Simplified Search Query in Rails

Context: My last couple of posts were about setting up a simple search in my Rails app, and I have since revisited that code and revised it to be more clean and efficient. For the search I use a plain old Ruby object (PORO) to create a deck search object, and then use those attributes to finds decks that have matching fields. These fields are :admin_approved, :level, and :user_id. Initially I filtered through one at a time rather than crafting a succinct search. Here is what the original deck search class looked like:

class DeckSearch
    attr_accessor :admin_approved, :level, :user_id

    DEFAULT_ATTRS = {
        admin_approved: "",
        level: "", 
        user_id: ""
    }

    def initialize(attributes=DEFAULT_ATTRS)
        attributes.each{ |key, value| self.send("#{key}=", value) }
    end

    def decks 
        #=>  1) filter_admin, 2) filter_level, 3) filter_user
        decks_array = filter_user(filter_level(filter_admin))
    end

    def filter_admin
        self.admin_approved == "" ? Deck.all : Deck.where("admin_approved = #{self.admin_approved}")
    end

    def filter_level(decks_array)
        self.level == "" ? decks_array : decks_array.where("level = #{self.level}")
    end

    def filter_user(decks_array)
        self.user_id == "" ? decks_array : decks_array.where("user_id = #{self.user_id}")
    end

end

As you can see in the decks instance method, each filter method runs independently of the others. At the time when I put this together, I figured there was probably a more succinct, efficient way, but I didn’t really have time to dig around and find it. After thinking about it and taking a closer look at ActiveRecord’s querying options, I found a way to conduct this search much more cleanly.

The query method: Basically, all I did was convert the ruby object to a hash using as_json, then filter out all empty values within the hash, and finally pass that hash into ActiveRecord’s .where method to get my criteria to seach through the decks. And here is what I ended up with:

class DeckSearch
    attr_accessor :admin_approved, :level, :user_id

    DEFAULT_ATTRS = {
        admin_approved: "",
        level: "", 
        user_id: ""
    }

    def initialize(attributes=DEFAULT_ATTRS)
        attributes.each{ |key, value| self.send("#{key}=", value) }
    end

    def decks 
        Deck.where(self.as_hash)
    end

    def as_hash
        self.as_json.delete_if{|key, value| value == ""}
    end

end

And there you go. Less code and just one query rather than a different filter method for each attribute. Also, it’s abstracted out so that this search object could have ten times as many attributes, but decks and as_hash would still remain the same. Pretty cool!

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