A complete rails beginner here.
How do I go about handling a query string in rails?
For example for:
www.something.com/movie?sort=title
For implementing the the view in the haml file, how can I make it so that clicking on Movie title will send that query string,
And more importantly how do I handle it. Where should I implement the function which can access that query string using :params .
I have been on this for more than a day now and could not understand whether that query string will call a controller function or a module from helper.
I hope I was clear enough about the question.
Any help will be appreciated.
PS:- there is a movie table with title as one of its column.
Not sure I really understand what you want. Does this suit you?
link_to "My Link", movie_index_path(sort: :title)
Then access param with params[:sort] ?
(Accord movie_index_path with your routes configuration)
Since your question is not focused let me assume part of your problem.
Assumptions
You have a controller name movies_controller.rb in app/controllers/
folder You have a model named movie.rb in app/models folder
Then you should tell Rails to route requests with path /movies to movies_controller.rb. This can be done by adding the below lines in config/routes.rb
resources :movies
The if you call www.something.com/movies this will invoke the method index in movies_controller.rb. So you should write some code to display movies here.
class MoviesController < ApplicationController
def index
#movies = Movie.all
end
end
Then you should use app/views/movies/index.haml file to display the movies. There give a link to sort the movies by title.
link_to "Sort by title", movies_path(:sort=>"title")
No when click on the link the user will reach the same index method with params now. You can get the sort value like below.
params[:sort]
SO to support sorting you need to change the controller code little bit.
class MoviesController < ApplicationController
def index
if params[:sort]
#movies = Movie.order('#{params[:sort]} ASC')
else
#movies = Movie.all
end
end
end
I strongly suggest you to go through the http://guides.rubyonrails.org/index.html before asking question.
Related
I have a store application with a Product scaffold and I want to enable categories and pages that show each category of products.
My product model has a "category" attribute and I use the link_to helper to create links to each category.
In my products controller I added a method called index_by_category(cat):
def index_by_category(cat)
#products_by_category = Product.where(category: cat)
end
I'm trying to iterate #products_by_category in a view I created with the corresponding name (product/index_by_category.html.erb) just like the regular index method do. For some reason it render me the regular index method of products which shows ALL of them, even though the URL is:
http://localhost:3000/products?index_by_category=Food
This is what I did in my route.rb file:
get 'products/index_by_category'
I'm newbie to Rails development so if I did something which is wrong from the roots and the rails approach to the problem should be entirely different I also be happy to know for the sake of learning.
You are doing things a bit wrong. Try to write your controller like this:
def index_by_category
#products_by_category = Product.where(category: params[:category])
end
And update your route
get 'products/category/:category', to: 'products#index_by_category
Then visit
http://localhost:3000/products/category/Food
UPDATE
if you really want to use index method for both cases you could do that by modifying it to something like this
def index
if params[:category]
#products = Product.where(category: params[:category])
else
#products = Product.all
end
end
and then just visit
http://localhost:3000/products?category=Food
My rails app has a database set.
def index
#clubs = Club.all
end
This is my controller.
If i type in my Index.html.erb
<% #clubs.each do |club| %>
<%= club.name %>
<% end %>
I get all the names of my database show in my index view.
What if I just want to pick one or just a couple?
Thru the rails console i can by typing c=Club.find(1) 1 by default takes id=1.
So how can i just display several ID's and not all one the database in the same index.html.erb.
thanks anyway!
Try this:
Let us consider that params[:ids] contains all the ids that belong to the records you want to get.
def index
#clubs = Club.where(id: params[:ids])
end
Fix
The straightforward answer here is to recommend you look at the ActiveRecord methods you can call in your controller; specifically .where:
#app/controllers/clubs_controller.rb
Class ClubsController < ApplicationController
def index
#clubs = Club.where column: "value"
end
end
This will populate the #clubs instance variable with only the records which match that particular condition. Remember, it's your Rails app, so you can do what you want with it.
Of course, it's recommended you stick with convention, but there's nothing stopping you populating specific data into your #clubs variable
--
RESTful
As someone mentioned, you shouldn't be including "filtered" records in an index action. Although I don't agree with this idea personally, the fact remains that Rails is designed to favour convention over configuration - meaning you should really leave the index action as showing all the records
You may wish to create a collection-specific action:
#config/routes.rb
resources :clubs do
collection do
get :best #-> domain.com/clubs/best
end
end
#app/controllers/clubs_controller.rb
Class ClubsController < ApplicationController
def best
#clubs = Club.where attribute: "value"
render "index"
end
end
There are several ways to select a specific record or group of records from the database. For example, you can get a single club with:
#club = Club.find(x)
where x is the id of the club. Then in your view (the .html.erb file), you can simply access the #club object's attributes.
You can also cast a wider net:
#disco_clubs = Club.where(type: "disco") # returns an ActiveRecord Relation
#disco_clubs = Club.where(type: "disco").to_a # returns an array
And then you can iterate over them in the same manner you do in your index.html.erb. Rails has a rich interface for querying the database. Check it out here.
Also note that individual records - such as those selected with the find method - are more commonly used with the show action, which is for displaying a single record. Of course, that's for generic CRUD applications. It't not a hard rule.
change
def index
#clubs = Club.all
end
to this
def index
#clubs = Club.find(insert_a_number_that_is_the_id_of_the_club_you_want)
end
Querying your database is a complex thing and gives you a ton of options so that you can get EXACTLY what you want and put it into your #clubs variable. I suggest reading this part of the rails guide
It should also be noted that if you're only going to query your database for one record then change #clubs to #club so you know what to expect.
