Looking up a NSString constant at runtime
Is there a way to lookup what and NString constant is at runtime? I want to know what the string is for a given constant. For example I would like to pass in the constant name ( i.e. NSDeviceResolution) and get back the NSString that constant represents. I know in this case that the Constant name and the string are the same but I suspect that is not always true. Any ideas? thanks -dave ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Looking up a NSString constant at runtime
On Mon, Jan 4, 2010 at 4:56 PM, David Alter alterconsult...@gmail.com wrote: Is there a way to lookup what and NString constant is at runtime? Have you tried [NSDeviceResolution description] or [NSString stringWithString:NSDeviceResolution] ? Soong ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Looking up a NSString constant at runtime
I think you're confused: the constant *is* the string; there is no lookup to perform. You can do anything with it that you would do with any other non-mutable string: log it, setStringValue on a text field in the user interface, setMessageText in an alert, and so on. -- Scott Ribe scott_r...@killerbytes.com http://www.killerbytes.com/ (303) 722-0567 voice ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Looking up a NSString constant at runtime
This would work for finding out what the name is as well as logging it. What if I'm getting a string passed in that is the name of the constant and I want to return the constants string value. Is there a way to do that? something like... NSString * constValue = [SomeToolToLookupConstants constant:@ NSDeviceResolution']; any idea? -dave On Mon, Jan 4, 2010 at 2:19 PM, Oftenwrong Soong oftenwrongso...@yahoo.comwrote: On Mon, Jan 4, 2010 at 4:56 PM, David Alter alterconsult...@gmail.com wrote: Is there a way to lookup what and NString constant is at runtime? Have you tried [NSDeviceResolution description] or [NSString stringWithString:NSDeviceResolution] ? Soong ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/alterconsulting%40gmail.com This email sent to alterconsult...@gmail.com ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Looking up a NSString constant at runtime
The constant *is* an NSString; essentially you could do: NSString *constValue = NSDeviceResolution; Though, that may be a little redundant. --Nick Paulson On Jan 4, 2010, at 6:09 PM, David Alter wrote: This would work for finding out what the name is as well as logging it. What if I'm getting a string passed in that is the name of the constant and I want to return the constants string value. Is there a way to do that? something like... NSString * constValue = [SomeToolToLookupConstants constant:@ NSDeviceResolution']; any idea? -dave On Mon, Jan 4, 2010 at 2:19 PM, Oftenwrong Soong oftenwrongso...@yahoo.comwrote: On Mon, Jan 4, 2010 at 4:56 PM, David Alter alterconsult...@gmail.com wrote: Is there a way to lookup what and NString constant is at runtime? Have you tried [NSDeviceResolution description] or [NSString stringWithString:NSDeviceResolution] ? Soong ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/alterconsulting%40gmail.com This email sent to alterconsult...@gmail.com ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/cocoa%40nickpaulson.com This email sent to co...@nickpaulson.com ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Looking up a NSString constant at runtime
What if I'm getting a string passed in that is the name of the constant and I want to return the constants string value. Is there a way to do that? This is C, and just as with variables, the names are not there at runtime. If you really need to do this, you'll have to build your own lookup table, possibly using some macro magic to avoid having to type the name twice for each entry. -- Scott Ribe scott_r...@killerbytes.com http://www.killerbytes.com/ (303) 722-0567 voice ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Looking up a NSString constant at runtime
I can open a library and lookup a function by name using dlsym. These constants are EXTERN. It seams there should be away to look these up as well. -dave On Mon, Jan 4, 2010 at 3:39 PM, Scott Ribe scott_r...@killerbytes.comwrote: What if I'm getting a string passed in that is the name of the constant and I want to return the constants string value. Is there a way to do that? This is C, and just as with variables, the names are not there at runtime. If you really need to do this, you'll have to build your own lookup table, possibly using some macro magic to avoid having to type the name twice for each entry. -- Scott Ribe scott_r...@killerbytes.com http://www.killerbytes.com/ (303) 722-0567 voice ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Looking up a NSString constant at runtime
On 05/01/2010, at 11:03 AM, David Alter wrote: I can open a library and lookup a function by name using dlsym. These constants are EXTERN. It seams there should be away to look these up as well. Functions are not the same, because a function's name is a necessary part of the runtime. A constant's name is just a convenience for the programmer and doesn't make it into the binary. There is no built-in standard way to do this - you're on your own. --Graham ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Looking up a NSString constant at runtime
On 4/Jan/2010, at 4:24 PM, glenn andreas wrote:
CFBundle has routines for looking up both functions and data by name. It
does require you figure out what framework the symbol comes from (and then
get the corresponding CFBundle), but it is doable.
Cool, I didn't know that CFBundle exposed access to external symbols at run
time! I've always used nm (or some such) to look at the symbol table. This
was a fun exercise to work out how to get access to the value of the symbol at
runtime. Apologies if I've done something weird, I don't work in CF very often.
If you know the bundle identifier, then it would seem that this code will find
the symbol and allow access to its value:
CFBundleRef bundle =
CFBundleGetBundleWithIdentifier(CFSTR(com.apple.AppKit));
if(bundle){
NSString **pointer = (NSString **)CFBundleGetDataPointerForName
(bundle, CFSTR(NSDeviceResolution));
if(pointer){
NSLog(@NSDeviceResolution = %@, *pointer);
}
}
If you don't know the bundle identifier then I assume you have to iterate over
the available bundles (left as an exercise for someone else. ;-)
As to the usefulness of this, I can't say. The original poster never said why
they were trying to do so I don't know if this will be suitable for the task...
Today however, at this moment, it worked for me!
M.
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Re: Looking up a NSString constant at runtime
Ah yes, external symbols in a dynamic library--you do have some chance of looking them up at run time ;-) -- Scott Ribe scott_r...@killerbytes.com http://www.killerbytes.com/ (303) 722-0567 voice ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
