# Error "undefined method 'stringify\_keys' for "tag1":String" on multi-model form submission

**URL:** <https://www.ruby-forum.com/t/error-undefined-method-stringify-keys-for-tag1-string-on-multi-model-form-submission/175537>\
**Category:** Rails\
**Created:** [September 15, 2009, 10:10am UTC](https://www.ruby-forum.com/t/error-undefined-method-stringify-keys-for-tag1-string-on-multi-model-form-submission/175537 "2009-09-15T10:10:00Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![jonathan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/aeb1de/32.png) [@jonathan](https://www.ruby-forum.com/u/jonathan)\
**Post date:** [September 15, 2009, 10:10am UTC](https://www.ruby-forum.com/t/error-undefined-method-stringify-keys-for-tag1-string-on-multi-model-form-submission/175537/1 "2009-09-15T10:10:00Z")

</div>

I’m following the tutorial on  
[Getting Started with Rails — Ruby on Rails Guides](http://guides.rubyonrails.org/getting_started.html),  
and got stuck on the very last section, “Building a Multi-Model Form”.  
I’m trying to do two models in the same form, and I get the following  
error:  
undefined method `stringify\_keys’ for “tag1”:String

Here is the partial view I am using:

\<% form\_for(@post) do |f| %\>  
\<%= f.error\_messages %\>

\<%= f.label :name %\>  
 \<%= f.text\_field :name %\>

\<%= f.label :title %\>  
 \<%= f.text\_field :title %\>

\<%= f.label :content %\>  
 \<%= f.text\_area :content %\>

## Tags
 \<% f.fields\_for :tags\_attributes do |tag\_form| %\> 

\<%= tag\_form.label :name, 'Tag:' %\> \<%= tag\_form.text\_field :name %\>

\<% unless tag\_form.object.nil? || tag\_form.object.new\_record? %\>

\<%= tag\_form.label :\_delete, 'Remove:' %\> \<%= tag\_form.check\_box :\_delete %\>

\<% end %\> \<% end %\> 

\<%= f.submit 'Update' %\>

This was rendered by a partial view!

\<% end %\>

I’m still a beginner, so I hope this question isn’t too dumb, but I’m  
scratching my head here - any help?