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What are the differences between LinearLayout, RelativeLayout, and AbsoluteLayout?
...n align views one by one (vertically/ horizontally).
RelativeLayout means based on relation of views from its parents and other views.
ConstraintLayout is similar to a RelativeLayout in that it uses relations to position and size widgets, but has additional flexibility and is easier to use in the ...
Paperclip::Errors::MissingRequiredValidatorError with Rails 4
...s_attachment_content_type in Model
Rails 3
class User < ActiveRecord::Base
attr_accessible :avatar
has_attached_file :avatar, :styles => { :medium => "300x300>", :thumb => "100x100>" }, :default_url => "/images/:style/missing.png"
validates_attachment_content_type :avatar, :co...
`static` keyword inside function?
... static $cache = null;
if ($cache === null) {
$cache = '%heavy database stuff or something%';
}
// code using $cache
}
In this example, the if would only be executed once. Even if multiple calls to doStuff would occur.
...
How to create SBT project with IntelliJ Idea?
...g. Afterwards one can just do File -> New Project -> Scala -> SBT based. IntelliJ will generate basic build.sbt, download necessary dependencies and open project.
SBT Plugin
Sbt plugin that generate an idea project based on the sbt files can be found here: https://github.com/mpeltonen/sb...
belongs_to through associations
...
You can also delegate:
class Company < ActiveRecord::Base
has_many :employees
has_many :dogs, :through => :employees
end
class Employee < ActiveRescord::Base
belongs_to :company
has_many :dogs
end
class Dog < ActiveRecord::Base
belongs_to :employee
deleg...
SQLAlchemy: cascade delete
...ld object from parent.children, should that object be deleted from the database, or should only it's reference to the parent be removed (ie. set parentid column to null, instead of deleting the row)
– Steven
Feb 8 '16 at 13:04
...
Update multiple rows in same query using PostgreSQL
...
Based on the solution of @Roman, you can set multiple values:
update users as u set -- postgres FTW
email = u2.email,
first_name = u2.first_name,
last_name = u2.last_name
from (values
(1, 'hollis@weimann.biz', 'Holli...
Java8: Why is it forbidden to define a default method for a method from java.lang.Object
...single Displayable to implement toString() or extend a DisplayableToString base class.
– Brandon
Jun 10 '14 at 22:07
...
Design Patterns: Abstract Factory vs Factory Method
...oduct. (It is better than the Static Factory. When new types are added the base Product class does not need to be changed only the Simple Factory Class)
Factory Method
Contains one method to produce one type of product related to its type. (It is better than a Simple Factory because the type is ...
Load dimension value from res/values/dimension.xml from source code
...etrieve a dimensional for a particular resource ID. Unit conversions
are based on the current DisplayMetrics associated with the resources.
so if you want exact dp value just as in xml just divide it with DisplayMetrics density
int dp = (int) (getResources().getDimension(R.dimen.test) / getReso...