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  • jQuery trigger custom event synchronously?

    - by Miguel Angelo
    I am using the jQuery trigger method to call an event... but it behaves inconsistently. Sometimes it call the event, sometimes it does not. <a href="#" onclick=" $(this).trigger('custom-event'); window.location.href = 'url'; return false; ">text</a> The custom-event has lots of listeners added to it. It is as if the trigger method is not synchronous, allowing the window.location.href be changed before executing the events. And when window.location.href is changed a navigation occurs, interrupting everything. How can I trigger events synchronously? Using jQuery 1.8.1. Thanks! EDIT I have found that the event, when called has a stack trace like this: jQuery.fx.tick (jquery-1.8.1.js:9021) tick (jquery-1.8.1.js:8499) jQuery.Callbacks.self.fireWith (jquery-1.8.1.js:1082) jQuery.Callbacks.fire (jquery-1.8.1.js:974) jQuery.speed.opt.complete (jquery-1.8.1.js:8991) $.customEvent (myfile.js:28) This proves that jQuery trigger method is asynchronous. Oohhh my... =\

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  • How to store arbitrary data for some HTML tags

    - by nickf
    I'm making a page which has some interaction provided by javascript. Just as an example: links which send an AJAX request to get the content of articles and then display that data in a div. Obviously in this example, I need each link to store an extra bit of information: the id of the article. The way I've been handling it in case was to put that information in the href link this: <a class="article" href="#5"> I then use jQuery to find the a.article elements and attach the appropriate event handler. (don't get too hung up on the usability or semantics here, it's just an example) Anyway, this method works, but it smells a bit, and isn't extensible at all (what happens if the click function has more than one parameter? what if some of those parameters are optional?) The immediately obvious answer was to use attributes on the element. I mean, that's what they're for, right? (Kind of). <a articleid="5" href="link/for/non-js-users.html"> In my recent question I asked if this method was valid, and it turns out that short of defining my own DTD (I don't), then no, it's not valid or reliable. A common response was to put the data into the class attribute (though that might have been because of my poorly-chosen example), but to me, this smells even more. Yes it's technically valid, but it's not a great solution. Another method I'd used in the past was to actually generate some JS and insert it into the page in a <script> tag, creating a struct which would associate with the object. var myData = { link0 : { articleId : 5, target : '#showMessage' // etc... }, link1 : { articleId : 13 } }; <a href="..." id="link0"> But this can be a real pain in butt to maintain and is generally just very messy. So, to get to the question, how do you store arbitrary pieces of information for HTML tags?

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  • Java How to find a value in a linked list iteratively and recursively

    - by Roxy
    Hi I have a method that has a reference to a linked list and a int value. So, this method would count and return how often the value happens in the linked list. So, I decided to make a class, public class ListNode{ public ListNode (int v, ListNode n) {value = v; next = n;) public int value; public ListNode next; } Then, the method would start with a public static int findValue(ListNode x, int valueToCount){ // so would I do it like this?? I don't know how to find the value, // like do I check it? for (int i =0; i< x.length ;i++){ valueToCount += valueToCount; } So, I CHANGED this part, If I did this recursively, then I would have public static int findValue(ListNode x, int valueToCount) { if (x.next != null && x.value == valueToCount { return 1 + findValue(x, valueToCount);} else return new findvalue(x, valueToCount); SO, is the recursive part correct now?

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  • SQL Server Connection Timeout C#

