Making advanced search forms for your backend kinda sucks, right? I ran into this problem with a project and decided to come up with something similar to how Google handles search queries. No dropdowns, no checkboxes, no radios, none of that stuff. I just wanted to be able to type status:active user:rob [term] and get what I asked for. I came up with a pretty nice utility class that can handle some basic query syntaxes and give you back hashes or arrays and the left over query.
With this class I can make links that perform my basic “advanced” queries, without littering the query string. For example, if I wanted to ‘get a list of all guest users with the name “jake” in NJ, NY, or FL’ I could search for the following: guest:true state:nj,ny,fl jake. I would then take that in the controller’s params and parse it out using terms = SearchTerms.new(params[:q]) which would give me the elements broken down:
>> terms = SearchTerms.new("guest:true state:nj,ny,fl jake")
=> #<SearchTerms:0x007fc239072008 @query="jake", @parts={"guest"=>true, "state"=>["nj", "ny", "fl"]}, @split=true>
>> terms.guest
=> true
>> terms.state
=> ["nj", "ny", "fl"]
>> terms.query
=> "jake"Then we can use those tokens with ActiveRecord’s scopes.
@user = @user.registered(false) if terms.guest
The Code
# Search term parser from https://gist.github.com/1477730
# Modified to allow periods (and other non-letter chars) in unquoted field values
# and field names.
#
# Helper class to help parse out more advanced saerch terms
# from a form query
#
# Note: all hash keys are downcased, so ID:10 == {'id' => 10}
# you can also access all keys with methods e.g.: terms.id = terms['id'] = 10
# this doesn't work with query as thats reserved for the left-over pieces
#
# Usage:
# terms = SearchTerms.new('id:10 search terms here')
# => @query="search terms here", @parts={"id"=>"10"}
# => terms.query = 'search terms here'
# => terms['id'] = 10
#
# terms = SearchTerms.new('name:"support for spaces" state:pa')
# => @query="", @parts={"name"=>"support for spaces", "state"=>"pa"}
# => terms.query = ''
# => terms['name'] = 'support for spaces'
# => terms.name = 'support for spaces'
#
# terms = SearchTerms.new('state:pa,nj,ca')
# => @query="", @parts={"state"=>["pa","nj","ca"]}
#
# terms = SearchTerms.new('state:pa,nj,ca', false)
# => @query="", @parts={"state"=>"pa,nj,c"}
#
# Useful to drive custom logic in controllers
class SearchTerms
attr_reader :query, :parts
# regex scanner for the parser
SCANNER = %r{
(?:
([\w\.]+) # look for any word
)
(?: # check if it has a value attached
: # find the value delimiter
(
[\w,\-]+ # match any word-like values
| # -or-
(?:"(?:.+|[^\"])*") # match any quoted values
)
)?
}x
# query:: this is what you want tokenized
# split:: if you'd like to split values on "," then pass true
def initialize(query, split = true)
@query = query
@parts = {}
@split = split
parse_query!
end
def [](key)
@parts[key]
end
private
def parse_query!
tmp = []
@query.scan(SCANNER).map do |key,value|
if value.nil?
tmp << key
else
key.downcase!
@parts[key] = clean_value(value)
define_metaclass_method(key){ @parts[key] } unless key == 'query'
end
end
@query = tmp.join(' ')
end
def clean_value(value)
return value.tr('"', '') if value.include?('"')
return value.split(',') if @split && value.include?(',')
return true if value == 'true'
return false if value == 'false'
return value.to_i if value =~ /^[1-9][0-9]*$/
value
end
def define_metaclass_method(method, &block)
(class << self; self; end).send :define_method, method, &block
end
end
if $0 == __FILE__
require 'test/unit'
class SearchTermsTest < Test::Unit::TestCase
TEST_CASES = {
"simple" => ["foo","foo",{}],
"simple_field" => ["one:two","",{"one" => "two"}],
"quotes" => [%{foo:"quoted value"}, "", {"foo" => "quoted value"}],
"term_with_period" => ["1.5","1.5",{}],
"multiple_fields" => ["one:two three:four","",{"one" => "two", "three" => "four"}],
"int_parse" => ["id:123","",{"id" => 123}],
"int_parse_leading_letter" => ["id:a01","","id" => "a01"],
"int_parse_leading_zero" => ["id:001","","id" => "001"],
"mixed_fields_terms" => ["one two:three four five:six","one four",{"two" => "three", "five" => "six"}]
}
TEST_CASES.each do |name, (input, query, parts)|
define_method("test_#{name}") do
terms = SearchTerms.new(input)
assert_equal query, terms.query
assert_equal parts, terms.parts
end
end
end
end
Usage
# basic usage to search users from your #index action
class UsersController < ApplicationController
def index
if params[:q]
terms = SearchTerms.new(params[:q])
if terms['id']
return redirect_to user_path(terms['id'])
else
@users = @users.search_by_name(terms.query) unless terms.query.blank?
@users = @users.with_role(terms['role']) if terms['role']
@users = @users.registered(false) if terms['guest']
end
end
end
end