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Rails - Validate Presence Of Association?
...siness requirement that an insert into A requires at least 1 associated record to B. Is there a method I can call to make sure this is true, or do I need to write a custom validation?
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How does C compute sin() and other math functions?
I've been poring through .NET disassemblies and the GCC source code, but can't seem to find anywhere the actual implementation of sin() and other math functions... they always seem to be referencing something else.
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Difference between android-support-v7-appcompat and android-support-v4
I wanted to know the difference between android-support-v4.jar
and android-support-v7-appcompat.jar . If I want to add appcompat Action Bar in my application do I need to add both android-support-v7-appcompat.jar and android-support-v4.jar or only android-support-v7-appcompat.jar .
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Invoke(Delegate)
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The answer to this question lies in how C# Controls work
Controls in Windows Forms are bound to a specific thread and are not
thread safe. Therefore, if you are calling a control's method from a
different thread, you must use one of the control's invoke methods to
mar...
What is the difference between hg forget and hg remove?
...ant mercurial to remove several files from the current state of the repository. However, I want the files to exist in prior history.
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'this' vs $scope in AngularJS controllers
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"How does this and $scope work in AngularJS controllers?"
Short answer:
this
When the controller constructor function is called, this is the controller.
When a function defined on a $scope object is called, this is the "scope in effect when the f...
what is the right way to treat Python argparse.Namespace() as a dictionary?
...) , which is a Namespace object, with a method that expects a dictionary or mapping-like object (see collections.Mapping ), what is the right way to do it?
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How do I put a bunch of uncommitted changes aside while working on something else
If I have a bunch of uncommitted changes and want to set it aside while working on something else instead, and then later (f.i. after several days) come back to it and proceed working. What would be the easiest workflow to accomplish this? (So far I have only experience with Mercurial's basic functi...
Can you make just part of a regex case-insensitive?
...on case-insensitive by using the (?i:) pattern modifier.
Modern regex flavors allow you to apply modifiers to only part of the regular expression. If you insert the modifier (?ism) in the middle of the regex, the modifier only applies to the part of the regex to the right of the modifier. You can t...
How to construct a WebSocket URI relative to the page URI?
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If your Web server has support for WebSockets (or a WebSocket handler module) then you can use the same host and port and just change the scheme like you are showing. There are many options for running a Web server and Websocket server/module together....