    - by Termin8tor
    First off I'd like to let everyone know I have searched my particular problem and can't seem to find what's causing my problem. I have an SQL Server 2008 instance running on a network machine and a client I have written connecting to it. To connect I have a small segment of code that establishes a connection to an sql server 2008 instance and returns a DataTable populated with the results of whatever query I run against the server, all pretty standard stuff really. Anyway the issue is, whenever I open my program and call this method, upon the first call to my method, regardless as to what I've set my Connection Timeout value as in the connection string, it takes about 15 seconds and then times out. Bizarrely though the second or third call I make to the method will work without a problem. I have opened up the ports for SQL Server on the server machine as outlined in this article: How to Open firewall ports for SQL Server and verified that it is correctly configured. Can anyone see a particular problem in my code? string _connectionString = "Server=" + @Properties.Settings.Default.sqlServer + "; Initial Catalog=" + @Properties.Settings.Default.sqlInitialCatalog + ";User Id=" + @Properties.Settings.Default.sqlUsername + ";Password=" + @Properties.Settings.Default.sqlPassword + "; Connection Timeout=1"; private DataTable ExecuteSqlStatement(string command) { using (SqlConnection conn = new SqlConnection(_connectionString)) { try { conn.Open(); using (SqlDataAdapter adaptor = new SqlDataAdapter(command, conn)) { DataTable table = new DataTable(); adaptor.Fill(table); return table; } } catch (SqlException e) { throw e; } } } The SqlException that is caught at my catch is : "Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding." This occurs at the conn.Open(); line in the code snippet I have included. If anyone has any ideas that'd be great!

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  • Linq2Sql - attempting to update but the Set statement in sql is empty

    - by MrTortoise
    This is weird ... done updates loads of times before but cannot spot why this is different. I have a client class from the dbml I added a method called update public void UpdateSingle() { L2SDataContext dc = new L2SDataContext(); Client c = dc.Clients.Single<Client>(p => p.ID == this.ID); c.CopyToMe(this); c.updatedOn = DateTime.Now; dc.SubmitChanges(); dc.Dispose(); } The CopytoMe method public void CopyToMe(Client theObject) { if (ID != theObject.ID) { ID = theObject.ID; } /// this is redundant as generated code checks field for a change. deleted = theObject.deleted; deletedBy = theObject.deletedBy; deletedOn = theObject.deletedOn; insertedBy = theObject.insertedBy; insertedOn = theObject.insertedOn; name = theObject.name; updatedBy = theObject.updatedBy; updatedOn = theObject.updatedOn; } Im taking a client that was selected, changing its name and then calling this update method. The generated sql is as follows exec sp_executesql N'UPDATE [dbo].[tblClient] SET WHERE ([ID] = @p0) AND ([name] = @p1) AND ([insertedOn] = @p2) AND ([insertedBy] = @p3) AND ([updatedOn] = @p4) AND ([updatedBy] = @p5) AND ([deletedOn] IS NULL) AND ([deletedBy] IS NULL) AND (NOT ([deleted] = 1))',N'@p0 int,@p1 varchar(8000),@p2 datetime,@p3 int,@p4 datetime,@p5 int',@p0=103,@p1='UnitTestClient',@p2=''2010-05-17 11:33:22:520'',@p3=3,@p4=''2010-05-17 11:33:22:520'',@p5=3 I have no idea why this is not working ... used this kind of select object, set field to new value submit the selected object pattern many times and not had this problem. there is also nothing obviously wrong with the dbml - although this is probably a false statement any ideas?

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  • Need help with java map and javabean

    - by techoverflow
    Hi folks, I have a nested map: Map<Integer, Map<Integer, Double>> areaPrices = new HashMap<Integer, Map<Integer, Double>>(); and this map is populated using the code: while(oResult.next()) { Integer areaCode = new Integer(oResult.getString("AREA_CODE")); Map<Integer, Double> zonePrices = areaPrices.get(areaCode); if(zonePrices==null) { zonePrices = new HashMap<Integer, Double>(); areaPrices.put(areaCode, zonePrices); } Integer zoneCode = new Integer(oResult.getString("ZONE_CODE")); Double value = new Double(oResult.getString("ZONE_VALUE")); zonePrices.put(zoneCode, value); myBean.setZoneValues(areaPrices); } I want to use the value of this Map in another method of the same class. For that I have a bean. How do I populate it on the bean, so that I can get the ZONE_VALUE in this other method In my bean I added one new field as: private Map<Integer, Map<Integer, Double>> zoneValues; with getter and setter as: public Map<Integer, Map<Integer, Double>> getZoneValues() { return zoneValues; } public void setZoneValues(Map<Integer, Map<Integer, Double>> areaPrices) { this.zoneValues = areaPrices; } What I am looking for to do in the other method is something like this: Double value = myBean.get(areaCode).get(zoneCode); How do I make it happen :(

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  • self-destructing objects in php5?

