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PORails 3.2: Chaining lambda scopes?
 

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  1. PORails 3.2: Chaining lambda scopes?
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    <p>In my Rails 3.2.8 app I have some named scopes I would like to chain together in some circumstances.</p> <p>So, for example, I have these two scopes:</p> <pre><code>scope :by_status, lambda { |status| if status == "All" then WorkRequest.all else WorkRequest.find_all_by_status(status) end } scope :in_date_range, lambda { |start_date, end_date| includes([:person, :pier_module]).where("(status_date &gt;= ?) AND (status_date &lt;= ?)", start_date, end_date) } </code></pre> <p>I use them separately, but I'd also like to be able to call them together like this:</p> <pre><code>WorkRequest.by_status("Accepted").in_date_range("2012-01-01", "2012-10-02") </code></pre> <p>When I try that it complains that in_date_range is not a method of Array.</p> <p>But I have another scope, </p> <pre><code>scope :active, includes([:person, :pier_module]).where("status = 'New Request'") </code></pre> <p>and if I do</p> <pre><code>WorkRequest.active.in_date_range("2012-01-01", "2012-10-02") </code></pre> <p>it works! Apparently the active scope returns a Relation, whereas the lambda scopes return Arrays, and so can't be chained.</p> <p>I'd love to know why the difference between simpler scopes and lambda scopes, how the parameters affect it, and whether there's anything I can do short of writing a combined scope, which I've done.</p> <pre><code>scope :by_status_in_date_range, lambda { |status, start_date, end_date| includes([:person, :pier_module]).where("(status = ?) AND (status_date &gt;= ?) AND (status_date &lt;= ?)", status, start_date, end_date) } </code></pre> <p>Works, but not very DRY (since I need the individual scopes, too) or Rails-ish. Searching here and elsewhere I've seen similar questions but none that seem to apply to this situation, where I'm trying to chain two lambdas with parameters.</p>
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    1. USDan Barron
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    1. COJust out of curiosity, does `WorkRequest.in_date_range("2012-01-01", "2012-10-02").by_status("Accepted")` work?
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      1. PORails 3.2: Chaining lambda scopes?
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    2. COI does! I was too "tunnel visioned" to try it. I was convinced it was due to the lambdas, but apparently not. This is is great, I can call it that way, but still leaves me wondering why in_date_range returns a Relation, and by_status an Array. Curiouser and curiouser.
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      1. PORails 3.2: Chaining lambda scopes?
      1. USDan Barron
 

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