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    <p>Here is a two part railscast covering aspects of implementing a poll/survey application. It covers most of your model related doubts.</p> <p><a href="http://railscasts.com/episodes/196-nested-model-form-part-1" rel="nofollow">http://railscasts.com/episodes/196-nested-model-form-part-1</a></p> <p><a href="http://railscasts.com/episodes/197-nested-model-form-part-2" rel="nofollow">http://railscasts.com/episodes/197-nested-model-form-part-2</a></p> <p>I would create the dependent objects during assignment by over-riding the setter for <code>text_body</code>.</p> <p>Eg:</p> <pre><code>def text_body=(val) write_attribute(:text_body, val).tap do |v| append_new_tags_and_mentions end end def append_new_tags_and_mentions tag_list, mention_list = extract_tags_and_mentions new_mentions = mention_list - mentions.where(name =&gt; mention_list).pluck(:name) mentions.concat(*new_mentions) if new_mentions.present? new_tags = tag_list - hashtags.where(tag =&gt; tag_list).pluck(:tag) hashtags.concat(*new_tags) if new_tags.present? end def extract_tags_and_mentions tag_list = [] mention_list = [] text_body.scan(ENTITY_PATTERN) do |boundary, token, value| if token == "@" mention_list &lt;&lt; value else tag_list &lt;&lt; value end end [tag_list, mention_list] end </code></pre> <p>Add a validator to check the dependencies.</p> <p>General guideline I wish I knew before I started programming in rails after working in Java/C++/SQL for a long time.</p> <ul> <li><p>Do not hand code the table generation SQL</p></li> <li><p>Use db:create rake tasks for creating tables</p></li> <li><p>Rails does not support foregin keys. You can enforce it through validators.</p></li> <li><p>Do not use semicolons to terminate the line. One of the joys of ruby is you don't have terminate lines.</p></li> <li><p>Do not use explicit hashes for DSL API parameters.</p> <p>Use this idiom</p> <pre><code>belongs_to :content, :polymorphic =&gt; true </code></pre> <p>Instead of:</p> <pre><code>belongs_to :content, { :polymorphic =&gt; true }; </code></pre></li> <li><p>Use modules instead of inheritance for code re-usage.</p></li> <li><p>Use <code>each</code> instead of <code>for</code></p></li> <li><p>Learn <code>map</code>, <code>reduce</code> (i.e. <code>inject</code>) functions on an array.</p></li> </ul>
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    1. USHarish Shetty
    1. USHarish Shetty
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    1. COThanks a lot for the answer, I'll go watch the screen-casts when I get home. However I have a few issues with some of the later points you made. This may be due to my somewhat "stricter" background of languages though. `Do not use explicit hashes for DSL API parameters.` Why? One thing I've hated about ruby is that it doesn't enforce wrapping parenthesis around method arguments and it lets you lazily write hashes without the braces. For me, at least, writing arguments in that fashion makes it so much harder to decipher at a glance. Could be because I'm new to ruby, but I like the verbosity.
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    2. COAs for the explicit line terminators; I've spent so long writing them as a matter of course during C/C++,PHP,C#,Javascript...etc that it's so ingrained as to require a physical effort to remember to leave them out :)
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    3. COI empathize with the need to terminate the lines with semi-colons and explicitly surround the hashes with braces. In fact that is what I used when I started coding in Ruby. Convention is not to use them. I am quite sure year from now you will feel differently about this. There is a very good talk by Dave Thomas http://vimeo.com/61255738#t=2246. In one section he talks about the progression of code written by a non native Ruby developer. I found it apt.
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