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Determine what attributes were changed in Rails after_save callback?
I'm setting up an after_save callback in my model observer to send a notification only if the model's published attribute was changed from false to true. Since methods such as changed? are only useful before the model is saved, the way I'm currently (and unsuccessfully) trying to do so is as fol...
Ruby on Rails - Import Data from a CSV file
...
require 'csv'
csv_text = File.read('...')
csv = CSV.parse(csv_text, :headers => true)
csv.each do |row|
Moulding.create!(row.to_hash)
end
share
|
...
Using pickle.dump - TypeError: must be str, not bytes
..., that's why you are here.
import pickle
class MyUser(object):
def __init__(self,name):
self.name = name
user = MyUser('Peter')
print("Before serialization: ")
print(user.name)
print("------------")
serialized = pickle.dumps(user)
filename = 'serialized.native'
with open(filename,...
Best way to parse RSS/Atom feeds with PHP [closed]
...e RSS experience and needs a better parser.
– duality_
Jul 30 '11 at 13:49
3
In case somebody nee...
How do I print a double value with full precision using cout?
...cision of a float or double.
#include <limits>
typedef std::numeric_limits< double > dbl;
double d = 3.14159265358979;
cout.precision(dbl::max_digits10);
cout << "Pi: " << d << endl;
share
...
Class vs. static method in JavaScript
...thing similar to a class in a standard OOP language.
I'd suggest ignoring __proto__ most of the time because it has poor cross browser support, and instead focus on learning about how prototype works.
If you have an instance of an object created from a function2 and you access one of its members (...
How to iterate a loop with index and element in Swift
...100, height: 100)
button.addTarget(self, action: #selector(iterate(_:)), for: .touchUpInside)
view.addSubview(button)
}
@objc func iterate(_ sender: UIButton) {
let tuple = generator.next()
print(String(describing: tuple))
}
}
PlaygroundPage.current.liv...
XAMPP - Port 80 in use by “Unable to open process” with PID 4! 12
...This worked for me too, except I exited out of everything, clicked on xampp_start in C:/xampp and then changed it to port 81. 8080 didn't work for me.
– user3553260
Oct 4 '16 at 20:41
...
Captured variable in a loop in C#
...riencing is something known as Closure http://en.wikipedia.org/wiki/Closure_(computer_science). Your lamba has a reference to a variable which is scoped outside the function itself. Your lamba is not interpreted until you invoke it and once it is it will get the value the variable has at execution t...
Do sealed classes really offer performance Benefits?
... Release build configuration) emits identical MSIL, which is as follows:
L_0000: newobj instance void <NormalClass or SealedClass>::.ctor()
L_0005: stloc.0
L_0006: ldloc.0
L_0007: ldstr "a string"
L_000c: callvirt instance void <NormalClass or SealedClass>::WriteIt(string)
L_0011: ret...