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  • How to programatically set cell.textLabel.text from a different view?

    - by Andy
    I've got a view controller, call it VC1, that's a table view. When I tap a cell in the table view, I am presented with a new view controller, call it VC2, which is a short list of choices. After making a choice, I want to dismiss VC2 and set the cell.textLabel.text property of the VC1 cell I originally tapped to the value I selected in VC2. Conceptually speaking, what is the proper way to do this? I've tried a handful of different approaches, but all of them seem wonky at best, and only one of them actually worked - although it was the most cumbersome of all, passing references to both view controllers and table view cells and all kinds of things. It just feels like I'm making a mountain out of what is probably a mole hill. This is such a common paradigm that I find it hard to believe there's not a simple method for doing it. Thanks in advance for any input you can offer.

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  • How can I consolidate deferred/delayed calls in Objective-C ?

    - by thrusty
    I'd like to ensure that certain maintenance tasks are executed "eventually". For example, after I detect that some resources might no longer be used in a cache, I might call: [self performSelector:@selector(cleanupCache) withObject:nil afterDelay:0.5]; However, there might be numerous places where I detect this, and I don't want to be calling cleanupCache continuously. I'd like to consolidate multiple calls to cleanupCache so that we only periodically get ONE call to cleanupCache. Here's what I've come up with do to this-- is this the best way? [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(cleanupCache) object:nil]; [self performSelector:@selector(cleanupCache) withObject:nil afterDelay:0.5];

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  • Is this casting safe?

    - by Itsik
    I need to write a Util function (in my c++cli app) that converts a String to a Double or Float or Int. template<typename T> static T MyConvert(String^ str) { return static_cast<T>(System::Convert::ToDouble(str)); } Is this safe? Can it somehow convert 2 to 1.999 and then to 1 if I call MyConvert<int>("2") ? I was wondering why the Convert class isn't templated in the first place? (That would let me call Convert<T> instead of Convert.ToDouble() for all types) This is C++/Cli so I can use any convert methods in c++ or .net, but I only know Convert.ToDouble()|ToString()|ToInt32()) Thanks

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  • Tracing\profiling instructions

    - by LeChuck2k
    Hi Y'all. I'd like to statistically profile my C code at the instruction level. I need to know how many additions, multiplications, devides, etc,... I'm performing. This is not your usual run of the mill code profiling requirement. I'm an algorithm developer and I want to estimate the cost of converting my code to hardware implementations. For this, I'm being asked the instruction call breakdown during run-time (parsing the compiled assembly isn't sufficient as it doesn't consider loops in the code). After looking around, It seems VMWare may offer a possible solution, but I still couldn't find the specific feature that will allow me to trace the instruction call stream of my process. Are you aware of any profiling tools which enable this?

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  • car and cdr in Scheme are driving me crazy ...

    - by kristian Roger
    Hi Im facing a problem with the car and cdr functions for example: first I defined a list called it x (define x (a (bc) d ( (ef) g ) )) so x now is equal to (a (bc) d ( (ef) g ) ) now for example I need to get the g from this list using only car and cdr (!! noshortcuts as caddr cddr !!) the correct answer is: (car(cdr(car(cdr(cdr(cdr x)))))) BUT how ? :-( I work according to the rules (the car gives the head of list and cdr gives the tail) and instead of getting the answer above I keep reaching wrong answers. Can any one help me in understanding this ... give me step or a way to solve it step by step Thanks in advance. I'm really sick of Scheme.

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  • Save VM properties with EF code first

    - by Julien
    I thought this would be simple but can't find any good examples. public Class BookVm : ImplementsPropertyChanged { public int BookId {get;set;} private bool _favorite; public bool Favorite { get { return _favorite; } set { _favorite = value; OnPropertyChanged("Favorite"); MyDbContext.SaveChanges() // this does not work } } Then in my XAML bound to Book <CheckBox Content="Favorite" IsChecked="{Binding Favorite}" /> How and when do I call SaveChanges() on my DatabaseContext? I don't want to implement a save button. If I intercept the PropertyChange event and call SaveChanges, nothing seems to happen. My object is modified in memory but the database does not see a change. My BookVm class is created on application startup like so: foreach (var book in MyDbContext.Books) Books.Add(book); Where Books is an ObservableCollection<Book> in my MainWindowVm

