CODEWITHSUNDEEP
ruby-on-railsimageconditional-statements
Kyle Reierson
Kyle Reierson

Reputation: 55

Ruby on Rails: Displaying images at random

I'm trying to display one image based on an if/else statement related to "price". I have 5 folders in my /assets/images directory as follows:

very_bad
bad
ok
good
very_good

Each folder contains multiple images and I would like to grab only one image from the appropriate folder at random, so the user doesn't always have to see the same image.

For example, if the price is less than -2%, I would want to randomly display an image from the "very_bad" folder. If the price is greater than 2%, I would want to randomly display an image from the "very_good" folder.

How would you tackle this issue? Thanks for the help!

Upvotes: 4

Views: 4898

Answers (4)

Cruz Nunez
Cruz Nunez

Reputation: 3149

Here's a combo of tina and bevan's answers

module ImageHelper
  def random_image(folder)
    image_path_prefix = "app/assets/images/"
    image_files = Dir.new("#{image_path_prefix}#{folder}")
                     .to_a.select { |f| f.downcase.match(/\.jpg|\.jpeg|\.png/) }
    image = image_files.sample
    "#{folder}/#{image}"
  end
end

Use it like this

<%= asset_path(random_image('good/really_good')) %>

Upvotes: 0

Tina
Tina

Reputation: 1234

You can do this pretty easily using the Dir.glob, and array .sample and .split methods.

Let's say I have all the random images in a folder called ./backgrounds in my Rails image assets folder:

app/assets/images/
└── backgrounds
    ├── beach.jpeg
    ├── bright-flowers-pink-skies.jpeg        
    ├── fall-autumn-red-season.jpg
    └── fjord.jpeg

I can create a helper in ./app/helpers/application_helpers.rb—or wherever you'd like to put the helper—that has the following code:

module ApplicationHelper
  def get_random_image
    image_path_prefix = "app/assets/images/"
    image_files = Dir.glob("#{image_path_prefix}backgrounds/*")
    image_files.sample.split(image_path_prefix)[1]
  end
end

What this does is globs all of the paths inside of ./app/assets/images/backgrounds, returns a random one (using .sample), removes the image path prefix by splitting the string, and returns the end part of it.

Then in your ERB template, you can display the image like so:

<%= image_tag get_random_image %>

This should result in an image tag for a random image being generated. Be careful to pay attention to leading and trailing slashes.

Upvotes: 6

bevanb
bevanb

Reputation: 8521

Here's a solution without renaming your images.

Once you know your folder, do this to select a picture within that folder at random:

=image_tag Dir.new(Rails.root.to_s + "/app/assets/images/my-folder").to_a.select{|f|    f.downcase.match(/\.jpg|\.jpeg|\.png/) }.sample

Upvotes: 10

hiattp
hiattp

Reputation: 2336

Once you've determined the folder name (let's use very_good as an example), determine a random number based on the number of images you have. Let's say you have four images in each folder, use rand(4) to get a random number among [0,1,2,3]. Name your images 0.png, 1.png, etc. within each folder. Now you should be able to display one of the images at random, given the folder name, as follows:

<%= image_tag "very_good/#{rand(4)}.png" %>

Since your folder name is probably dynamic, it would look more like this:

<%= image_tag "#{@folder_name}/#{rand(4)}.png" %>

Upvotes: 10

Related Questions