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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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Check if passed argument is file or directory in Bash
... pass it either a filename or a directory, and be able to do something specific when it's a file, and something else when it's a directory. The problem I'm having is when the directory name, or probably files too, has spaces or other escapable characters are in the name.
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How do I use the ternary operator ( ? : ) in PHP as a shorthand for “if / else”?
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The
(condition) ? /* value to return if condition is true */
: /* value to return if condition is false */ ;
syntax is not a "shorthand if" operator (the ? is called the conditional operator) because you cannot execute code in the same manner as i...
Parse v. TryParse
What is the difference between Parse() and TryParse()?
8 Answers
8
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PHP + MySQL transactions examples
... transaction
$db->beginTransaction();
// A set of queries; if one fails, an exception should be thrown
$db->query('first query');
$db->query('second query');
$db->query('third query');
// If we arrive here, it means that no exception was thrown
// i....
How to get the last value of an ArrayList
...st implements):
E e = list.get(list.size() - 1);
E is the element type. If the list is empty, get throws an IndexOutOfBoundsException. You can find the whole API documentation here.
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How can I delete a query string parameter in JavaScript?
... parameter ‘bar’ would match:
?a=b&foobar=c
Also, it would fail if parameter contained any characters that are special in RegExp, such as ‘.’. And it's not a global regex, so it would only remove one instance of the parameter.
I wouldn't use a simple RegExp for this, I'd parse the pa...
How do I check (at runtime) if one class is a subclass of another?
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If there's one thing that's a constant on Stack Overflow, it is that any questions with an answer that implies isinstance or issubclass will also be accompanied with lectures about duck typing!
– B Robst...
“unary operator expected” error in Bash if condition
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If you know you're always going to use bash, it's much easier to always use the double bracket conditional compound command [[ ... ]], instead of the Posix-compatible single bracket version [ ... ]. Inside a [[ ... ]] compou...
Deleting a file in VBA
...ere's a function for you:
Sub DeleteFile(ByVal FileToDelete As String)
If FileExists(FileToDelete) Then 'See above
' First remove readonly attribute, if set
SetAttr FileToDelete, vbNormal
' Then delete the file
Kill FileToDelete
End If
End Sub
Aga...