I'm wondering if it's possible to edit the default Rails routing convention to fetch a specific record based on a field that is not the ID?
For instance, instead of retrieving a specific record based on ID, with the verb/url combination:
GET /users/:id
Retrieve a specific record based on username, with the verb/url combination:
GET /users/:username
I don't see why this would be a problem theoretically, as long as usernames were required to be unique, but I'm having trouble understanding how to implement it based on the Rails Routing Guide.
I have gathered that I will need to add a line to my routes.rb file, to define a singular resource, just prior to:
resources :users
However, I'm having trouble understanding the syntax to accomplish this. Any help in understanding this would be greatly appreciated.
Yes it is possible and they are called Non Restful Routes in the rails documentation
A trivial example is doing the below in your routes.rb
get ':users/:show/:username', controller: "users", action: "show"
and in your UsersController you have a show action that looks like this:
def show
if params[:id].present?
#user = User.find(params[:id])
elsif params[:username].present?
#user = User.find_by(username: params[:username])
end
end
This way you support showing by id and username, if you want do disable support for either of them, modify the if clause as you wish
I think you are looking to change the to_param method like so:
class User < ActiveRecord::Base
def to_param
"#{id} #{name}".parameterize
end
end
This would give the url as: /user/id-name. If you want to get rid of the id before the name it gets a little more complicated. If you were just to remove it, it will more than likely break since ActiveRecord needs the id first for finds.
To get around this I would suggest using FriendlyId gem: https://github.com/norman/friendly_id
There is also a RailsCast showing how to use Friendly_id but its pretty straight forward.
The routes does not care if it is an ID or username.
It is really how you find it in the controller.
Just in the user show controller:
def show
#user = User.find_by_username params[:id]
end
I have models that looks like
search.rb:
id eg: 101
name eg: San Francisco
cars.rb
id
name
The search controller redirects user to cars.
search_controller.rb
if search.search_type=='cars'
redirect_to :controller=>'cars', :action=>'index', :id=>search
end
A query to find list of cars from San Francisco looks like:
http://localhost/cars?id=101
I overrode to_param method in search.rb like:
search.rb
def to_param
normalized_name = name.gsub(' ', '-').gsub(/[^a-zA-Z0-9\_\-\.]/, '')
"#{self.id}-#{normalized_name}"
end
This works to some extent:
It generates URLs that look like:
http://localhost/cars?id=101-San-Francisco
However, I would like is to generate a URL that looks like
http://localhost/cars/San-Francisco
How would I go about doing that?
Do I fix the routes?
Thanks for your help.
This can be tricky if you're not prepared for it. The method that controls how a model shows up in the params is pretty straightforward, as you've identified, but that's only the half of it. Later you'll have to retrieve it, so you need to set up for that:
class Search < ActiveRecord::Base
before_save :assign_slug
def self.from_param(id)
self.find_by_slug(id)
end
def to_param
self.slug
end
protected
def assign_slug
self.slug = self.name.gsub(' ', '-').gsub(/[^\w\-\.]/, '')
end
end
This requires adding a slug column to your Search model in order to make it possible to look up a search by it. It may be a good idea to add an index, possibly a unique one, to help retrieve these later in an efficient manner.
In your controller you don't use find but from_param instead to do the retrieval.
You'll also need to add a custom route that takes this parameter:
match '/cars/:search', :to => 'cars#index', :as => 'cars_search'
As a note you should use the route path generator methods whenever possible because multiple routes may match the same parameters. For instance:
redirect_to cars_search_path(:search => search)
How do I get the to_param method to deliver keyword slugs all the time? I have trouble getting it to work with this route:
map.pike '/auction/:auction_id/item/:id', :controller => 'items', :action => 'show'
Earlier the overridden to_param was working for
'items/1-cashmere-scarf'
but fails with 'auction/123/item/1'
Update:
I'm not sure if the syntax is correct[(edit: it's correct: it works :-)], or even efficient.... but using haml, I found that the following code works to generate the desired link ('auction/:auction_id/item/:id')
- for auction in #auctions.sort{|a, b| a.scheduled_start <=> b.scheduled_start}
-for item in #items
- unless auction.current_auction
... pike_path(auction.auction_id, item)
I'm not sure whether I understand your question. (it's 3:41 AM here)
From what I see, you directly access auction_id method, instead of using pike_path(auction, item) that'd use #to_param.
Also, it might fail for auction/123/item/1 because you haven't changed your controller.
I think it'd be helpful to describe how to get working slugs.
Broadly speaking, if you override #to_param, IDs no longer works. It means, that if you go with slugs, every time polymorpic URL is generated (eg, link_to object, object), it passes to_param's value. It is worth noting that you must change your controller as well.
Personally I think that the best way to generate slugs easily is to use techno-weenie's permalink_fu, adding has_permalink to your model, and then, override to_param. For example
class Auction < ActiveRecord::Base
has_permalink :title, :slug
end
assuming that you have slug, a string field, and want to slugize your title.
You also need to adjust your controller:
class AuctionsController < ApplicationController
def show
#auction = Auction.find_by_slug(params[:id]) || raise(ActiveRecord::RecordNotFound)
respond_to do |format|
format.html # show.html.erb
end
end
Then, you can generate routes, in the views, this way:
link_to #action, #action
By the way, you should NOT sort your actions in the view. The best way is to use named_scope.