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Detect when browser receives file download
I have a page that allows the user to download a dynamically-generated file. It takes a long time to generate, so I'd like to show a "waiting" indicator. The problem is, I can't figure out how to detect when the browser has received the file, so I can hide the indicator.
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Proper use of beginBackgroundTaskWithExpirationHandler
...l need to wrap it in a background task. It's also very important that you call endBackgroundTask when you're finished - otherwise the app will be killed after its allotted time has expired.
Mine tend look something like this:
- (void) doUpdate
{
dispatch_async(dispatch_get_global_queue(DISPAT...
jQuery attr vs prop?
...ns (<1.6), we just had attr. To get to DOM properties such as nodeName, selectedIndex, or defaultValue you had to do something like:
var elem = $("#foo")[0];
if ( elem ) {
index = elem.selectedIndex;
}
That sucked, so prop was added:
index = $("#foo").prop("selectedIndex");
This was great, bu...
How to open multiple pull requests on GitHub
When I open a pull request on GitHub .
All commits since my last request and all new ones are automatically added to this request .
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Python logging: use milliseconds in time format
...d of a struct_time, then (at least with modern versions of Python) we can call ct.strftime and then we can use %f to format microseconds:
import logging
import datetime as dt
class MyFormatter(logging.Formatter):
converter=dt.datetime.fromtimestamp
def formatTime(self, record, datefmt=None...
How to detect that animation has ended on UITableView beginUpdates/endUpdates?
...ates . I am also using beginUpdates/endUpdates when adjusting rowHeight. All these operations are animated by default.
7 ...
Is using Random and OrderBy a good shuffle algorithm?
...e naive version). Durstenfeld/Knuth achieve O(n) not by assignment, but by selection from a decreasing set and swapping. This way the random number selected may repeat and the algorithm only takes O(n).
– tvanfosson
Aug 17 '09 at 12:18
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Why is pow(a, d, n) so much faster than a**d % n?
...was taking so long (> 20 seconds) for midsize numbers (~7 digits). I eventually found the following line of code to be the source of the problem:
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How do I apply a perspective transform to a UIView?
...zip it
Go into the folder you unzipped, open its iCarousel subfolder, then select iCarousel.h and iCarousel.m and drag them into your project navigation – that's the left pane in Xcode. Just below Info.plist is fine.
Check "Copy items if needed" then click Finish.
Xcode will prompt you with the me...
Immutable vs Mutable types
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Almost, but not exactly. Technically, all variables are passed by reference in Python, but have a semantics more like pass by value in C. A counterexample to your analogy is if you do def f(my_list): my_list = [1, 2, 3]. With pass-by-reference in C, the val...