DZone Snippets: rexml code

Using ruby to upload multiple files to Amazon S3

jrobertson (James Robertson) — Sat, 26 Apr 2008 14:17:58 GMT

This ruby code builds upon the code S3 upload client for Ruby [dzone.com] by reading the account details and file details from XML files.



#!/usr/bin/env ruby

#file : rubys3file2upload.rb



require 'rubygems'

require 'aws/s3'

require 'rexml/document'

include REXML



class S3FileUpload



  def initialize(xml_accounts_file, xml_upload_file)

    initialize_account(xml_accounts_file)

    main(xml_upload_file)

  end



  def initialize_account(accounts_file)



    file = File.new(accounts_file)

    doc = Document.new(file)



    account = doc.root.elements['records/access']

    h = Hash.new

    h[:access_key_id] = account.elements['key_id'].text.to_s

    h[:secret_access_key] = account.elements['secret'].text.to_s

    AWS::S3::Base.establish_connection!(h)



  end



  def main(xml_upload_file)

    file = File.new(xml_upload_file)

    doc = Document.new(file)

puts doc

    doc.root.elements.each('records/file') do |f|

      local_file = f.elements['local'].text.to_s

      bucket = f.elements['bucket'].text.to_s

      mime_type = f.elements['mime_type'].text.to_s

      upload(local_file, mime_type, bucket)

    end

  end



  def upload(local_file, mime_type, bucket)



    base_name = File.basename(local_file)



    puts "Uploading #{local_file} as '#{base_name}' to '#{bucket}'"



    AWS::S3::S3Object.store(

      base_name,

      File.open(local_file),

      bucket,

      :content_type => mime_type,

      :access => :public_read

    )



    puts "Uploaded!"

  end



end



if __FILE__ == $0

  s3fu = S3FileUpload.new('s3accounts.xml', 's3files2upload.xml')

end

file: s3accounts.xml



  

    REPLACE_MEREPLACE_MEREPLACE_ME

file: s3files2upload.xml



  

    

      autocomplete.html

      t2000

      text/html

    

    

      autocomplete2.html

      t2000

      text/html

    

    

      autocomplete3.html

      t2000

      text/html

Note: The file given the correct permission could be read from http://t2000.s3.amazonaws.com/autocomplete.html

Reference: http://amazon.rubyforge.org/

Converting text to SVG

jrobertson (James Robertson) — Fri, 18 Apr 2008 18:14:11 GMT

First of all the Ruby code reads the text, splits it into an array and then saves it in XML format.



require 'rexml/document'

include REXML



a = "Open source is a development method for software that harnesses the power of distributed peer 

review and transparency of process. The promise of open source is better quality, higher reliability, 

more flexibility, lower cost, and an end to predatory vendor lock-in.".split(' ') 



doc = Document.new

doc.add_element('text')

oline = Element.new('line')



char_count = 0

a.each do |word|

  

  oword = Element.new('word')

  oword.text = word.to_s

  oword.add_attribute('length',char_count)

  oline << oword 

  char_count += word.length

  

  if char_count > 50

    doc.root << oline

    oline = Element.new('line')

    char_count = 0

  end

end

doc.root << oline

puts char_count

puts doc

Here's a sample of the XML created





  

    Opensourceis

    adevelopmentmethod

    forsoftwarethat

    harnesses

  

  

    thepower

    ofdistributedpeer

    reviewandtransparency

    ofprocess.

  

  

    The

    promiseofopen

    sourceisbetter

    quality,higherreliability,

  

  

    moreflexibility,lower

    cost,andan

    endtopredatory

    vendor

  

  

    lock-in.

The XML is then transformed to SVG using the following XSL file











            method="xml"

            indent="yes"/>

            

  

                      xmlns:xlink="http://www.w3.org/1999/xlink" >

      

        

      

    

  

  

  

    12

    20

The final SVG output [twitxr.com] shows 5 lines of text with each word as a separate SVG text element.

Append an XML element using the append operator

jrobertson (James Robertson) — Thu, 17 Apr 2008 23:50:25 GMT

This Ruby code appends an XML node to an XML document using the append << operator.



      doc2 = Document.new(xml_svg)

      obody.text = ''

      obody << doc2.root

In this example the original obody.text contained escaped xml, which was then initialised as an XML document and appended to obody to be processed as pure XML.

Deleting a redundant shape message from the whiteboard queue

jrobertson (James Robertson) — Sat, 05 Apr 2008 19:39:02 GMT

This code is used to remove a message from the whiteboard queue containing a shape which has recently moved it's position (x and y coordinates) on the board. Code extract from whiteboardqueue.rb



  def call_delete_shape(params)

    #get the shape's message id.

    doc = Document.new(params)

    shape_id = doc.root.elements["param[@var='id']"].text.to_s

    initialize_doc



    doc_xml = Document.new(decode2(@doc_file.root.to_s))

    id = doc_xml.root.elements["records/message/body/*[@id='#{shape_id}']"].parent.parent.attributes.get_attribute('id')

    delete_record(id)

    save_file

  end

*update 10:04pm*
Added the link to the project code http://github.com/jrobertson/whiteboardqueue/tree

Save a Ruby source text file to XML.

jrobertson (James Robertson) — Fri, 22 Feb 2008 15:18:00 GMT

This code will output a text file as an XML file which can later be transformed into an HTML file using a back-end XSLT processor called Gorg.



