Rails 3.0 Parsing XML and Inserting into Database

I'm new to Rails, and am trying to hook up my application to a third-party API (it does't have a gem or plugin for Rails).

Ideally, what I want to be able to do is parse the data (I've heard good things about Nokogiri, but don't know how to use it for what I want to do do. not for lack of trying), and then insert it into the database.

Could anybody provide instructions or point me in the right direction? Cheers.

UPDATE:

Rake Task:

task :fetch_flyers => :environment do

require 'nokogiri'
require 'open-uri'

doc = Nokogiri::XML(open(url))

  events = doc.search('//event')

    events.each do |event|
      @data = Event.new(
        :name           => event.at('name').text,
        :date           => '2011-09-18',
        :time           => '17:00',
        :description    => event.at('long_description').text,
        :address        => event.at('street').text,
        :postcode       => event.at('postcode').text,   
        :price          => event.at('costs').text,
        :user_id        => 1,
        :genre_id       => 1,   
        :town_id        => 1)

    @data.save

    if @data.save
        puts "Success"
    else
        puts "This didn't save, F***"
    end
    end
end

I've specified the URL in my code, just hidden it from this code paste. This code does not work. I can not for the life of me figure out why. All I get is the output in terminal saying "This didn't save, F** which means that for some reason the Events are not being saved. Could anyone shed some light on this?

UPDATE 2:

I've checked the URL is correct, and have checked the XML is being parsed correctly by using:

# Printing Out the Variables to make sure they work.
    puts @name
    puts @date
    puts @time
    puts @desc
    puts @address
    puts @postcode
    puts @price
    puts @user
    puts @genre
    puts @town

..Which successfully prints out the values in terminal. However, it still won't insert into my database.

My Model is as follows:

belongs_to :user
    belongs_to :genre
    belongs_to :town

    has_attached_file :image, :styles => { :grid => '90x128#', :list => '140x200#', :full => '400x548'}
    validates_attachment_content_type :image, :content_type => ['image/jpeg', 'image/png']  
    before_post_process :normalise_file_name

  validates :name, :presence => true
  validates :date, :presence => true
  validates :time, :presence => true
  validates :description, :presence => true
  validates :address, :presence => true
  validates :town, :presence => true
  validates :postcode, :presence => true
  validates :price, :presence => true
  validates :user_id, :presence => true
  validates :viewcount, :presence => true

My Development.log file just shows a load of:

  [1m[35mTown Load (0.1ms)[0m  SELECT "towns".* FROM "towns" WHERE "towns"."id" = 1 LIMIT 1
      [1m[36mTown Load (0.1ms)[0m  [1mSELECT "towns".* FROM "towns" WHERE "towns"."id" = 1 LIMIT 1[0m
      [1m[35mTown Load (0.1ms)[0m  SELECT "towns".* FROM "towns" WHERE "towns"."id" = 1 LIMIT 1
      [1m[36mTown Load (0.1ms)[0m  [1mSELECT "towns".* FROM "towns" WHERE "towns"."id" = 1 LIMIT 1[0m
      [1m[35mTown Load (0.1ms)[0m  SELECT "towns".* FROM "towns" WHERE "towns"."id" = 1 LIMIT 1
      [1m[36mTown Load (0.1ms)[0m  [1mSELECT "towns".* FROM "towns" WHERE "towns"."id" = 1 LIMIT 1[0m
      [1m[35mTown Load (0.1ms)[0m  SELECT "towns".* FROM "towns" WHERE "towns"."id" = 1 LIMIT 1
    .......

Every time I try to run the rake task. Does this mean anything?

回答1:

When using nokogiri you can specify css or xpath selectors, like:

doc = Nokogiri::XML(xml_string)
events = doc.search('//event')
events.each do |event|
  puts event.at('short_description')
end

Also, check out nokogiri intro tutorials.

回答2:

I'd put a puts after getting the URL and another after defining events to see if there's any data being returned in the first instance. Then I'd check the Event model to see if there are any validations which aren't being met - does the model require a unique user_id or something. I'd also make data a non-instance variable to see if that made a difference. And I'd check that those time formats aren't causing an error in the model.

回答3:

I just see your log and find out that your Event model do have has_many realtion with Town Model and also consists town_id column in your event table . SO i think that might be the problem as its trying to get the town_id and save the foreign key of town in your event table . But as it doesn't get any so it's always rollback . Also if you want then try to **