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  • C#: Non-constructed generics as properties (eg. List<T>)

    - by Dav
    The Problem It's something I came across a while back and was able to work around it somehow. But now it came back, feeding on my curiosity - and I'd love to have a definite answer. Basically, I have a generic dgv BaseGridView<T> : DataGridView where T : class. Constructed types based on the BaseGridView (such as InvoiceGridView : BaseGridView<Invoice>) are later used in the application to display different business objects using the shared functionality provided by BaseGridView (like virtual mode, buttons, etc.). It now became necessary to create a user control that references those constructed types to control some of the shared functionality (eg. filtering) from BaseGridView. I was therefore hoping to create a public property on the user control that would enable me to attach it to any BaseGridView in Designer/code: public BaseGridView<T> MyGridView { get; set; }. The trouble is, it doesn't work :-) When compiled, I get the following message: The type or namespace name 'T' could not be found (are you missing a using directive or an assembly reference?) Solutions? I realise I could extract the shared functionality to an interface, mark BaseGridView as implementing that interface, and then refer to the created interface in my uesr control. But I'm curious if there exists some arcane C# command/syntax that would help me achieve what I want - without polluting my solution with an interface I don't really need :-)

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  • F# ref-mutable vars vs object fields

    - by rwallace
    I'm writing a parser in F#, and it needs to be as fast as possible (I'm hoping to parse a 100 MB file in less than a minute). As normal, it uses mutable variables to store the next available character and the next available token (i.e. both the lexer and the parser proper use one unit of lookahead). My current partial implementation uses local variables for these. Since closure variables can't be mutable (anyone know the reason for this?) I've declared them as ref: let rec read file includepath = let c = ref ' ' let k = ref NONE let sb = new StringBuilder() use stream = File.OpenText file let readc() = c := stream.Read() |> char // etc I assume this has some overhead (not much, I know, but I'm trying for maximum speed here), and it's a little inelegant. The most obvious alternative would be to create a parser class object and have the mutable variables be fields in it. Does anyone know which is likely to be faster? Is there any consensus on which is considered better/more idiomatic style? Is there another option I'm missing?

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  • Help with create action in a different show page

    - by Andrew
    Hi, I'm a Rails newbie and want to do something but keep messing something up. I'd love some help. I have a simple app that has three tables. Users, Robots, and Recipients. Robots belong_to users and Recipients belong_to robots. On the robot show page, I want to be able to create recipients for that robot right within the robot show page. I have the following code in the robot show page which lists current recipients: <table> <% @robot.recipients.each do |recipient| %> <tr> <td><b><%=h recipient.chat_screen_name %></b> via <%=h recipient.protocol_name</td> <td><%= link_to 'Edit', edit_recipient_path(recipient) %>&nbsp;</td> <td><%= link_to 'Delete', recipient, :confirm => 'Are you sure?', :method => :delete %></td> </tr> <% end %> </table> What I'd like to do is have an empty field in which the user can add a new recipient, and have tried the following: I added this to the Robots Show view: <% form_for(@robot.recipient) do |f| %> Enter the screen name<br> <%= f.text_field :chat_screen_name %> <p> <%= f.submit 'Update' %> </p> <% end %> and then this to the Robot controller in the show action: @recipient = Recipient.new @recipients = Recipient.all Alas, I'm still getting a NoMethod error that says: "undefined method `recipient' for #" I'm not sure what I'm missing. Any help would be greatly appreciated. Thank you.

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  • Solved: Help with this compile error

    - by Scott
    I just picked up an old project and I'm not sure what the following error could mean. g++ -o BufferedReader.o -c -g -Wall -std=c++0x -I/usr/include/xmms2 -Ijsoncpp/include/json/ -fopenmp -I/usr/include/ImageMagick -I/usr/include/xmms2 -I/usr/include/libvisual-0.4 -D_GNU_SOURCE=1 -D_REENTRANT -I/usr/include/SDL -DQT_CORE_LIB -DQT_GUI_LIB -DQT_SCRIPT_LIB -DQT_SHARED -I/usr/include/QtCore -I/usr/include/QtGui -I/usr/include/QtScript BufferedReader.cpp In file included from BufferedReader.cpp:23: /usr/include/string.h:36:42: error: missing binary operator before token "(" In file included from /usr/lib/gcc/i686-redhat-linux/4.4.3/../../../../include/c++/4.4.3/cwchar:47, from /usr/lib/gcc/i686-redhat-linux/4.4.3/../../../../include/c++/4.4.3/bits/postypes.h:42, from /usr/lib/gcc/i686-redhat-linux/4.4.3/../../../../include/c++/4.4.3/iosfwd:42, from /usr/lib/gcc/i686-redhat-linux/4.4.3/../../../../include/c++/4.4.3/ios:39, from /usr/lib/gcc/i686-redhat-linux/4.4.3/../../../../include/c++/4.4.3/istream:40, from /usr/lib/gcc/i686-redhat-linux/4.4.3/../../../../include/c++/4.4.3/sstream:39, from BufferedReader.cpp:24: At line 24 of BufferedReader.cpp is #include <string.h>. I've tried it with just <string> but get the same thing. Any clue? Here's the snippet of code from string.h /* Tell the caller that we provide correct C++ prototypes. */ #if defined __cplusplus && __GNUC_PREREQ (4, 4) //line 36 # define __CORRECT_ISO_CPP_STRING_H_PROTO #endif Does that mean __GNUC_PREREQ isn't defined? Edit: Changing -Ijsoncpp/include/json/ to Ijsoncpp/include stopped the errors. I noticed I was including <json/json.h>. I'm about to switch to JsonGlib though, which is the reason I pulled the project up again. So it's all good. :)