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  • spidermonkey using JS_CallFunction for static function

    - by supersuraccoon
    JS_CallFunctionName can call a method of an object by name: JSObject* obj; JS_CallFunctionName(cx, obj, "doSomething", argc, vp, retVal); The code above works fine if the "doSomething" is a function declared in the prototype of the "obj". What I want to know is if there is a way to call a function that is a "class function". I tried: if(JS_HasProperty(getGlobalContext(), getGlobalObject(), "ClassToGet", &b)) { print("OK"); } and the output is "OK". But when tried: JS_GetProperty(getGlobalContext(), getGlobalObject(), "ClassToGet", &jsOwner); if (jsOwner != JSVAL_VOID) { } the jsOwner is a JSVAL_VOID. Maybe there is a function in SpiderMonkey can execute function in a JSClass ? Any suggestion will be appreciated, thanks :)

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  • How to return a value when destroying/cleaning-up an object instance

    - by Mridang Agarwalla
    When I initiate a class in Python, I give it some values. I then call method in the class which does something. Here's a snippet: class TestClass(): def __init__(self): self.counter = 0 def doSomething(self): self.counter = self.counter + 1 print 'Hiya' if __name__ == "__main__": obj = TestClass() obj.doSomething() obj.doSomething() obj.doSomething() print obj.counter As you can see, everytime I call the doSomething method, it prints some text and increments an internal variable i.e. counter. When I initiate the class, i set the counter variable to 0. When I destroy the object, I'd like to return the internal counter variable. What would be a good way of doing this? I wanted to know if there were other ways apart from doing stuff like: accessing the variable directly. Like obj.counter. creating a method like getCounter. Thanks.

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  • Why first arg to execve() must be path to executable

    - by EBM
    I understand that execve() and family require the first argument of its argument array to be the same as the executable that is also pointed to by its first argument. That is, in this: execve(prog, args, env); args[0] will usually be the same as prog. But I can't seem to find information as to why this is. I also understand that executables (er, at least shell scripts) always have their calling path as the first argument when running, but I would think that the shell would do the work to put it there, and execve() would just call the executable using the path given in its first argument ("prog" from above), then passing the argument array ("args" from above) as one would on the command line.... i.e., I don't call scripts on the command line with a duplicate executable path in the args list.... /bin/ls /bin/ls /home/john Can someone explain?

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  • save managed bean to notes document

    - by Ove Stoerholt
    In a managed bean you have fields, and the fields have getters and setters. But I also need to save values back to, in this case, a Notes profile document. So I have a loadProfileDocument and a saveProfileDocument method. I was thinking of using the bean in the application scope. How do I make sure the profile document is saved? Do I have to call the saveProfileDocument from the setter? Do I call the saveProfileDocument() explisitly? Could I use a destructor (finalize)? Or what...???...

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  • multithreading with database

    - by Darsin
    I am looking out for a strategy to utilize multithreading (probably asynchronous delegates) to do a synchronous operation. I am new to multithreading so i will outline my scenario first. This synchronous operation right now is done for one set of data (portfolio) based on the the parameters provided. The (psudeo-code) implementation is given below: public DataSet DoTests(int fundId, DateTime portfolioDate) { // Get test results for the portfolio // Call the database adapter method, which in turn is a stored procedure, // which in turns runs a series of "rule" stored procs and fills a local temp table and returns it back. DataSet resultsDataSet = GetTestResults(fundId, portfolioDate); try { // Do some local processing on the results DoSomeProcessing(resultsDataSet); // Save the results in Test, TestResults and TestAllocations tables in a transaction. // Sets a global transaction which is provided to all the adapter methods called below // It is defined in the Base class StartTransaction("TestTransaction"); // Save Test and get a testId int testId = UpdateTest(resultsDataSet); // Adapter method, uses the same transaction // Update testId in the other tables in the dataset UpdateTestId(resultsDataSet, testId); // Update TestResults UpdateTestResults(resultsDataSet); // Adapter method, uses the same transaction // Update TestAllocations UpdateTestAllocations(resultsDataSet); // Adapter method, uses the same transaction // It is defined in the base class CommitTransaction("TestTransaction"); } catch { RollbackTransaction("TestTransaction"); } return resultsDataSet; } Now the requirement is to do it for multiple set of data. One way would be to call the above DoTests() method in a loop and get the data. I would prefer doing it in parallel. But there are certain catches: StartTransaction() method creates a connection (and transaction) every time it is called. All the underlying database tables, procedures are the same for each call of DoTests(). (obviously). Thus my question are: Will using multithreading anyway improve performance? What are the chances of deadlock especially when new TestId's are being created and the Tests, TestResults and TestAllocations are being saved? How can these deadlocked be handled? Is there any other more efficient way of doing the above operation apart from looping over the DoTests() method repeatedly?

