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• Magento Replacing super attributes table with dropdown

  - by thrice801

  Hi, I am trying to replace my magento super attributes table with a drop down menu in place of it, Ive got the menu created but I am struggling to get it to actually use the data from the select dropdown. On submit it calls up function productAddToCartForm, which I feel like if I could modify, I could figure it out. But I have no idea where that function is. My php code looks like the following. <?php if (count($_associatedProducts)): ?> <select name="selectedSku"> <?php foreach ($_associatedProducts as $_item): ?> <?php $prodname = $this->htmlEscape($_item->getName()); $prodprice = $this->htmlEscape($_item->getPrice()); $prodcolor = $_item->getFullColor(); $prodsize = $_item->getTopSize(); $prodcombined = $prodname; $prodcombined .= " / "; $prodcombined .= $prodprice; echo "<option "; echo "value ='"; echo $_item->getId(); echo "'>"; echo $prodcombined; echo "</option>"; ?> <?php endforeach; ?> </select> Any help would be much appreciated. Thanks!

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• Class initialization and synchronized class method

  - by nybon

  Hi there, In my application, there is a class like below: public class Client { public synchronized static print() { System.out.println("hello"); } static { doSomething(); // which will take some time to complete } } This class will be used in a multi thread environment, many threads may call the Client.print() method simultaneously. I wonder if there is any chance that thread-1 triggers the class initialization, and before the class initialization complete, thread-2 enters into print method and print out the "hello" string? I see this behavior in a production system (64 bit JVM + Windows 2008R2), however, I cannot reproduce this behavior with a simple program in any environments. In Java language spec, section 12.4.1 (http://java.sun.com/docs/books/jls/second_edition/html/execution.doc.html), it says: A class or interface type T will be initialized immediately before the first occurrence of any one of the following: T is a class and an instance of T is created. T is a class and a static method declared by T is invoked. A static field declared by T is assigned. A static field declared by T is used and the reference to the field is not a compile-time constant (§15.28). References to compile-time constants must be resolved at compile time to a copy of the compile-time constant value, so uses of such a field never cause initialization. According to this paragraph, the class initialization will take place before the invocation of the static method, however, it is not clear if the class initialization need to be completed before the invocation of the static method. JVM should mandate the completion of class initialization before entering its static method according to my intuition, and some of my experiment supports my guess. However, I did see the opposite behavior in another environment. Can someone shed me some light on this? Any help is appreciated, thanks.

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• Python's asyncore to periodically send data using a variable timeout. Is there a better way?

  - by Nick Sonneveld

  I wanted to write a server that a client could connect to and receive periodic updates without having to poll. The problem I have experienced with asyncore is that if you do not return true when dispatcher.writable() is called, you have to wait until after the asyncore.loop has timed out (default is 30s). The two ways I have tried to work around this is 1) reduce timeout to a low value or 2) query connections for when they will next update and generate an adequate timeout value. However if you refer to 'Select Law' in 'man 2 select_tut', it states, "You should always try to use select() without a timeout." Is there a better way to do this? Twisted maybe? I wanted to try and avoid extra threads. I'll include the variable timeout example here: #!/usr/bin/python import time import socket import asyncore # in seconds UPDATE_PERIOD = 4.0 class Channel(asyncore.dispatcher): def __init__(self, sock, sck_map): asyncore.dispatcher.__init__(self, sock=sock, map=sck_map) self.last_update = 0.0 # should update immediately self.send_buf = '' self.recv_buf = '' def writable(self): return len(self.send_buf) > 0 def handle_write(self): nbytes = self.send(self.send_buf) self.send_buf = self.send_buf[nbytes:] def handle_read(self): print 'read' print 'recv:', self.recv(4096) def handle_close(self): print 'close' self.close() # added for variable timeout def update(self): if time.time() >= self.next_update(): self.send_buf += 'hello %f\n'%(time.time()) self.last_update = time.time() def next_update(self): return self.last_update + UPDATE_PERIOD class Server(asyncore.dispatcher): def __init__(self, port, sck_map): asyncore.dispatcher.__init__(self, map=sck_map) self.port = port self.sck_map = sck_map self.create_socket(socket.AF_INET, socket.SOCK_STREAM) self.bind( ("", port)) self.listen(16) print "listening on port", self.port def handle_accept(self): (conn, addr) = self.accept() Channel(sock=conn, sck_map=self.sck_map) # added for variable timeout def update(self): pass def next_update(self): return None sck_map = {} server = Server(9090, sck_map) while True: next_update = time.time() + 30.0 for c in sck_map.values(): c.update() # <-- fill write buffers n = c.next_update() #print 'n:',n if n is not None: next_update = min(next_update, n) _timeout = max(0.1, next_update - time.time()) asyncore.loop(timeout=_timeout, count=1, map=sck_map)

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• XML Schema: How to specify an attribute with a custom 'simpleType' type?

