Module: AutoCompleteMacrosHelper

Defined in:
app/helpers/auto_complete_macros_helper.rb

Instance Method Summary collapse

Instance Method Details

#auto_complete_field(field_id, options = {}) ⇒ Object

Adds AJAX autocomplete functionality to the text input field with the DOM ID specified by field_id.

This function expects that the called action returns an HTML <ul> list, or nothing if no entries should be displayed for autocompletion.

You’ll probably want to turn the browser’s built-in autocompletion off, so be sure to include an autocomplete="off" attribute with your text input field.

The autocompleter object is assigned to a Javascript variable named field_id_auto_completer. This object is useful if you for example want to trigger the auto-complete suggestions through other means than user input (for that specific case, call the activate method on that object).

Required options are:

:url

URL to call for autocompletion results in url_for format.

Addtional options are:

:update

Specifies the DOM ID of the element whose innerHTML should be updated with the autocomplete entries returned by the AJAX request. Defaults to field_id + ‘_auto_complete’

:with

A JavaScript expression specifying the parameters for the XMLHttpRequest. This defaults to ‘fieldname=value’.

:frequency

Determines the time to wait after the last keystroke for the AJAX request to be initiated.

:indicator

Specifies the DOM ID of an element which will be displayed while autocomplete is running.

:tokens

A string or an array of strings containing separator tokens for tokenized incremental autocompletion. Example: :tokens => ',' would allow multiple autocompletion entries, separated by commas.

:min_chars

The minimum number of characters that should be in the input field before an Ajax call is made to the server.

:on_hide

A Javascript expression that is called when the autocompletion div is hidden. The expression should take two variables: element and update. Element is a DOM element for the field, update is a DOM element for the div from which the innerHTML is replaced.

:on_show

Like on_hide, only now the expression is called then the div is shown.

:after_update_element

A Javascript expression that is called when the user has selected one of the proposed values. The expression should take two variables: element and value. Element is a DOM element for the field, value is the value selected by the user.

:select

Pick the class of the element from which the value for insertion should be extracted. If this is not specified, the entire element is used.

:method

Specifies the HTTP verb to use when the autocompletion request is made. Defaults to POST.



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# File 'app/helpers/auto_complete_macros_helper.rb', line 58

def auto_complete_field(field_id, options = {})
  function =  "var #{field_id}_auto_completer = new Ajax.Autocompleter("
  function << "'#{field_id}', "
  function << "'" + (options[:update] || "#{field_id}_auto_complete") + "', "
  function << "'#{url_for(options[:url])}'"

  js_options = {}
  js_options[:tokens] = array_or_string_for_javascript(options[:tokens]) if options[:tokens]
  js_options[:callback]   = "function(element, value) { return #{options[:with]} }" if options[:with]
  js_options[:indicator]  = "'#{options[:indicator]}'" if options[:indicator]
  js_options[:select]     = "'#{options[:select]}'" if options[:select]
  js_options[:paramName]  = "'#{options[:param_name]}'" if options[:param_name]
  js_options[:frequency]  = "#{options[:frequency]}" if options[:frequency]
  js_options[:method]     = "'#{options[:method].to_s}'" if options[:method]

  { :after_update_element => :afterUpdateElement,
    :on_show => :onShow, :on_hide => :onHide, :min_chars => :minChars }.each do |k,v|
    js_options[v] = options[k] if options[k]
  end

  function << (', ' + options_for_javascript(js_options) + ')')

  javascript_tag(function)
end

#auto_complete_result(entries, field, phrase = nil) ⇒ Object

Use this method in your view to generate a return for the AJAX autocomplete requests.

Example action:

def auto_complete_for_item_title
  @items = Item.find(:all,
    :conditions => [ 'LOWER(description) LIKE ?',
    '%' + request.raw_post.downcase + '%' ])
  render :inline => "<%= auto_complete_result(@items, 'description') %>"
end

The auto_complete_result can of course also be called from a view belonging to the auto_complete action if you need to decorate it further.



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# File 'app/helpers/auto_complete_macros_helper.rb', line 96

def auto_complete_result(entries, field, phrase = nil)
  return unless entries
  items = entries.map { |entry| content_tag("li", phrase ? highlight(entry[field], phrase) : entry[field]) }
  content_tag("ul", safe_join(items.uniq))
end

#text_field_with_auto_complete(object, method, tag_options = {}, completion_options = {}) ⇒ Object

Wrapper for text_field with added AJAX autocompletion functionality.

In your controller, you’ll need to define an action called auto_complete_for to respond the AJAX calls,



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# File 'app/helpers/auto_complete_macros_helper.rb', line 107

def text_field_with_auto_complete(object, method, tag_options = {}, completion_options = {})
  (completion_options[:skip_style] ? "".html_safe : auto_complete_stylesheet) +
  text_field(object, method, tag_options) +
  content_tag("div", "", :id => "#{object}_#{method}_auto_complete", :class => "auto_complete") +
  auto_complete_field("#{object}_#{method}", { :url => { :action => "auto_complete_for_#{object}_#{method}" } }.update(completion_options))
end