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  • rails error on create action

    - by ash34
    SQL (2.0ms) SELECT task_report_requests_seq.NEXTVAL id FROM dual TaskReportRequest Create (2.2ms) INSERT INTO task_report_requests (location, created_at, updated_at, id, freq, login, task_dt) VALUES('020', TO_DATE('2010-05-25 05:02:38','YYYY-MM-DD HH24:MI:SS'), TO_DATE('2010-05-25 05:02:38','YYYY-MM-DD HH24:MI:SS'), 10023, 'M', NULL, TO_DATE('2010-05-30 00:00:00','YYYY-MM-DD HH24:MI:SS')) NoMethodError (You have a nil object when you didn't expect it! The error occurred while evaluating nil.call): app/controllers/task_report_requests_controller.rb:45:in `create' It says error evaluating nil.call . Can someone tell me when I would get such an error. I am not able to figure out with this information. thanks, ash

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  • How can I receive messages using C# over http without MSMQ

    - by pduncan
    I need a reliable messaging framework that runs over http/https (due to client security requirements) and that doesn't use MSMQ (because some clients will use Windows XP Home). The clients only need to be able to receive messages, not send them. We already have a message queue on the server for each user, and the receivers have been getting messages by connecting to an HttpHandler on the server and getting a Stream from WebResponse.GetResponseStream() We keep this stream open, and pull messages off of it using Stream.Read(). This MOSTLY works, but Stream.Read() is a blocking call, and we can't reliably interrupt it. We need to be able to stop and start the receiver without losing messages, but the old stream often hangs around, even after we call Thread.Abort on its thread. Any suggestions?

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  • def constrainedMatchPair(firstMatch,secondMatch,length):

    - by smart
    matches of a key string in a target string, where one of the elements of the key string is replaced by a different element. For example, if we want to match ATGC against ATGACATGCACAAGTATGCAT, we know there is an exact match starting at 5 and a second one starting at 15. However, there is another match starting at 0, in which the element A is substituted for C in the key, that is we match ATGC against the target. Similarly, the key ATTA matches this target starting at 0, if we allow a substitution of G for the second T in the key string. consider the following steps. First, break the key string into two parts (where one of the parts could be an empty string). Let's call them key1 and key2. For each part, use your function from Problem 2 to find the starting points of possible matches, that is, invoke starts1 = subStringMatchExact(target,key1) and starts2 = subStringMatchExact(target,key2) The result of these two invocations should be two tuples, each indicating the starting points of matches of the two parts (key1 and key2) of the key string in the target. For example, if we consider the key ATGC, we could consider matching A and GC against a target, like ATGACATGCA (in which case we would get as locations of matches for A the tuple (0, 3, 5, 9) and as locations of matches for GC the tuple (7,). Of course, we would want to search over all possible choices of substrings with a missing element: the empty string and TGC; A and GC; AT and C; and ATG and the empty string. Note that we can use your solution for Problem 2 to find these values. Once we have the locations of starting points for matches of the two substrings, we need to decide which combinations of a match from the first substring and a match of the second substring are correct. There is an easy test for this. Suppose that the index for the starting point of the match of the first substring is n (which would be an element of starts1), and that the length of the first substring is m. Then if k is an element of starts2, denoting the index of the starting point of a match of the second substring, there is a valid match with one substitution starting at n, if n+m+1 = k, since this means that the second substring match starts one element beyond the end of the first substring. finally the question is Write a function, called constrainedMatchPair which takes three arguments: a tuple representing starting points for the first substring, a tuple representing starting points for the second substring, and the length of the first substring. The function should return a tuple of all members (call it n) of the first tuple for which there is an element in the second tuple (call it k) such that n+m+1 = k, where m is the length of the first substring.