  - by mackenir

  In my XML schema definition, I'm trying to restrict the value of an attribute to be an integer between 0 and 100. With reference to the sample schema below, I want attribute 'attr' on element 'root' to have this restriction. To achieve this I define a simpleType 'Percentage' and set this as the 'type' of 'attr'. However, my XML schema editor (VS 2008) flags the attribute up as having a problem: "Type 'Percentage' is not declared or is not a simple type". <?xml version="1.0" encoding="utf-8"?> <xs:schema elementFormDefault="qualified" id="test" xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="http://testtttt"> <xs:simpleType name="Percentage"> <xs:restriction base="xs:integer"> <xs:minInclusive value="0"/> <xs:maxInclusive value="100"/> </xs:restriction> </xs:simpleType> <xs:element name="root"> <xs:complexType> <xs:attribute name="attr" type="Percentage" use="optional" /> </xs:complexType> </xs:element>

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• how to find a control inside ItemsPanelTemplate in wpf?

  - by kakopappa

  I am trying to access a Grid inside the DataTemplate while the ItemsControl is binded by ItemsSource. this is the full XMAL code, How do i find a certain element from outside? for (int i = 0; i < allViewControl.Items.Count; i++) { var container = allViewControl.ItemContainerGenerator.ContainerFromItem(allViewControl.Items[i]) as FrameworkElement; var grid = allViewControl.ItemTemplate.FindName("grid", container) as DataGrid; } i found this always returning null ? <ScrollViewer Grid.Row="0" HorizontalScrollBarVisibility="Disabled" VerticalScrollBarVisibility="Auto"> <ItemsControl x:Name="allViewControl" Focusable="False" HorizontalContentAlignment="Center" Grid.IsSharedSizeScope="true" ItemsSource="{Binding AllClassCharacters}" ItemTemplate="{StaticResource CharacterViewModelTemplate}" > <ItemsControl.ItemsPanel> <ItemsPanelTemplate> <Extensions:AnimatedWrapPanel IsItemsHost="true" /> </ItemsPanelTemplate> </ItemsControl.ItemsPanel> </ItemsControl> </ScrollViewer> <DataTemplate x:Key="CharacterViewModelTemplate" DataType="{x:Type ViewModel:CharacterViewModel}"> <Grid x:Name="grid" Width="200" Height="Auto" MinHeight="115" Margin="1" MinWidth="130" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" RenderTransformOrigin="0.5,0.5" Background="#66000000" > <Grid.RowDefinitions> <RowDefinition Height="70"/> <RowDefinition Height="*"/> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <ProgressBar x:Name="playerProgressBar" VerticalAlignment="Top" Background="Transparent" Height="5" Width="Auto" Value="0" Visibility="Collapsed" Grid.Column="0" Grid.Row="0" Grid.ColumnSpan ="2" Grid.RowSpan="2" Foreground="White" BorderThickness="0" Style="{DynamicResource ProgressBarStyle1}" /> </Grid>

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• SQL query recursion for a web-like structure

  - by MickeyD

  I have a table here, named "Foo". The data is set up something like this. ID TableReference DataId0 DataId1 DataId2 -- -------------- ------- ------- ------- 1 Prize 3 4 5 2 Prize 4 5 NULL 3 Cash 1 NULL NULL 4 Prize 8 NULL 12 5 Foo 2 3 NULL 6 Cash 8 1 10 7 Foo 5 1 2 Etc. The data is horribly set up, I know, but I didn't set it up that way. :) I'm only dealing with the after effect. I'm trying to come up with a way to essentially "flatten" the table; that is, to display all the data to a point where the table "Foo" does not reference itself. I'm trying to figure out a sql query that I can do to get there. Usually when I deal with recursion, I have (or can establish) parent IDs and set it up that way, but for this table there are seemingly multiple child and parent IDs creating a web-like structure instead of a hierarchy. So I'm at a loss where to even begin to write a sql query for something like this. Note: There is no infinite looping (where one Foo points to another Foo, which points back to the original Foo) from what I've found. Using t-sql. Thanks for any assistance, if at all possible.