    - by user151841
    I am working on a class in php that is basically an interface to a database row. I wanted to create a delete() method that would 1. delete the database row and 2. destroy the instance of itself so that further attempts to manipulate the row via the object would throw warnings. Doing some googling, it seems that, in php5, it's not possible for an object to unset itself. http://bugs.php.net/bug.php?id=36971 In fact they discuss the very situation I was wanting to do :( So how should I proceed? I could make boolean flag as a class property, for whether the row still exists, and have each operation check that flag and throw an error if the row has been deleted. This maintains the oo structure of code, so I would have $objDbRow->delete(); But then I have to put checks at the beginning of each method. Or, I could implement a __destruct method that deletes the row. But that would seem counter-intuitive to me; if I saw in code unset($objDbRow); All I would suspect that's happening is that the object is being discarded, not that a row is being deleted. So that to me would seem like bad practice.

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  • Understanding Basic Prototyping & Updating Key/Value pairs

    - by JordanD
    First time poster, long time lurker. I'm trying to learn some more advanced features of .js, and have two ojectives based on the pasted code below: I would like to add methods to a parent class in a specific way (by invoking prototype). I intend to update the declared key/value pairs each time I make an associated method call. execMTAction as seen in TheSuper will execute each function call, regardless. This is by design. Here is the code: function TheSuper(){ this.options = {componentType: "UITabBar", componentName: "Visual Browser", componentMethod: "select", componentValue: null}; execMTAction(this.options.componentType, this.options.componentName, this.options.componentMethod, this.options.componentValue); }; TheSuper.prototype.tapUITextView = function(val1, val2){ this.options = {componentType: "UITextView", componentName: val1, componentMethod: "entertext", componentValue: val2}; }; I would like to execute something like this (very simple): theSuper.executeMTAction(); theSuper.tapUITextView("a", "b"); Unfortunately I am unable to overwrite the "this.options" in the parent, and the .tapUITextView method throws an error saying it cannot find executeMTAction. All I want to do, like I said, is to update the parameters in the parent, then have executeMTAction run each time I make any method call. That's it. Any thoughts? I understand this is basic but I'm coming from a long-time procedural career and .js seems to have this weird confluence of oo/procedural that I'm having a bit of difficulty with. Thanks for any input!

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  • JAVA : How to get the positions of all matches in a String?

    - by user692704
    I have a text document and a query (the query could be more than one word). I want to find the position of all occurrences of the query in the document. I thought of the documentText.indexOf(query) and using regular expression but I could not make it work. I end up with the following method: First, I have create a dataType called QueryOccurrence public class QueryOccurrence implements Serializable{ public QueryOccurrence(){} private int start; private int end; public QueryOccurrence(int nameStart,int nameEnd,String nameText){ start=nameStart; end=nameEnd; } public int getStart(){ return start; } public int getEnd(){ return end; } public void SetStart(int i){ start=i; } public void SetEnd(int i){ end=i; } } Then, I have used this datatype in the following method: public static List<QueryOccurrence>FindQueryPositions(String documentText, String query){ // Normalize do the following: lower case, trim, and remove punctuation String normalizedQuery = Normalize.Normalize(query); String normalizedDocument = Normalize.Normalize(documentText); String[] documentWords = normalizedDocument.split(" ");; String[] queryArray = normalizedQuery.split(" "); List<QueryOccurrence> foundQueries = new ArrayList(); QueryOccurrence foundQuery = new QueryOccurrence(); int index = 0; for (String word : documentWords) { if (word.equals(queryArray[0])){ foundQuery.SetStart(index); } if (word.equals(queryArray[queryArray.length-1])){ foundQuery.SetEnd(index); if((foundQuery.End()-foundQuery.Start())+1==queryArray.length){ //add the found query to the list foundQueries.add(foundQuery); //flush the foundQuery variable to use it again foundQuery= new QueryOccurrence(); } } index++; } return foundQueries; } This method return a list of all occurrence of the query in the document each one with its position. Could you suggest any easer and faster way to accomplish this task. Thanks

