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jQuery: checking if the value of a field is null (empty)
...ype]').val().length != 0){}
If you want to check if the element exist at all, you should do that before calling val:
var $d = $('#person_data[document_type]');
if ($d.length != 0) {
if ($d.val().length != 0 ) {...}
}
s...
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
add a comment
...
Why can't Python parse this JSON data?
... You have [] when you should have {}:
[] are for JSON arrays, which are called list in Python
{} are for JSON objects, which are called dict in Python
Here's how your JSON file should look:
{
"maps": [
{
"id": "blabla",
"iscategorical": "0"
},
...
Adding an arbitrary line to a matplotlib plot in ipython notebook
...e taken in account in the legend by adding a label argument starting with "_". Ex: plt.plot([70, 70], [100, 250], 'k-', lw=2, label="_not in legend")
– gcalmettes
Oct 29 '16 at 5:40
...
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...
C++, Free-Store vs Heap
Dynamic allocations with new/delete are said to take place on the free-store , while malloc/free operations use the heap .
I'd like to know if there is an actual difference, in practice.
Do compilers make a distinction between the two terms? ( Free store and Heap , not new/malloc )
...
Iterating each character in a string using Python
...
If that seems like magic, well it kinda is, but the idea behind it is really simple.
There's a simple iterator protocol that can be applied to any kind of object to make the for loop work on it.
Simply implement an iterator that defines a next() method, and implement an __iter__ method on a c...
In Visual Studio C++, what are the memory allocation representations?
In Visual Studio, we've all had "baadf00d", have seen seen "CC" and "CD" when inspecting variables in the debugger in C++ during run-time.
...
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...
How to create a shared library with cmake?
...le, but now I want to switch to cmake. The tree looks like this (I removed all the irrelevant files):
4 Answers
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