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How to check file MIME type with javascript before upload?
...adAsDataURL(blob);
}
// Add more from http://en.wikipedia.org/wiki/List_of_file_signatures
function mimeType(headerString) {
switch (headerString) {
case "89504e47":
type = "image/png";
break;
case "47494638":
type = "image/gif";
break;
case "ffd8ff...
Incrementing in C++ - When to use x++ or ++x?
...t; 42; ++i)
{
std::cout << i << std::endl;
}
}
_
$> g++ -S pre.cpp
$> g++ -S post.cpp
$> diff pre.s post.s
1c1
< .file "pre.cpp"
---
> .file "post.cpp"
share
|...
How do you create an asynchronous method in C#?
...s = new TaskCompletionSource<T>();
ThreadPool.QueueUserWorkItem(_ =>
{
try
{
T result = function();
tcs.SetResult(result);
}
catch(Exception exc) { tcs.SetException(exc); }
});
return tcs.Task;
}
Fro...
Fast way of counting non-zero bits in positive integer
...p://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetTable
POPCOUNT_TABLE16 = [0] * 2**16
for index in range(len(POPCOUNT_TABLE16)):
POPCOUNT_TABLE16[index] = (index & 1) + POPCOUNT_TABLE16[index >> 1]
def popcount32_table16(v):
return (POPCOUNT_TABLE16[ v & 0xf...
What is “the inverse side of the association” in a bidirectional JPA OneToMany/ManyToOne association
...
// "One" Customer owns the associated orders by storing them in a customer_orders join table
public class Customer {
@OneToMany(cascade = CascadeType.ALL)
private List<Order> orders;
}
// if the Customer owns the orders using the customer_orders table,
// Order has no knowledge of it...
Rails formatting date
...
Use
Model.created_at.strftime("%FT%T")
where,
%F - The ISO 8601 date format (%Y-%m-%d)
%T - 24-hour time (%H:%M:%S)
Following are some of the frequently used useful list of Date and Time formats that you could specify in strftime metho...
C++11 range based loop: get item by value or reference to const
...se, but in the way it is written):
long long SafePop(std::vector<uint32_t>& v)
{
auto const& cv = v;
long long n = -1;
if (!cv.empty())
{
n = cv.back();
v.pop_back();
}
return n;
}
Here, the author has created a const reference to v to use for...
Why not use exceptions as regular flow of control?
...ionError or StandardError or something that does correspond to bad things happening. If you have trouble with that, then how do you do logging -- don't you log by level and class, precisely so you can filter on them? Do you think that's a bad idea, too?
– Ken
...
What is the difference between screenX/Y, clientX/Y and pageX/Y?
...Y should be used instead of clientX/clientY?
– techie_28
Jul 6 '16 at 9:58
1
...
How to set size for local image using knitr for markdown?
...tion:
Resizing local images
As of knitr 1.12, there is the function include_graphics. From ?include_graphics (emphasis mine):
The major advantage of using this function is that it is portable in the sense that it works for all document formats that knitr supports, so you do not need to think if you...