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How to change the opacity (alpha, transparency) of an element in a canvas element after it has been
...;
Notes:
Set the 'src' last, to guarantee that your onload handler is called on all platforms, even if the image is already in the cache.
Wrap changes to stuff like globalAlpha between a save and restore (in fact use them lots), to make sure you don't clobber settings from elsewhere, particularl...
Cannot serve WCF services in IIS on Windows 8
...you get an error then use the below
C:\> DISM /Online /Enable-Feature /all /FeatureName:WCF-HTTP-Activation
C:\> DISM /Online /Enable-Feature /all /FeatureName:WCF-HTTP-Activation45
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Too many 'if' statements?
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@JoeHarper "Theoretically" is one thing, "practically" is another. Of course I try to use descriptive naming (with the exception of the i/j/k convention for loop variables), named constants, arranging my code in a readable fashion, etc., but when...
Why is it impossible to build a compiler that can determine if a C++ function will change the value
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@mrsoltys, quantum computers are "only" exponentially faster for some problems, they can not solve undecidable problems.
– zch
Jul 1 '13 at 18:52
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how to reset
...ted in the comments obviously works, but if you look at the actual jQuery call it's pretty easy to see what jQuery is doing, just setting the value attribute to an empty string. So in "pure" JavaScript it would be:
document.getElementById("uploadCaptureInputFile").value = "";
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Determine if a function exists in bash
..., built-in function, external command, or just not defined. Example:
$ LC_ALL=C type foo
bash: type: foo: not found
$ LC_ALL=C type ls
ls is aliased to `ls --color=auto'
$ which type
$ LC_ALL=C type type
type is a shell builtin
$ LC_ALL=C type -t rvm
function
$ if [ -n "$(LC_ALL=C type -t rvm)...
Regex expressions in Java, \\s vs. \\s+
...e, whereas the second one matches one or many whitespaces. They're the so-called regular expression quantifiers, and they perform matches like this (taken from the documentation):
Greedy quantifiers
X? X, once or not at all
X* X, zero or more times
X+ X, one or more times
X{n} X, exactly n ti...
Add vertical whitespace using Twitter Bootstrap?
...g the documentation for used notation:
Spacing utilities that apply to all breakpoints, from xs to xl,
have no breakpoint abbreviation in them. This is because those classes
are applied from min-width: 0 and up, and thus are not bound by a
media query. The remaining breakpoints, however, d...
Create a variable name with “paste” in R?
...oss: a <- rnorm(1); a - eval(parse(text=paste(a))) does not return 0 usually.
– user10307643
Oct 7 '19 at 13:31
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Convert datetime to Unix timestamp and convert it back in python
...m UTC.
If you have, or can upgrade to, Python 3.3 or later, you can avoid all of these problems by just using the timestamp method instead of trying to figure out how to do it yourself. And even if you don't, you may want to consider borrowing its source code.
(And if you can wait for Python 3.4, ...