require File.dirname(__FILE__) + '/tag_helper'
module ActionView
module Helpers
# You must call <%= define_javascript_functions %> in your application before using these helpers.
module JavascriptHelper
# Returns a link that'll toggle the visibility of the DOM objects which ids are mentioned in +tags+. If they're visible, we hide them,
# and vice versa. This is particularly useful for hiding and showing input and edit forms on in-page elements.
#
# Examples:
# link_to_toggle_display "Toggle controls", "control_box"
# link_to_toggle_display "Add note", %w( add_link add_form )
def link_to_toggle_display(name, tags, html_options = {})
html_options.symbolize_keys!
toggle_functions = [ tags ].flatten.collect { |tag| "toggle_display_by_id('#{tag}'); " }.join
content_tag(
"a", name,
html_options.merge(:href => "#", :onclick => "#{toggle_functions}#{html_options[:onclick]}; return false;")
)
end
# Returns a link that'll trigger a javascript +function+ using the onclick handler and return false after the fact.
#
# Examples:
# link_to_function "Greeting", "alert('Hello world!')"
# link_to_function(image_tag("delete"), "if confirm('Really?'){ do_delete(); }")
def link_to_function(name, function, html_options = {})
content_tag(
"a", name,
html_options.symbolize_keys.merge(:href => "#", :onclick => "#{function}; return false;")
)
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 who's id can be specified
# with <tt>options[:update]</tt>. Usually, the result would be a partial prepared by the controller with either render_partial
# or render_partial_collection.
#
# 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" })
def link_to_remote(name, options = {})
link_to_function(name, remote_function(options))
end
def form_remote_tag(options = {})
options[:form] = true
options[:html] ||= { }
options[:html][:onsubmit] = "#{remote_function(options)}; return false;"
tag("form", options[:html], true)
end
def define_javascript_functions
<<-EOF
<script language="JavaScript">
/* XMLHttpRequest Methods */
function update_with_response() {
var container = o(arguments[0]);
var url = arguments[1];
var parameters = arguments[2];
container.innerHTML = xml_request(url, parameters);
}
function xml_request() {
var url = arguments[0];
var parameters = arguments[1];
var async = arguments[2];
var type = parameters ? "POST" : "GET";
req = xml_http_request_object();
req.open(type, url, async);
req.send(parameters);
return req.responseText;
}
function xml_http_request_object() {
var req = false;
try {
req = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
try {
req = new ActiveXObject("Microsoft.XMLHTTP");
} catch (E) {
req = false;
}
}
if (!req && typeof XMLHttpRequest!='undefined') {
req = new XMLHttpRequest();
}
return req;
}
/* Common methods ------------------------------ */
function toggle_display_by_id(id) {
o(id).style.display = (o(id).style.display == "none") ? "" : "none";
}
function o(id) {
return document.getElementById(id);
}
/* Serialize a form by Sam Stephenson ------------------------------ */
Form = {
Serializers: {
input: function(element) {
switch (element.type.toLowerCase()) {
case 'hidden':
case 'text':
return Form.Serializers.textarea(element);
case 'checkbox':
case 'radio':
return Form.Serializers.inputSelector(element);
}
},
inputSelector: function(element) {
if (element.checked)
return [element.name, element.value];
},
textarea: function(element) {
return [element.name, element.value];
},
select: function(element) {
var index = element.selectedIndex;
return [element.name, element.options[index].value];
}
},
serialize: function(form) {
var elements = Form.getFormElements(form);
var queryComponents = new Array();
for (var i = 0; i < elements.length; i++) {
var element = elements[i];
var method = element.tagName.toLowerCase();
var parameter = Form.Serializers[method](element);
if (parameter) {
var queryComponent = encodeURIComponent(parameter[0]) + '=' +
encodeURIComponent(parameter[1]);
queryComponents.push(queryComponent);
}
}
return queryComponents.join('&');
},
getFormElements: function(form) {
var elements = new Array();
for (tagName in Form.Serializers) {
var tagElements = form.getElementsByTagName(tagName);
for (var j = 0; j < tagElements.length; j++)
elements.push(tagElements[j]);
}
return elements;
}
}
</script>
EOF
end
private
def remote_function(options)
function = options[:update] ?
"update_with_response('#{options[:update]}', '#{url_for(options[:url])}'#{', Form.serialize(this)' if options[:form]})" :
"xml_request('#{url_for(options[:url])}'#{', Form.serialize(this)' if options[:form]})"
function = [ options[:before], function, options[:before] ].join("; ")
function = "if (#{options[:condition]}) { #{function}; }" if options[:condition]
return function
end
end
end
end
