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OO Design in Rails: Where to put stuff
I'm really enjoying Rails (even though I'm generally RESTless), and I enjoy Ruby being very OO. Still, the tendency to make huge ActiveRecord subclasses and huge controllers is quite natural (even if you do use a controller per resource). If you were to create deeper object worlds, where would you p...
Can not connect to local PostgreSQL
...really looks like a file permissions error. Unix domain sockets are files and have user permissions just like any other. It looks as though the OSX user attempting to access the database does not have file permissions to access the socket file. To confirm this I've done some tests on Ubuntu and p...
Iterate over a Javascript associative array in sorted order
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You cannot iterate over them directly, but you can find all the keys and then just sort them.
var a = new Array();
a['b'] = 1;
a['z'] = 1;
a['a'] = 1;
function keys(obj)
{
var keys = [];
for(var key in obj)
{
if(obj.hasOwnProperty(key))
{
keys.pus...
What's wrong with nullable columns in composite primary keys?
...keys is not clean relational database design.
If there are two entities A and B where A can optionally be related to B, the clean solution is to create a resolution table (let's say AB). That table would link A with B: If there is a relationship then it would contain a record, if there isn't then i...
What is Scala's yield?
I understand Ruby and Python's yield. What does Scala's yield do?
9 Answers
9
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Is there a quicker / better way to clear the iPhone Simulator cache than deleting its directory?
So I'm still reasonably new to iOS development and I'm finding myself quite regularly needing to delete either DerivedData, or the contents of the iPhone Simulator directory, to get things to actually execute from my code. Clean in Xcode doesn't do the same as emptying those directories, right? And ...
How do Trigonometric functions work?
So in high school math, and probably college, we are taught how to use trig functions, what they do, and what kinds of problems they solve. But they have always been presented to me as a black box. If you need the Sine or Cosine of something, you hit the sin or cos button on your calculator and you'...
Regular expression to match a word or its prefix
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Square brackets are meant for character class, and you're actually trying to match any one of: s, |, s (again), e, a, s (again), o and n.
Use parentheses instead for grouping:
(s|season)
or non-capturing group:
(?:s|season)
Note: Non-capture groups tell the engin...
How to pretty print nested dictionaries?
... U know @Ken's conventional answer is much better than this. Json already handles everything and this can give errors such: UnicodeEncodeError: 'ascii' codec can't encode character u'\xf3' in position 50: ordinal not in range(128)
– wonderwhy
Aug 27 '14 at 13:2...
How do I use Node.js Crypto to create a HMAC-SHA1 hash?
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And to verify a hash, you should use crypto.timingSafeEqual(Buffer.from(a), Buffer.from(b)): stackoverflow.com/questions/31095905/…
– baptx
Aug 2 '19 at 15:19
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