Advanced search query parsing with Ruby

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

Heres the gist

# 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 # 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(/(?:(\w+))(?::([\w,\-]+|(?:"(?:.+|[^\"])*")))?/).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 =~ /^[^0]\d+$/ value end def define_metaclass_method(method, &block) (class << self; self; end).send :define_method, method, &block end end

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Advanced search query parsing with Ruby

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