#!/usr/bin/ruby 



#file: rubytxt2xml.rb



require 'rexml/document'

include REXML



class RubyTxt2XML

  

  def rubytxt2xml(h)

    h[:infilepath] = './' if h[:infilepath].nil?

    h[:outfilepath] = './' if h[:outfilepath].nil?

    h[:xmlfile] = h[:sourcefile][/^(.*)\.\w+$/,1] + '.xml' if h[:xmlfile].nil?

    buffer = File.new(h[:infilepath] + h[:sourcefile],'r').read

    

    doc = Document.new

    doc.add_element('ruby_txt')

    body = Element.new('source')

    body.text = CData.new(buffer)

    doc.root.add_element(body)

    

    file = File.new(h[:outfilepath] + h[:xmlfile],'w')

    file.puts doc

    file.close

    

  end

end



if __FILE__ == $0

  rt2x = RubyTxt2XML.new

  rt2x.rubytxt2xml(:sourcefile  => 'rubytxt2xml.rb')

end

output:





  

          #!/usr/bin/ruby 



      #file: rubytxt2xml.rb



      require 'rexml/document'

      include REXML



      class RubyTxt2XML

        

        def rubytxt2xml(h)

          h[:infilepath] = './' if h[:infilepath].nil?

          h[:outfilepath] = './' if h[:outfilepath].nil?

          h[:xmlfile] = h[:sourcefile][/^(.*)\.\w+$/,1] + '.xml' if h[:xmlfile].nil?

          buffer = File.new(h[:infilepath] + h[:sourcefile],'r').read

          

          doc = Document.new

          doc.add_element('ruby_txt')

          body = Element.new('source')

          body.text = CData.new(buffer)

          doc.root.add_element(body)

          

          file = File.new(h[:outfilepath] + h[:xmlfile],'w')

          file.puts doc

          file.close

          

        end

      end



      if __FILE__ == $0

        rt2x = RubyTxt2XML.new

        rt2x.rubytxt2xml(:sourcefile  => 'rubytxt2xml.rb')

      end

    ]]>

ProjectX client-side code

jrobertson (James Robertson) — Mon, 18 Feb 2008 18:49:42 GMT

This Ruby code uses a unified XML format to create a password record on a web server. It's intended to be run as a batch file which gets called from another Ruby application called maintain_projectx which gets called from a cronjob.

In this example the password is stored on the server not for authentication but simply to provide a reminder service in the event the user forgets it.



require 'net/http'

require 'rexml/document'

include REXML



class ProjectXClient

  attr :doc

  def initialize(raw_url)

    url = URI.escape(raw_url)

    xml_data = Net::HTTP.get_response(URI.parse(url)).body

    @doc = Document.new(xml_data)

  end

  

end



if __FILE__ == $0



  xml_project = <  

    

      

        

        

      

    

  

PROJECT

  

  pxc = ProjectXClient.new("http://yourdomain.com/p/projectx.cgi?xml_project=" + xml_project)

  doc = pxc.doc

  puts doc

    

end

output -what's returned from the server is an XML response containing a result. The result echos the method executed and the output from that method, which in this instance is the xml record node 'entry'.





  

    

      p6789c

      hotmail

Scrape an XHTML document using Ruby

jrobertson (James Robertson) — Sun, 27 Jan 2008 14:09:24 GMT

A simple Ruby script to scrape an XHTML file with the selected content being saved to an xml file ready for transformation into an RSS feed. This example uses the XHTML file from http://newsgang.net/audio/ which is then saved locally as 'thegang.xml'.



#!/usr/bin/ruby

# file: thegang.rb



require 'rexml/document'

include REXML



class TheGang

  def initialize()

  end

  

  def rssify()

    file = File.new('thegang.xml','r')

    doc = Document.new(file)

    rss_doc = Document.new

    root = Element.new('rss')

    rss_doc.add_element(root)

    

    doc.root.elements.each("body/div/ul/li/h2/a") do |node|    

      o_rssitem = Element.new('item')

      o_li = node.parent.parent

      

      o_rsstitle = Element.new('title')

      o_rsstitle.text = node.text.gsub(/[\n,' ']/,'')

      o_rssitem.add_element(o_rsstitle)

      

      o_rsshref_audio = Element.new('href_audio')

      o_rsshref_audio.text = node.attributes.get_attribute('href').to_s.gsub('amp;&','')      

      o_rssitem.add_element(o_rsshref_audio)

      

      o_rsshref = Element.new('href')

      o_rsshref.text = o_rsshref_audio.text.gsub('&from=audio','')      

      o_rssitem.add_element(o_rsshref)

      

      o_rssdate = Element.new('date')

      o_rssdate.text = "#{o_li.elements["p/span[1]"].text} #{o_li.elements["p/span[2]"].text}"

      o_rssitem.add_element(o_rssdate)

      rss_doc.root.add_element(o_rssitem)