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• JQuery methods and DOM properties

  - by Bob Smith

  I am confused as to when I can use the DOM properties and when I could use the Jquery methods on a Jquery object. Say, I use a selector var $elemSel = $('#myDiv').find('[id *= \'select\']') At this point, $elemSel is a jquery object which I understand to be a wrapper around the array of DOM elements. I could get a reference to the DOM elements by iterating through the $elemSel object/array (Correct?) My questions: 1. Is there a way to convert this $elemSel into a non JQuery regular array of DOM elements? 2. Can I combine DOM properties and JQuery methods at the same time (something like this) $elemSel.children('td').nodeName (nodeName is DOM related, children is JQuery related) EDIT: What's wrong with this? $elemSel.get(0).is(':checked') EDIT 2: Thanks for the responses. I understand now that I can use the get(0) to get a DOM element. Additional questions: How would I convert a DOM element to a JQuery object? If I assign "this" to a variable, is that new var DOM or JQuery? If it's JQuery, how can I convert this to a DOM element? (Since I can't use get(0)) var $elemTd = $(this); When I do a assignment like the one above, I have seen some code samples not include the $ sign for the variable name. Why? And as for my original question, can I combine the DOM properties and JQuery functions at the same time on a JQuery object? $elemSel.children('td').nodeName

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• How to Create a Folder in the Current Document Library if it's not already present?

  - by Rosh Malai

  All I want to do is to create a folder "MetaFolder" inside a document library. User can be on any document library and I would like to create this folder after item is added (so on itemAdded event handler). I do NOT want workflow so please dont suggest workflow. This code works but I have to hardcode the url but need to get url from current url. also need to verify the folder uHippo does not exists in the current doc library... public override void ItemAdded(SPItemEventProperties properties) { base.ItemAdded(properties); using (SPSite currentSite = new SPSite(properties.WebUrl)) using (SPWeb currentWeb = currentSite.OpenWeb()) { // This code works and creates Folder in the "My TEST Doc library" //SPList docLib = currentWeb.Lists["My TEST Doc Library"]; //SPListItem folder = docLib.Folders.Add(docLib.RootFolder.ServerRelativeUrl, SPFileSystemObjectType.Folder, "My folder"); //folder.Update(); string doclibname = "Not a doclib"; //SPList doclibList = currentWeb.GetList(HttpContext.Current.Request.RawUrl); // NOT WORKING. Tried properties.weburl SPList doclibList = currentWeb.GetListFromUrl("https://mycompanyportal/sites/testsitecol/testwebsite/My%20TEST%20Doc%20Library/Forms/AllItems.aspx"); if (null != doclibList) { doclibname = doclibList.Title; } // this section also not working. // getting Object reference not set to an instance of an object or something like that. //if (currentWeb.GetFolder("uHippo").Exists == false) //{ SPListItem folder = doclibList.Folders.Add(doclibList.RootFolder.ServerRelativeUrl, SPFileSystemObjectType.Folder, "uHippo"); folder.Update(); //} } }

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• Awkward looking uses of Contract.ValueAtReturn()

