Dear Evadne and all,
I appreciate so much for your replies!
You change the return value from (const char *) to (NSString *). In my
system, since I need to send the XML to a server via BSD socket. I have to
convert it to (const char *).
But I got another problem. If autoreleasing xmlStr or release xmlStr before
returning the (const char *) value, the system got exceptions. Why?
For this problem, I have to remove the lines. But how to manage the memory
of xmlStr?
Best regards,
Bing
On Fri, May 20, 2011 at 11:19 PM, Evadne Wu <monocerosfu...@gmail.com>wrote:
> Hi Bing,
>
> Re-factored this method a bit to try out some idea — have a look? It’s
> almost certainly asking for trouble to pass C strings around if you’re
> working with Cocoa, but I am not sure of your scenario, so maybe I am
> (what’s assumed to almost always be true) wrong with returning an NSString.
>
>
> + (NSString *) signInMessageWithPeerKey:(NSString *)aKey name:(NSString
> *)aName password:(NSString *)aPassword {
>
> NSParameterAssert(aKey && aName && aPassword);
>
> NSXMLNode *rootNode = [NSXMLNode
> elementWithName:MessageConstants.XML.MESSAGE_ROOT children:[NSArray
> arrayWithObjects:
>
> [NSXMLNode elementWithName:MessageConstants.XML.PEERKEY
> stringValue:aKey],
> [NSXMLNode elementWithName:MessageConstants.XML.PEERNAME
> stringValue:aName],
> [NSXMLNode elementWithName:MessageConstants.XML.PASSWORD
> stringValue:aPassword],
>
> nil] attributes:nil];
>
> NSXMLDocument *document = [[[NSXMLDocument alloc]
> initWithRootElement:rootNode] autorelease];
> [document setVersion:MessageConstants.XML.XML_VERSION];
> [document setCharacterEncoding:MessageConstants.XML.XML_ENCODING];
>
> return [[[NSString alloc] initWithData:[document
> XMLDataWithOptions:NSXMLNodePrettyPrint] encoding:[document
> characterEncoding]] autorelease];
>
> }
>
>
> -ev
>
> On May 20, 2011, at 22:43, Bing Li wrote:
>
> > Dear Jeff and all,
> >
> > I appreciate so much for your help! After reading the document from
> > apple.com, I changed my code as follows. It must be fine.
> >
> > Best regards,
> > Bing
> >
> > + (const char *) CreateSignInMessage: (NSString *)peerKey PN: (NSString
> > *)peerName PW:(NSString *)password
> > {
> > NSXMLElement *root = [NSXMLNode
> > elementWithName:MessageConstants.XML.MESSAGE_ROOT];
> > NSXMLDocument *xmlDoc = [[NSXMLDocument alloc]
> > initWithRootElement:root];
> > [xmlDoc setVersion:MessageConstants.XML.XML_VERSION];
> > [xmlDoc setCharacterEncoding:MessageConstants.XML.XML_ENCODING];
> >
> > NSXMLElement *peerKeyElement = [NSXMLNode
> > elementWithName:MessageConstants.XML.PEERKEY];
> > [root addChild:peerKeyElement];
> > [peerKeyElement addChild:[NSXMLNode textWithStringValue:peerKey]];
> >
> > NSXMLElement *peerNameElement = [NSXMLNode
> > elementWithName:MessageConstants.XML.PEERNAME];
> > [root addChild:peerNameElement];
> > [peerNameElement addChild:[NSXMLNode
> textWithStringValue:peerName]];
> >
> > NSXMLElement *passwordElement = [NSXMLNode
> > elementWithName:MessageConstants.XML.PASSWORD];
> > [root addChild:passwordElement];
> > [passwordElement addChild:[NSXMLNode
> textWithStringValue:password]];
> >
> > NSData *data = [xmlDoc XMLDataWithOptions:NSXMLNodePrettyPrint];
> > NSString *xmlStr = [[NSString alloc] initWithData:data
> > encoding:NSUTF8StringEncoding];
> > const char *xmlChar = [xmlStr UTF8String];
> >
> > /*
> > [passwordElement release];
> > [root release];
> > [xmlStr release];
> > [data release];
> > */
> > [xmlDoc release];
> > [xmlStr autorelease];
> > return xmlChar;
> > }
> >
> >
> > On Thu, May 19, 2011 at 4:23 PM, Jeffrey Walton <noloa...@gmail.com>
> wrote:
> >
> >> On Wed, May 18, 2011 at 2:16 PM, Ken Thomases <k...@codeweavers.com>
> wrote:
> >>> On May 18, 2011, at 12:55 PM, Bing Li wrote:
> >>>
> >>>> NSXMLElement *root = [NSXMLNode elementWithName:"MessageRoot"];
> >>>
> >>> As per Cocoa's memory management conventions, you don't not own the
> >> object returned by -[NSXMLNode elementWithName:]. You have not invoked
> a
> >> method whose name contains "alloc", "new", or "copy" or which is
> explicitly
> >> documented as giving its caller ownership rights and responsibilities.
> >>>
> >>>> NSXMLElement *peerKeyElement = [NSXMLNode
> >> elementWithName:"PeerKey"];
> >>>
> >>> Same here.
> >>>
> >>>> NSXMLElement *peerNameElement = [NSXMLNode
> >> elementWithName:"PeerName"];
> >>>
> >>> Same here.
> >>>
> >>>> NSXMLElement *passwordElement = [NSXMLNode
> >> elementWithName:"Password"];
> >>>
> >>> Same here.
> >>>
> >>>> NSData *data = [xmlDoc XMLDataWithOptions:NSXMLNodePrettyPrint];
> >>>
> >>> Same here.
> >>>
> >>>> [passwordElement release];
> >>>> // [peerNameElement release];
> >>>> // [peerKeyElement release];
> >>>> [root release];
> >>>> [xmlDoc release];
> >>>> [xmlStr release];
> >>>> [data release];
> >>>
> >>> Many of these releases are wrong, not just the ones you have commented
> >> out.
> >>> Of these, you only own xmlDoc and xmlStr, so those are the only ones
> you
> >> are
> >>> entitled to release. If you didn't happen to get exceptions from
> >> releasing the
> >>> others, it was an unhappy accident. (Unhappy because it hid your bug.
> >> It is
> >>> always better for bugs to be found early.)
> >> If it helps Bing (and coming from someone who frequently needs the
> >> same sort of help): (1) Run you code using Instruments, or (2) select
> >> Executable -> Arguments and add NSZombieEnabled = YES. Both should
> >> help you flush out the problems early (as Ken suggests).
> >>
> >>> Please review the Memory Management Programming Guide <
> >>
> http://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/MemoryMgmt/
> >.
> >> It explains all of this.
> >>>
> >> Also grab a book or two. It will help you digest it. Nuremberg's book
> >> would be a good choice since the doctor stays active on this list.
> >>
> >> Jeff
> >>
> > _______________________________________________
> >
> > 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/ev%40monoceroi.com
> >
> > This email sent to e...@monoceroi.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
