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What is the difference between `after_create` and `after_save` and when to use which?
... readers should note that, according to the docs, ActiveRecord's update_all does not invoke any callbacks, including after_*
– user2426679
Jan 10 at 19:34
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What are the mathematical/computational principles behind this game?
My kids have this fun game called Spot It! The game constraints (as best I can describe) are:
9 Answers
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Easiest way to check for an index or a key in an array?
... associative array)
[ ${array[key]+abc} ] && echo "exists"
Basically what ${array[key]+abc} does is
if array[key] is set, return abc
if array[key] is not set, return nothing
References:
See Parameter Expansion in Bash manual and the little note
if the colon is omitted, the ope...
Gesture recognizer and button actions
...nizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
// Disallow recognition of tap gestures in the segmented control.
if ((touch.view == yourButton)) {//change it to your condition
return NO;
}
return YES;
}
hope it will help
Edit
As Daniel noted you must con...
Understanding PrimeFaces process/update and JSF f:ajax execute/render attributes
...and updating the model values (EditableValueHolder components only) and finally invoke the queued ActionEvent (ActionSource components only). JSF will skip processing of all other components which are not covered by process attribute. Also, components whose rendered attribute evaluates to false duri...
Octave-Gnuplot-AquaTerm error: set terminal aqua enhanced title “Figure 1”…unknown terminal type"
I've installed Octave and gnuplot via Homebrew, and downloaded AquaTerm.dmg.
When I try to plot, I get the following message:
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How do you increase the max number of concurrent connections in Apache?
...ts 200
MinSpareThreads 25
MaxSpareThreads 75
ThreadsPerChild 25
First of all, whenever an apache is started, it will start 2 child processes which is determined by StartServers parameter. Then each process will start 25 threads determined by ThreadsPerChild parameter so this means 2 process can se...
Specifying and saving a figure with exact size in pixels
...):
plt.figure(figsize=(800/my_dpi, 800/my_dpi), dpi=my_dpi)
So you basically just divide the dimensions in inches by your DPI.
If you want to save a figure of a specific size, then it is a different matter. Screen DPIs are not so important anymore (unless you ask for a figure that won't fit in ...
Given final block not properly padded
...here:
http://www.rsa.com/products/bsafe/documentation/cryptoj35html/doc/dev_guide/group_CJ_SYM__PAD.html
(I assume you have the issue when you try to encrypt)
You can choose your padding schema when you instantiate the Cipher object. Supported values depend on the security provider you are using. ...
Join strings with a delimiter only if strings are not null or empty
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.filter(Boolean) (which is the same as .filter(x => x)) removes all "falsy" values (nulls, undefineds, empty strings etc). If your definition of "empty" is different, then you'll have to provide it, for example:
[...].filter(x => typeof x === 'string' && x.length > 0)
wi...