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  • singledispatch in class, how to dispatch self type

    - by yanxinyou
    Using python3.4. Here I want use singledispatch to dispatch different type in __mul__ method . The code like this : class Vector(object): ## some code not paste @functools.singledispatch def __mul__(self, other): raise NotImplementedError("can't mul these type") @__mul__.register(int) @__mul__.register(object) # Becasue can't use Vector , I have to use object def _(self, other): result = Vector(len(self)) # start with vector of zeros for j in range(len(self)): result[j] = self[j]*other return result @__mul__.register(Vector) # how can I use the self't type @__mul__.register(object) # def _(self, other): pass # need impl As you can see the code , I want support Vector*Vertor , This has Name error Traceback (most recent call last): File "p_algorithms\vector.py", line 6, in <module> class Vector(object): File "p_algorithms\vector.py", line 84, in Vector @__mul__.register(Vector) # how can I use the self't type NameError: name 'Vector' is not defined The question may be How Can I use class Name a Type in the class's method ? I know c++ have font class statement . How python solve my problem ? And it is strange to see result = Vector(len(self)) where the Vector can be used in method body .

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  • Access property of a class from within a class instantiated in the original class.

    - by Iain
    I'm not certain how to explain this with the correct terms so maybe an example is the best method... $master = new MasterClass(); $master-doStuff(); class MasterClass { var $a; var $b; var $c; var $eventProccer; function MasterClass() { $this->a = 1; $this->eventProccer = new EventProcess(); } function printCurrent() { echo '<br>'.$this->a.'<br>'; } function doStuff() { $this->printCurrent(); $this->eventProccer->DoSomething(); $this->printCurrent(); } } class EventProcess { function EventProcess() {} function DoSomething() { // trying to access and change the parent class' a,b,c properties } } My problem is i'm not certain how to access the properties of the MasterClass from within the EventProcess-DoSomething() method? I would need to access, perform operations on and update the properties. The a,b,c properties will be quite large arrays and the DoSomething() method would be called many times during the execuction of the script. Any help or pointers would be much appreciated :)

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  • Why does LogonUser place user profiles in c:\users of the server?

    - by Lalit_M
    We have developed a ASP.NET web application and has implemented a custom authentication solution using active directory as the credentials store. Our front end application uses a normal login form to capture the user name and password and leverages the Win32 LogonUser method to authenticate the user’s credentials. When we are calling the LogonUser method, we are using the LOGON32_LOGON_NETWORK as the logon type. The issue we have found is that user profile folders are being created under the C:\Users folder of the web server. The folder seems to be created when a new user who has never logged on before is logging in for the first time. As the number of new users logging into the application grows, disk space is shrinking due to the large number of new user folders getting created. Has anyone seen this behavior with the Win32 LogonUser method? Does anyone know how to disable this behavior? I have tried LOGON32_LOGON_BATCH but it was giving an error 1385 in authentication user. I need either of the solution 1) Is there any way to stop the folder generation. 2) What parameter I need to pass this to work? Thanks

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  • WIN32 API question - Looking for answer asap

    - by Lalit_M
    We have developed a ASP.NET web application and has implemented a custom authentication solution using active directory as the credentials store. Our front end application uses a normal login form to capture the user name and password and leverages the Win32 LogonUser method to authenticate the user’s credentials. When we are calling the LogonUser method, we are using the LOGON32_LOGON_NETWORK as the logon type. The issue we have found is that user profile folders are being created under the C:\Users folder of the web server. The folder seems to be created when a new user who has never logged on before is logging in for the first time. As the number of new users logging into the application grows, disk space is shrinking due to the large number of new user folders getting created. Has anyone seen this behavior with the Win32 LogonUser method? Does anyone know how to disable this behavior? I have tried LOGON32_LOGON_BATCH but it was giving an error 1385 in authentication user. I need either of the solution 1) Is there any way to stop the folder generation. 2) What parameter I need to pass this to work? Thanks

