure to include the JavaScript libraries in the layout:

<%= javascript_include_tag :defaults %>

5.7.1. Linking to Remote Action

<%= link_to_remote "link", :update => 'some_div', :url => { :action => 'show', :id => post.id } %> <%= link_to_remote "link", :url => { :action => 'create', :update => { :success => 'good_div', :failure => 'error_div' }, :loading => 'Element.show('spinner'), :complete => 'Element.hide('spinner') } %>

5.7.2. Callbacks

:loading: Called when the remote document is being loaded with data by the browser.
:loaded: Called when the browser has finished loading the remote document.
:interactive: Called when the user can interact with the remote document, even though it has not finished loading.
:success: Called when the XMLHttpRequest is completed, and the HTTP status code is in the 2XX range.
:failure: Called when the XMLHttpRequest is completed, and the HTTP status code is not in the 2XX range.
:complete: Called when the XMLHttpRequest is complete (fires after success/failure if they are present).

You can also specify reactions to return codes directly:

link_to_remote word, :url => { :action => "action" }, 404 => "alert('Not found...? Wrong URL...?')", :failure => "alert('HTTP Error ' + request.status + '!')"

5.7.3. Ajax Forms

You can create a form that will submit via an XMLHttpRequest instead of a POST request. The parameters are passed exactly the same way (so the controller can use the params method to access the parameters). Fallback for non-JavaScript-enabled browsers can be specified by using the :action methods in the :html option:

form_remote_tag :html => { :action => url_for(:controller => 'controller', :action => 'action'), :method => :post }

5.7.4. Autocompleting Text Field

In the view t\emplate:

<%= text_field_with_auto_complete :model, :attribute %>

In the controller:

auto_complete_for :model, :attribute

5.7.5. Observe Field

<label for="search">Search term:</label> <%= text_field_tag :search %> <%= observe_field(:search, :frequency => 0.5, :update => :results, :url => { :action => :search }) %> <div id="results"></div>

Optionally specify:

:on => :blur # trigger for event (default :changed or :clicked) :with => ... # a JavaScript expression to specify what value is sent # defaults to "value" :with => 'bla' # "'bla' = value" :with => 'a=b' # "a=b"

5.7.6. Observe Form

Same semantics as observe_field .

5.7.7. periodically_call_remote

<%= periodically_call_remote(:update => 'process-list', :url => { :action => :ps }, :frequency => 2 ) %>

Learn more: http://api.rubyonrails.com/classes/ActionView/Helpers/JavaScriptHelper.html.