  - by devoured elysium

  I am designing a method that will add an element to an internal list. The structure of the class is something along the lines of: class MyCustomerDatabase { private IList<Customer> _customers = new List<Customer>(); public int NumberOfCustomers { get { return _customers; } } public void AddCustomer(Customer customer) { _customers.Add(customer); } } Now, I was thinking of adding a Contract.Ensures() about the size of the _customers growing by 1 with this call. The problem is that I end up with some weird looking code: public void AddCustomer(Customer customer) { int numberOfCustomersAtReturn; Contract.Ensures(Contract.ValueAtReturn<int>(out numberOfCustomersAtReturn) == Contract.OldValue<int>(NumberOfCustomers) + 1); _customers.Add(customer); numberOfCustomersAtReturn = NumberOfCustomers; } The main problem is that properties are in fact methods, so you can't just reference them direcly when using Contract.ValueAtReturn() as its only parameter accepts variables as out. The situation gets even odder if I want to achieve the same but this time with a method that should return a value: public int MyReturningMethod() { ... return abc(); //abc will add by one the number of customers in list } //gets converted to public int MyReturningMethod() { int numberOfCustomersAtReturn; Contract.Ensures(Contract.ValueAtReturn<int>(out numberOfCustomersAtReturn) == Contract.OldValue<int>(NumberOfCustomers) + 1); int returnValue = abc(); numberOfCustomersAtReturn = NumberOfCustomers; return returnValue; } This seems pretty clumsy :( Code Contracts should aim to get things clearer and this seems right the opposite. Am I doing something wrong? Thanks

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• Add dynamic charts using ASP.NET CHART CONTROL, c#

  - by dhareni

  I wanted to add dynamic charts in the webpage. It goes like this... I get the start and end date from user and draw separate charts for each date bewteen the start and end date. I get the data from sql database and bind it with the chart like this: SqlConnection UsageLogConn = new SqlConnection(ConfigurationManager.ConnectionStrings["UsageConn"].ConnectionString); UsageLogConn.Open();//open connection string sql = "SELECT v.interval,dateadd(mi,(v.interval-1)*2,'" + startdate + " 00:00:00') as 'intervaltime',COUNT(Datediff(minute,'" + startdate + " 00:00:00',d.DateTime)/2) AS Total FROM usage_internet_intervals v left outer join (select * from Usage_Internet where " + name + " LIKE ('%" + value + "%') and DateTime BETWEEN '" + startdate + " 00:00:00' AND '" + enddate + " 23:59:59') d on v.interval = Datediff(minute,'" + startdate + " 00:00:00',d.DateTime)/2 GROUP BY v.interval,Datediff(minute,'" + startdate + " 00:00:00',d.DateTime)/2 ORDER BY Interval"; SqlCommand cmd = new SqlCommand(sql, UsageLogConn); SqlDataAdapter mySQLadapter = new SqlDataAdapter(cmd); Chart1.DataSource = cmd; // set series members names for the X and Y values Chart1.Series["Series 1"].XValueMember = "intervaltime"; Chart1.Series["Series 1"].YValueMembers = "Total"; UsageLogConn.Close(); // data bind to the selected data source Chart1.DataBind(); cmd.Dispose(); The above code adds only one chart for one date and I have added 'chart1' to design view and its not created dynamic. But I wanted to add more charts dynamic at runtime to the webpage. Can anyone help me with this? I am using VS 2008, ASP.NET 3.5 and the charting lib is: using System.Web.UI.DataVisualization.Charting;

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• Explaining the forecasts from an ARIMA model

  - by Samik R.

  I am trying to explain to myself the forecasting result from applying an ARIMA model to a time-series dataset. The data is from the M1-Competition, the series is MNB65. For quick reference, I have a google doc spreadsheet with the data. I am trying to fit the data to an ARIMA(1,0,0) model and get the forecasts. I am using R. Here are some output snippets: > arima(x, order = c(1,0,0)) Series: x ARIMA(1,0,0) with non-zero mean Call: arima(x = x, order = c(1, 0, 0)) Coefficients: ar1 intercept 0.9421 12260.298 s.e. 0.0474 202.717 > predict(arima(x, order = c(1,0,0)), n.ahead=12) $pred Time Series: Start = 53 End = 64 Frequency = 1 [1] 11757.39 11786.50 11813.92 11839.75 11864.09 11887.02 11908.62 11928.97 11948.15 11966.21 11983.23 11999.27 I have a few questions: (1) How do I explain that although the dataset shows a clear downward trend, the forecast from this model trends upward. This also happens for ARIMA(2,0,0), which is the best ARIMA fit for the data using auto.arima (forecast package) and for an ARIMA(1,0,1) model. (2) The intercept value for the ARIMA(1,0,0) model is 12260.298. Shouldn't the intercept satisfy the equation: C = mean * (1 - sum(AR coeffs)), in which case, the value should be 715.52. I must be missing something basic here. (3) This is clearly a series with non-stationary mean. Why is an AR(2) model still selected as the best model by auto.arima? Could there be an intuitive explanation? Thanks.