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  • Is the below thread pool implementation correct(C#3.0)

    - by Newbie
    Hi Experts, For the first time ever I have implemented thread pooling and I found it to be working. But I am not very sure about the way I have done is the appropriate way it is supposed to be. Would you people mind in spending some valuable time to check and let me know if my approach is correct or not? If you people find that the approach is incorrect , could you please help me out in writing the correct version. I have basicaly read How to use thread pool and based on what ever I have understood I have developed the below program as per my need public class Calculation { #region Private variable declaration ManualResetEvent[] factorManualResetEvent = null; #endregion public void Compute() { factorManualResetEvent = new ManualResetEvent[2]; for (int i = 0; i < 2; i++){ factorManualResetEvent[i] = new ManualResetEvent(false); ThreadPool.QueueUserWorkItem(ThreadPoolCallback, i);} //Wait for all the threads to complete WaitHandle.WaitAll(factorManualResetEvent); //Proceed with the next task(s) NEXT_TASK_TO_BE_EXECUTED(); } #region Private Methods // Wrapper method for use with thread pool. public void ThreadPoolCallback(Object threadContext) { int threadIndex = (int)threadContext; Method1(); Method2(); factorManualResetEvent[threadIndex].Set(); } private void Method1 () { //Code of method 1} private void Method2 () { //Code of method 2 } #endregion }

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  • QMetaMethods for regular methods missing?

    - by oleks
    Hi, I'm new in QT, and I'm just testing out the MOC. For a given class: class Counter : public QObject { Q_OBJECT int m_value; public: Counter() {m_value = 0;} ~Counter() {} int value() {return m_value;} public slots: void setValue(int value); signals: void valueChanged(int newValue); }; I want to get a list of all methods in a class, but seem to only be getting a list of signals and slots, although the documentation says it should be all methods? Here's my code: #include <QCoreApplication> #include <QObject> #include <QMetaMethod> #include <iostream> using std::cout; using std::endl; int main(int argc, char *argv[]) { QCoreApplication app(argc, argv); const QMetaObject cntmo = Counter::staticMetaObject; for(int i = 0; i != cntmo.methodCount(); ++i) { QMetaMethod qmm(cntmo.method(i)); cout << qmm.signature() << endl; } return app.exec(); } Please beware this is my best c/p, perhaps I forgot to include some headers. My output: destroyed(QObject*) destroyed() deleteLater() _q_reregisterTimers(void*) valueChanged(int) setValue(int) Does anyone know why this is happening? Does qt not recognise int value() {return m_value;} as a valid method? If so, is there a macro I've forgotten or something like that? P.S. I'm using 4.6.2 UPDATE I forgot the implementation of the setValue method, not that it makes too much a difference to my actual question. void Counter::setValue(int value) { if(value != m_value) { m_value = value; emit valueChanged(value); } }

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  • NoInitialContextException: in ejb 3

    - by JavaDeveloper
    My client class code Hashtable hs = new Hashtable(); hs.put(Context.INITIAL_CONTEXT_FACTORY, "org.jnp.interfaces.NamingContextFactory"); hs.put(Context.PROVIDER_URL, "jnp://10.20.52.41:1200"); hs.put(Context.URL_PKG_PREFIXES, "org.jboss.naming:org.jnp.interfaces"); Context context = new InitialContext(hs); System.out.println("-----"); try { Example helloWorld = (Example) context .lookup("Example"); helloWorld.display("HelloWorld"); } catch (NamingException e) { System.out.println("naming exception occoured"); e.printStackTrace(); } My session bean code public class Example implements javax.ejb.SessionBean { //method here.. } getting following exception. how to resolve? Exception in thread "main" javax.naming.NoInitialContextException: Cannot instantiate class: org.jnp.interfaces.NamingContextFactory [Root exception is java.lang.ClassNotFoundException: org.jnp.interfaces.NamingContextFactory] at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:657) at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:288) at javax.naming.InitialContext.init(InitialContext.java:223) at javax.naming.InitialContext.(InitialContext.java:197) at comtest.client.Example.main(Test.java:22) Caused by: java.lang.ClassNotFoundException: org.jnp.interfaces.NamingContextFactory at java.net.URLClassLoader$1.run(URLClassLoader.java:202) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:190) at java.lang.ClassLoader.loadClass(ClassLoader.java:306) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301) at java.lang.ClassLoader.loadClass(ClassLoader.java:247) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:249) at com.sun.naming.internal.VersionHelper12.loadClass(VersionHelper12.java:46) at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:654) ... 4 more

