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Difference between case object and object
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Case classes differ from regular classes in that they get:
pattern matching support
default implementations of equals and hashCode
default implementations of serialization
a prettier default implementation of toString, and
the small amount of...
ViewDidAppear is not called when opening app from background
...roller in which my value is 0 (label) and when I open that View Controller from another ViewController I have set viewDidAppear to set value 20 on label. It works fine but when I close my app and than again I open my app but the value doesn't change because viewDidLoad , viewDidAppear and v...
How to upgrade PostgreSQL from version 9.6 to version 10.1 without losing data?
...s10.1 -E utf8
run pg_upgrade (note: change bin version if you're upgrading from something other than below):
pg_upgrade -v \
-d /usr/local/var/postgres \
-D /usr/local/var/postgres10.1 \
-b /usr/local/Cellar/postgresql/9.6.5/bin/ \
-B /usr/local/Cellar/postgresql/10.1/bin/
-v to e...
return statement vs exit() in main()
...ata might not be flushed is in the opposite case: i.e. if one uses return from main() and one has called setbuf() or setvbuf() with a buffer declared as automatic storage in main() (as discussed in R.'s answer below). It's really too bad this question is tagged with both C and C++ (and coding-styl...
What does FETCH_HEAD in Git mean?
...TCH_HEAD is a short-lived ref, to keep track of what has just been fetched from the remote repository. git pull first invokes git fetch, in normal cases fetching a branch from the remote; FETCH_HEAD points to the tip of this branch (it stores the SHA1 of the commit, just as branches do). git pull th...
How to manage local vs production settings in Django?
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In settings.py:
try:
from local_settings import *
except ImportError as e:
pass
You can override what needed in local_settings.py; it should stay out of your version control then. But since you mention copying I'm guessing you use none ;)
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When should I use RequestFactory vs GWT-RPC?
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I went through a transition from RPC to RF. First I have to say my experience is limited in that, I used as many EntityProxies as 0.
Advantages of GWT RPC:
It's very easy to set-up, understand and to LEARN!
Same class-based objects are used on the c...
Design Patterns: Abstract Factory vs Factory Method
...omplicated refer to next diagram for better real-life example).
Example From The .NET Framework
DbFactoriesProvider is a Simple Factory as it has no sub-types. The DbFactoryProvider is an abstract factory as it can create various related database objects such as connection and command objects.
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Add text to Existing PDF using Python
... with canvas>
can.save()
packet.seek(0)
input = PdfFileReader(packet)
From here you can merge the pages of the input file with another document.
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Android update activity UI from service
...ground operations even when no
Activity is running, also start the service from the Application
class so that it does not get stopped when unbound.
The advantages I have found in this approach compared to the startService()/LocalBroadcast technique are
No need for data objects to implement Parce...