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• How can I tackle 'profoundly found elsewhere' syndrome (inverse of NIH)?

  - by Alistair Knock

  How can I encourage colleagues to embrace small-scale innovation within our team(s), in order to get things done quicker and to encourage skills development? (the term 'profoundly found elsewhere' comes from Wikipedia, although it is scarcely used anywhere else apart from a reference to Proctor & Gamble) I've worked in both environments where there is a strong opposition to software which hasn't been developed in-house (usually because there's a large community of developers), and more recently (with far fewer central developers) where off-the-shelf products are far more favoured for the usual reasons: maintenance, total cost over product lifecycle, risk management and so on. I think the off the shelf argument works in the majority of cases for the majority of users, even though as a developer the product never quite does what I'd like it to do. However, in some cases there are clear gaps where the market isn't able to provide specifically what we would need, or at least it isn't able to without charging astronomical consultancy rates for a bespoke solution. These can be small web applications which provide a short-term solution to a particular need in one specific department, or could be larger developments that have the potential to serve a wider audience, both across the organisation and into external markets. The problem is that while development of these applications would be incredibly cheap in terms of developer hours, and delivered very quickly without the need for glacial consultation, the proposal usually falls flat because of risk: 'Who'll maintain the project tracker that hasn't had any maintenance for the past 7 years while you're on holiday for 2 weeks?' 'What if one of our systems changes and the connector breaks?' 'How can you guarantee it's secure/better/faster/cheaper/holier than Company X's?' With one developer behind these little projects, the answers are invariably: 'Nobody, but...' 'It will break, just like any other application would...' 'I, uh...' How can I better answer these questions and encourage people to take a little risk in order to stimulate creativity and fast-paced, short-lifecycle development instead of using that 6 months to consult about what tender process we might use?

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• window.setInterval from inside an object

  - by Keith Rousseau

  I'm currently having an issue where I have a javascript object that is trying to use setInterval to call a private function inside of itself. However, it can't find the object when I try to call it. I have a feeling that it's because window.setInterval is trying to call into the object from outside but doesn't have a reference to the object. FWIW - I can't get it to work with the function being public either. The basic requirement is that I may need to have multiple instances of this object to track multiple uploads that are occurring at once. If you have a better design than the current one or can get the current one working then I'm all ears. The following code is meant to continuously ping a web service to get the status of my file upload: var FileUploader = function(uploadKey) { var intervalId; var UpdateProgress = function() { $.get('someWebService', {}, function(json) { alert('success'); }); }; return { BeginTrackProgress: function() { intervalId = window.setInterval('UpdateProgress()', 1500); }, EndTrackProgress: function() { clearInterval(intervalId); } }; }; This is how it is being called: var fileUploader = new FileUploader('myFileKey'); fileUploader.BeginTrackProgress();

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• Create a new delegate class for each asynchronous image download?

  - by Charles S.

  First, I'm using an NSURLConnection to download JSON data from twitter. Then, I'm using a second NSURLConnection to download corresponding user avatar images (the urls to the images are parsed from the first data download). For the first data connection, I have my TwitterViewController set as the NSURLConnection delegate. I've created a separate class (ImageDownloadDelegate) to function as the delegate for a second NSURLConnection that handles the images. After the tweets are finished downloading, I'm using this code to get the avatars: for(int j=0; j<[self.tweets count]; j++){ ImageDownloadDelegate *imgDelegate = [[ImageDownloadDelegate alloc] init]; Tweet *myTweet = [self.tweets objectAtIndex:j]; imgDelegate.tweet = myTweet; imgDelegate.table = timeline; NSURLRequest* request = [NSURLRequest requestWithURL:[NSURL URLWithString:myTweet.imageURL] cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60]; imgConnection = [[NSURLConnection alloc] initWithRequest:request delegate:imgDelegate]; [imgDelegate release]; } So basically a new instance of the delegate class is created for each image that needs to be downloaded. Is this the best way to go about this? But then there's no way to figure out which image is associate with which tweet, correct? The algorithm works fine... I'm just wondering if I'm going about it the most efficient way.

