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PORails 3: How to display data of multiple intra-dependent models in a table in the view?
 

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  1. PORails 3: How to display data of multiple intra-dependent models in a table in the view?
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    <p>I have a betting application, where users can bet on sports matches (e.g. basketball). I have something like this:</p> <pre><code>Group has_many :users Group belongs_to :league League has_many :matches Match has_many :bets User has many :bets Bet belongs_to :group Bet belongs_to :match Bet belongs_to :user </code></pre> <p>As you can see, users bet in groups. A group bets on one league (e.g. soccer season 2011/2012) and a league consists of many matches, that can be betted on.</p> <p>I want to render the view for an action in the Group Controller (so Group is the base model). It should display a table with the matches on the horizontal table header and the users on the vertical table header. A table cell should show the bet of a user for the given match, like so:</p> <pre><code> | Team 1 vs Team 2 | Team 3 vs Team 4 =======+==================+================= User 1 | 1 : 2 | 0 : 0 -------+------------------+----------------- User 2 | 2 : 0 | 1 : 0 </code></pre> <p><strong>Now the question is: how to best setup access to my data?</strong></p> <p>I could set up the @group attribute in the controller and then access data in the view like so:</p> <pre><code>&lt;table&gt; &lt;thead&gt; &lt;tr&gt; &lt;th&gt;&amp;nbsp;&lt;/th&gt; &lt;% for match in @group.league.matches %&gt; &lt;th&gt;&lt;%= "#{match.team1.name} vs. #{match.team2.name}" %&gt;&lt;/th&gt; &lt;% end %&gt; &lt;/tr&gt; &lt;/thead&gt; &lt;tbody&gt; &lt;% for user in @group.users %&gt; &lt;tr&gt; &lt;th&gt;&lt;%= user.name %&gt;&lt;/th&gt; &lt;% for match in @group.league.matches %&gt; &lt;td&gt;&lt;%= ?????? %&gt;&lt;/td&gt; &lt;% end %&gt; &lt;/tr&gt; &lt;% end %&gt; &lt;/tbody&gt; &lt;/table&gt; </code></pre> <p><strong>My problem is denoted with "??????": How to access the correct bet?</strong></p> <pre><code>match.bets.find_by_group_id_and_user_id( ... ) # this will generate a new SELECT on DB match.bets.to_a.find{|bet| bet.user_id == user.id &amp;&amp; bet.group_id == @group.id}.home_score # seems cluttered and should not belong in the view </code></pre> <p>Your input on this is greatly appreciated. Thanks!</p>
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