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POundefined method `model_name' for NilClass:Class with Partials and Form for
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  1. POundefined method `model_name' for NilClass:Class with Partials and Form for
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    copied!<p>I am having a weird issue where my rails application seemingly isn't reading the local variable passed to the partial, but <strong><em>only</em></strong> inside of <code>form_for</code>.</p> <p>I have a set up a button where a user can bookmark an object, let's call it <code>zoo</code>.</p> <p>The code looks like this:</p> <p>Zoo Listing View:</p> <pre><code>&lt;li&gt;&lt;%= render 'directory/bookmarks', zoo: zoo %&gt;&lt;/i&gt;&lt;/li&gt; </code></pre> <p>Then the directory/bookmarks partial:</p> <pre><code>&lt;% if user_signed_in? %&gt; &lt;% if current_user.has_zoo_bookmarked_already? %&gt; &lt;%= form_for(current_user.bookmarks.find_by_zoo_id(zoo.id), html: { method: :delete }, remote: true) do |f| %&gt; &lt;%= button_tag do %&gt; &lt;button class="btn btn-lg btn-block btn-primary"&gt;remove bookmark &lt;% end %&gt; &lt;% end %&gt; &lt;% else %&gt; &lt;%= form_for(current_user.bookmarks.build(zoo_id: zoo.id)) do |f| %&gt; &lt;%= f.hidden_field :zoo_id, value: zoo.id %&gt; &lt;%= button_tag do %&gt; &lt;button class="btn btn-lg btn-block btn-primary"&gt;bookmark &lt;% end %&gt; &lt;% end %&gt; &lt;% end %&gt; &lt;% else %&gt; &lt;% end %&gt; </code></pre> <p>Anyway, the problem is the <code>zoo.id</code> on the 3rd line is not being evaluated. I get this error.</p> <p><strong>undefined method `model_name' for NilClass:Class</strong></p> <p>The weird part is that locals are being read on the page.</p> <p>If I place this code snippet <code>&lt;%= zoo.id %&gt;</code> anywhere on the page, I get the id. Then, the <code>find_by_zoo_id</code> is being evaluated also...if I put <code>255</code> a hardcoded number, it works. Or if I set it to a variable, <code>@id = 255</code> and then pass in the <code>@id</code>, it works. </p> <p>The zoo.id only does not work inside of the form_for for some reason. If I set it to an instance variable on the page, <code>@id = zoo.id</code>, that doesn't work either. </p> <p>Any ideas? I'm sure it is something minor.</p> <p>EDITED:</p> <p>The relationship is has_many :through. Forgot to mention, I use this code for a different association in the same application and it works fine.</p>
 

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