I decided to give Nokogiri a try, and copied the following program straight from http://nokogiri.rubyforge.org/nokogiri/Nokogiri.html (adding only the require 'rubygems' and the I_KNOW_I_AM_USING_AN_OLD_AND_BUGGY_VERSION_OF_LIBXML2 constant):
require 'rubygems'
I_KNOW_I_AM_USING_AN_OLD_AND_BUGGY_VERSION_OF_LIBXML2 = 1
require 'nokogiri'
require 'open-uri'
# Get a Nokogiri::HTML:Document for the page we’re interested in...
doc = Nokogiri::HTML(open('http://www.google.com/search?q=tenderlove'))
# Do funky things with it using Nokogiri::XML::Node methods...
####
# Search for nodes by css
doc.css('h3.r a.l').each do |link|
puts link.content
end
It returned no results. But when I changed
doc = Nokogiri::HTML(open('http://www.google.com/search?q=tenderlove'))
to
doc = Nokogiri::HTML(open('http://www.google.com/search?q=tenderlove').read)
the program worked as expected. Notice that the only difference was the addition of the .read at the end of the line. I would never have figured this out by myself, because just about every bit of example code leaves off the .read. The one place that included it, ironically was a post by one of the Nokogiri developers (at http://tenderlovemaking.com/2008/11/18/underpant-free-excitement). Did something in the API change? What am I missing?
I'm using Nokogiri 1.3.2.
Thank you.
I copied and pasted your (original) code into a Ruby file and ran it on my system (ruby 1.8.6p369, Nokogiri 1.3.2) and it worked fine. Might there be something else in your environment that could be causing the problem? Nokogiri aside, what does open('http://www.google.com/search?q=tenderlove') return for you?
Not sure what your issue is, but the call to open is from open-uri not nokogiri. So do some experimenting taking nokogiri out of play.
$ irb
>> require 'open-uri'
=> true
>> f = open('http://www.google.com/search?q=tenderlove')
=> #<File:/var/folders/LA/LACsuKOVHtaEgmBzsJcGAE+++TI/-Tmp-/open-uri.7455.0>
>> f.read
=> "<!doctype html><head><title>tenderlove - Google Search</title>...
I upgraded to Nokogiri 1.3.3, and upgraded libxml2 to 2.7.3. I no longer need to use the ridiculous I_KNOW_I_AM_USING_AN_OLD_AND_BUGGY_VERSION_OF_LIBXML2 = 1 statement to avoid error messages, and the program works without the extraneous .read.
It's always good to check your version of Nokogiri and libxml to make sure they're current.
As of today (9/22/09) this is current on MacOS:
nokogiri -v
---
nokogiri: 1.3.3
warnings: [ ]
libxml:
compiled: 2.7.4
loaded: 2.7.4
binding: extension
(I put a space inside the empty warnings array to keep it from looking like a box.)
Related
I am new to ruby and trying to use it's csv libary.
The first thing i tried was just to write a simple script:
require "csv"
average_money_spent = Array.new
CSV.foreach('customers.csv', converters: :numeric) do |row|
average_money_spent << row[2] / row[1]
end
This gave the error message: Unclosed quoted field on line 1.
So then i tried the exact same thing but require 'csv'.
I got this error message: Unclosed quoted field on line 1.
I thought it may be to do with not having CSV gems installed on my ruby so i tried :
$ gem install csv
This said it could not be installed:
csv requires Ruby version >= 2.5.0dev.
But i tried to install this and checked .. it isn't the latest most stable version of Ruby, the version I have is.
Is there anything I am doing wrong in the way I require csv? Thanks so much for any help. I am new to coding and Ruby.
Please check and make sure your csvfile is in the correct format.
I am trying to run a script from my Github Gist page but OpenURI or something else seems to cache it on they way and it never actually updates. I am using the code below on Ubuntu 16.04 and Ruby 2.3.1. I just want it to fetch the script from the url every time instead of using a cached version.
#!/usr/bin/ruby -w
require "open-uri"
url = "https://gist.githubusercontent.com/*/*/raw/*/*.rb"
code_from_url = open(url) {|f| f.read }
eval(code_from_url)
Nevermind, there was no cache. It was just an incorrect link to a revision specific gist. The correct way to get the latest version of the first file in a gist is https://gist.githubusercontent.com/{username}/{gist}/raw
So I am running Ruby 1.9.3 and I am trying to use the Prime class.
I have added require mathn at the top of my .rb file
Other than the method name, this code came from the documentation page:
http://www.ruby-doc.org/stdlib-1.9.3/libdoc/prime/rdoc/Prime.html
def prime_number(n)
Prime.each(n) do |prime|
p prime
end
end
prime_number(100)
Any ideas why this doesn't work? The error I get says
undefined method each for Prime:Class
I tried it in Ruby 1.9.3 and it worked. Tried it again in Ruby 1.8.7 and got your error message. A newer version of Ruby will probably solve your problem.
