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Adding :default => true to boolean in existing Rails column
... that you would have to create a rake task or just go in the rails console and update all the records (which I would not recommend in production).
When you added t.boolean :show_attribute, :default => true to the create_profiles migration, it's expected that it didn't do anything. Only migrations...
How to use Git Revert
...tion(+), 1 deletion(-)
In this example the commit history has two commits and the last one is a mistake. Using git revert:
$ git revert HEAD
[master 1db4eeb] Revert "bad update"
1 file changed, 1 insertion(+), 1 deletion(-)
There will be 3 commits in the log:
$ git log --oneline
1db4eeb Revert "b...
How does Junit @Rule work?
...n a more generic way.
For instance, ExternalResource executes code before and after a test method, without having to use @Before and @After. Using an ExternalResource rather than @Before and @After gives opportunities for better code reuse; the same rule can be used from two different test classes....
What is the difference between Pan and Swipe in iOS?
...antics: a pan recognizer looks for the beginning of translational movement and continues to report movement in any direction over time, while a swipe recognizer makes an instantaneous decision as to whether the user's touches moved linearly in the required direction.
By default, no two recognizers...
How do I disable the “Press ENTER or type command to continue” prompt in Vim?
Is there any way to disable the "Press ENTER or type command to continue" prompt that appears after executing an external command?
...
What's the difference between ES6 Map and WeakMap?
Looking this and this MDN pages it seems like the only difference between Maps and WeakMaps is a missing "size" property for WeakMaps. But is this true? What's the difference between them?
...
How do I delete NuGet packages that are not referenced by any project in my solution?
Somehow during the upgrade to VS2012 and .NET 4.5, I've managed to get NuGet confused. There are packages that appear in the package manager (and the packages folder) that I cannot delete (I believe they are legacy ASP.NET NuGet packages that have been replaced with new package names with the new v...
What are all the valid self-closing elements in XHTML (as implemented by the major browsers)?
...nly) browsers to accept XHTML 1.0 documents by following the
guidelines, and serving them as text/html. Therefore, documents served as
text/html should be treated as HTML and not as XHTML.
It's a very common pitfall, because W3C Validator largely ignores that rule, but browsers follow it relig...
How do I find out if first character of a string is a number?
...s, you must first be sure that the string isn't empty. If it is, charAt(0) and substring(0, 1) will throw a StringIndexOutOfBoundsException. startsWith does not have this problem.
To make the entire condition one line and avoid length checks, you can alter the regexes to the following:
s.matches("...
proper name for python * operator?
...
In Ruby and Perl 6 this has been called "splat", and I think most people from those communities will figure out what you mean if you call it that.
The Python tutorial uses the phrase "unpacking argument lists", which is long and des...