[RUBY] [Rails] Make a breadcrumb trail

Target audience

--People who want to implement breadcrumb trails in Rails. --People who forgot how to use it. ――It is for beginners. The content also explains the rudimentary part.

What is gretel?

Breadcrumb trail. The story of Hansel and Gretel. You can see the path you have taken by dropping breadcrumbs.

Install Gem

Click here for gretel's github

`Gemfile`


gem 'gretel'

After bundle install, generate the necessary files.

$ bundle install
$ rails g gretel:install

It is OK if the file is generated as follows.

Running via Spring preloader in process 6675
      create  config/breadcrumbs.rb

This is the contents.

`breadcrumbs.rb`


crumb :root do
  link "Home", root_path
end

# crumb :projects do
#   link "Projects", projects_path
# end

# crumb :project do |project|
#   link project.name, project_path(project)
#   parent :projects
# end

#
#
#Omitted below
#
#
#

Write settings

The file breadcrumbs.rb mentioned earlier is a file that can be set to drop bread crumbs. For example

Home> Category

If you want to remove breadcrumbs like

`breadcrumb.rb`


crumb :root do
  link "Home", root_path
end

crumb :articles do
  link "List of articles", articles_path #パスは該当ページのパスを書く（ここではList of articles）
  parent :root
end

Since we want the page before the category to be Home, parent specifies : root.

Display in View

All you have to do is output it in View.

`erb:application.html.erb`


<!DOCTYPE html>
<html>
  <head>
    <title>Bread crumb app</title>
    <%= stylesheet_link_tag    'application', media: 'all', 'data-turbolinks-track': 'reload' %>
    <%= javascript_include_tag 'application', 'data-turbolinks-track': 'reload' %>
  </head>
  <body>
    <%= breadcrumbs separator: " &rsaquo; " %> #Add here
    <%= yield %>
  </body>
</html>

`erb:articles/index.html.erb`


<% breadcrumb :articles %>

with this

Home> Article List

The breadcrumb trail is ready.

I want to display the registered data without breadcrumbs

Home> Article List> [Article Title]

If you want to do something like this, you need to devise a little.

You have to send the data from View to breadcrumb.rb as shown below. This time, I want to output the title of the article as breadcrumbs, so I will pass the data by specifying @article as the second argument.

`erb:articles/show.html.erb`


<% breadcrumb :article_show, @article %>

`breadcrumb.rb`


crumb :root do
  link "Home", root_path
end

crumb :articles do
  link "List of articles", articles_path #パスは該当ページのパスを書く（ここではList of articles）
  parent :root
end

crumb :article_show do |article| #Received here
  link article.title, article_path(article) #<Character string to display>、<Article detail path>
  parent :articles  #Set parent
end

Home> Article list> I made a breadcrumb trail

If you want to output the creation date and time,

`breadcrumbs.rb`


crumb :article_show do |article|
  link article.created_at, article_path(article) #Change (title=> created_at）
  parent :articles
end

If you change it to, it's OK.