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• Giving another object a NSManagedObject

  - by Wayfarer

  Alright, so I'm running into an issue with my code. What I have done is subclassed UIButton so I can give it some more infomormation that pertain to my code. I have been able to create the buttons and they work great. Capiche. However, one of the things I want my subclass to hold is a reference to a NSMangedObject. I have this code in my header file: @interface ButtonSubclass : UIButton { NSManagedObjectContext *context; NSManagedObject *player; } @property (nonatomic, retain) NSManagedObject *player; @property (nonatomic, retain) NSManagedObjectContext *context; - (id)initWithFrame:(CGRect)frame andTitle:(NSString*)title; //- (void)setPlayer:(NSManagedObject *)aPlayer; @end As you can see, it has a instance variable to the NSMangedobject I want it to hold (as well as the Context). But for the life of me, I can't get it to hold that NSManagedObject. I run both the @synthesize methods in the Implementation file. @synthesize context; @synthesize player; So I'm not sure what I'm doing wrong. This is how I create my button: ButtonSubclass *playerButton = [[ButtonSubclass alloc] initWithFrame:frame andTitle:@"20"]; //works playerButton.context = self.context; //works playerButton.player = [players objectAtIndex:i]; //FAILS And I have initilaized the players array earlier, where I get the objects. Another weird thing is that when it gets to this spot in the code, the app crashes (woot) and the the console output stops. It doesn't give me any error, and notification at all that the app has crashed. It just... stops. So I don't even know what the error is that is crashing the code, besides it has to do with that line up there setting the "player" variable. Thoughts and ideas? I'd love your wisdom!

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• C# Configuration Manager . ConnectionStrings

  - by Yoda

  I have a console app containing an application configuration file containing one connection string as shown below: <configuration> <connectionStrings> <add name="Target" connectionString="server=MYSERVER; Database=MYDB; Integrated Security=SSPI;" /> </connectionStrings> </configuration> When I pass this to my Connection using: ConfigurationManager.ConnectionStrings[1].ToString() I have two values in there, hence using the second in the collection, my question is where is this second coming from? I have checked the Bin version and original and its not mine! Its obviously a system generated one but I have not seen this before? Can anyone enlighten me? The mystery connection string is: data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|aspnetdb.mdf;User Instance=true This isn't a problem as such I would just like to know why this is occuring? Thanks in advance! For future reference to those who may or may not stumble on this, after discovering the machine.config its become apparent it is bad practice to refer to a config by its index as each stack will potentially be different, which is why "Keys" are used. Cheers all!

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• Natural problems to solve using closures

  - by m.u.sheikh

  I have read quite a few articles on closures, and, embarassingly enough, I still don't understand this concept! Articles explain how to create a closure with a few examples, but I don't see any point in paying much attention to them, as they largely look contrived examples. I am not saying all of them are contrived, just that the ones I found looked contrived, and I dint see how even after understanding them, I will be able to use them. So in order to understand closures, I am looking at a few real problems, that can be solved very naturally using closures. For instance, a natural way to explain recursion to a person could be to explain the computation of n!. It is very natural to understand a problem like computing the factorial of a number using recursion. Similarly, it is almost a no-brainer to find an element in an unsorted array by reading each element, and comparing with the number in question. Also, at a different level, doing Object-oriented programming also makes sense. So I am trying to find a number of problems that could be solved with or without closures, but using closures makes thinking about them and solving them easier. Also, there are two types to closures, where each call to a closure can create a copy of the environment variables, or reference the same variables. So what sort of problems can be solved more naturally in which of the closure implementations?

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• Associating an object with another object for GC clearup

  - by thecoop

  Is there any way of associating an object instance (object A) with a second object (object B) in a generalised way, so that when B gets collected A becomes eligable for collection? The same behaviour that would happen if B had an instance variable pointing to A, but without explicitly changing the class definition of B, and being able to do this in a dynamic way? The same sort of effect could be done by using the Component.Disposed event in a funky way, but I don't want to make B disposable EDIT I'm basically creating a cache of objects that are associated with a single 'root' object, and I don't want the cache to be static, as there can be lots of root objects using different caches, so lots of memory will be used up when a root object is no longer used but the cached objects are still around. So, I want a collection of cached objects to be associated with each 'root' object, without changing the root object definition. Sort of like metadata of an extra object reference attached to each root object instance. That way, each collection will get collected when the root object is collected, and not hang around like they would if a static cache was used.