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  • How would a user stay logged in to a REST-based website?

    - by unforgiven3
    A year or so ago I asked this question: Can you help me understand this? “Common REST Mistakes: Sessions are irrelevant”. My question was essentially this: Okay, I get that HTTP authentication is done automatically on every message - but how? Is the username/password sent with every request? Doesn't that just increase attack surface area? I feel like I'm missing part of the puzzle. The answers I received made perfect sense in the context of a mobile (iPhone, Android, WP7) app - when talking to a REST service, the app would just send user credentials along with each request. That worked great for me. But now, I would like to better understand how one would secure a REST-like website, like StackOverflow itself or something like Reddit. How would things work if it was a user logged in via a web browser instead of logged in via an iPhone app? What happens when a user logs in? Are the credentials saved in the browser somehow? How would the browser know what credentials to send with subsequent REST requests? What if it's a JavaScript call to a webservice? How would the JavaScript call include user credentials? I'll be quite frank: my understanding of security when it comes to websites is pretty limited. I enjoyed working with REST services from an app perspective, but now I want to try and build a website that is based on REST principles, and I'm finding myself to be pretty lost. If there is anything in the above question that is unclear that you'd like me to clarify, please leave a comment and I'll address it.

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  • calling same function on different buttons not loaded yet

    - by Jordan Faust
    I can not get this to work for every button and I cannot find anything explaining why. I guessing it is something small that I am missing $(document).ready(function() { // delete the selected row from the database $(document).on('click', '#business-area-delete-button', { model: "BusinessArea" }, deleteRow); $(document).on('click', '#business-type-delete-button', { model: "BusinessType" }, deleteRow); $(document).on('click', '#client-delete-button', { model: "Client" }, deleteRow); $(document).on('click', '#client-type-delete-button', { model: "ClientType" }, deleteRow); $(document).on('click', '#communication-channel-type', { model: "CommunicationChannelType" }, deleteRow); $(document).on('click', '#parameter-type-delete-button', { model: "ParameterType" }, deleteRow); $(document).on('click', '#validation-method-delete-button', { model: "ValidationMethod" }, deleteRow); } the event function deleteRow(event){ $.ajax( { type:'POST', data: { id: $(".delete-row").attr("id") }, url:"/mysite/admin/delete" + event.data.model, success:function(data,textStatus){ $('#main-content').html(data); }, error:function(XMLHttpRequest,textStatus,errorThrown){ jQuery('#alerts').html(XMLHttpRequest.responseText); }, complete:function(XMLHttpRequest,textStatus){ placeAlerts() } } ); return false }; This works only for a the button with id validation-method-delete-button. I use document and not the button its self because the button is contained in a template that is loaded later via ajax. I have this working for a similar function that is selecting a row in a table however I am not attempting to pass data in that scenario.

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  • Need help profiling .NET caching extension method.

