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When to use a “has_many :through” relation in Rails?
I am trying to understand what has_many :through is and when to use it (and how). However, I am not getting it. I am reading Beginning Rails 3 and I tried Googling, but I am not able to understand.
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Regex exactly n OR m times
...ou are doing it is fine.
An alternative is:
X{m}(X{k})?
where m < n and k is the value of n-m.
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Change key pair for ec2 instance
...e it in the same subnet, otherwise you will have to terminate the instance and create it again. - see here
Attach volume A to the new micro instance, as /dev/xvdf (or /dev/sdf)
SSH to the new micro instance and mount volume A to /mnt/tmp
$ sudo mount /dev/xvdf1 /mnt/tmp
Copy ~/.ssh/authorized_keys ...
What is the use for Task.FromResult in C#
In C# and TPL ( Task Parallel Library ), the Task class represents an ongoing work that produces a value of type T.
6 Ans...
Difference between java.util.Random and java.security.SecureRandom
My team got handed over some server side code (in Java) that generates random tokens and I have a question regarding the same -
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How do I undo the most recent local commits in Git?
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Undo a commit and redo
$ git commit -m "Something terribly misguided" # (1)
$ git reset HEAD~ # (2)
<< edit files as necessary >> # (3)
$ git add...
How to handle the modal closing event in Twitter Bootstrap?
... to figure out if there is a way to listen to the close event of the modal and execute a function.
5 Answers
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How do Third-Party “tracking cookies” work?
...rd-party tracking cookies work, but am still very confused.
I don't understand how if I visit Website A (a normal website with ads) how Website B (an advertising website) can assign my computer an ID, and then figure out that I was on website A, and other websites after it that have its ads.
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Difference between std::result_of and decltype
I have some trouble understanding the need for std::result_of in C++0x. If I understood correctly, result_of is used to obtain the resulting type of invoking a function object with certain types of parameters. For example:
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How can I set the max-width of a table cell using percentages?
... definition of max-width in the CSS 2.1 spec, “the effect of 'min-width' and 'max-width' on tables, inline tables, table cells, table columns, and column groups is undefined.” So you cannot directly set max-width on a td element.
If you just want the second column to take up at most 67%, then y...