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• Dangling pointers and double free

  - by user151410

  After some painful experiences, I understand the problem of dangling pointers and double free. I am seeking proper solutions. aStruct has a number of fields including other arrays. aStruct *A=NULL, *B = NULL; A = (aStruct*) calloc(1, sizeof(sStruct)); B = A; free_aStruct(A); ... //bunch of other code in various places. ... free_aStruct(B); Is there any way to write free_aStruct(X) so that free_aStruct(B) exists gracefully?? void free_aStruct(aStruct *X){ if (X ! = NULL){ if (X->a != NULL){free(X->a); x->a = NULL;} free(X); X = NULL; } } Doing above only sets A = NULL when free_aStruct(A); is called. B is now dangling. How can this situation be avoided / remedied? Is reference counting the only viable solution? or, are there other "defensive" free approaches, to prevent free_aStruct(B); from exploding? Thanks, Russ

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• DataGridView with row-specific DataGridViewComboBoxColumn contents in C# Windows Forms 3.5

  - by XXXXX

  So I have something like the following data structure (constructors omitted) class Child { public string Name { get; set; } public int Age { get; set; } } class Parent { public string Name { get; set; } public List <Child> Children { get; private set; } // never null; list never empty public Child FavoriteChild { get; set; } // never null; always a reference to a Child in Children } List < Parent > Parents; What I want to do is show a DataGridView where each row is a Parent from Parent list. Each row should have two columns: a text box showing the parent's name and a DataGridViewComboBoxColumn containing that parent's children, from which the user can select the parent's favorite child. I suppose I could do the whole thing manually, but I'd like to do all this with more-or-less standard Data Binding. It's easy enough to bind the DataGridView to the list of parents, and easy enough to bind the selected child to the FavoriteChild property. The part that's giving me difficulty is that it looks like the Combo Box column wants to bind to one data source for all the combo-box's contents on all rows. I'd like each instance of the combo box to bind to the list of each parent's children. I'm fairly new to C#/Windows Forms, so I may well be missing something obvious. Or it could be that "you can't get there from here." It's not too tough to make a separate list of all the children and filter it by parent; I'm looking into that possibility right now. Is this feasible, or is there a better way?

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• wcf trying to set up tracing to debug, not writing to log file

  - by joey j

  here's my web.config, running a WCF service in an application on IIS7, but nothing is being written to the specified file. permission on the file has been granted for everyone. </listeners> I can add a service reference just fine. I then try to call the service from a windows app and, after a few minutes, get an error on the machine running the windows app "Client is unable to finish the security negotiation within the configured timeout (00:00:00). The current negotiation leg is 1 (00:00:00)." but absolutely nothing is written to the trace log file specified in config. Is there something else I need to do to enable tracing? thanks for your help EDIT: "sources" section now matches the section recommended here: http://msdn.microsoft.com/en-us/library/aa702726.aspx I've added the "diagnostics and the event viewer shows: "Message Logging has been turned on. Sensitive information may be logged in the clear, even if it was encrypted on the wire: for example, message bodies. Process Name: w3wp Process ID: 1784 " but the log file is still empty

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• How to find Tomcat's PID and kill it in python?

  - by 4herpsand7derpsago

  Normally, one shuts down Apache Tomcat by running its shutdown.sh script (or batch file). In some cases, such as when Tomcat's web container is hosting a web app that does some crazy things with multi-threading, running shutdown.sh gracefully shuts down some parts of Tomcat (as I can see more available memory returning to the system), but the Tomcat process keeps running. I'm trying to write a simple Python script that: Calls shutdown.sh Runs ps -aef | grep tomcat to find any process with Tomcat referenced If applicable, kills the process with kill -9 <PID> Here's what I've got so far (as a prototype - I'm brand new to Python BTW): #!/usr/bin/python # Imports import sys import subprocess # Load from imported module. if __init__ == "__main__": main() # Main entry point. def main(): # Shutdown Tomcat shutdownCmd = "sh ${TOMCAT_HOME}/bin/shutdown.sh" subprocess.call([shutdownCmd], shell=true) # Check for PID grepCmd = "ps -aef | grep tomcat" grepResults = subprocess.call([grepCmd], shell=true) if(grepResult.length > 1): # Get PID and kill it. pid = ??? killPidCmd = "kill -9 $pid" subprocess.call([killPidCmd], shell=true) # Exit. sys.exit() I'm struggling with the middle part - with obtaining the grep results, checking to see if their size is greater than 1 (since grep always returns a reference to itself, at least 1 result will always be returned, methinks), and then parsing that returned PID and passing it into the killPidCmd. Thanks in advance!

