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Unique fields that allow nulls in Django
...the CharField that allows empty strings to be stored as NULL.
"""
description = "CharField that stores NULL but returns ''."
def from_db_value(self, value, expression, connection, contex):
"""
Gets value right out of the db and changes it if its ``None``.
"""
...
Detect permission of camera in iOS
...aType)")
}
}
}
Since iOS 10 you need to specify
NSCameraUsageDescription key in your Info.plist to be able ask for camera access, otherwise your app will crash at runtime. See APIs Requiring Usage Descriptions.
As an interesting side note, did you know that iOS kills the app if it's r...
Check for internet connection availability in Swift
...ype: CustomStringConvertible {
case WWAN
case WiFi
public var description: String {
switch self {
case .WWAN: return "WWAN"
case .WiFi: return "WiFi"
}
}
}
public enum ReachabilityStatus: CustomStringConvertible {
case Offline
case Online(Re...
Using psql how do I list extensions installed in a database?
...T e.extname AS "Name", e.extversion AS "Version", n.nspname AS "Schema", c.description AS "Description"
FROM pg_catalog.pg_extension e
LEFT JOIN pg_catalog.pg_namespace n ON n.oid = e.extnamespace
LEFT JOIN pg_catalog.pg_description c ON c.objoid = e.oid AND c.classoid = 'pg_catalog.pg_extension'...
How can I programmatically check whether a keyboard is present in iOS app?
...fication
For more information about these
notifications, see their descriptions
in UIWindow Class Reference. For
information about how to show and hide
the keyboard, see Text and Web.
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MVVM: Tutorial from start to finish?
...VVM. It makes a nice introduction to MVVM before you try and tackle a full description like Josh Smith's article. I'm glad that I read Reed's tutorial before Josh's article, because it gives me a little context to understand the details that Josh is digging into.
...
How to Sign an Already Compiled Apk
...
Thanks for your description! tried uber-apk-signer first but failed probably because I have openJDK installed on my system instead of oracles "official" java. So I tried the manual way and also failed (still same error [INSTALL_PARSE_FAILED_...
How do you get a query string on Flask?
...st every attribute that contains in any way the query string, as well as a description from the O'Reilly book of that attribute.
First there is args which is "a dictionary with all the arguments passed in the query string of the URL." So if you want the query string parsed into a dictionary, you'd...
Android Studio Checkout Github Error “CreateProcess=2” (Windows)
...d7effa1a4a322478cd29c826b52a0c118ad3db11\cmd\git.exe
Test it
enter image description here
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Django CharField vs TextField
...nse when you primarily implement generic class views. It works great for a description field or the like. I also like how renderbox mentioned that you wouldn't want to use it for any filters/searches.
– Mitchell Walls
Jul 12 '18 at 13:10
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