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Query for documents where array size is greater than 1
...r: [{name: {$exists: false}}, {name: {$size: 0}}, {name: {$size: 1}}]})
{ "_id" : ObjectId("511907e3fb13145a3d2e225b"), "name" : [ "George", "Raymond" ] }
{ "_id" : ObjectId("511907e3fb13145a3d2e225c"), "name" : [ "George", "Raymond", "Richard" ] }
{ "_id" : ObjectId("511907e3fb13145a3d2e225d"), "na...
Converting Long to Date in Java returns 1970
...ternally, a count of nanoseconds since 1970-01-01T00:00Z.
.ofEpochSecond( 1_220_227_200L ) // Pass a count of whole seconds since the same epoch reference of 1970-01-01T00:00Z.
Know Your Data
People use various precisions in tracking time as a number since an epoch. So when you obtain some numb...
Auto reloading python Flask app upon code changes
...letsprojects.com/en/1.1.x/quickstart/#debug-mode
Example:
$ export FLASK_APP=main.py
$ export FLASK_ENV=development
$ flask run
or in one command:
$ FLASK_APP=main.py FLASK_ENV=development flask run
If you want different port than the default (5000) add --port option.
Example:
$ FLASK_APP=...
Safari 3rd party cookie iframe trick no longer working?
...back to facebook.
Add this code in the top of your index.php and set $page_url to your application final tab/app URL and you’ll see your application will work without any problem.
<?php
// START SAFARI SESSION FIX
session_start();
$page_url = "http://www.facebook.com/pages/.../......
How to access component methods from “outside” in ReactJS?
...
class Parent extends React.Class {
constructor(props) {
this._child = React.createRef();
}
componentDidMount() {
console.log(this._child.current.someMethod()); // Prints 'bar'
}
render() {
return (
<div>
<Child ref=...
Why are unnamed namespaces used and what are their benefits?
... You explain the relation to static. Can you please also compare with __attribute__ ((visibility ("hidden")))?
– phinz
Mar 22 at 15:16
...
Wrap a delegate in an IEqualityComparer
...t;T> : IEqualityComparer<T>
{
readonly Func<T, T, bool> _comparer;
readonly Func<T, int> _hash;
public FuncEqualityComparer( Func<T, T, bool> comparer )
: this( comparer, t => 0 ) // NB Cannot assume anything about how e.g., t.GetHashCode() interact...
Getting a better understanding of callback functions in JavaScript
...epending how you call the function
alert(this);
};
callback(argument_1, argument_2);
callback.call(some_object, argument_1, argument_2);
callback.apply(some_object, [argument_1, argument_2]);
The method you choose depends whether:
You have the arguments stored in an Array or as distinct v...
Polymorphism in C++
...rtual Base& operator+=(int) = 0; };
struct X : Base
{
X(int n) : n_(n) { }
X& operator+=(int n) { n_ += n; return *this; }
int n_;
};
struct Y : Base
{
Y(double n) : n_(n) { }
Y& operator+=(int n) { n_ += n; return *this; }
double n_;
};
void f(Base& x) { x...
Render basic HTML view?
...te.
Using express 3.0.0 and 3.1.0, the following works:
app.set('views', __dirname + '/views');
app.engine('html', require('ejs').renderFile);
See the comments below for alternative syntax and caveats for express 3.4+:
app.set('view engine', 'ejs');
Then you can do something like:
app.get('/...