Ruby (the programming language) doesn&#39;t have `10.hours`, that&#39;s `ActiveSupport` as part of Ruby on Rails (the web framework). And yes, it does have both [`minutes`](http://api.rubyonrails.org/classes/Numeric.html#method-i-minutes) and [`seconds`](http://api.rubyonrails.org/classes/Numeric.html#method-i-seconds) methods.

However, [`Time#+`](http://ruby-doc.org/core/classes/Time.html#M000357) (the + method on Time instances) returns a new Time instance that is that many seconds in the future. So without any Ruby on Rails sugar, you can simply do:

    irb&gt; t = Time.now
    #=&gt; 2011-08-03 22:35:01 -0600

    irb&gt; t2 = t + 10               # 10 Seconds
    #=&gt; 2011-08-03 22:35:11 -0600

    irb&gt; t3 = t + 10*60            # 10 minutes
    #=&gt; 2011-08-03 22:45:01 -0600

    irb&gt; t4 = t + 10*60*60         # 10 hours
    #=&gt; 2011-08-04 08:35:01 -0600




If you are using ActiveSupport, what you are looking for is the full `.minutes` and `.seconds`.

    Time.now + 10.minutes
    Time.now + 10.seconds

Also in ActiveSupport you can do:

    10.minutes.from_now

    10.minutes.ago

I think you&#39;re talking about extensions added by Rails. I think you need `15.minutes`.

See the [Active Support Core Extensions for Date, DateTime and Time][1] for more information.


  [1]: https://guides.rubyonrails.org/active_support_core_extensions.html#extensions-to-date

Time Object

`time = Time.now`

Adding minutes to a time object:

`time + 5.minutes`

I would like to understand relationship between jQuery object and DOM element..

When jQuery returns an element it shows up as `[object Object]` in an alert. 
When `getElementByID` returns an element it shows up as `[object HTMLDivElement]`. What does that mean exactly? I mean are both of them objects with a difference ?

Also what methods can operate on jQuery object vs DOM element? Can a single jQuery object represent multiple DOM elements ?

jQuery object and DOM element

How to get specific product attribute value if i know product ID without loading whole product?

Magento Product Attribute Get Value

In Ruby, how do I do `Time.now + 10.hours`?

Is there an equivalent for `secs` and `mins`?  For example:

    Time.now + 15.mins

How to add minutes to a Time object

In Ruby, how do I do <code>Time.now + 10.hours</code>?
Is there an equivalent for <code>secs</code> and <code>mins</code>? For example:
<pre><code class="hljs language-css">Time.now + 15.mins
</code></pre>

For some reason, Delayed::Job&#39;s has decided to queue up but not excecute anything even though I&#39;ve restarted it several times, even kill -9&#39;d it and restarted it. It won&#39;t run any jobs.

Can I , in /console, specify a specific job and tell it to work?

Ex:.. `Delayed::Job.find(x).run`

How do you tell a specific Delayed::Job to run in console?

What would the difference be?

Example Match:&lt;br/&gt;
`match &#39;photos/show&#39; =&gt; &#39;photos#show&#39;`

Example Get:&lt;br/&gt;
`get &#39;photos/show&#39;`

Wouldn&#39;t both make it possible to reach the photos/show URL and also use the show action in the photos controller?

Thanks

Ruby on Rails Routes - difference between get and match

A `Person` can have many `Events` and each `Event` can have one polymorphic `Eventable` record.  How do I specify the relationship between the `Person` and the `Eventable` record?

Here are the models I have:

    class Event &lt; ActiveRecord::Base
      belongs_to :person
      belongs_to :eventable, :polymorphic =&gt; true
    end
    
    class Meal &lt; ActiveRecord::Base
      has_one :event, :as =&gt; eventable
    end
   
    class Workout &lt; ActiveRecord::Base
      has_one :event, :as =&gt; eventable
    end

The main question concerns the `Person` class:

    class Person &lt; ActiveRecord::Base
      has_many :events
      has_many :eventables, :through =&gt; :events  # is this correct???
    end

Do I say `has_many :eventables, :through =&gt; :events` like I did above?

Or do I have to spell them all out like so:

    has_many :meals, :through =&gt; :events
    has_many :workouts, :through =&gt; :events

If you see an easier way to accomplish what I&#39;m after, I&#39;m all ears! :-)


Rails: has_many through with polymorphic association - will this work?

