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Rails Object to hash
... edited Jul 28 at 17:58
David Moles
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answered Oct 6 '10 at 12:12
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Programmatically create a UIView with color gradient
I'm trying to generate a view with a gradient color background (A solid color to transparent) at runtime. Is there a way of doing that?
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TypeError: unhashable type: 'dict'
...e the keys have to be hashable. As a general rule, only immutable objects (strings, integers, floats, frozensets, tuples of immutables) are hashable (though exceptions are possible). So this does not work:
>>> dict_key = {"a": "b"}
>>> some_dict[dict_key] = True
Traceback (most re...
Symfony2 : How to get form validation errors after binding the request to the form
...s($child);
}
}
return $errors;
}
To get all errors as a string:
$string = var_export($this->getErrorMessages($form), true);
Symfony 2.5 / 3.0:
$string = (string) $form->getErrors(true, false);
Docs:
https://github.com/symfony/symfony/blob/master/UPGRADE-2.5.md#form
h...
Monad in plain English? (For the OOP programmer with no FP background)
...rable<T>. It is an amplifier of types. It lets you take a type, say, string, and add a new capability to that type, namely, that you can now make a sequence of strings out of any number of single strings.
What are the "certain rules"? Briefly, that there is a sensible way for functions on the...
How do you create a hidden div that doesn't create a line break or horizontal space?
I want to have a hidden checkbox that doesn't take up any space on the screen.
10 Answers
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When to use in vs ref vs out
... difference, an out parameter needs not be initialized.
Example for out:
string a, b;
person.GetBothNames(out a, out b);
where GetBothNames is a method to retrieve two values atomically, the method won't change behavior whatever a and b are. If the call goes to a server in Hawaii, copying the in...
SQL Server equivalent to Oracle's CREATE OR REPLACE VIEW
...rocedures as follows.
IF NOT EXISTS (SELECT * FROM sys.views WHERE object_id = OBJECT_ID(N'[dbo].[vw_myView]'))
EXEC sp_executesql N'CREATE VIEW [dbo].[vw_myView] AS SELECT ''This is a code stub which will be replaced by an Alter Statement'' as [code_stub]'
GO
ALTER VIEW [dbo].[vw_myView]
AS
S...
Java Generics: Cannot cast List to List? [duplicate]
... tried a standalone Java class that had: 1. List x = new ArrayList<String>(); 2. List<Object> x = new ArrayList<String>(); #1 compiles fine but #2 gives an error: incompatible types found : java.util.ArrayList<java.lang.String> required: java.util.List<java.lan...
How to remove multiple indexes from a list at the same time? [duplicate]
... Looping over indices backwards. Genius! I was here dreaming up some ridiculous situation of decrementing indices as I went along, when this was so much more elegant!
– Neil
Apr 20 '15 at 22:37
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