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What is the colon operator in Ruby?
...
There're some quotes from the famous book Agile Web Development with Rails, which may be helpful to understand the symbol as well :
Rails uses symbols to identify things. In particular, it uses them as keys when naming method parameters and l...
Unique BooleanField value in Django?
...if you've set the boolean to True, make sure all others are set to False.
from django.db import transaction
class Character(models.Model):
name = models.CharField(max_length=255)
is_the_chosen_one = models.BooleanField()
def save(self, *args, **kwargs):
if not self.is_the_chos...
Using ZXing to create an Android barcode scanning app [duplicate]
...ode scanning.
The easiest way to do this is to call the ZXing SCAN Intent from your application, like this:
public Button.OnClickListener mScan = new Button.OnClickListener() {
public void onClick(View v) {
Intent intent = new Intent("com.google.zxing.client.android.SCAN");
int...
What is the equivalent of the C# 'var' keyword in Java?
...a 10.
Edit: 6 years after being posted, to collect some of the comments from below:
The reason C# has the var keyword is because it's possible to have Types that have no name in .NET. Eg:
var myData = new { a = 1, b = "2" };
In this case, it would be impossible to give a proper type to myDat...
What's the best way to do “application settings” in Android? [closed]
...e the preferences instance, here is how you can retrieve the stored values from the preferences:
int storedPreference = preferences.getInt("storedInt", 0);
To store values in the preference file SharedPreference.Editor object has to be used. Editor is the nested interface of the SharedPreference...
Is there an opposite to display:none?
...he documentation for these values here ).
display:none removes an element from the page layout entirely, as if it wasn’t there.
All other values for display cause the element to be a part of the page, so in a sense they’re all opposite to display:none.
But there isn’t one value that’s the...
Is it possible to listen to a “style change” event?
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I think the best answer if from Mike in the case you can't launch your event because is not from your code. But I get some errors when I used it. So I write a new answer for show you the code that I use.
Extension
// Extends functionality of ".css()"...
fatal: git-write-tree: error building trees
I did a git pull from a shared git repository, but something went really wrong, after I tried a git revert . Here is the situation now:
...
How to detect a loop in a linked list?
...ial linked list is like this 1->2->3->4->5->2 (with a cycle from 5 to 2), then the reversed list looks like 1->2<-3<-4<-5 ? And if the reverse is that , the final reconstructed list will be screwed up ?
– Zenil
Mar 8 '15 at 1:08
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In Python, how do I indicate I'm overriding a method?
...I created a pip installable package https://github.com/mkorpela/overrides
From time to time I end up here looking at this question.
Mainly this happens after (again) seeing the same bug in our code base: Someone has forgotten some "interface" implementing class while renaming a method in the "inter...