A search bar is an especial feature as a web application grows. There are several ways to implement this feature in a Rails application. This article will explore one of these, by searching a Postgres database with the pg_search
gem.
Install pg_search
In a smaller application you can query the database using ActiveRecord, a simple way to prototype search and filtering. It allows you to quickly find related records for databases of fewer than 1000 records, but, as your database grows, ActiveRecord queries can get overly complex and make your app lag.
Install the gem as usual. Add gem pg_search
to your Gemfile
and bundle install
.
There are two basic search configurations with pg_search
, a Single Model search scope or a multi Model configuration. In my case I am only using the Single Model configuration, but you can read more about multi-search in the documentation.
I am using my Rails Your Congress as an example, and I am setting up a search bar on the Senator's search page.
Model
To start using pg_search
, you need to include PgSearch
in your model and set up the pg_search_scope
:
class Senator < ApplicationRecord
include PgSearch
scope :sorted, ->{ order(last_name: :asc) }
pg_search_scope :global_search,
against: [:first_name, :last_name, :state],
using: { tsearch: { prefix: true } }
end
In this example, I am searching from the Senator resource, by first_name
, last_name
, and state
.
Controller
Since, I am providing a search on the index page, the index method in the Senators controller:
class SenatorsController < ApplicationController
def index
if params[:query].present?
@senator_search = Senator.global_search(params[:query])
@senators = @senator_search.paginate(page: params[:page], per_page: 20)
else
@senators = Senator.paginate(page: params[:page], per_page: 20)
end
respond_to do |format|
format.html
format.json { render json: { senators: @senators } }
end
end
In this method, we set a conditional to determine if we are searching or not. If we are searching we are setting two instance variables. The variable @senators
is used in the views, and I had to set up two variables to get will_paginate
to play nicely with the pg_search
results.
Improvements
With each search the entire page re-renders. So next week we will look at how I set up StimulusJS to make the Senator container reactive.
Footnote
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Top comments (4)
Excellent! I look forward to the Stimulus post.
Shouldnt the paginate method be defined somewhere?
Thanks for reading. Pagination is handled by the gem
will_paginate
which you can read more about here: github.com/mislav/will_paginateIn regards to testing the api, shouldnt the paginate method be defined somewhere?