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  • Create Rails model with argument of associated model?

    - by Kyle Carlson
    I have two models, User and PushupReminder, and a method create_a_reminder in my PushupReminder controller (is that the best place to put it?) that I want to have create a new instance of a PushupReminder for a given user when I pass it a user ID. I have the association via the user_id column working correctly in my PushupReminder table and I've tested that I can both create reminders & send the reminder email correctly via the Rails console. Here is a snippet of the model code: class User < ActiveRecord::Base has_many :pushup_reminders end class PushupReminder < ActiveRecord::Base belongs_to :user end And the create_a_reminder method: def create_a_reminder(user) @user = User.find(user) @reminder = PushupReminder.create(:user_id => @user.id, :completed => false, :num_pushups => @user.pushups_per_reminder, :when_sent => Time.now) PushupReminderMailer.reminder_email(@user).deliver end I'm at a loss for how to run that create_a_reminder method in my code for a given user (eventually will be in a cron job for all my users). If someone could help me get my thinking on the right track, I'd really appreciate it. Thanks!

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  • How duplicate an object in a list and update property of duplicated objects ?

    - by user359706
    Hello What would be the best way to duplicate an object placed in a list of items and change a property of duplicated objects ? I thought proceed in the following manner: - get object in the list by "ref" + "article" - Cloned the found object as many times as desired (n times) - Remove the object found - Add the clones in the list What do you think? A concrete example: Private List<Product> listProduct; listProduct= new List<Product>(); Product objProduit_1 = new Produit; objProduct_1.ref = "001"; objProduct_1.article = "G900"; objProduct_1.quantity = 30; listProducts.Add(objProduct_1); ProductobjProduit_2 = new Product; objProduct_2.ref = "002"; objProduct_2.article = "G900"; objProduct_2.quantity = 35; listProduits.Add(objProduct_2); desired method: public void updateProductsList(List<Product> paramListProducts,Produit objProductToUpdate, int32 nbrDuplication, int32 newQuantity){ ... } Calling method example: updateProductsList(listProducts,objProduct_1,2,15); Waiting result: Replace follow object : ref = "001"; article = "G900"; quantite = 30; By: ref = "001"; article = "G900"; quantite = 15; ref = "001"; article = "G900"; quantite = 15; The Algorithm is correct? Would you have an idea of the method implementation "updateProductsList" Thank you in advance for your help.

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  • (Java) Is there a type of object that can handle anything from primitives to arrays?

    - by Michael
    I'm pretty new to Java, so I'm hoping one of you guys knows how to do this. I'm having the user specify both the type and value of arguments, in any XML-like way, to be passed to methods that are external to my application. Example: javac myAppsName externalJavaClass methodofExternalClass [parameters] Of course, to find the proper method, we have to have the proper parameter types as the method may be overloaded and that's the only way to tell the difference between the different versions. Parameters are currently formatted in this manner: (type)value(/type), e.g. (int)71(/int) (string)This is my string that I'm passing as a parameter!(/string) I parse them, getting the constructor for whatever type is indicated, then execute that constructor by running its method, newInstance(<String value>), loading the new instance into an Object. This works fine and dandy, but as we all know, some methods take arrays, or even multi-dimensional arrays. I could handle the argument formatting like so: (array)(array)(int)0(/int)(int)1(/int)(/array)(array)(int)2(/int)(int)3(/int)(/array)(/array)... or perhaps even better... {{(int)0(/int)(int)1(/int)}{(int)2(/int)(int)3(/int)}}. The question is, how can this be implemented? Do I have to start wrapping everything in an Object[] array so I can handle primitives, etc. as argObj[0], but load an array as I normally would? (Unfortunately, I would have to make it an Object[][] array if I wanted to support two-dimensional arrays. This implementation wouldn't be very pretty.)

