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Rails - Validate Presence Of Association?
...has a "has_many" association to another model B. I have a business 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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Is it correct to use alt tag for an anchor link?
Is it correct to use alt tag for an anchor link, something like
7 Answers
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Why don't C++ compilers define operator== and operator!=?
...r comparison or a deep (internal) comparison.
It's safer to just not implement it and let the programmer do that themselves. Then they can make all the assumptions they like.
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CGridCellNumeric - A numeric cell class for the MFC Grid - C/C++ - 清...
CGridCellNumeric - A numeric cell class for the MFC GridCGridCellNumeric-A-numeric-cell-class-for-the-MFC-GridA locale aware, editable, self validating numeric cell class for the MFC Grid. Configurable for integers, floating...A locale aware, editable, self validating numeric cell class for the MFC ...
adb update a non-market apk?
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There is some data I store in the app which I would like to retain across updates/reinstalls. I figure if this is a limitation, the only way I have is to store it in the SD Card, but thats again a risk if the user deletes the data from ...
Why can a class not be defined as protected?
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Because it makes no sense.
Protected class member (method or variable) is just like package-private (default visibility), except that it also can be accessed from subclasses.
Since there's no such concept as 'subpackage' or 'package-inheritance' in Java, declaring cla...
One-line list comprehension: if-else variants
... if y else z is the syntax for the expression you're returning for each element. Thus you need:
[ x if x%2 else x*100 for x in range(1, 10) ]
The confusion arises from the fact you're using a filter in the first example, but not in the second. In the second example you're only mapping each value ...
Styles.Render in MVC4
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@skmasq, at the time of writing these lines, I was using VS2013. Things may have changed until now. Thanks for mentioning that :)
– codea
Jan 27 '16 at 12:17
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grant remote access of MySQL database from any IP address
... The trick when connecting to a db instance running on the same OS instance (e.g. your development machine), is to pass in the -h my_machine_name parameter. This tricks the client to identify you as 'user'@my_machine_name.example.com, rather than 'user'@localhost. This way you don't ...
How to make asynchronous HTTP requests in PHP
...nchronous HTTP calls? I don't care about the response, I just want to do something like file_get_contents() , but not wait for the request to finish before executing the rest of my code. This would be super useful for setting off "events" of a sort in my application, or triggering long processes.
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