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Objective-C: Where to remove observer for NSNotification?
...his is obviously not a satisfying answer.
I'd recommend, that you add a call [notificationCenter removeObserver: self] in method dealloc of those classes, which you intend to use as observers, as it is the last chance to unregister an observer cleanly. This will, however, only protect you against ...
MySQL “WITH” clause
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Update: MySQL 8.0 is finally getting the feature of common table expressions, including recursive CTEs.
Here's a blog announcing it: http://mysqlserverteam.com/mysql-8-0-labs-recursive-common-table-expressions-in-mysql-ctes/
Below is my earlier answ...
ElasticSearch - Return Unique Values
How would I get the values of all the languages from the records and make them unique.
5 Answers
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Nginx reverse proxy causing 504 Gateway Timeout
...nd it had to do with not using a keep-alive on the connection. I can't actually answer why this is but, in clearing the connection header I solved this issue and the request was proxied just fine:
server {
location / {
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header ...
How to generate a random int in C?
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Note: Don't use rand() for security. If you need a cryptographically secure number, see this answer instead.
#include <time.h>
#include <stdlib.h>
srand(time(NULL)); // Initialization, should only be called once.
int r = rand(); // Returns a pseudo-random integer bet...
When to encode space to plus (+) or %20?
...value is query value with a space, but the folder name in the path is literally foo+bar, not foo bar.
%20 is a valid way to encode a space in either of these contexts. So if you need to URL-encode a string for inclusion in part of a URL, it is always safe to replace spaces with %20 and pluses with ...
Python: How to create a unique file name?
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I didn't think your question was very clear, but if all you need is a unique file name...
import uuid
unique_filename = str(uuid.uuid4())
share
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Keyboard shortcuts with jQuery
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Since this question was originally asked, John Resig (the primary author of jQuery) has forked and improved the js-hotkeys project. His version is available at:
http://github.com/jeresig/jquery.hotkeys
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Difference between Destroy and Delete
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Basically destroy runs any callbacks on the model while delete doesn't.
From the Rails API:
ActiveRecord::Persistence.delete
Deletes the record in the database and freezes this instance to reflect that no changes should be ...
What does the smiley face “:)” mean in CSS?
...wsers.
Also there's a hack for <= IE 8:
div {
color: blue; /* All browsers */
color: purple\9; /* IE8 and earlier */
*color: pink; /* IE7 and earlier */
}
However that's not a good idea, they don't validate. You always feel free to work with Conditional comments for targeting...