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How to represent multiple conditions in a shell if statement?
... else statement and have the code between then and fi put in a function in order to avoid repeating it. In very simple cases you could use a case statement with ;& fallthrough (in Bash 4).
– Paused until further notice.
Dec 11 '15 at 22:15
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Create an empty data.frame
... Nice solution, however I found that I get a data frame with 0 rows. In order to keep the size of the data frame the same, I suggest new_df = df[NA,]. This also allows to store any previous column into the new data frame. For example to obtain the "Date" column from original df (while keeping res...
Can constructors be async?
...pon its completion. An "async property", not an "async constructor", is in order.
I just released AsyncMVVM, which solves exactly this problem (among others). Should you use it, your ViewModel would become:
public class ViewModel : AsyncBindableBase
{
public ObservableCollection<TData> ...
Detect permission of camera in iOS
...default:
completion?(.unknown)
}
}
}
And then in order to use it you do
AVCaptureDevice.authorizeVideo(completion: { (status) in
//Your work here
})
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How can I wait for set of asynchronous callback functions?
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@philx_x - Thought so. You need a polyfill library in order to use fetch nowadays. Takes a little air out of your comment about avoiding an ajax library. Fetch is nice, but it's years away from being able to use it without a polyfill. It's not even in the latest version of al...
How can I create a link to a local file on a locally-run web page?
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Highly active question. Earn 10 reputation in order to answer this question. The reputation requirement helps protect this question from spam and non-answer activity.
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Launching Google Maps Directions via an intent on Android
...sk for directions.
If you use the query parameter "geo:lat,lon?q=name" in order to label your geopoint, it uses the query for search and dismiss the lat/lon parameters.
I found a way to center the map with lat/lon and display a pin with a custom label, very nice to display and useful when asking f...
Reference alias (calculated in SELECT) in WHERE clause
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You can't reference an alias except in ORDER BY because SELECT is the second last clause that's evaluated. Two workarounds:
SELECT BalanceDue FROM (
SELECT (InvoiceTotal - PaymentTotal - CreditTotal) AS BalanceDue
FROM Invoices
) AS x
WHERE BalanceDue > 0;...
What is the difference between user variables and system variables?
...nment variables are 'evaluated' (ie. they are attributed) in the
following order:
System variables
Variables defined in autoexec.bat
User variables
Every process has an environment block that contains a set of environment variables and their values. There are two types of environment variables: ...
sed error: “invalid reference \1 on `s' command's RHS”
...
Nevermind my mistake was to use -ire instead of use -ri. Order matters :-)
– m3nda
Jun 10 '18 at 15:22
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