Using this modified example from [the Rails guides][1], how does one model a relational &quot;has_many :through&quot; association using mongoid?

The challenge is that mongoid does not support has_many :through as ActiveRecord does.

    # doctor checking out patient
    class Physician &lt; ActiveRecord::Base
      has_many :appointments
      has_many :patients, :through =&gt; :appointments
      has_many :meeting_notes, :through =&gt; :appointments
    end
    
    # notes taken during the appointment
    class MeetingNote &lt; ActiveRecord::Base
      has_many :appointments
      has_many :patients, :through =&gt; :appointments
      has_many :physicians, :through =&gt; :appointments
    end
    
    # the patient
    class Patient &lt; ActiveRecord::Base
      has_many :appointments
      has_many :physicians, :through =&gt; :appointments
      has_many :meeting_notes, :through =&gt; :appointments
    end
     
    # the appointment
    class Appointment &lt; ActiveRecord::Base
      belongs_to :physician
      belongs_to :patient
      belongs_to :meeting_note
      # has timestamp attribute
    end


  [1]: http://guides.rubyonrails.org/association_basics.html#the-has-many-through-association

How to implement has_many :through relationships with Mongoid and mongodb?

I want to truncate a string as follows:

**input:**

    string = &quot;abcd asfsa sadfsaf safsdaf aaaaaaaaaa aaaaaaaaaa dddddddddddddd&quot;

**output:**

    string = &quot;abcd asfsa sadfsaf safsdaf aa...ddddd&quot;

Truncate string with Rails?

Maybe it&#39;s just my lack of abilities to find stuff here that is the problem, but I can&#39;t find anything about how to create multidimensional arrays in Ruby.

Could someone please give me an example on how to do it? 

Ruby multidimensional array

I&#39;m using ruby 1.9.2

I&#39;m trying to **parse a CSV file** that contains some French words (e.g. sp&#233;cifi&#233;) and place the contents in a MySQL database.


When I read the lines from the CSV file,

    file_contents = CSV.read(&quot;csvfile.csv&quot;, col_sep: &quot;$&quot;)

The elements come back as Strings that are **ASCII-8BIT** encoded (sp&#233;cifi&#233; becomes sp\xE9cifi\xE9), and strings like &quot;sp&#233;cifi&#233;&quot; are then NOT properly saved into my MySQL database. 

[Yehuda Katz][1] says that ASCII-8BIT is really &quot;binary&quot; data meaning that CSV has no idea how to read the appropriate encoding.

So, if I try to make CSV force the encoding like this:

`file_contents = CSV.read(&quot;csvfile.csv&quot;, col_sep: &quot;$&quot;, encoding: &quot;UTF-8&quot;)` 

I get the following error

    ArgumentError: invalid byte sequence in UTF-8: 

If I go back to my original ASCII-8BIT encoded Strings and examine the String that my CSV read as ASCII-8BIT, it looks like this &quot;Non sp\xE9cifi\xE9&quot; instead of &quot;Non sp&#233;cifi&#233;&quot;.

I can&#39;t convert &quot;Non sp\xE9cifi\xE9&quot; to &quot;Non sp&#233;cifi&#233;&quot; by doing this 
`&quot;Non sp\xE9cifi\xE9&quot;.encode(&quot;UTF-8&quot;)` 

because I get this error: 

`Encoding::UndefinedConversionError: &quot;\xE9&quot; from ASCII-8BIT to UTF-8`, 

which Katz indicated would happen because ASCII-8BIT isn&#39;t really a proper String &quot;encoding&quot;.

**Questions:**

 1. **Can I get CSV to read my file in the appropriate encoding?  If so, how?**
 2. **How do I convert an ASCII-8BIT string to UTF-8 for proper storage in MySQL?** 

  [1]: http://yehudakatz.com/2010/05/05/ruby-1-9-encodings-a-primer-and-the-solution-for-rails/

Ruby read CSV file as UTF-8 and/or convert ASCII-8Bit encoding to UTF-8

Since upgrading to Rails 3.1 I&#39;m seeing this warning message in my development log:

&gt; WARN  Could not determine content-length of response body. Set content-length of the response or set `Response#chunked = true`

What does this mean and how can I remove it? Is it a problem?