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  • Sending a message to nil?

    - by Ryan Delucchi
    As a Java developer who is reading Apple's Objective-C 2.0 documentation: I wonder as to what sending a message to nil means - let alone how it is actually useful. Taking an excerpt from the documentation: There are several patterns in Cocoa that take advantage of this fact. The value returned from a message to nil may also be valid: If the method returns an object, any pointer type, any integer scalar of size less than or equal to sizeof(void*), a float, a double, a long double, or a long long, then a message sent to nil returns 0. If the method returns a struct, as defined by the Mac OS X ABI Function Call Guide to be returned in registers, then a message sent to nil returns 0.0 for every field in the data structure. Other struct data types will not be filled with zeros. If the method returns anything other than the aforementioned value types the return value of a message sent to nil is undefined. Has Java rendered my brain incapable of grokking the explanation above? Or is there something that I am missing that would make this as clear as glass? Note: Yes, I do get the idea of messages/receivers in Objective-C, I am simply confused about a receiver that happens to be nil.

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  • Wrong class type in objective C

    - by Max Hui
    I have a parent class and a child class. GameObjectBase (parent) GameObjectPlayer(child). When I override a method in Child class and call it using [myPlayerClass showNextFrame] It is calling the parent class one. It turns out in the debugger, I see the myPlayerClass was indeed class type GameObjectBase (which is the parent class) How come? GameObjectBase.h #import <Foundation/Foundation.h> #import "cocos2d.h" @class GameLayer; @interface GameObjectBase : NSObject { /* CCSprite *gameObjectSprite; // Sprite representing this game object GameLayer *parentGameLayer; */ // Reference of the game layer this object // belongs to } @property (nonatomic, assign) CCSprite *gameObjectSprite; @property (nonatomic, assign) GameLayer *parentGameLayer; // Class method. Autorelease + (id) initWithGameLayer:(GameLayer *) gamelayer imageFileName:(NSString *) fileName; // "Virtual methods" that the derived class should implement. // If not implemented, this method will be called and Assert game - (void) update: (ccTime) dt; - (void) showNextFrame; @end GameObjectPlayer.h #import <Foundation/Foundation.h> #import "GameObjectBase.h" @interface GameObjectPlayer : GameObjectBase { int direction; } @property (nonatomic) int direction; @end GameLayer.h #import "cocos2d.h" #import "GameObjectPlayer.h" @interface GameLayer : CCLayer { } // returns a CCScene that contains the GameLayer as the only child +(CCScene *) scene; @property (nonatomic, strong) GameObjectPlayer *player; @end When I call examine in debugger what type "temp" is in this function inside GameLayer class, it's giving parent class GameObjectBase instead of subclass GameObjectPlayer - (void) update:(ccTime) dt { GameObjectPlayer *temp = _player; [temp showNextFrame]; }

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  • Problem in thread pool implementation(C#3.0)

    - by Newbie
    Hi Experts, I have done the below thread pool program but the problem is that the WaitCallBackMethod(here ThreadPoolCallback) is getting called 2 times(which ideally should be called 1ce). what is the misktake I am making? public class Calculation { #region Private variable declaration ManualResetEvent[] factorManualResetEvent = null; #endregion public void Compute() { factorManualResetEvent = new ManualResetEvent[2]; for (int i = 0; i < 2; i++){ factorManualResetEvent[i] = new ManualResetEvent(false); ThreadPool.QueueUserWorkItem(ThreadPoolCallback, i);} //Wait for all the threads to complete WaitHandle.WaitAll(factorManualResetEvent); //Proceed with the next task(s) NEXT_TASK_TO_BE_EXECUTED(); } #region Private Methods // Wrapper method for use with thread pool. public void ThreadPoolCallback(Object threadContext) { int threadIndex = (int)threadContext; Method1(); Method2(); factorManualResetEvent[threadIndex].Set(); } private void Method1 () { //Code of method 1} private void Method2 () { //Code of method 2 } #endregion } I am using C#3.0 Thanks

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  • Modifying an ObservableCollection using move() ?

