Sample code for displaying a MIME email message on a web page?

rubyonrails-talk
1

Can anyone point me to a good source of sample code for taking a raw email message (multipart, with attachments) and displaying it on a web page? Also same thing for composing a new message with attachments?

~Josh

2

Josh, I found the following very helpful:

http://www.ruby-doc.org/stdlib/libdoc/net/pop/rdoc/classes/Net/POP3.html

Cheers, --Kip

3

Thanks for the pointer! That looks useful, but doesn't address what I'm looking for. I want to be able to read in an mbox file, parse off a message, and display it on a web page similar to how you would view it in Hotmail or Gmail. That means decoding the MIME but also "sanitizing" the HTML.

~Josh

4

Josh, I have done a *very* simple wrapper around this message parsing bit. This will let you get at the parts of a mime multipart message. I guess you could use sanitize() strip_tags() and strip_links() to help make the html more displayable. Note I just put this together for a proof-of-concept for emailing articles and images to a content system I'm writing so i sure wouldn't cut and paste!

  require 'hermes_messages.rb'   my_messages.HermesMessages.new   my_messages.get_messages(pop server parameters)   my_messages.message.each do |m|     # Each message has many parts, but we simplifiy with some helper methods     puts m.subject     puts m.from     puts m.body # Note the 'body' method retrieves the text/ plain part for my needs - modify as required to get the html part   end

Hope this helps a little more,

--Kip

class HermesMessages   require 'net/pop'   require 'action_mailer'

  EMPTY_PART = " \r\n\r\n"   TEXT_PLAIN = 'text/plain'   MULTIPART_ALTERNATIVE = 'multipart/alternative'

  attr_reader :messages

  def get_messages(host, user, password, port, *args)     options = args.last.is_a?(Hash) ? args.pop : {}     @messages =     begin       Net::POP3.start(host, port, user, password) do |pop|         if pop.mails.empty?           puts 'No mail.'         else           puts "#{pop.mails.size} messages will be processed."           pop.each_mail do |m|            @messages << IncomingImageHandler.receive(m.pop)            m.delete if options[:delete] == true           end         end         puts "#{pop.mails.size} mails popped."         return pop.mails.size       end     rescue       puts "Exception detected - could not retrieve email"       return -1     end   end

  class Message     attr_accessor :subject, :from     attr_reader :parts

    def initialize       @parts =     end

    def add_part(p)       @parts << p     end

    def has_jpeg?       parts.each {|p| return true if p.sub_type == "jpeg"}       return false     end

    def has_body?       parts.each {|p| return true if p.main_type == "text" && p.sub_type == "plain"}       return false     end

    def body       parts.each {|p| return p.body if p.main_type == "text" && p.sub_type == "plain"}       return ""     end

    def jpeg       parts.each {|p| return p.body if p.main_type == "image" && p.sub_type == "jpeg"}       return ""     end

    def image_filename       parts.each {|p| return p.filename if p.main_type == "image" && p.sub_type == "jpeg"}       return ""     end

  end

  class Content

attr_accessor :main_type, :sub_type, :body, :filename, :file_extension, :index   end

  class IncomingImageHandler < ActionMailer::Base     # email is a TMail::Mail     def receive(email)       @message = Message.new       @message.from = email.from[0]       @message.subject = email.subject       puts "Processing message: #{@message.subject}"       process(email)     end

  protected

    def process(part)       if part.multipart? then         part.parts.each {|p| process(p) } unless           part.content_type == MULTIPART_ALTERNATIVE &&           plain_part_is_empty(part)       else         process_part(part)       end       return @message     end

    def process_part(part)       puts " part: #{part.content_type} with size #{part.body.length}"       pp " content is: '#{part.body}'" if part.body.length <= 10       content = Content.new       content.main_type = part.main_type       content.sub_type = part.sub_type       content.body = part.body       content.filename = part_filename(part)       content.file_extension = ext(part)       @message.add_part(content)     end

  private

    def plain_part_is_empty(part)       part.parts.each do |p|         return true if p.content_type == TEXT_PLAIN && p.body == EMPTY_PART       end       return false     end

    def part_filename(part)       # get filename       if part['content-location'] != nil && part['content- location'].body.length != 0         filename = part['content-location'].body       elsif part.type_param('name') != nil && part.type_param('name').length != 0         filename = part.type_param('name')       elsif part.disposition_param('filename') != nil && part.disposition_param('filename').length != 0         filename = part.disposition_param('filename')       else         filename = nil       end     end

    CTYPE_TO_EXT = {       'image/jpeg' => 'jpg',       'image/gif' => 'gif',       'image/png' => 'png',       'image/tiff' => 'tif'     }

    def ext( mail )       CTYPE_TO_EXT[mail.content_type] || 'txt'     end   end #class end

5

Thanks Kip!

I just found sanitize() and that seems to be a big part of what I'm looking for. I'll check out strip_links and strip_tags also!

~Josh

6

What's the best place to find documentation on sanitize, strip_links, etc. and find other functions like this? I'm looking through Ruby Core and Ruby Standard Libs and don't see it.

~Josh

7

Josh, here: http://rails.rubyonrails.org/classes/ActionView/Helpers/TextHelper.html

Cheers, --Kip

8

That was exactly what I was looking for. Thanks!

~Josh

9

Sorry one last question on TextHelper... I can call sanitize from within a view (.rhtml file) no problem, but when I try to use it within a controller or model it complains that the method is unknown. What do I need to require/include to reference sanitize from within a controller or model?

~Josh