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How to tell if browser/tab is active [duplicate]
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You would use the focus and blur events of the window:
var interval_id;
$(window).focus(function() {
if (!interval_id)
interval_id = setInterval(hard_work, 1000);
});
$(window).blur(function() {
clearInterval(interval_id);
interval_id = 0;
});
To Answer the Commented ...
Get records with max value for each group of grouped SQL results
...ou want is first, then group by the columns you want the value for.
You avoid complicated subqueries that try to find the max() etc, and also the problems of returning multiple rows when there are more than one with the same maximum value (as the other answers would do)
Note: This is a mysql-only so...
Is there a naming convention for MySQL?
... about how you would cope with a single table foo_bar that has columns foo_id and another_foo_id both of which reference the foo table foo_id column. You might want to consider how to deal with this. This is a bit of a corner case though!
Point 4 - Similar to Point 3. You may want to introduce a nu...
Is there a float input type in HTML5?
...alue attribute, if specified and not empty, must have a value that is a valid floating point number."
8 Answers
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How do I add a password to an OpenSSH private key that was generated without a password?
...pecifies the filename of the key file.
Example:
ssh-keygen -p -f ~/.ssh/id_rsa
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How to select from subquery using Laravel Query Builder?
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@Kannan nope. it's a candidate for a PR I guess, but in the end that's not very common use case. Probably this is the reason for not having it there up to this day..
– Jarek Tkaczyk
Feb 28 '16 at 12:28
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ExpandableListView - hide indicator for groups with no children
In an ExpandableListView , is there a way to hide the group indicator for groups with no children?
13 Answers
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How to use HTML to print header and footer on every printed page of a document?
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This did not work for me, I'm using Chrome 15.0. All it does is print the element where it would be on the screen, e.g. in the middle of the page, if that's where I scrolled to. It certainly doesn't print on every page.
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Why use symbols as hash keys in Ruby?
...source code, is always stored as the same entity, e.g. has the same object id.
Strings on the other hand are mutable, they can be changed anytime. This implies that Ruby needs to store each string you mention throughout your source code in it's separate entity, e.g. if you have a string "name" mul...
Detect permission of camera in iOS
I am developing a very simple video app. I use the official control: UIImagePickerController.
6 Answers
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