ruby on rails, search results to json array (jbuilder) - ruby

Question

I'm new to rails and I just have a quick question...
I have a calendar gem which currently pulls event data from json as such (viewings/index.json.jbuilder)
json.array!(#viewings) do |viewing|
json.extract! viewing, :id, :room_id, :user_id, :start_time, :end_time, :notes
json.title viewing.user.name
json.start viewing.start_time
json.end viewing.end_time
json.url viewing_url(viewing, format: :html)
end
anyway, I have created a search feature on my "viewings" index page, where a user selects the room from a drop-down and it displays the corresponding viewings.
However, I need to make a JSON array from the results of the search, so it can be fed to the calendar.
I know I can achieve this by doing something like, which does work:
#viewings = Viewing.where(room_id: 1 )
but obviously I want to pass a variable in to that line of code, something like
#viewings = Viewing.where(room_id: params[:search_string] )
The search string will always be a room ID, but the above code (and any variations I can think of) don't seem to work.
OR can I make a JSON array from my search output. my search is as so...
def search
#rooms = Room.all
#viewings = Viewing.simple_search(params[:search_string])
render :action => "index"
end
Can anyone help?!
EDIT:
I'm still struggling with this one a lot. I had a look at the jquery page below but its still not doing what I hoped.
I have simplified the function in my viewings controller as so:
def rmselect
#query1 = params[:rmno]
#rooms = Room.all
#viewings=Room.find(params[:rmno]).viewings
render :action => "index"
end
And I have created an _rmselect.json.jbuilder as so:
#viewings = Viewing.where(room_id: #query1 )
json.array!(#viewings) do |viewing|
json.title viewing.user.name
json.start viewing.start_time
json.end viewing.end_time
end
I was hoping the #query1 variable would be passed into the jbuilder page which would cause it only to display viewings for the selected room. However, it seems that jbuilder cannot see any variables unless they are in def index (where it's no good).
I also can't understand why _rmselect.json.jbuilder is taking the #viewings.all from def index, rather then the #viewings=Room.find(params[:rmno]).viewings from def rmselect.

Answer 1

Ok, I suppose the situation is like that:
Viewing model:
class Viewing < ActiveRecord::Base
...
belongs_to :room
...
end
Room model:
class Room < ActiveRecord::Base
...
has_many :viewings
...
end
Retrive viewings from room id, you can do something like:
#viewings=Room.find(params[:search_string]).viewings
For create JSON array of result, render jbuilder view who contains something like that:
# #people = People.all
json.array! #people, :id, :name
# => [ { "id": 1, "name": "David" }, { "id": 2, "name": "Jamie" } ]
I report an example of official jbuilder docs I think you can use json.array with viewings:
json.array! #viewings, field1, field2, ...
Otherwise you can use this in your controller:
render json: #viewings
but if you've used jbuilder, I think it's better you continue that way.