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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:
...
Django Passing Custom Form Parameters to Formset
...m functools import partial, wraps
from django.forms.formsets import formset_factory
ServiceFormSet = formset_factory(wraps(ServiceForm)(partial(ServiceForm, affiliate=request.affiliate)), extra=3)
I think this is the cleanest approach, and doesn't affect ServiceForm in any way (i.e. by making it ...
How to calculate age (in years) based on Date of Birth and getDate()
...ated method does not have the issue with leap years, I'd suggest (if you really want to keep it at all) to move it down the bottom of your answer.
– ajbeaven
Jul 4 '17 at 23:14
1
...
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...
How to use Global Variables in C#?
...er the behavior of static variables declared inside, but it doesn't look really useful.
– Tommaso Belluzzo
Feb 2 at 18:01
...
Display names of all constraints for a table in Oracle SQL
...
You need to query the data dictionary, specifically the USER_CONS_COLUMNS view to see the table columns and corresponding constraints:
SELECT *
FROM user_cons_columns
WHERE table_name = '<your table name>';
FYI, unless you specifically created your table with ...
Saving image from PHP URL
...
If you have allow_url_fopen set to true:
$url = 'http://example.com/image.php';
$img = '/my/folder/flower.gif';
file_put_contents($img, file_get_contents($url));
Else use cURL:
$ch = curl_init('http://example.com/image.php');
$fp = f...
jQuery AJAX file upload PHP
...ript to look like this:
$('#upload').on('click', function() {
var file_data = $('#sortpicture').prop('files')[0];
var form_data = new FormData();
form_data.append('file', file_data);
alert(form_data);
$.ajax({
url: 'uploa...
How do I animate constraint changes?
...
Two important notes:
You need to call layoutIfNeeded within the animation block. Apple actually recommends you call it once before the animation block to ensure that all pending layout operations have been completed
You need to call it specifically on the ...
How to dump a dict to a json file?
...
you can supply all those parameters to dump(sample, file, ...) too. The extra step of writing to a string is not needed. dump internally writes in chunks. This could be more efficient than to compile a (possibly huge) string first.
...