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• c++ - strange problem with polymorphism - cellular automaton

  - by Green

  Hello, I am making "game of life" implementation that, when cell has: two live neighbours I make object of class CCellB two live neighbours I make object of class CCellA when has 3 or <2 I make object of class CCellX (dead) Class CCell is base of CCellA, CCellB, CCellX My problem is: That works fine, until I change new CCell(); to new CCellB();: CCell ***temp = allocateArray(); for(int i = 0; i < n; i++) { for(int j = 0; j < m; j++) { c = arr[i][j]->countAliveNeighbor(); if(c == 3) { temp[i][j] = new CCellA(); temp[i][j]->alive = 1; }else if(c == 2) { temp[i][j] = new CCell(); // HERE, WHEN I CHANGE IT TO CCELLB IT DON'T WORKS temp[i][j]->alive = tab[i][j]->alive; }else if((c >= 4)||(c < 2)) { temp[i][j] = new CCellX(); } } } Then it seems don't work properly... Seems like neighbours are not count properly, Cell with 4,5 neighbours still alive alive var is member of base class - CCell, all is public, please help!

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• xml to hashmap - php

  - by csU

  Hi, Given an xml structure like this <gesmes:Envelope> <gesmes:subject>Reference rates</gesmes:subject> <gesmes:Sender> <gesmes:name>European Central Bank</gesmes:name> </gesmes:Sender> <Cube> <Cube time="2010-03-26"> <Cube currency="USD" rate="1.3353"/> <Cube currency="JPY" rate="124.00"/> <Cube currency="BGN" rate="1.9558"/> <Cube currency="CZK" rate="25.418"/> ... ... </Cube> </Cube> </gesmes:Envelope> how can i go about getting the values stored in to a hashmap or similar structure in php? Have been trying to do this for the last few hours now but cant manage it :D It is homework so i guess no full solutuins please( tho the actual assignment is to use the web services, i am just stuck with parsing it :D ). Maybe someone could show me a brief example for a made up xml file that i could apply to mine? Thanks

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• Better way to summarize data about stop times?

  - by Vimvq1987

  This question is close to this: http://stackoverflow.com/questions/2947963/find-the-period-of-over-speed Here's my table: Longtitude Latitude Velocity Time 102 401 40 2010-06-01 10:22:34.000 103 403 50 2010-06-01 10:40:00.000 104 405 0 2010-06-01 11:00:03.000 104 405 0 2010-06-01 11:10:05.000 105 406 35 2010-06-01 11:15:30.000 106 403 60 2010-06-01 11:20:00.000 108 404 70 2010-06-01 11:30:05.000 109 405 0 2010-06-01 11:35:00.000 109 405 0 2010-06-01 11:40:00.000 105 407 40 2010-06-01 11:50:00.000 104 406 30 2010-06-01 12:00:00.000 101 409 50 2010-06-01 12:05:30.000 104 405 0 2010-06-01 11:05:30.000 I want to summarize times when vehicle had stopped (velocity = 0), include: it had stopped since "when" to "when" in how much minutes, how many times it stopped and how much time it stopped. I wrote this query to do it: select longtitude, latitude, MIN(time), MAX(time), DATEDIFF(minute, MIN(Time), MAX(time)) as Timespan from table_1 where velocity = 0 group by longtitude,latitude select DATEDIFF(minute, MIN(Time), MAX(time)) as minute into #temp3 from table_1 where velocity = 0 group by longtitude,latitude select COUNT(*) as [number]from #temp select SUM(minute) as [totaltime] from #temp3 drop table #temp This query return: longtitude latitude (No column name) (No column name) Timespan 104 405 2010-06-01 11:00:03.000 2010-06-01 11:10:05.000 10 109 405 2010-06-01 11:35:00.000 2010-06-01 11:40:00.000 5 number 2 totaltime 15 You can see, it works fine, but I really don't like the #temp table. Is there anyway to query this without use a temp table? Thank you.

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