    - by rockinthesixstring
    I've got the following extension Public Module CacheExtensions Sub New() End Sub Private sync As New Object() Public Const DefaultCacheExpiration As Integer = 1200 ''# 20 minutes <Extension()> Public Function GetOrStore(Of T)(ByVal cache As Cache, ByVal key As String, ByVal generator As Func(Of T)) As T Return cache.GetOrStore(key, If(generator IsNot Nothing, generator(), Nothing), DefaultCacheExpiration) End Function <Extension()> Public Function GetOrStore(Of T)(ByVal cache As Cache, ByVal key As String, ByVal generator As Func(Of T), ByVal expireInSeconds As Double) As T Return cache.GetOrStore(key, If(generator IsNot Nothing, generator(), Nothing), expireInSeconds) End Function <Extension()> Public Function GetOrStore(Of T)(ByVal cache As Cache, ByVal key As String, ByVal obj As T) As T Return cache.GetOrStore(key, obj, DefaultCacheExpiration) End Function <Extension()> Public Function GetOrStore(Of T)(ByVal cache As Cache, ByVal key As String, ByVal obj As T, ByVal expireInSeconds As Double) As T Dim result = cache(key) If result Is Nothing Then SyncLock sync If result Is Nothing Then result = If(obj IsNot Nothing, obj, Nothing) cache.Insert(key, result, Nothing, DateTime.Now.AddSeconds(expireInSeconds), cache.NoSlidingExpiration) End If End SyncLock End If Return DirectCast(result, T) End Function End Module From here, I'm using the extension is a TagService to get a list of tags Public Function GetTagNames() As List(Of String) Implements Domain.ITagService.GetTags ''# We're not using a dynamic Cache key because the list of TagNames ''# will persist across all users in all regions. Return HttpRuntime.Cache.GetOrStore(Of List(Of String))("TagNamesOnly", Function() _TagRepository.Read().Select(Function(t) t.Name).OrderBy(Function(t) t).ToList()) End Function All of this is pretty much straight forward except when I put a breakpoint on _TagRepository.Read(). The problem is that it is getting called on every request, when I thought that it is only to be called when Result Is Nothing Am I missing something here?

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  • T4 trouble compiling transformation

    - by John Leidegren
    I can't figure this one out. Why doesn't T4 locate the IEnumerable type? I'm using Visual Studio 2010. And I just hope someone knows why? <#@ template debug="true" hostspecific="false" language="C#" #> <#@ assembly name="System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" #> <#@ import namespace="System" #> <#@ import namespace="System.Data" #> <#@ import namespace="System.Data.SqlClient" #> <#@ output extension=".cs" #> public static class Tables { <# var q = @" SELECT tbl.name 'table', col.name 'column' FROM sys.tables tbl INNER JOIN sys.columns col ON col.object_id = tbl.object_id "; // var source = Execute(q); #> } <#+ static IEnumerable Execute(string cmdText) { using (var conn = new SqlConnection(@"Data Source=.\SQLEXPRESS;Initial Catalog=t4build;Integrated Security=True;")) { conn.Open(); var cmd = new SqlCommand(cmdText, conn); using (var reader = cmd.ExecuteReader()) { while (reader.Read()) { } } } } #> Error 2 Compiling transformation: The type or namespace name 'IEnumerable' could not be found (are you missing a using directive or an assembly reference?) c:\Projects\T4BuildApp\T4BuildApp\TextTemplate1.tt 26 9

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  • How to write an R function that evaluates an expression within a data-frame

    - by Prasad Chalasani
    Puzzle for the R cognoscenti: Say we have a data-frame: df <- data.frame( a = 1:5, b = 1:5 ) I know we can do things like with(df, a) to get a vector of results. But how do I write a function that takes an expression (such as a or a > 3) and does the same thing inside. I.e. I want to write a function fn that takes a data-frame and an expression as arguments and returns the result of evaluating the expression "within" the data-frame as an environment. Never mind that this sounds contrived (I could just use with as above), but this is just a simplified version of a more complex function I am writing. I tried several variants ( using eval, with, envir, substitute, local, etc) but none of them work. For example if I define fn like so: fn <- function(dat, expr) { eval(expr, envir = dat) } I get this error: > fn( df, a ) Error in eval(expr, envir = dat) : object 'a' not found Clearly I am missing something subtle about environments and evaluation. Is there a way to define such a function?

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  • How to automatically display relationships in logical diagram?

    - by Cliff Chaney
    Consider a Logical Model where Entity A and Entity B are connected via Relationship Z. If I create a Logical Diagram (note: not another logical MODEL), I am able to drag Entity A and Entity B onto the diagram. Since the Logical Model already "knows" that Entity A and Entity B have a relationship, I would like to be able to easily add it to my logical diagram. I am already aware of the "Show Symbols" option whereby I can select the specific relationship that I want and have it appear. That is not a solution for me. The problem is that I have a LARGE logical model consisting of HUNDREDS of Entities and their various relationships. I then need to create application-specific diagrams consisting of a subset of those entities. I can easily identify and drag the 50+ entities onto a new diagram. But identifying and selecting all the associations is an exercise in frustration. Is there an option or some sort of feature that I'm missing - or any other trick - that would allow me to add only the relationships between selected entities or all entities on a diagram?