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  • Where are the function literals in c++?

    - by academicRobot
    First of all, maybe literals is not the right term for this concept, but its the closest I could think of (not literals in the sense of functions as first class citizens). The idea is that when you make a conventional function call, it compiles to something like this: callq <immediate address> But if you make a function call using a function pointer, it compiles to something like this: mov <memory location>,%rax callq *%rax Which is all well and good. However, what if I'm writing a template library that requires a callback of some sort with a specified argument list and the user of the library is expected to know what function they want to call at compile time? Then I would like to write my template to accept a function literal as a template parameter. So, similar to template <int int_literal> struct my_template {...};` I'd like to write template <func_literal_t func_literal> struct my_template {...}; and have calls to func_literal within my_template compile to callq <immediate address>. Is there a facility in C++ for this, or a work around to achieve the same effect? If not, why not (e.g. some cataclysmic side effects)? How about C++0x or another language? Solutions that are not portable are fine. Solutions that include the use of member function pointers would be ideal. I'm not particularly interested in being told "You are a <socially unacceptable term for a person of low IQ>, just use function pointers/functors." This is a curiosity based question, and it seems that it might be useful in some (albeit limited) applications. It seems like this should be possible since function names are just placeholders for a (relative) memory address, so why not allow more liberal use (e.g. aliasing) of this placeholder. p.s. I use function pointers and functions objects all the the time and they are great. But this post got me thinking about the don't pay for what you don't use principle in relation to function calls, and it seems like forcing the use of function pointers or similar facility when the function is known at compile time is a violation of this principle, though a small one.

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  • how have defined connection within function for pdo communication with DB

    - by Scarface
    hey guys I just started trying to convert my query structure to PDO and I have come across a weird problem. When I call a pdo query connection within a function and the connection is included outside the function, the connection becomes undefined. Anyone know what I am doing wrong here? I was just playing with it, my example is below. include("includes/connection.php"); function query(){ $user='user'; $id='100'; $sql = 'SELECT * FROM users'; $stmt = $conn->prepare($sql); $result=$stmt->execute(array($user, $id)); echo $count=$stmt->rowCount(); if (!$result || $stmt->rowCount()>=1){ echo 'balls'; } // now iterate over the result as if we obtained // the $stmt in a call to PDO::query() while($r = $stmt->fetch(PDO::FETCH_ASSOC)) { echo "$r[username] $r[id] \n"; } } query();

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  • Python: User-Defined Exception That Proves The Rule

    - by bandana
    Python documentations states: Exceptions should typically be derived from the Exception class, either directly or indirectly. the word 'typically' leaves me in an ambiguous state. consider the code: class good(Exception): pass class bad(object): pass Heaven = good() Hell = bad() >>> raise Heaven Traceback (most recent call last): File "<pyshell#163>", line 1, in <module> raise Heaven good >>> raise Hell Traceback (most recent call last): File "<pyshell#171>", line 1, in <module> raise Hell TypeError: exceptions must be classes or instances, not bad so when reading the python docs, should i change 'typically' with ''? what if i have a class hierarchy that has nothing to do with the Exception class, and i want to 'raise' objects belonging to the hierarchy? i can always raise an exception with an argument: raise Exception, Hell This seems slightly awkward to me What's so special about the Exception class, that only its family members can be raised?

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  • Can I destroy a class instance even if there are still references?

    - by DR
    For debugging reasons I want to destroy a class instance which still as references. Is that possible? It doesn't have to be elegant or stable, because this'll never end up in production code. To clarify: Public Sub Main Dim o as MyClass Set o = New MyClass //o is created, one reference DestroyObject o //Class_Terminate is called and the object destroyed //Further code, not using o End Sub //Possible runtime error here (don't care) Is that possible? One way would be to call IUnknown::Release to manually decrease the reference count, but how do I now how often I must call it?

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  • Limiting the number of threads executing a method at a single time.

