How do I add an image placeholder to fix this bug - ruby-on-rails

I am a beginner programmer. I'm building my first project which shows a list of my favorite athletes and when clicked the "show" page loads an image of them, their name, and weight.
Overall when adding a new athlete everything works fine. If I decide to add a new athlete and skip adding an image I get this error "Can't resolve image into URL: undefined method `persisted?' for nil:NilClass", it also highlights my code "<%= image_tag(#fighter.image) %>" that's in my show.html.erb
I've tried adding an alt: but I get another error of "wrong number of arguments (given 1, expected 0)".
I've searched for answers and one thread mentioned my controller page and the params section. I did notice that (:image) is preceded by "params.require" which I would assume could be the problem if I'm not adding an element that is required. How do I solve this issue? What would be the best way to add a placeholder, I've added a default.png in my images folder.
Thank you
show.html.erb
fighters_controller.rb

If you're using ActiveStorage for uploading athlete images. You can check if an image was attached to your model with #fighter.image.attached?.
So I would suggest wrapping the image_tag in an IF-clause like so:
<% if #fighter.image.attached? %>
<%= image_tag(#fighter.image) %>
<% else %>
<%= image_tag("default.png") %>
<% end %>
If you're using Paperclip then try the following:
<% if #fighter.image.exists? %>
<%= image_tag(#fighter.image) %>
<% else %>
<%= image_tag("default.png") %>
<% end %>
With Carrierwave use:
<% if #fighter.image.present? %>
<%= image_tag(#fighter.image) %>
<% else %>
<%= image_tag("default.png") %>
<% end %>

Related

How to make the images from the bootstrap cards clickable on your index pages?

I was using the Bootstrap cards for my index page for my app but wasn't really liking the event details button, I feel it's more modern to just click on the image.
I found SOF articles pointing to how to use clickable images if the image was local and/or hosted somewhere online, but nothing that pointed to using images that are already a part of your database.
The code I had before was:
<% if artist.avatar.attached? %>
<%= image_tag artist.avatar, class: "even-size-artist" %>
<% else %>
<img src=<%= "https://dancewise.s3.amazonaws.com/misc-images/Blank+Avatar.png" %> class="even-size-artist">
<% end %>
The code that I found that will give you the option to have the top image clickable to the appropriate record is as follows:
<% if artist.avatar.attached? %>
<%= link_to image_tag(artist.avatar, class: "card-img-top artist-img").html_safe, artist %>
<% else %>
<img src=<%= "https://dancewise.s3.amazonaws.com/misc-images/Blank+Avatar.png" %> class="card-img-top artist-img">
<% end %>
Hopefully, this helps someone else out there learning RoR!

How to display only the first image out of an array of images rails

In the index page of my app, i want to display only the first image of a post that has multiple images attached to it.
<% (0...job.images.count).each do |image| %>
<%= image_tag(job.images[image]) %>
<% end %>
I have tried:
<%= image_tag job.images.first.try[image] %>
But get a no method given error
You should be able to treat it as a normal ActiveRecord query
<%= image_tag job.images.first if job.images.attached? %>
Based on the first bit of code you've provided, you should be able to use this:
<%= image_tag job.images.first %>
Assuming that job.images is an array of paths to the images?

How to check if an array index exists using Ruby and/or Rails

Is there a Ruby (preferably) or Rails way to check if the second index of an array exists?
In my Rails (4.2.6) app I have the following code in my view that shows the first two thumbnails for an array of photos:
<% if array.photos.any? %>
<%= image_tag array.photos.first.image.url(:thumb) %>
<%= image_tag array.photos[1].image.url(:thumb) %>
<% end %>
However if there is no second item in the array, then there is an error
I've tried the following if statements to make the rendering of the second thumbnail conditional, but they don't work:
<% if array.photos.include?(1) %>
<% if array.photos.second? %>
<% if array.photos[1]? %>
<% if array.photos[1].any? %>
I figured that another way to get what I want would be to simply check the length of the array
Still I was wondering if Ruby (or Rails) had a method or way to check if a specific index in an array exists or not. Thanks in advance
EDIT: To clarify I just want to show the first two thumbnails in the array, if any
You can use an .each, but if you want to follow this approach.
Instead of this:
<%= image_tag array.photos[1].image.url(:thumb) %>
Maybe you can use this:
<%= if(!array.photos[1].nil?) image_tag array.photos[1].image.url(:thumb) %>
Or:
<%= image_tag array.photos[1].image.url(:thumb) unless array.photos[1].nil? %>
Here, why not
(0...array.photos.size).each do |photo|
......
end
array.photos.each do |photo|
......
end

Displaying images from associated models

I'm trying to get my miniatures view to display all associated photos from the collections model.
My sample miniature has two photos but the following code gives an error "undefined method `photo' for #".
<% #miniature.collections(:photo).each do |photo| %>
<%= image_tag #miniature.collections.photo.url(:medium) %>
<% end %>
I think that the relationships are all correct though because rails console works fine with them and the following code shows the first image, twice.
<% #miniature.collections(:photo).each do |photo| %>
<%= image_tag #miniature.collections.first.photo.url(:medium) %>
<% end %>
Equally I can swap out first for last and show the 2nd image twice. What am I doing wrong?
Without knowing a huge amount about your associations, I'm relatively sure you want to use the instance variable that you instantiated in the each loop. That would look like something to the effect of:
<% #miniature.collections(:photo).each do |collection| %>
<% if !collection.photo.url(:medium).nil? %>
<%= image_tag collection.photo.url(:medium) %>
<% end %>
<% end %>
Using #miniature.collections.first.photo.url(:medium) would display the first image of the collection once for each photo in the collection. Likely this is not what you want.

How do I get multiple paperclip uploads to display in the view?

I'm very new to programming and have followed this screencast at emersonlackey.com on adding multiple paperclip uploads for a record. It all works great but I can't figure out how to display the uploaded images in the records show page.
They display fine on the edit page using:
<%= f.fields_for :venuephotos do |photo| %>
<% unless photo.object.new_record? %>
<p>
<%= link_to image_tag(photo.object.venuephoto.url(:thumb)), photo.object.venuephoto.url(:original) %>
<%= photo.check_box :_destroy %>
</p>
<% end %>
<% end %>
I've used paperclip in other models but they are the standard each record only has one upload so the images display fine with <%= #model.photo.url %> type call but I cant figure out this other way.
Any help is much apprectiated!
You want to do something like this:
<% for asset in #post.assets %>
<%= link_to image_tag(asset.asset.url(:thumb)), asset.asset.url(:original) %>
<% end %>
as per the code that goes along with the screencast.
https://github.com/Emerson/Multiple-File-Uploads-with-Paperclip-and-Rails-3/blob/master/app/views/posts/show.html.erb

Resources