Ruby on Rails

Thanks, Rob

I tried a variant of your suggestion, where I redirect instead of send_data (since in my case, the images are coming from elsewhere)  - I still have the same issue (that the images are all rendered once in the end,not one by one as they are retrieved). Here is the current code:

main controller:

def show_images
   render :update do |page|
      page.replace_html 'images-div', ''
      @query.load_images! do |image|
       @image = image
       page.insert_html :bottom, 'images-div', :partial => 'image' unless @image.id.nil?
      end
    end
end

query model:

def load_images!
...
  for(some_loop_that_gets_one_image_at_a_time)
    block.call(image)
  end
...
end

_image.html.erb

<%=image_tag('/images/%s/show' % @image.id)%>

images_controller:

def show
    @image = Image.find(params[:id])
    redirect_to @image.url
  end

Thanks
Anand

On Mon, May 3, 2010 at 11:01 AM, Rob Biedenharn <Rob@agileconsultingllc.com> wrote:

On May 3, 2010, at 1:49 PM, candor wrote:

I tried a couple other approaches, but no success yet:

1. I reversed the blocks below - calling the load_images from within
render :update - that did give me the results, but all at once in the
end, not as the images show up.
2. I called redirect_to <controller/show_image?image_id=1 within the
inner loop in 1, and created a show_image.js.rjs file which calls
page.insert_html :bottom, 'images-div', :partial => 'image', but I get
an error 'ActionView::MissingTemplate (Missing template <mycontroller>/
show_image.erb in view path app/views) I dont really understand why
this is happening - shouldnt it pick the rjs template if present
instead of the erb?

What I really want is to leverage http to parallelize the retrieval
and rendering of images. How do I do that?

Thanks
Anand

<img src="/controller/show_image?image_id=1" />

Then the browser will ask for that URL and you can respond with a send_file or send_data (rather than a render or redirect).

-Rob

On May 3, 9:11 am, candor <rcan...@gmail.com> wrote:

Hi,

I have a rails application where I respond to a request by fetching
image urls from various web api calls and need to display them as they
come available. I am able to display all the images once I get them
all, but that causes an unacceptable delay for my user.

One approach I am trying is, from my controller, set an @image
variable, and then pass in a block to the model that retrieves the
image urls. In the block, I call
    In the controller, I have:
 @query.load_images! do |image|
     @image = image
     render :update do |page|
       page.insert_html :bottom, 'images-div', :partial => 'images'
     end
   end

In my query model, I have:

def load_images! &block
  for(some_loop_that_gets_one_image_at_a_time) do
      image = get_next_image
      block.call(image)
  end
end

In the _images.html.erb, I have:

<%=image_tag @image.url %>

The problem is that with this approach, I get a DoubleRenderError, and
I think this is because render is being called multiple times in the
block call within the loop.

What is the best way to get the effect I need (to load images one at a
time as they become available)?

Thanks
Anand

Rob Biedenharn          http://agileconsultingllc.com
Rob@AgileConsultingLLC.com