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Rails :dependent => :destroy VS :dependent => :delete_all
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The difference is with the callback.
The :delete_all is made directly in your application and deletes by SQL :
DELETE * FROM users where compagny_id = XXXX
With the :destroy, there is an instantiation of all of your children. So, if you can't destro...
Can scrapy be used to scrape dynamic content from websites that are using AJAX?
...and am dipping my hand into building a web-scraper. It's nothing fancy at all; its only purpose is to get the data off of a betting website and have this data put into Excel.
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How to concatenate twice with the C preprocessor and expand a macro as in “arg ## _ ## MACRO”?
...ssing token (see below), is
replaced by the corresponding argument after all macros contained therein have been
expanded. Before being substituted, each argument’s preprocessing tokens are
completely macro replaced as if they formed the rest of the preprocessing file; no other
preprocessin...
How to localize ASP.NET MVC application?
...ial with recent update on How to localize asp.net mvc application covering all aspects including DisplayName localization, Validation, using Routing (storing culture name in URL), issues with output cache and so on... Alex Adamyan Blog - While my keyboard gently weeps
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Zooming MKMapView to fit annotation pins?
...ew.h:
// Position the map such that the provided array of annotations are all visible to the fullest extent possible.
- (void)showAnnotations:(NSArray *)annotations animated:(BOOL)animated NS_AVAILABLE(10_9, 7_0);
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Binding an enum to a WinForms combo box, and then setting it
...dView.CurrentRow.Cells["comboColumnCell"].Value. I can see value but internally it throws null pointer exception
– ssal
Jun 5 '14 at 17:18
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Rails :include vs. :joins
...de functionality was changed with Rails 2.1. Rails used to do the join in all cases, but for performance reasons it was changed to use multiple queries in some circumstances. This blog post by Fabio Akita has some good information on the change (see the section entitled "Optimized Eager Loading")....
PHP $_SERVER['HTTP_HOST'] vs. $_SERVER['SERVER_NAME'], am I understanding the man pages correctly?
...you either go with that or you check the host name against a white list:
$allowed_hosts = array('foo.example.com', 'bar.example.com');
if (!isset($_SERVER['HTTP_HOST']) || !in_array($_SERVER['HTTP_HOST'], $allowed_hosts)) {
header($_SERVER['SERVER_PROTOCOL'].' 400 Bad Request');
exit;
}
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How to import module when module name has a '-' dash or hyphen in it?
...appens with sys.modules, you don't need it to import itself), just getting all of the file's globals into your own scope, you can use execfile
# contents of foo-bar.py
baz = 'quux'
>>> execfile('foo-bar.py')
>>> baz
'quux'
>>>
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When should we call System.exit in Java
...its. This is a convenient way to handle shutdown in bigger programs, where all parts of the program can't (and shouldn't) be aware of each other. Then, if someone wants to quit, he can simply call System.exit(), and the shutdown hooks (if properly set up) take care of doing all necessary shutdown ce...