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Foreign keys in mongo?
...his:
class Student
include Mongoid::Document
field :name
embeds_many :addresses
embeds_many :scores
end
class Address
include Mongoid::Document
field :address
field :city
field :state
field :postalCode
embedded_in :student
end
class Score
include Mongoi...
How do I list loaded plugins in Vim?
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Not a VIM user myself, so forgive me if this is totally offbase. But according to what I gather from the following VIM Tips site:
" where was an option set
:scriptnames : list all plugins, _vimrcs loaded (super)
:verbose set history? : reveals value of hist...
How do I trim leading/trailing whitespace in a standard way?
... C? I'd roll my own, but I would think this is a common problem with an equally common solution.
38 Answers
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Automatic Retina images for web sites
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There is a new attribute for the img tag that allows you to add a retina src attribute, namely srcset. No javascript or CSS needed, no double loading of images.
<img src="low-res.jpg" srcset="high-res.jpg 2x">
Browser Support: http://caniuse.com/#search=srcset
O...
Rails: Open link in new tab (with 'link_to')
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The target: :_blank parameter should be a parameter of link_to, whereas you put it in image_tag parameters. Modify your code like this:
<%= link_to image_tag("facebook.png", class: :facebook_icon, alt: "Facebook"), "http://www.facebo...
Why can't yield return appear inside a try block with a catch?
...ty. I suspect there are very, very few times where this restriction is actually an issue that can't be worked around - but the added complexity in the compiler would be very significant.
There are a few things like this that I've already encountered:
Attributes not being able to be generic
Inabil...
StringIO in Python3
... of the question and is included only as something to consider when generically addressing the missing StringIO module. For a more direct solution the message TypeError: Can't convert 'bytes' object to str implicitly, see this answer.
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@UniqueConstraint annotation in Java
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@Entity
@Table(uniqueConstraints={@UniqueConstraint(columnNames = {"id_1" , "id_2"})})
public class class_name {
@Id
@GeneratedValue
public Long id;
@NotNull
public Long id_1;
@NotNull
public Long id_2;
}
Hope it helped.
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Add a new item to a dictionary in Python [duplicate]
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default_data['item3'] = 3
Easy as py.
Another possible solution:
default_data.update({'item3': 3})
which is nice if you want to insert multiple items at once.
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In Python, what is the difference between “.append()” and “+= []”?
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In general case append will add one item to the list, while += will copy all elements of right-hand-side list into the left-hand-side list.
Update: perf analysis
Comparing bytecodes we can assume that append version wastes cycles in LOAD_ATTR + CALL_FUNCTION, and += version -- in BUILD_LIST. App...