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Why can't I use a list as a dict key in python?
... value breaks as soon as a list used as key is modified, and for lookup by identity requires you to keep around exactly the same list - which isn't requires for any other common list operation (at least none I can think of).
Other objects such as modules and object make a much bigger deal out of th...
Warn user before leaving web page with unsaved changes
...tepickers or checkbox/radiobutton beautifiers which save their value in a hidden input through JavaScript.
The change event also doesn't trigger on values set from JavaScript code, so also won't work for virtual inputs.
Binding the input event to all inputs (and textareas and selects) on your pa...
Check if a subview is in a view
...
You will end up with a code like :
Objective-C
- (IBAction)showPopup:(id)sender {
if(![self.myView isDescendantOfView:self.view]) {
[self.view addSubview:self.myView];
} else {
[self.myView removeFromSuperview];
}
}
Swift 3
@IBAction func showPopup(sender: AnyObj...
Mongodb Explain for Aggregation framework
...rations
explain:true
db.collection.aggregate([
{ $project : { "Tags._id" : 1 }},
{ $unwind : "$Tags" },
{ $match: {$or: [{"Tags._id":"tag1"},{"Tags._id":"tag2"}]}},
{ $group: {
_id : "$_id",
count: { $sum:1 }
}},
{$sort: {"count":-1}}
],
{
explain:...
Accessing an SQLite Database in Swift
... the sqlite3_open documentation makes it explicit that we must do so to avoid leaking memory:
Whether or not an error occurs when it is opened, resources associated with the database connection handle should be released by passing it to sqlite3_close() when it is no longer required.
Use sqlite3...
How do I convert a String object into a Hash object?
...o turn it back into a hash because #<Object:0x7f66b65cf4d0> isn't valid Ruby syntax.
However, if all that's in the hash is strings, symbols, numbers, and arrays, it should work, because those have string representations that are valid Ruby syntax.
...
How do I update if exists, insert if not (AKA “upsert” or “merge”) in MySQL?
...ERT ... ON DUPLICATE KEY UPDATE. For example:
INSERT INTO `usage`
(`thing_id`, `times_used`, `first_time_used`)
VALUES
(4815162342, 1, NOW())
ON DUPLICATE KEY UPDATE
`times_used` = `times_used` + 1
share
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...
Make anchor link go some pixels above where it's linked to
...// This is here so that when you enter the page with a hash,
// it can provide the offset in that case too. Having a timeout
// seems necessary to allow the browser to jump to the anchor first.
window.setTimeout(offsetAnchor, 1); // The delay of 1 is arbitrary and may not always work right (although...
Migrating from JSF 1.2 to JSF 2.0
...n.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
id="YourWebappID"
version="2.5">
Note: when you're using Servlet 3.0 or newer, use the http://xmlns.jcp.org namespace domain instead of http://java.sun.com throughout the above XML snippet.
JSP 2.x to JSP 2.x
If...
Is it possible to deserialize XML into List?
...c List<User> Items {get;set;}
}
public class User
{
[XmlElement("id")]
public Int32 Id { get; set; }
[XmlElement("name")]
public String Name { get; set; }
}
static class Program
{
static void Main()
{
XmlSerializer ser= new XmlSerializer(typeof(UserList));
...