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How to determine if a record is just created or updated in after_save
The #new_record? function determines if a record has been saved. But it is always false in the after_save hook. Is there a way to determine whether the record is a newly created record or an old one from update?
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Why is no one using make for Java?
Just about every Java project that I've seen either uses Maven or Ant. They are fine tools and I think just about any project can use them. But what ever happened to make ? It's used for a variety of non-Java projects and can easily handle Java. Sure you have to download make.exe if you use Win...
How to debug heap corruption errors?
I am debugging a (native) multi-threaded C++ application under Visual Studio 2008. On seemingly random occasions, I get a "Windows has triggered a break point..." error with a note that this might be due to a corruption in the heap. These errors won't always crash the application right away, altho...
Defining a variable with or without export
What is export for?
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Use 'class' or 'typename' for template parameters? [duplicate]
When defining a function template or class template in C++, one can write this:
10 Answers
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Selecting multiple columns in a pandas dataframe
I have data in different columns but I don't know how to extract it to save it in another variable.
18 Answers
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Does python have an equivalent to Java Class.forName()?
I have the need to take a string argument and create an object of the class named in that string in Python. In Java, I would use Class.forName().newInstance() . Is there an equivalent in Python?
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ReactJS state vs prop
This may be treading that line between answerable and opinionated, but I'm going back and forth as to how to structure a ReactJS component as complexity grows and could use some direction.
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How do I insert a linebreak where the cursor is without entering into insert mode in Vim?
Is possible to insert a line break where the cursor is in Vim without entering into insert mode? Here's an example ( [x] means cursor is on x ):
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How to check whether a string contains a substring in Ruby
I have a string variable with content:
9 Answers
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