From: rrajeshh@...
Date: 2007-11-21T01:45:05+09:00
Subject: Re: Arrays not working as I expected - help

On Nov 20, 11:11 am, Cameron McBride <cameron.mcbr...@gmail.com>
wrote:
> Hello,
>
> On Nov 20, 2007 11:00 AM,  <rraje...@gmail.com> wrote:
>
>
>
>
>
> > Hi
> > I am new programmer to Ruby. Just 1 days old. I do have some
> > background in java.
>
> > I am having a problem that is troubling me since yesterday and having
> > spend several hours on it, I still dont have any idea.
>
> > CODE WORKING GREAT BELOW
>
> > require 'rubygems'
> > require 'hpricot'
> > require 'open-uri'
>
> >         page = Hpricot(open("http://finance.google.com/finance/historical?
> > q=ORCL&histperiod=weekly&start=01&num=2"))
>
> >          page.search("#prices").each do |timesection|
>
> >         values=timesection.search("td")
> >                 datePointValue = {
> >                         "date"  => values[0].inner_html,
> >                         "open"  => values[1].inner_html,
> >                         "high"  => values[2].inner_html,
> >                         "low"   => values[3].inner_html,
> >                         "close" => values[4].inner_html,
> >                         "volume" => values[5].inner_html
> >                 }
>
> >                 datePointValue.each do |key, value|
> >                         puts key + " - " + value
> >                 end
> >     end
>
> > But when I add a loop and change the code as follows. It gives me
> > error message
> > UPDATED CODE - NOT WORKING -
>
> >         page = Hpricot(open("http://finance.google.com/finance/historical?
> > q=ORCL&histperiod=weekly&start=01&num=1"))
>
> >          page.search("#prices").each do |timesection|
>
> >         timesection.search("tr").each do |datePointSets|
> >                         values = datePointSets.search("td")
>
> >                         datePointValue = {
> >                                 "date"  => values[0].inner_html,
> >                                 "open"  => values[1].inner_html,
> >                                 "high"  => values[2].inner_html,
> >                                 "low"   => values[3].inner_html,
> >                                 "close" => values[4].inner_html,
> >                                 "volume" => values[5].inner_html
> >                         }
>
> >                         datePointValue.each do |key, value|
> >                                 puts key + " - " + value
> >                         end
> >                 end
> >     end
>
> > ERROR MESSAGE
> > htest.rb:14: undefined method `inner_html' for nil:NilClass
> > (NoMethodError)
> >         from htest.rb:10:in `each'
> >         from htest.rb:10
> >         from htest.rb:8:in `each'
> >         from htest.rb:8
>
> > Kindly suggest.
>
> At a knee-jerk guess, you've changed how 'values' is populated.  I'd
> wager that the values result from the Hpricot search isn't properly
> set.  You should print values before you set the datePointValue hash
> and see what it contains.
>
> In addition, you might consider another sanity check if you explicitly
> access 6 elements of an array.  Like
>
> raise "Parsing Error: values not set correctly" if (values.nil? or
> values.size < 6)
>
> Cheers.
>
> Cameron- Hide quoted text -
>
> - Show quoted text -

Thats is exactly what i thought so I printed the values as shown
below. this worked fine....

	page = Hpricot(open("http://finance.google.com/finance/historical?
q=ORCL&histperiod=weekly&start=01&num=1"))

	 page.search("#prices").each do |timesection|

    	timesection.search("tr").each do |datePointSets|
			values = datePointSets.search("td")

			values.length.times  do |i|
				puts values[i].inner_html    # WORKS GREAT!!  Prints 5 values
			end
		end
    end

Interestingly the loop prints the values correctly but when access
these as shown below I get the same error.
	page = Hpricot(open("http://finance.google.com/finance/historical?
q=ORCL&histperiod=weekly&start=01&num=1"))

	 page.search("#prices").each do |timesection|

    	timesection.search("tr").each do |datePointSets|
			values = datePointSets.search("td")

			puts values[0].inner_html   # ERRORS HERE
			puts values[1].inner_html   # ERRORS HERE

		end
    end