      

    end



    file = File.new('thegang_rss.xml','w')

    file.puts rss_doc

    file.close

  end

end





if __FILE__ == $0

  gang = TheGang.new

  gang.rssify

end

see also: www.dapper.net

output (extract)





  TheGangXII-II/gangitem/id=6501&from=audio/gangitem/id=6501Jan 25

  TheGangXII-I/gangitem/id=6499&from=audio/gangitem/id=6499Jan 25

  NewsGangLive01.24.08/gangitem/id=6445&from=audio/gangitem/id=6445Jan 24

  NewsGangLiveII/gangitem/id=6377&from=audio/gangitem/id=6377Jan 23

  ...

Automate the insertion of text into a file.

jrobertson (James Robertson) — Wed, 23 Jan 2008 15:19:09 GMT

This example updates an xsl file with a new xsl:include declaration, and with a javascript header declaration. It reads 'guide.xsl' as a text file, and reads the template 'guide_ptemplate.xml' as a rexml document.



#!/usr/bin/ruby

#file: create add2guide_xsl.rb



require 'rexml/document'

include REXML



class Add2GuideTxt

  def initialize

    @guide = 'guide.xsl'

    @guide_template = 'guide_ptemplate.xml'

  end

  

  def insertText(project)

    # read guide.txt and return the buffer

    buffer = readGuide(@guide)    

    replaceBuffer(project, buffer, @guide) if not buffer.match("")

  end

  

  def replaceBuffer(project, buffer, output_file)

    # read guide_ptemplate.xsl and return the doc

    doc = readGuideTemplate(@guide_template)    

    # read the xsl:include

    xsl_include = buildIncludeTemplate(project, doc)

    # read the xsl:if

    xsl_if = buildIfTemplate(project,doc)

    

    eoi = ""

    buffer = buffer.gsub(eoi, "#{xsl_include}\n" + eoi)

    eoj = ""

    buffer = buffer.gsub(eoj, "\n#{xsl_if}\n" + eoj)

    

    file = File.new(output_file,'w')

    file.puts buffer.gsub(""","'")

    file.close

  end

  

  def buildIncludeTemplate(project, doc)

    xsl_include = doc.root.elements['xsl:include']

    xsl_include.attributes['href'] = '/xsl/' + project + '.xsl'

    xsl_include

  end

  

  def buildIfTemplate(project, doc)

    xsl_if = doc.root.elements['xsl:if']

    xsl_if.attributes['test'] = project

    xsl_if.elements['script[3]'].text = 'const ProjectX = "' + project + '";'

    xsl_if

  end

  

  def readGuide(filename) 

    file = File.new(filename,'r')

    buffer = file.read

    file.close

    buffer

  end

  

  def readGuideTemplate(filename) 

    file = File.new(filename)

    Document.new(file)

  end

  

end



if __FILE__ == $0

  a2g = Add2GuideTxt.new

  #add the new project to the guide.xsl file  

  a2g.insertText('tasks')

end

file: guide.xsl (target file)

...

file: guide_ptemplate.xml (template used to insert blocks of code into guide.xsl)

Unify the handling of XML records

jrobertson (James Robertson) — Sun, 02 Dec 2007 13:50:18 GMT

This Ruby code creates, updates or deletes an XML record, using a hash, record handling objects, and XML to invoke the correct method.



#file: recordx_handler.rb

require 'recordx'



class RecordX_Update < RecordX

  def call(params)

    #todo: write the code to read the xml parameter string

    update_record(h)

    save_file 

  end

end



class RecordX_Create < RecordX

  def call(params)

    #todo: write the code to read the xml parameter string  

    create_record(h)

  end

end



class RecordX_Delete < RecordX

  def call(params)

    doc = Document.new(params)

    node = doc.root.elements["param[@var='id']"]

    puts node

    id = node.attributes.get_attribute('val').to_s

    delete_record(id)

    puts 'deleted record ' + id

    save_file

  end

end



class RecordX_handler

  def invoke(method, params)

    h = Hash.new

    h["create"] = RecordX_Create.new

    h["update"] = RecordX_Update.new

    h["delete"] = RecordX_Delete.new

    h[method].call(params)

  end

end



if __FILE__ == $0

  xml_method = ""

  doc = Document.new(xml_method)

  method = doc.root.attributes.get_attribute('name').to_s

  params = doc.root.elements['params'].to_s



  rh = RecordX_handler.new

  rh.invoke(method, params)

end

This code is intended to be called by a Ruby CGI script which can simply relay the cgi post argument to the recordx_handler object.

Deleting an xml node from a REXML::document

jrobertson (James Robertson) — Wed, 26 Sep 2007 18:13:10 GMT

// Reads an XML file, then deletes the root element's 1st child element.



require 'rexml/document'

include REXML



file = File.new('journal250907.xml')

doc = Document.new(file)



puts doc



o_element = Element.new('abc')

o_element.text = "123"



o_node = doc.elements['journal/entry']



o_node.parent.delete(o_node)