Loading CSS background images before normal images?

Question

I have a ruby on rails web app, and in some views i have many heavy images( <img> ) to render .The <img> are generated in a Helper.

The problem is that the css is loaded first, then the js, then the heavy images , and then finally the css refereneced background images.

It takes quite a while for all of the heavy images to load, which therefore holds the whole site up.

I want to load first the css background images then load the other images, as they obviously hold visual structure of the page.

rails version: 2.3.8

EDIT: Thank you guys, I apologize for not having shared the code earlier.

I have two models : Categories and Images, each Category has many images. In the view i have a list of categories, which is generated by a helper :

 
categories.each do |cat|
    html << "<a href='##{cat.id}' class='mapcat' >#{cat.libelle}</a>"
end

and when I click on the category the images are displayed

 categories_images.each do |i|
    html << "<div id='#{i.id}' class='#{css}'><img src='/images_moi/categories/#{cat.libelle}/#{i.path_file_name}' />"
  end

I have css background image associated to the list of category The problem is that the images (<img>) is displayed before the css background images of the list of categories.

Solution 1

We need to assume things because you haven't shared your code.

Coming to your query, for now you can preload images using jQuery:

function preload(arrayOfImages) {
    $(arrayOfImages).each(function(){
        $('<img/>')[0].src = this;
        // Alternatively you could use:
        // (new Image()).src = this;
    });
}

// Usage:

preload([
    'img/imageName.jpg',
    'img/anotherOne.jpg',
    'img/blahblahblah.jpg'
]);

This saves the loading time of loading images.

Solution 2

Use a base64 string.

Example:

background-image: url(data:image/png;base64,*CONVERTED IMAGE DATA HERE*);

• without: **
• online converter: http://webcodertools.com/imagetobase64converter
• note: I only would suggest this if the image size is not too heavy.