    - by user1202434
    I have a question relating to modifying the individual items in an ObservableCollection that is bound to a ListBox in the UI. The user in the UI can multiselect items and then drop them at a particular index to re-order them. So, if I have items {0,1,2,3,4,5,6,7,8,9} the user can choose items 2, 5, 7 (in that order) and choose to drop them at index 3, so that the collection now becomes, {0,1,3, 2, 5, 7, 4, 8,9} The way I have it working now, is like this inside of ondrop() method on my control, I do something like: foreach (Item item in draggedItems) { int oldIndex = collection.IndexOf(item.DataContext as MyItemType); int newIndex = toDropIndex; if (newIndex == collection.Count) { newIndex--; } if (oldIndex != newIndex) { collection.Move(oldIndex, newIndex); } } But the problem is, if I drop the items before the index where i start dragging my first item, the order becomes reversed...so the collection becomes, {0,1,3, 7, 5, 2, 4, 8,9} It works fine if I drop after index 3, but if i drop it before 3 then the order becomes reversed. Now, I can do a simple remove and then insert all items at the index I want to, but "move" for me has the advantage of keeping the selection in the ui (remove basically de-selects the items in the list..)....so I will need to make use of the move method, what is wrong with my method above and how to fix it? Thanks!

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  • Best Methods for Dynamically Creating New Objects

    - by frankV
    I'm looking for a method to dynamically create new class objects during runtime of a program. So far what I've read leads me to believe it's not easy and normally reserved for more advanced program requirements. What I've tried so far is this: // create a vector of type class vector<class_name> vect; // and use push_back (method 1) vect.push_back(*new Object); //or use for loop and [] operator (method 2) vect[i] = *new Object; neither of these throw errors from the compiler, but I'm using ifstream to read data from a file and dynamically create the objects... the file read is taking in some weird data and occasionally reading a memory address, and it's obvious to me it's due to my use/misuse of the code snippet above. The file read code is as follows: // in main ifstream fileIn fileIn.open( fileName.c_str() ); // passes to a separate function along w/ vector loadObjects (fileIn, vect); void loadObjects (ifstream& is, vector<class_name>& Object) { int data1, data2, data3; int count = 0; string line; if( is.good() ){ for (int i = 0; i < 4; i++) { is >> data1 >> data2 >> data3; if (data1 == 0) { vect.push_back(*new Object(data2, data3) ) } } } }

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  • Generating an identifier for objects so that they can be added to a hashtable I have created

    - by dukenukem
    I have a hashtable base class and I am creating different type of hashtable by deriving from it. I only allow it to accept objects that implement my IHashable interface.For example - class LinearProbingHashTable<T> : HashTableBase<T> where T: IHashable { ... ... ... } interface IHashable { /** * Every IHashable implementation should provide an indentfying value for use in generating a hash key. */ int getIdentifier(); } class Car : IHashable { public String Make { get; set; } public String Model { get; set; } public String Color { get; set; } public int Year { get; set; } public int getIdentifier() { /// ??? } } Can anyone suggest a good method for generating an identifier for the car that can be used by the hash function to place it in the hash table? I am actually really looking for a general purpose solution to generating an id for any given class. I would like to have a base class for all classes, HashableObject, that implements IHashable and its getIdentifier method. So then I could just derive from HashableObject which would automatically provide an identifier for any instances. Which means I wouldn't have to write a different getIdentifier method for every object I add to the hashtable. public class HashableObject : IHashable { public int getIdentifier() { // Looking for code here that would generate an id for any object... } } public class Dog : HashableObject { // Dont need to implement getIdentifier because the parent class does it for me }

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