Your problem is that you did require mathn and you must have require 'mathn' at the top of your file.
Either that, or you have neglected the quotes when you described your code above.
I'm quite new to Ruby language (up to now I developed in Groovy + Grails) but since I was curious about it I wanted to try Sinatra on Ruby 1.9.2-p0.
I have a trivial website that is contained in /mywebpage and has 2 files:
# blog.rb
get '/' do
'Hello World!'
end
get '/impossible' do
haml :index
end
and
#config.ru
path = File.expand_path "../", __FILE__
$LOAD_PATH << (File.expand_path ".") + "/views"
require 'haml'
require 'sinatra'
require "#{path}/blog"
run Sinatra::Application
then in the same folder I have a /views/ folder that contains index.haml.
I try to run the server with rackup -p8080 but when I try to get /impossible I receive the following error:
Errno::ENOENT at /impossible
No such file or directory - /home/jack/mywebpage/<internal:lib/rubygems/views/index.haml
By searching over internet it seems that this maybe caused by "." not being included in $LOAD_PATH so I tried to add it or add directly views ./views so that actually $LOAD_PATH.inspect gives me correct path: ..., "/home/jack/mywebpage/views"]
But still it doesn't seem to work. Being quite new to the framework and the language I was wondering if I'm doing something wrong. any clues?
Running Sinatra with Ruby 1.9.2 the template directory is no longer implicitly 'views', you need to set it yourself.
set :views, File.dirname(__FILE__) + "/views"
Note that currently Ruby also has Kernel#__dir__() method that is equivalent to File.dirname(__FILE__).
This, and other issues with 1.9, will be have been solved in Sinatra 1.1. You could use this fork: http://github.com/rkh/sinatra/tree/1.1
I ran into a similar problem, and solved it like this. I didn't dig into the problem, but this is what I found and it works. It'll supposedly be fixed in the next version of Sinatra (which they should really get out the door, just to fix these few 1.9.2 bugs).
#!/usr/bin/env ruby
require 'rubygems'
require 'sinatra'
enable :run
get '/' do
"Hello, world!"
end
Edit: It seems there are multiple bugs with Sinatra on 1.9.2. This one will fix Sinatra apps not starting on 1.9.2. I don't use a views directory (I like to keep my apps single-file), so I didn't run into your particular problem. This fix most likely won't help you at all. I probably should have read your problem more closely..
gem install sinatra --pre
I ran into that last week and didn't find a suitable fix on the Sinatra site short of tweaking the sinatra code. I'm using rvm for my development and switched to try sinatra on Ruby 1.8.7 and it works fine again, so that's where I left it.
Oh, since you're new to Ruby, you might not know about rvm, so here's the lowdown. RVM is Mac only and highly recommended for managing your Ruby version and gems. It makes it trivial to have multiple Ruby versions and alternate groups of gems for development and testing. Everything is stored in your ~/.rvm directory so it's easy to blow it all away if you need to.
http://rvm.beginrescueend.com/
I just looked at the Sinatra site again about the problem to see if there was anything new, but it appears they consider the following to be an acceptable fix:
http://github.com/sinatra/sinatra/issues/#issue/50
I'm a bit adverse to having to edit the source of Sinatra as recommended by issue #50, but it's not real hard to do. I'd like to see them put out an update so we'd have an official fix but I haven't seen anything yet:
gem env will tell you the "GEM PATHS". Sinatra's gem will be in one of those. The line mentioned in issue #50 goes into base.rb. On my machine it's something like ...gems/ruby-1.9.2-p0/gems/sinatra-1.0/lib/sinatra/base.rb.
Insert:
/<internal:/, # ruby 1.9.2-p0 hacks
at line 1020.
Save the file and you should be good to go.
I was trying to create a quick little script that would insert data into an SQLite db for me but I can't get past the first few steps.
I have done "sudo gem install sqlite3-ruby", my Ruby version is 1.8.7 (I used the Ruby one click installer from rubyforge.org).
My script is incredibly simple. It looks like this:
#!/usr/bin/ruby -w
require "csv.rb"
require "sqlite3"
begin
CSV.open('updateddata.sql', 'r') do |row|
p row
end
rescue => err
puts "Exception : #{err}"
err
end
It never makes it past the line require "sqlite3". It just errors and tells me that it can't find that file to load.
I don't understand how it won't work even after using the One click installer (which is supposed to have SQLite built into the install).
I'm not even sure where to go from here.
I am not a Ruby developer at all, I just wanted to use it as a learning experience and to quickly complete this task for myself.
Dunno if Ruby in OS X behaves differently, but normally you need to do require 'rubygems' before requiring any gems.
You can also add
export RUBYOPT=rubygems
to your profile.
http://groups.google.com/group/rubyonrails-talk/browse_thread/thread/43fc65132487f98e/?pli=1 using sqlite3-ruby gem solved my issue on this