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module PrototypeHelper
# 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 = {})
button_to_function(name, remote_function(options), html_options)
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" onclick="new Ajax.Request('/testing/create',
# # {asynchronous:true, evalScripts:true, parameters:Form.serialize(this.form)});
# # return false;" type="button" value="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" onclick="new Ajax.Updater({success:'succeed',failure:'fail'},
# # '/testing/update', {asynchronous:true, evalScripts:true, parameters:Form.serialize(this.form)});
# # return false;" type="button" value="Update" />
# <%= 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 = {})
options[:with] ||= 'Form.serialize(this.form)'
html_options = options.delete(:html) || {}
html_options[:name] = name
button_to_remote(value, options, html_options)
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="#" onclick="new Ajax.Updater('posts', '/blog/destroy/3', {asynchronous:true, evalScripts:true});
# # return false;">Delete this post</a>
# link_to_remote "Delete this post", :update => "posts",
# :url => { :action => "destroy", :id => post.id }
#
# # Generates: <a href="#" onclick="new Ajax.Updater('emails', '/mail/list_emails', {asynchronous:true, evalScripts:true});
# # return false;"><img alt="Refresh" 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>.
#
# 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="#" onclick="new Ajax.Updater({success:'posts',failure:'error'}, '/blog/destroy/5',
# # {asynchronous:true, evalScripts:true}); return false;">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="#" onclick="new Ajax.Request('/person/4', {asynchronous:true, evalScripts:true, method:'delete'});
# # return false;">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="#" onclick="new Ajax.Request('/words/undo?n=33', {asynchronous:true, evalScripts:true,
# # onComplete:function(request){undoRequestCompleted(request)}}); return false;">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):
#
# <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="#" onclick="new Ajax.Request('/testing/action', {asynchronous:true, evalScripts:true,
# # on404:function(request){alert('Not found...? Wrong URL...?')},
# # onFailure:function(request){alert('HTTP Error ' + request.status + '!')}}); return false;">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:
# 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, options = {}, html_options = nil)
link_to_function(name, remote_function(options), html_options || options.delete(:html))
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 <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" onsubmit="new Ajax.Request('',
# # {asynchronous:true, evalScripts:true, parameters:Form.serialize(this)}); return false;">
# form_remote_tag :html => { :action =>
# url_for(:controller => "some", :action => "place") }
#
# 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" onsubmit="new Ajax.Request('/',
# # {asynchronous:true, evalScripts:true, parameters:Form.serialize(this)});
# # return false;"> <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)
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 = ActiveModel::Naming.singular(object)
apply_form_for_options!(record_or_name_or_array, options)
args.unshift object
else
object = record_or_name_or_array
object_name = ActiveModel::Naming.singular(record_or_name_or_array)
apply_form_for_options!(object, options)
args.unshift object
end
form_remote_tag options do
fields_for object_name, *(args << options), &proc
end
end
alias_method :form_remote_for, :remote_form_for
# Returns '<tt>eval(request.responseText)</tt>' which is the JavaScript function
# that +form_remote_tag+ can call in <tt>:complete</tt> to evaluate a multiple
# update return document using +update_element_function+ calls.
def evaluate_remote_response
"eval(request.responseText)"
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.
#
# 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(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
# 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 = {})
frequency = options[:frequency] || 10 # every ten seconds by default
code = "new PeriodicalExecuter(function() {#{remote_function(options)}}, #{frequency})"
javascript_tag(code)
end
protected
def build_observer(klass, name, options = {})
if options[:with] && (options[:with] !~ /[\{=(.]/)
options[:with] = "'#{options[:with]}=' + encodeURIComponent(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 << ")"
javascript_tag(javascript)
end
end
ActionController::Base.helper PrototypeHelper
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