CODEWITHSUNDEEP
ruby-on-railsruby-on-rails-3
Mellon
Mellon

Reputation: 38902

How to implement this dynamic select options in view using "select_tag"?

I have two model objects which are Event and Task , they have one-to-many association.

Event model:

class Event < ActiveRecord
  has_many :Task

Task model:

class Task < ActiveRecord
  belongs_to :Event

My controller has a index function which return the list of events (@events), Maybe return also a list of tasks(@tasks):

class MyController < ApplicationController

  def index
    @events = Event.all
    @tasks.....

  end

In my view (index.html.haml), I have defined a multi-select field for all events in a table column as below:

%td
  =select_tag('events',options_from_collection_for_select(@events, 'id', 'name'), {:multiple=>'multiple'})

the output code of the above select_tag is:

<td>
<select id="events" multiple="multiple" name="events">
    <option value="1">Event 1</option>
    <option value="2">Event 2 </option>
</select>
</td>

What I want is in another table column I have another multi-select field for tasks which looks just like the events multi-select field, BUT the key feature is that, the content of the tasks select options is dynamically changed based on which event or events user selected from the events multi-select field.

For example, suppose event_1 is associated with task_1 and task_2, if user mouse click on event_1, the tasks multi-select field will show task_1 and task_2 as options which is available for user to select next.

How to implement this feature in rails? I am using Rails 3. I guess this feature needs some ajax magic to play, but I have no idea how to implement it, it is better if someone can give a simple example on this issue. Thanks!

Upvotes: 0

Views: 3061

Answers (1)

Daniel
Daniel

Reputation: 3027

Check this example is exactly what you need for your models http://pullmonkey.com/2008/03/30/dynamic-select-boxes-ruby-on-rails/.

And I would recommend you to keep a logic for your models.What I mean is

 class Event < ActiveRecord
     has_many :tasks # also notice...no capital "t"
 end

Same for Task model

Upvotes: 2

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