From: Robert Klemme <shortcutter@...>
Date: 2011-04-28T23:03:04+09:00
Subject: Re: writing csv into file

On Thu, Apr 28, 2011 at 3:04 PM, Alfred Pier
<marineforlifecobra@yahoo.gr> wrote:
> Hello guys ! I'm new in Ruby....Hope you can help because i'm trying a
> lot and just can't see where is the problem..
> I have this xml, and not only this, i want just for any xml file that i
> might put :
>
> <?xml version="1.0"?>
> <records>
>   <company>
>     <id>p1</id>
>     <name>Skoda</name>
>     <price>10000</price>
>     <stock>4</stock>
>     <country>Czech Republic</country>
>  </company>
>  <company>
>     <id>p2</id>
>     <name>Mercedes</name>
>     <price>50000</price>
>     <stock>5</stock>
>     <country>Germany</country>
>  </company>
>  <company>
>     <id>p3</id>
>     <name>Alfa Romeo</name>
>     <price>18000</price>
>     <stock>19</stock>
>     <country>Italy</country>
>  </company>
>  <company>
>     <id>p4</id>
>     <name>Fiat</name>
>     <price>1500</price>
>     <stock>15000</stock>
>     <country>Italy</country>
>  </company>
> </records>
>
>
> AND USING THE CODE BELOW:
>
> require 'nokogiri'
> require 'pp'
>
> xmldoc = Nokogiri::XML(IO.read("xmlinputfile.xml"))
> columns = xmldoc.xpath('/*/*[position()=1]/*').map(&:name)

IMHO this is sufficient as XPath: '/*/*[1]/*'

> print "give csv output file\n"
> csvoutputfile = gets.chomp
> File.open(csvoutputfile, 'w') do |f|
>   rows =[]
>   xmldoc.xpath('/*/*').each do |row_xml|
>          row_values = []
>          f.puts "  #{rows << row_values}"

You should separate filling your data structure from doing CSV output
above.  Right now you are printing rows for every record!

>          row_xml.xpath('./*').each do |field|
>                f.puts "#{row_values << field.text}"

Again, you should separate filling your data structure from doing CSV
output above (or completely get rid of "rows") e.g.

puts row_xml.xpath('./*').map(&:text).join

>          end
>   end
>   pp rows

You are seeing output of that last line.

>
>  end

I would also consider using CSV for writing because that will give you
proper quoting

CSV.open("foo.txt", "w", col_sep:",") do |csv|
...
  csv << row_xml.xpath('./*').map(&:text)
...
end

>  I WANT TO CONVERT IT TO CSV FORMAT LIKE THIS:
>
> id,name,price,stock,country
> p1,Skoda,10000,4,Czech Republic,
> p2,Mercedes,50000,5,Germany,
> .
> .
> .
> . and so on
>
>
>
> THE RUBY CODE OF CONVERTION WORKS FINE BUT ONLY WHEN I RUN IT IN THE
> COMMAND PROMT, ONLY THERE IS SHOWS THE CSV FORMAT RIGHT
>
> BUT I WANT TO WRITE IT IN A TXT FILE AND THIS IS WHAT I GET WHEN I TRY
> WRITING IT INTO A txt :

Do you use output redirection for your script?

>    [[]]
>
> ["p1"]
> ["p1", "Skoda"]
> ["p1", "Skoda", "10000"]
> ["p1", "Skoda", "10000", "4"]
> ["p1", "Skoda", "10000", "4", "Czech Republic"]
> [["p1", "Skoda", "10000", "4", "Czech Republic"], []]
> ["p2"]
> ["p2", "Mercedes"]
> ["p2", "Mercedes", "50000"]
> ["p2", "Mercedes", "50000", "5"]
> ["p2", "Mercedes", "50000", "5", "Germany"]
>
> [["p1", "Skoda", "10000", "4", "Czech Republic"], ["p2", "Mercedes",
> "50000", "5", "Germany"], []]
> ["p3"]
> ["p3", "Alfa Romeo"]
> ["p3", "Alfa Romeo", "18000"]
> ["p3", "Alfa Romeo", "18000", "19"]
> ["p3", "Alfa Romeo", "18000", "19", "Italy"]
> [["p1", "Skoda", "10000", "4", "Czech Republic"], ["p2", "Mercedes",
> "50000", "5", "Germany"],
> ["p3", "Alfa     Romeo", "18000", "19", "Italy"],[]]
>
>
>
> PLEASE CAN ANYBODY SHOW ME MY MISTAKE AND WHAT SHOULD I DO BECAUSE I
> CANNOT FIND IT... AND I
> DON'T UNDERSTAND THE REASON THAT IT SHOWS IT LIKE THIS IN THE txt FILE.
>
> THANK YOU IN ADVANCE !!

Please do NOT shout.

robert

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