使用IF语句将类添加到Rails中的image_tag

Question

I have a image tag setup for a blog that if an image has been attached to the blog then display the image.

<%= image_tag blog.image_url(:thumb) if blog.image? %>

I am trying to add a class to this image tag so that I can use CSS to edit it. I have tried a few different ways to add the class but none seem to work.

<%= image_tag blog.image_url(:thumb) if blog.image?, :class => "img" %>

or

<%= image_tag (blog.image_url(:thumb), :class => "img") if blog.image? %>

or

<%= image_tag (blog.image_url(:thumb) if blog.image?), :class => "img" %>

does anyone know how to add a class to this type of statement?

Answer 1

<%= image_tag(blog.image_url(:thumb), class: 'img') if blog.image? %>

I use <%= image_tag(@user.image_url, size: 50, class: 'gravatar') if @user.image_url? %> <%= image_tag(@user.image_url, size: 50, class: 'gravatar') if @user.image_url? %> in my project, and it works.