Non-local requests result in user-friendly error pages.  Local requests, assumed to come from developers, see a more useful error message that includes line numbers and a backtrace.  &lt;code&gt;consider_all_requests_local&lt;/code&gt; allows your app to display these developer-friendly messages even when the machine making the request is remote.

At development level we set:

&gt; consider_all_requests_local set = true

because developer needs to take a look at full error showing layout/view as you can see in the image below.

[![enter image description here][1]][1]


But at production level, we don&#39;t need to show our internal coding bug so we set  false:

&gt; config.consider_all_requests_local = false

[![enter image description here][2]][2]


  [1]: https://i.stack.imgur.com/s9U2y.png
  [2]: https://i.stack.imgur.com/EpFqw.png

In Python, the where and when of using string concatenation versus string substitution eludes me. As the string concatenation has seen large boosts in performance, is this (becoming more) a stylistic decision rather than a practical one?

For a concrete example, how should one handle construction of flexible URIs:

    DOMAIN = &#39;http://stackoverflow.com&#39;
    QUESTIONS = &#39;/questions&#39;

    def so_question_uri_sub(q_num):
        return &quot;%s%s/%d&quot; % (DOMAIN, QUESTIONS, q_num)

    def so_question_uri_cat(q_num):
        return DOMAIN + QUESTIONS + &#39;/&#39; + str(q_num)

Edit: There have also been suggestions about joining a list of strings and for using named substitution. These are variants on the central theme, which is, which way is the Right Way to do it at which time? Thanks for the responses!

String concatenation vs. string substitution in Python

If I have a string with a valid math expression such as:

    String s = &quot;1 + 2 * 7&quot;;

Is there a built in library/function in .NET that will parse and evaluate that expression for me and return the result? In this case 15.

Is there a string math evaluator in .NET?

What is the purpose of this Rails config setting...

    config.action_controller.consider_all_requests_local = true

It&#39;s set to true by default in `config/environments/development.rb`.

Thanks,

Ethan

Purpose of &quot;consider_all_requests_local&quot; in config/environments/development.rb?

What is the purpose of this Rails config setting...
<pre><code class="hljs language-ini">config.action_controller.consider_all_requests_local = true
</code></pre>
It's set to true by default in <code>config/environments/development.rb</code>.
Thanks,
Ethan

An example of what I&#39;m talking about:

    class Person &lt; ActiveRecord::Base
      def name=(name)
        super(name.capitalize)
      end
      def name
        super().downcase  # not sure why you&#39;d do this; this is just an example
      end
    end

This seems to work, but I was just read the section on overriding attribute methods in the [ActiveRecord::Base docs](http://rails.rubyonrails.com/classes/ActiveRecord/Base.html), and it suggests using the `read_attribute` and `write_attribute` methods. I thought there must be something wrong with what I&#39;m doing in the example above; otherwise, why would they bless these methods as the &quot;right way&quot; to override attribute methods? They&#39;re also forcing a much uglier idiom, so there must be a good reason...

My real question: Is there something wrong with this example?

Override ActiveRecord attribute methods

I have two versions of rails (2.1.0 and 2.2.2) installed in my computer.

When I create a  new application, is it possible to specify that I want to use the older (2.1.0) version?


Specifying rails version to use when creating a new application

I&#39;ve been coding in Ruby for sometime now, but I don&#39;t understand when to use:

    def self.METHOD_NAME
    end

or just:

    def METHOD_NAME
    end

In any Rails model. Is &quot;self&quot; a modifier like private in Java? When should I use it and when not?. Thanks a ton.


To use self. or not.. in Rails

Say I need to call a javascript file in the `&lt;head&gt;` of an ERb template.
My instinct is to do the usual:

    &lt;head&gt;
	&lt;%= javascript_include_tag :defaults %&gt; &lt;!-- For example --&gt;
    &lt;/head&gt;

in my application&#39;s layout. The problem of course becoming that these javascript files are loaded into every page in my application, regardless of whether or not they are needed for the page being viewed.

So what I&#39;m wondering is if there&#39;s a good way of loading a javascript into the the headers of, for example, all ERb templates found only in a specific directory.


Javascript Include Tag Best Practice in a Rails Application

I&#39;m writing a rake task that does some DB work outside of Rails/ActiveRecord.

Is there a way to get the DB connection info (host, username, password, DB name) for the current environment as defined in `database.yml`?

I&#39;d like to get it so I can use it to connect like this...

    con = Mysql.real_connect(&quot;host&quot;, &quot;user&quot;, &quot;pw&quot;, &quot;current_db&quot;)

Can you get DB username, pw, database name in Rails?

How can I get the filename from a file path in Ruby?

For example if I have a path of `&quot;C:\projects\blah.dll&quot;` and I just want the &quot;blah&quot;.

Is there a `LastIndexOf` method in Ruby?


How to get filename without extension from file path in Ruby

When I get exceptions, it is often from deep within the call stack.  When this happens, more often than not, the actual offending line of code is hidden from me:

&lt;!-- language: lang-none --&gt;

    tmp.rb:7:in `t&#39;: undefined method `bar&#39; for nil:NilClass (NoMethodError)
            from tmp.rb:10:in `s&#39;
            from tmp.rb:13:in `r&#39;
            from tmp.rb:16:in `q&#39;
            from tmp.rb:19:in `p&#39;
            from tmp.rb:22:in `o&#39;
            from tmp.rb:25:in `n&#39;
            from tmp.rb:28:in `m&#39;
            from tmp.rb:31:in `l&#39;
             ... 8 levels...
            from tmp.rb:58:in `c&#39;
            from tmp.rb:61:in `b&#39;
            from tmp.rb:64:in `a&#39;
            from tmp.rb:67

That &quot;... 8 levels...&quot; truncation is causing me a great deal of trouble.  I&#39;m not having much success googling for this one:  How do I tell ruby that I want dumps to include the full stack?

How do I get ruby to print a full backtrace instead of a truncated one?

I am looking for a more elegant way of concatenating strings in Ruby.

I have the following line:

    source = &quot;#{ROOT_DIR}/&quot; &lt;&lt; project &lt;&lt; &quot;/App.config&quot;

Is there a nicer way of doing this?

And for that matter what is the difference between `&lt;&lt;` and `+`?

String concatenation in Ruby

I&#39;ve been programming in Ruby for a few months now, and I&#39;m wondering when it is appropriate to use constants over class variables and vice versa. (I&#39;m working in Rails, thinking about constants in models).

    class Category
      TYPES = %w(listing event business).freeze
    end

OR

    class Category
      @@types = %w(listing event business).freeze
      cattr_reader :types
    end

Are there circumstances where one is preferable to another? Or is it just a matter of taste/style?

Content Type	Original Author	Original Content on Stackoverflow
Question	Ethan	View Question on Stackoverflow
Solution 1 - Ruby on-Rails	Gordon Wilson	View Answer on Stackoverflow
Solution 2 - Ruby on-Rails	Touseef Murtaza	View Answer on Stackoverflow

Purpose of "consider_all_requests_local" in config/environments/development.rb?

Ruby on-Rails Problem Overview

Ruby on-Rails Solutions

Solution 1 - Ruby on-Rails

Solution 2 - Ruby on-Rails

Is there a string math evaluator in .NET?

String concatenation vs. string substitution in Python

Attributions