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POWhat is the difference between using ":" and "@" in fields_for
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  1. POWhat is the difference between using ":" and "@" in fields_for
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    copied!<p>I am setting up embedded forms in my rails app.</p> <p>This does not work</p> <pre><code>&lt;h1&gt;PlayersToTeams#edit&lt;/h1&gt; &lt;%= form_for @players_to_teams do |field| %&gt; &lt;%= field.fields_for @players_to_teams.player do |f| %&gt; &lt;%= f.label :IsActive %&gt; &lt;%= f.text_field :IsActive %&gt; &lt;% end %&gt; &lt;%= field.label :BT %&gt; &lt;%= field.text_field :BT %&gt; &lt;br/&gt; &lt;%= field.submit "Save", class: 'btn btn-primary' %&gt; &lt;% end %&gt; </code></pre> <p>Gives me a <code>ActiveRecord::AssociationTypeMismatch</code> error. Notice the <code>@players_to_teams.player</code> in the <code>forms_for</code> line.</p> <p>This does work: </p> <pre><code>&lt;h1&gt;PlayersToTeams#edit&lt;/h1&gt; &lt;%= form_for @players_to_teams do |field| %&gt; &lt;%= field.fields_for :player do |f| %&gt; &lt;%= f.label :IsActive %&gt; &lt;%= f.text_field :IsActive %&gt; &lt;% end %&gt; &lt;%= field.label :BT %&gt; &lt;%= field.text_field :BT %&gt; &lt;br/&gt; &lt;%= field.submit "Save", class: 'btn btn-primary' %&gt; &lt;% end %&gt; </code></pre> <p>Notice the <code>:player</code> call in the <code>fields_for</code> line.</p> <p>Whats the difference between using a symbol and using an instance? I would think I would want to use an instance in this case, but I guess not?</p> <p><strong>Edit</strong> </p> <p>models:</p> <pre><code>class Player &lt; ActiveRecord::Base has_many :players_to_teams has_many :teams, through: :players_to_teams end class PlayersToTeam &lt; ActiveRecord::Base belongs_to :player belongs_to :team accepts_nested_attributes_for :player end </code></pre> <p>controller:</p> <pre><code>class PlayersToTeamsController &lt; ApplicationController def edit @players_to_teams=PlayersToTeam.find(params[:id]) end def update @players_to_teams=PlayersToTeam.find(params[:id]) respond_to do |format| if @players_to_teams.update_attributes(params[:players_to_team]) format.html { redirect_to @players_to_teams, notice: 'Player_to_Team was successfully updated.' } format.json { head :no_content } else format.html { render action: "edit" } format.json { render json: @players_to_teams.errors, status: :unprocessable_entity } end end end end </code></pre> <p><strong>Example Project</strong></p> <p>Github: <a href="https://github.com/workmaster2n/embedded-form-errors" rel="nofollow">https://github.com/workmaster2n/embedded-form-errors</a></p>
 

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