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How to change the Push and Pop animations in a navigation based app
...t common, everyday transitions (such as an ordinary slide), you do have to all the work of implementing a full custom transition.
Here's how to do it ...
1. You need a custom UIViewControllerAnimatedTransitioning
You need a bool of your own like popStyle . (Is it popping on, or popping off?)
You m...
Total memory used by Python process?
...os
import psutil
process = psutil.Process(os.getpid())
print(process.memory_info().rss) # in bytes
On my current Python 2.7 install with psutil 5.6.3, the last line should be
print(process.memory_info()[0])
instead (there was a change in the API).
Note: do pip install psutil if it is not in...
Continuously read from STDOUT of external process in Ruby
...iven by blender line by line to update a progress bar in a GUI. It's not really important that blender is the external process whose stdout I need to read.
...
How can I initialize base class member variables in derived class constructor?
...ince it would destroy encapsulation. Instead, create a constructor in A to allow B (or any subclass of A) to initialize them:
class A
{
protected:
A(int a, int b) : a(a), b(b) {} // Accessible to derived classes
// Change "protected" to "public" to allow others to instantiate A.
private:
...
How to get a JavaScript object's class?
...
ES5 has aditionally Object.getPrototypeOf()
– Christoph
Aug 8 '09 at 18:52
29
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When saving, how can you check if a field has changed?
...
Essentially, you want to override the __init__ method of models.Model so that you keep a copy of the original value. This makes it so that you don't have to do another DB lookup (which is always a good thing).
class Person(models.Model):
name = models.CharF...
What's wrong with nullable columns in composite primary keys?
...
Primary keys are for uniquely identifying rows. This is done by comparing all parts of a key to the input.
Per definition, NULL cannot be part of a successful comparison. Even a comparison to itself (NULL = NULL) will fail. This means a key containing NULL would not work.
Additonally, NULL is al...
Fastest Way to Serve a File Using PHP
...erywhere.
Using the X-SendFile header
As documented by others it's actually the best way. The basis is that you do your access control in php and then instead of sending the file yourself you tell the web server to do it.
The basic php code is :
header("X-Sendfile: $file_name");
header("Conten...
Token Authentication for RESTful API: should the token be periodically changed?
...
It is good practice to have mobile clients periodically renew their authentication token. This of course is up to the server to enforce.
The default TokenAuthentication class does not support this, however you can extend it to achieve this functionality.
For example:
from...
putting current class as return type annotation [duplicate]
...e. Instead, they are preserved in __annotations__ in string form. This is called Postponed Evaluation of Annotations, introduced in PEP 563.
Also note:
Deprecation policy
Starting with Python 3.7, a __future__ import is required to use the
described functionality. No warnings are raised...