如何在Rails中将所选文件的数据从一种形式转换为另一种形式的数据？

Question

I have a micropost form which makes it possible for users to post microposts. Now I'd like to give them the ability to upload photo/photos to represent microposts they'll post.

Here is the form:

   = form_for @micropost, :remote => true do |f|
        = f.file_field :image  # Needed for image previewing with html5 file api
        = f.hidden_field :user_id
        = f.text_area :content
        = f.submit "Post"

I already have already setup models, database tables for creating photo albums and uploading photos to them.

I have a photo model:

class Photo < ActiveRecord::Base

    belongs_to :photo_album

    attr_accessible :photo_album_id, :photo_title, :image, :remote_image_url
    mount_uploader :image, ImageUploader


    alpha_num_non_word_char = /^[a-zA-Z0-9\D_ -]*$/

    validates :image, :presence => true
    validates :photo_title, :presence => true,
      :length        => { :minimum => 2, :maximum => 50 },
      :format        => {
                          :with => alpha_num_non_word_char,
                          :message => "error"
                        }    
    validate :picture_size_validation, :if => "image?"

    def picture_size_validation
    errors[:image] << "Your photo should be less than 1MB" if image.size > 1.megabytes
    end

end

and a photo model:

class PhotoAlbum < ActiveRecord::Base

    belongs_to :user
    has_many :photos
    belongs_to :photo

    attr_accessible :album_title, :user_id, :photo_id


    alpha_num_non_word_char = /^[a-zA-Z0-9\D_ -]*$/

    validates :album_title, :presence => true,
      :length        => { :minimum => 2, :maximum => 50 },
      :format        => {
                          :with => alpha_num_non_word_char,
                          :message => "error"
                        }    
end

Upon user registration a "microposts album" is created for them and this will hold all the photos they upload for microposts.

I could easily get access to the microposts album like so:

@photo = Photo.new(:photo_album_id => PhotoAlbum.where(:user_id => current_user.id, :album_title => "microposts album").first.id)

Finally here is the form for upload photos to photo albums:

= form_for @photo, :html => {:multipart => true} do |f|
  = f.hidden_field :photo_album_id
  = f.label :photo_title
  = f.text_field :photo_title
  = f.file_field :image
  = f.submit

What I'd like a solution/help with:

Right now after a user selects a photo via the microposts form I use html5 file reader api to read the users selected local image and then display it on the page under the page. This is good but what I want to happen next is for the selected image to be uploaded and added to the "microposts album". I would then like to display it with the content of the micropost.

I access my content like this @microposts.each do |m|..... m.content so I could access the image like m.image. Some how I would need to get the path of the image that just got stored in the "microposts album" album into my image column of the microposts table so I could display it using an image_tag helper.

So to sum it all up I want for users selected photo from the microposts form to be uploaded to "microposts album" meaning the photo details are uploaded to the photos table and referenced from the photo_albums table if that makes sense at all.

I'm not sure if I have thought this out back to front but I'd like to get some help, ideas or solutions if possible.

I just thought it would be better to use the existing image upload resources I have instead of creating a new one for microposts.

Thanks in advance

Kind regards

Answer 1

Cobbling this together, and speaking from a Paperclip point of view, why don't you just have paperclip handle all image uploads in a 'micropost' whatever that is. Is that like a tweet with an image in it? Or facebook status update?

Also, if that won't work, I'd just create a Photo in a user's PhotoAlbum and save the Id or path or something in the Micropost model, so you can do something like image_tag User.first.microposts.last.image_path this is pseudo code, but you get the idea.If a guy has more than one image to save, then you do the image uploader angle.