    - by Steve_
    We have a situation where we want to limit the number of paralell requests our application can make to its application server. We have potentially 100+ background threads running that will want to at some point make a call to the application server but only want 5 threads to be able to call SendMessage() (or whatever the method will be) at any one time. What is the best way of achieving this? I have considered using some sort of gatekeeper object that blocks threads coming into the method until the number of threads executing in it has dropped below the threshold. Would this be a reasonable solution or am I overlooking the fact that this might be dirty/dangerous? We are developing in C#.NET 3.5. Thanks, Steve

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  • VB.Net List.Find. Pass values to predicate

    - by Beta033
    Having a bit of trouble using the List.Find with a custom predicate i have a function that does this private function test () Dim test As Integer = keys.Find(AddressOf FindByOldKeyAndName).NewKey here's the function for the predicate Private Shared Function FindByOldKeyAndName(ByVal k As KeyObj) As Boolean If k.OldKey = currentKey.OldKey And k.KeyName = currentKey.KeyName Then Return True Else Return False End If End Function by doing it this way means i have to have a shared "currentKey" object in the class, and i know there has to be a way to pass in the values i'm interested in of CurrentKey (namely, keyname, and oldkey) ideally i'd like to call it by something like keys.Find(AddressOf FindByOldKeyAndName(Name,OldVal)) however when i do this i get compiler errors. How do i call this method and pass in the values?

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  • Is there a way to animate on a Home Widget?

    - by David
    Hi All, I want to use an animation on a Home page Widget, i.e. an AppWidgetProvider. I was hoping to use the "Frame Animation" technique: http://developer.android.com/guide/topics/graphics/2d-graphics.html#frame-animation which I've used successfully in an activity. But I can't translate that code to an AppWidgetProvider. Basically, in an AppWidgetProvider, I create and work with a RemoteViews object, which AFAIK doesn't provide me with a method to get a reference to an ImageView in the layout for me to call start() on the animation. There is also not a handler or a callback for when the widget displays so I can make the start() call. Is there another way this can be done? I suppose that I can probably do the animation on my own with very fast onUpdate() calls on the widget, but that seems awfully expensive.

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  • How to "serialize" and "deserialize" command line arguments to string in bash?

    - by Vi
    I call my script: $ ./script 'a!#*`*& ^$' "sdf sdf\"qw sdsdf" 1 -- 2 3 It gets arguments: 1: a!#*`*& ^$ 2: sdf sdf"qw sdsdf 3: 1 4: -- 5: 2 6: 3 If I need to call something with the same arguments locally, I do this: someprogram "$@" But how can I put all that array to a string (to store in file or in environment variable or pass over TCP eaisly) and then turn it back to command line arguments somewhere? I want it to be simple, short and secure. export CMDLINE="$@" # What is in CMDLINE now? Escaped or not? sh -c "someprogram $CMDLINE" # Will it do what I mean? Ideally I want two bash subroutines: the first turns turns any Bash array into a [a-zA-Z0-9_]* string, the other turns it back to Bash array I can use.

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  • How to override inner class methods if the inner class is defined as a property of the top class

    - by Maddy
    I have a code snippet like this class A(object): class b: def print_hello(self): print "Hello world" b = property(b) And I want to override the inner class b (please dont worry about the lowercase name) behaviour. Say, I want to add a new method or I want to change an existing method, like: class C(A): class b(A.b): def print_hello(self): print "Inner Class: Hello world" b = property(b) Now if I create C's object as c = C(), and call c.b I get TypeError: 'property' object is not callable error. How would I get pass this and call print_hello of the extended inner class? Disclaimer: I dont want to change the code for A class.

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  • RAII: Initializing data member in const method

    - by Thomas Matthews
    In RAII, resources are not initialized until they are accessed. However, many access methods are declared constant. I need to call a mutable (non-const) function to initialize a data member. Example: Loading from a data base struct MyClass { int get_value(void) const; private: void load_from_database(void); // Loads the data member from database. int m_value; }; int MyClass :: get_value(void) const { static bool value_initialized(false); if (!value_initialized) { // The compiler complains about this call because // the method is non-const and called from a const // method. load_from_database(); } return m_value; } My primitive solution is to declare the data member as mutable. I would rather not do this, because it suggests that other methods can change the member. How would I cast the load_from_database() statement to get rid of the compiler errors?

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