Error in editing courses: ‘model_name’ missing in nested lesson form. For instance, consider this alternate snippet below:
<% alt_fields_for @module_object do |input_field| %>
<%= input_field.text_field :label %>
<% end %>
Hey everyone, I stumbled across a similar error a little while back and it really got me thinking about how Rails handles our nested forms behind the scenes. From what I’ve seen, this issue usually pops up when Rails can’t identify the model associated with the form elements, so it doesn’t know what to do about a missing model_name. One thing to double-check is that your @module_object really is an instance of a model that responds to model_name (and that any nested associations are properly set up, maybe using accepts_nested_attributes_for if applicable).
I wonder if switching to a more explicit reference in your fields_for call might help at all? For instance, ensuring that your nested objects are all correctly instantiated before being passed into the form builder. Has anyone else played around with tweaking their controller or model setup to resolve this? I’d love to hear your thoughts or any insights you might have come up with. What configurations worked for you? 
I encountered a similar issue in a project where the error indicated that Rails couldn’t correctly identify the model for the nested form. I resolved the problem by explicitly ensuring that all nested objects were properly instantiated in the controller before rendering the form. This involved creating new instances if needed so that fields_for would have a valid object to work with. By closely examining the object relationships and verifying that each instance responded to model_name, I was able to resolve the error and achieve proper form behavior.
hey, i ran into this issue too. i sorted it out by making sure the nested model was instantiated properly before the form builder took over. might be worth checking associations and initializations too. cheers!