ActiveRecord and [] accessors - Ruby on Rails: Core

The old Google Groups will be going away soon, but your browser is incompatible with the new version.
Message from discussion ActiveRecord and [] accessors
Received-SPF: pass (google.com: domain of k...@actionmoniker.com designates 209.85.216.52 as permitted sender) client-ip=209.85.216.52;
Subject: Re: [Rails-core] ActiveRecord and [] accessors
References: <4F7F0218.70...@gmail.com>
From: Ken Collins <k...@actionmoniker.com>
Content-Type: multipart/alternative;
	boundary=Apple-Mail-3F8870C6-145D-42C7-ACA1-9428EFF8581C
In-Reply-To: <4F7F0218.70...@gmail.com>
Message-Id: <9BF96CB2-5899-4EDD-8C23-05E183F29...@actionmoniker.com>
Date: Fri, 6 Apr 2012 11:24:54 -0400
To: "rubyonrails-core@googlegroups.com" <rubyonrails-core@googlegroups.com>
Content-Transfer-Encoding: 7bit
Mime-Version: 1.0 (1.0)


--Apple-Mail-3F8870C6-145D-42C7-ACA1-9428EFF8581C
Content-Transfer-Encoding: quoted-printable
Content-Type: text/plain;
	charset=us-ascii

They are established aliases to read and write attribute. I know changing wo=
uld break a ton of my own code and various gems I author.=20

Sent from my iPad

On Apr 6, 2012, at 10:47 AM, Rodrigo Rosenfeld Rosas <rr.ro...@gmail.com> wr=
ote:

> Currently [] and []=3D are defined as follows for ActiveRecord instances:
>=20
> https://github.com/rails/rails/blob/master/activerecord/lib/active_record/=
attribute_methods.rb
>=20
> def [](attr_name)
>   read_attribute(attr_name)
> end
>=20
> def []=3D(attr_name, value)
>   write_attribute(attr_name, value)
> end
>=20
> If those accessors are used then overridden attribute accessors wouldn't b=
e called.
>=20
> I didn't find any references about the []/[]=3D methods in the current API=
, so I just mentioned them in docrails:
>=20
> https://github.com/lifo/docrails/commit/a49fe6ec2cb9f22a3b18d7db5ae2ee9032=
5e9d09
>=20
> But then I realized that the given example may have undesired side effects=
:
>=20
> [:deleted, :disabled].each{|p| model[p] =3D params[p] =3D=3D 'true' }
>=20
> What if "deleted=3D" or "disabled=3D" were overridden? They wouldn't be ca=
lled.
>=20
> So I was thinking that maybe Rails 4 could change their implementation to:=

>=20
> def [](attr_name)
>   send attr_name.to_s
> end
>=20
> def []=3D(attr_name, value)
>   send :"#{attr_name}=3D", value
> end
>=20
> Better to read this style of code in some framework than inside some appli=
cation...
>=20
> Any thoughts?
>=20
> Happy Easter!
>=20
> Rodrigo.
>=20
> --=20
> You received this message because you are subscribed to the Google Groups "=
Ruby on Rails: Core" group.
> To post to this group, send email to rubyonrails-core@googlegroups.com.
> To unsubscribe from this group, send email to rubyonrails-core+unsubscribe=
@googlegroups.com.
> For more options, visit this group at http://groups.google.com/group/rubyo=
nrails-core?hl=3Den.

--Apple-Mail-3F8870C6-145D-42C7-ACA1-9428EFF8581C
Content-Transfer-Encoding: 7bit
Content-Type: text/html;
	charset=utf-8

<html><head></head><body bgcolor="#FFFFFF"><div>They are established aliases to read and write attribute. I know changing would break a ton of my own code and various gems I author.&nbsp;<br><br>Sent from my iPad</div><div><br>On Apr 6, 2012, at 10:47 AM, Rodrigo Rosenfeld Rosas &lt;<a href="mailto:rr.ro...@gmail.com">rr.ro...@gmail.com</a>&gt; wrote:<br><br></div><div></div><blockquote type="cite"><div>
  

    <meta http-equiv="content-type" content="text/html; charset=ISO-8859-1">
  
  
    Currently [] and []= are defined as follows for ActiveRecord
    instances:<br>
    <br>
    <meta http-equiv="content-type" content="text/html;
      charset=ISO-8859-1">
    <a href="https://github.com/rails/rails/blob/master/activerecord/lib/active_record/attribute_methods.rb">https://github.com/rails/rails/blob/master/activerecord/lib/active_record/attribute_methods.rb</a><br>
    <br>
    def [](attr_name)<br>
    &nbsp; read_attribute(attr_name)<br>
    end<br>
    <br>
    def []=(attr_name, value)<br>
    &nbsp; write_attribute(attr_name, value)<br>
    end<br>
    <br>
    If those accessors are used then overridden attribute accessors
    wouldn't be called.<br>
    <br>
    I didn't find any references about the []/[]= methods in the current
    API, so I just mentioned them in docrails:<br>
    <br>
    <meta http-equiv="content-type" content="text/html;
      charset=ISO-8859-1">
    <a href="https://github.com/lifo/docrails/commit/a49fe6ec2cb9f22a3b18d7db5ae2ee90325e9d09">https://github.com/lifo/docrails/commit/a49fe6ec2cb9f22a3b18d7db5ae2ee90325e9d09</a><br>
    <br>
    But then I realized that the given example may have undesired side
    effects:<br>
    <br>
    <meta http-equiv="content-type" content="text/html;
      charset=ISO-8859-1">
    [:deleted, :disabled].each{|p| model[p] = params[p] == 'true' }<br>
    <br>
    What if "deleted=" or "disabled=" were overridden? They wouldn't be
    called.<br>
    <br>
    So I was thinking that maybe Rails 4 could change their
    implementation to:<br>
    <br>
    def [](attr_name)<br>
    &nbsp; send attr_name.to_s<br>
    end<br>
    <br>
    def []=(attr_name, value)<br>
    &nbsp; send :"#{attr_name}=", value<br>
    end<br>
    <br>
    Better to read this style of code in some framework than inside some
    application...<br>
    <br>
    Any thoughts?<br>
    <br>
    Happy Easter!<br>
    <br>
    Rodrigo.<br>
    <br>
  


<p></p>

-- <br>
You received this message because you are subscribed to the Google Groups "Ruby on Rails: Core" group.<br>
To post to this group, send email to <a href="mailto:rubyonrails-core@googlegroups.com">rubyonrails-core@googlegroups.com</a>.<br>
To unsubscribe from this group, send email to <a href="mailto:rubyonrails-core+unsubscribe@googlegroups.com">rubyonrails-core+unsubscribe@googlegroups.com</a>.<br>

For more options, visit this group at <a href="http://groups.google.com/group/rubyonrails-core?hl=en">http://groups.google.com/group/rubyonrails-core?hl=en</a>.<br>


</div></blockquote></body></html>
--Apple-Mail-3F8870C6-145D-42C7-ACA1-9428EFF8581C--
Create a group - Google Groups - Google Home - Terms of Service - Privacy Policy
Account Options
