Path: csiph.com!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail
From: Robert Klemme <shortcutter@googlemail.com>
Newsgroups: comp.lang.ruby
Subject: Re: extract into a method - struggling to abstract
Date: Sun, 3 Jul 2016 18:52:29 +0200
Lines: 116
Message-ID: <dtsu6eFnso6U1@mid.individual.net>
References: <df5ec7e9-0d75-4810-9f8c-5396113e8cc4@googlegroups.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
X-Trace: individual.net T5SC+Wen3MBw5X1QkyY6Vgua/0eu5P/zEnLd0fWqaxSrOIQHA=
Cancel-Lock: sha1:+XV9OoIjJ1kz36EcVi3xLqnqNIk=
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0
In-Reply-To: <df5ec7e9-0d75-4810-9f8c-5396113e8cc4@googlegroups.com>
Xref: csiph.com comp.lang.ruby:7272

On 03.07.2016 16:01, Sayth Renshaw wrote:
> Hi
>
> I have working code that I have currently loops through an example returning matches via nokogiri module.
>
> This works
>
> require 'nokogiri'
> require 'awesome_print'
>
> @doc = Nokogiri::XML(File.open('/home/sayth/data/20160702RHIL0.xml'))

You are not closing the file here.  Better:

@doc = File.open('/home/sayth/data/20160702RHIL0.xml', 'rb') do |io|
   Nokogiri::XML(io)
end

> @doc.search('race').map do |race|
>    nominations = race.search('nomination')
>                      .map do |nomination|
>      {
>        number: nomination['number'].to_i,
>        id: nomination['id'].to_i,
>        horse: nomination['horse'].to_s,
>        age: nomination['age'].to_i,
>        sex: nomination['sex'].to_s,
>        colour: /\W(.+?)\d?\s/.match(nomination['description'].to_s)[1]
>      }
>    end
>
>    a = { race['id'].to_i => nominations }
>    ap a
> end
>
> _______________________________________________________________________________
>
> So at this point I know that I need to replicate this for 6 sections in total, logically to me then I want to abstract especially the middle.
>
>      {
>        number: nomination['number'].to_i,
>        id: nomination['id'].to_i,
>        horse: nomination['horse'].to_s,
>        age: nomination['age'].to_i,
>        sex: nomination['sex'].to_s,
>        colour: /\W(.+?)\d?\s/.match(nomination['description'].to_s)[1]
>      }
>
> and substitute a variable into race.search('nomination') this to replace the word nomination and to then replace all 'nomination' in the above section.

I would replace the variable name "nomination" by something more 
abstract, e.g. "node".irb

> So this is what I have done.
>
> data = %w(number id horse age sex colour)
>
> def extract_value(path_id, data)
>    @doc.search('race').map do |race|
>      puts path_id
>      nominations = race.search(path_id)
>                        .map do | |
>        data
>      end
>      values = { race['id'].to_i => nominations }
>      ap values
>      return values
>    end
> end
>
> extract_value('nomination', data)

I think you are almost there:

data = %w(number id horse age sex colour)

def extract_value(path_id, data)
   @doc.search('race').map do |race|
     puts path_id

     extracted_data =
       race.search(path_id).map do |node|
         {}.tap do |hash|
           data.each {|d| hash[d.to_sym] = Integer(node[d])}
         end
       end

     values = { race['id'].to_i => extracted_data }
     ap values

     # next line will prematurely return from the method,
     # do you want that?
     return values
   end
end

extract_value('nomination', data)

> _______________________________________________________________________________
>
> The main part I cannot wrap my head around is how to get these sections in without replicating it in the definition.
>
> number: nomination['number'].to_i,
>
> How can I better abstract this out?

See above.  Is this what you intended?

Kind regards

	robert


-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/