So, I've read through a bunch of other problem reports surrounding content_for and I have still not been able to figure out what is going on in my code.
I'm trying to add some bootstrap breadcrumb data from various views, that each have a different content_for based on the location in the code. Then in my application.html.erb I'm calling a partial that is rendering the breadcrumb data. But the data is empty when I view the source.
I thought I may have a ordering issue, I don't think that is the case but I'm not really sure.
Here is the order of events. I'm calling new.html.erb to render the view for new and also set the content_for data. Then in the layout I'm calling a partial _breadcrumb.html.erb in the body of the main layout to display the content_for data.
new.html.erb
<% content_for :breadcrumb do %>
<li class="breadcrumb-item"><%= link_to "Home", root_path %></li>
<li class="breadcrumb-item"><%= link_to "Examples", examples_path %></li>
<li class="breadcrumb-item active">Horizontal Form</li>
<% end %>
<div class="app-example container">
<div class="row">
<%= render partial: "bootstrap", layout: "card_bootstrap", locals: { title: "Horizontal Form" } %>
<%= render partial: "form", layout: "card_simple_form", locals: { title: "Horizontal Form" } %>
</div>
<%= render partial: "shared/tipps" %>
<%# move modals to bottom %>
<%= render partial: "shared/modal", locals: { id: "modal-bootstrap", title: "Bootstrap",
content: render_source(File.read(File.join(Rails.root,
'app/views/examples/horizontals/_bootstrap.html.erb'))) } %>
<%= render partial: "shared/modal", locals: { id: "modal-simpleform", title: "Simple Form",
content: render_source(File.read(File.join(Rails.root,
'app/views/examples/horizontals/_form.html.erb'))) } %>
</div>
_breadcrumb.html.erb
<div class="app-breadcrumb container">
<div class="d-flex flex-row justify-content-between">
<ol class="breadcrumb bg-transparent px-0">
<%= yield :breadcrumb %>
</ol>
<div>
<button type="button" class="btn btn-sm btn-outline-secondary mt-2 mr-2 d-none" data- tooltip data-placement="bottom" data-trigger="hover" title="compare by clicking fast" data-toggle="button" aria-pressed="false" autocomplete="off">
Swap
</button>
<div class="btn-group btn-group-toggle mt-2 d-none" data-toggle="buttons">
<label class="btn btn-sm btn-outline-secondary">
<input type="radio" name="view" id="stack" autocomplete="off"> Stack
</label>
<label class="btn btn-sm btn-outline-secondary active">
<input type="radio" name="view" id="split" autocomplete="off" checked> Split
</label>
</div>
</div>
</div>
</div>
application.html.erb
<!DOCTYPE html>
<html>
<head>
<title><%= full_title(yield(:title)) %></title>
<%= csrf_meta_tags %>
<%= csp_meta_tag %>
<%= stylesheet_link_tag "application", media: "all",
"data-turbolinks-track": 'reload' %>
<%= javascript_include_tag "application", "data-turbolinks-track": 'reload' %>
<meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body data-spy="scroll" data-target=".bs-docs-sidebar">
<%= render "header" %>
<div class="container">
<%= render "flash" %>
<%= render "breadcrumb" %>
<%= yield %>
<%= render "footer" %>
<%= debug(params) if Rails.env.development? %>
<!-- This debug code shows the HTTP headers/environment -->
<!-- ul>
<% request.env.each do |item| %>
<li><%= item[0] %> : <%= item[1] %></li>
<% end %>
</ul -->
</div>
</body>
</html>
I know the partial is being rendered because everything but the content_for data shows up in the source (and on the screen.)
However, I'm getting nothing where the yield :breadcrumb is in the code. The source just shows
<ol class="breadcrumb bg-transparent px-0">
</ol>
Can anyone offer any more insight on this issue? If I need to provide more information just let me know that as well. I'm a novice rails programmer and any help would be appreciated.
It turns out this was a routing issue and not a problem with content_for and yield. I had made some directory changes to better organize the app and the route being used was pointing to an older version of the file in a different directory. One which didn't have the content_for setup properly. The route was changed properly in the routes.rb file but not updated correctly in the view reference.
I appreciate everyone who looked at the problem and I apologize for any time wasted on what should have been an obvious problem. At least looking back at it now. It's a good teaching moment to not overlook all of the details you think you know well when focusing on something new you are trying to add. Lesson learned!