Re: Booleans
Re: Booleans
- Subject: Re: Booleans
- From: Jonathan Rochkind <email@hidden>
- Date: Thu, 11 Mar 2004 12:38:10 -0600
What I recommend is giving up on EOF giving you boolean values. It's
just too broken, sometimes in especially mysterious ways. (See also
http://www.wodev.com/cgi-bin/WebObjects/WODev.woa/wa/Main?wikiPage=Weird52EOFBug)
But you can still get booleanValues yourself. You just need to do
it yourself. Here's what I've taken to doing, to minimize any
convenience.
1) Provide your attribute in the EOModel just as you have, called
"isShipped". But make it not a class property. Nor should it have the
lock marker next to it. It can still be used for db fetches.
2) Provide another attribute to the same column, but call it, let's
say "shipped_integer". (Avoid the "is" on the front, because then I
think EOF will (undocumentedly) try to convert to boolean for you,
because of "is"! We want to avoid that here). [Don't worry about the
fact that we have two attributes pointing to the same column---the
fact that one is not used for locking and is not a class property
means that EOF pretty much ignores it---although it can still be used
to generate SQL, conveniently!].
3) There should not be "shipped_integer" and "setShipped_integer"
cover methods in your .java class. Instead, provide your own manual
cover methods with the name you really want, and with boolean
conversion built in. (It's up to you whether to use capital-B
Boolean, which is really three valued (null, false, or true), or use
a primitive 'boolean' which can not be false. Write the conversion
however you want, to map from Number to B/boolean, and back. this is
just an example)
public boolean isShipped() {
Number n = storedValueForKey("shipped_integer");
if ( n == null || n.intValue() == 0)
return false;
else
return true;
}
public boolean setIsShipped(boolean b) {
Integer integerValue;
if ( b )
integerValue = new Integer(1);
else
integerValue = new Integer(0);
takeStoredValueForKey( integerValue, "shipped_integer");
}
Once you've set up your model/entity like this, essentially doing the
boolean conversion by hand, all your existing code should just work.
You can still create db-qualifiers on "isShipped", you've got that
attribute in your model. Your Java code can still access the methods
isShipped/setIsShipped, because you've defined them, and done the
boolean conversion yourself manually. EOF does not know what's
going on, as far as it knows, there's just a simple numeric attribute
called "shipped_integer", and EOF isn't going to try and do any
boolean conversion. Becuase, when EOF does try to do the boolean
conversion, it seems to fail in sometimes spectacularly mysterious
ways.
So that's what I've taken to doing. A bit of a pain in the set-up,
but once you've gotten it set up, it works well.
--Jonathan
At 6:54 PM +0100 3/11/04, David Griffith wrote:
Hi Chuck,
Thanks for the link, had a look. Have actually read all of that on the list
already which is fine. The 'c' value type I have just added recently to see
if it helped, it didn't. I'm going to remove it again.
The truth is, I have used the first method described in that article, as
listed below, and it DOES NOT WORK. I am using custom classes by the way
(as generated by EOModeler) - would that have any impact? I have not
modified the custom class methods for this attribute. Basically, I don't
want to go and change all the columns that are boolean to use a numeric
format unless there is no other choice.
I can use a fetchSpec with the following bindings for example:
(fetch spec bindings):
isShipped = $isShipped
And pass it the bindings in code:
bindings.addObject(Boolean.TRUE, "isShipped");
And it will return exactly the correct records.
However, if I use a relationship traversal with an array filter to try and
locate the one I want, I get no results as the value of:
someEntity.isShipped()
ALWAYS returns false, no matter what, even though it is true in the
database.
Anyone else any suggestions before I go ripping my model apart and
recreating tables???? (which have DATA!)
Regards,
Dave.
Try removing the value type. I think that c is incorrect for this
usage.
See also
> http://wodev.spearway.com/cgi-bin/WebObjects/WODev.woa/wa/Main?
wikiPage=BooleanModeling
>
Chuck
On Mar 10, 2004, at 8:57 PM, David Griffith wrote:
HI all,
I have en EOPrototype set up in my EOModel like this:
Name: boolean
Value Class: java.lang.Boolean
Factory Method: valueOf
Conversion Method: toString
Init Arguament: NSString
And I have just added 'c' as the value type.
The value stored in the database as a result is 'true' or 'false' and
it is
getting stored ok.
However, anytime I reference the value in code, like:
orderStatus.oscIsShipped()
I ALWAYS get false. No matter what. Even though it is true in the
database.
It's got to be something small, can someone tell me why? It's
driving
me
crazy.
Regards,
Dave.
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| | >Re: Booleans (From: David Griffith <email@hidden>) |