What does &quot;WARN Could not determine content-length of response body.&quot; mean and how to I get rid of it?

I am new programmar in Ruby. Can someone take an example about opening file with r+,w+,a+ mode in Ruby? What is difference between them and r,w,a?

Please explain, and provide an example.

File opening mode in Ruby

What is the difference between `Timestamp` and `Datetime` SQL Server?

I thought Both formats are capable of storing date + time. Then, Where the difference is lying between them?

But `Timestamp` is not capable of storing date, time information.

Still Whats the difference?

Difference between datetime and timestamp in sqlserver?

The date string looks like this

`2011-08-19 17:14:40`

(year-month-day  hours:minutes:seconds)


How can I find out if the date is older than the current date with more than 30 days?

find if date is older than 30 days

Lets say I have an array as:

`int a[]={4,5,7,10,2,3,6}`

when I access an element, such as `a[3]`, what does actually happen behind the scenes?
Why do many algorithm books (such as the Cormen book...) say that it takes a constant time? 

(I&#39;m just a noob in low-level programming so I would like to learn more from you guys)

why does accessing an element in an array take constant time?

Is there a simple way / module to _correctly_ measure the elapsed time in python? I know that I can simply call `time.time()` twice and take the difference, but that will yield wrong results if the system time is changed. Granted, that doesn&#39;t happen very often, but it does indicate that I&#39;m measuring the wrong thing.

Using `time.time()` to measure durations is incredibly roundabout when you think about it. You take the difference of two absolute time measurements which are in turn constructed from duration measurements (performed by timers) and known absolute times (set manually or via ntp), that you aren&#39;t interested in at all.

So, is there a way to query this &quot;timer time&quot; directly? I&#39;d imagine that it can be represented as a millisecond or microsecond value that has no meaningful absolute representation (and thus doesn&#39;t need to be adjusted with system time). Looking around a bit it seems that this is exactly what `System.nanoTime()` does in Java, but I did not find a corresponding Python function, even though it should (hardware-technically) be easier to provide than `time.time()`.

Edit: To avoid confusion and address the answers below: This is not about DST changes, and I don&#39;t want CPU time either - I want elapsed physical time. It doesn&#39;t need to be very fine-grained, and not even particularly accurate. It just shouldn&#39;t give me negative durations, or durations which are off by several orders of magnitude (above the granularity), just because someone decided to set the system clock to a different value. Here&#39;s what the Python docs say about &#39;time.time()&#39;:

[&quot;While this function normally returns non-decreasing values, it can return a lower value than a previous call if the system clock has been set back between the two calls&quot;][1]

This is exactly what I want to avoid, since it can lead to strange things like negative values in time calculations. I can work around this at the moment, but I believe it is a good idea to learn using the proper solutions where feasible, since the kludges will come back to bite you one day.

Edit2: Some research shows that you can get a system time independent measurement like I want in Windows by using GetTickCount64(), under Linux you can get it in the return value of times(). However, I still can&#39;t find a module which provides this functionality in Python.

  [1]: http://docs.python.org/library/time.html#time.time

Measuring elapsed time in python

I am trying to figure out the differences between the `datetime` and `time` modules, and what each should be used for.

I know that `datetime` provides both dates and time.  What is the use of the `time` module?

Examples would be appreciated and differences concerning timezones would especially be of interest.

Content Type	Original Author	Original Content on Stackoverflow
Question	keruilin	View Question on Stackoverflow
Solution 1 - Ruby on-Rails	Phrogz	View Answer on Stackoverflow
Solution 2 - Ruby on-Rails	twe4ked	View Answer on Stackoverflow
Solution 3 - Ruby on-Rails	mahi-man	View Answer on Stackoverflow
Solution 4 - Ruby on-Rails	Gishu	View Answer on Stackoverflow
Solution 5 - Ruby on-Rails	Sushant	View Answer on Stackoverflow

How to add minutes to a Time object

Ruby on-Rails Problem Overview

Ruby on-Rails Solutions

Solution 1 - Ruby on-Rails

Solution 2 - Ruby on-Rails

Solution 3 - Ruby on-Rails

Solution 4 - Ruby on-Rails

Solution 5 - Ruby on-Rails

Magento Product Attribute Get Value

jQuery object and DOM element

Attributions