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  • Using input type="submit" to change content

    - by Conti
    Okay, I'm pretty sure I'm missing something very obvious here, but I just couldn't find a proper solution so far. What I'm trying to do is simple: Have a user write something into a form, have him submit the form, and write that input into a textarea on the same page. This is my code: <html><head></head> <body> <form name='registration'> <label for="input">Input:</label> <input type="text" id="input"/> <input type="submit" id="submit" value="Submit" onclick="execute()"/> </form> <div id="results"> <span>Result</span> <span><textarea cols="30" rows="5" id="resulttext" readonly="readonly"></textarea> </span> </div> <script> function execute() { var result = document.getElementById("input").value document.getElementById("resulttext").value=result; } </script> </body> </html> Now what happens if I enter something into the form is that the textarea briefly shows my input before reverting back to showing nothing. My guess is that the textarea field is only changed for the duration of the execute() function. When I change input type="submit" to a <button> everything works as intended, but I'm pretty sure I'm not supposed to do that.

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  • StreamReader returning another char

    - by Fernando
    I'm trying to read the content of a file with a StreamReader, that receives a FileStream. The file has some spaces inside (char 32) and the StreamReader is reading them as 0 (char 48). The screenshot shows the FileStream buffer and the StreamReader buffer. Both have the value 32, but when I call Read(), it returns 48. Am I missing something here? By the way, the code is running under .NET Compact Framework. The code that reads the data: public void Read() { using (StreamReader reader = new StreamReader(InputStream, Encoding.ASCII)) { foreach (var property in DataObject.EnumerateProperties()) { OffsetInfo offset = property.GetTextOffset(); reader.BaseStream.Position = offset.Start - 1; StringBuilder builder = new StringBuilder(offset.Size); int count = 0; while (reader.Peek() >= 0 && count < offset.Size) { char c = (char)reader.Read(); if ((int)c != 32 && c != '\r' && c != '\n') { builder.Append(c); count++; } else { reader.BaseStream.Position++; } } property.SetValue(DataObject, Convert.ChangeType(builder.ToString(), property.PropertyType, CultureInfo.CurrentCulture), null ); } } }

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  • Use a foreign key mapping to get data from the other table using Python and SQLAlchemy.

    - by Az
    Hmm, the title was harder to formulate than I thought. Basically, I've got these simple classes mapped to tables, using SQLAlchemy. I know they're missing a few items but those aren't essential for highlighting the problem. class Customer(object): def __init__(self, uid, name, email): self.uid = uid self.name = name self.email = email def __repr__(self): return str(self) def __str__(self): return "Cust: %s, Name: %s (Email: %s)" %(self.uid, self.name, self.email) The above is basically a simple customer with an id, name and an email address. class Order(object): def __init__(self, item_id, item_name, customer): self.item_id = item_id self.item_name = item_name self.customer = None def __repr__(self): return str(self) def __str__(self): return "Item ID %s: %s, has been ordered by customer no. %s" %(self.item_id, self.item_name, self.customer) This is the Orders class that just holds the order information: an id, a name and a reference to a customer. It's initialised to None to indicate that this item doesn't have a customer yet. The code's job will assign the item a customer. The following code maps these classes to respective database tables. # SQLAlchemy database transmutation engine = create_engine('sqlite:///:memory:', echo=False) metadata = MetaData() customers_table = Table('customers', metadata, Column('uid', Integer, primary_key=True), Column('name', String), Column('email', String) ) orders_table = Table('orders', metadata, Column('item_id', Integer, primary_key=True), Column('item_name', String), Column('customer', Integer, ForeignKey('customers.uid')) ) metadata.create_all(engine) mapper(Customer, customers_table) mapper(Orders, orders_table) Now if I do something like: for order in session.query(Order): print order I can get a list of orders in this form: Item ID 1001: MX4000 Laser Mouse, has been ordered by customer no. 12 What I want to do is find out customer 12's name and email address (which is why I used the ForeignKey into the Customer table). How would I go about it?

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  • Navigation Controller not Pushing/Popping View Controllers

    - by senfo
    I'm working on a view-based iPhone app that has the following flow: search - (list | map) - details To accomplish the transitions between views, I have a UINavigationController, with the search view controller being the root. After a user performs a search, I transition to a view with a segmented control, which acts as a tab to switch between the list and map functionality (per a suggestion from a related question I had). This view contains a UIViewController, which allows me to switch between the list/map view when a user taps the segmented control. I'm fine up until this point. As you can see from the above mentioned flow, I would like to provide the ability to transition into a details view. Each row of my table in the list view contains a details disclosure button for allowing the user to drill down into a details view. The problem is, when I try to push the details view onto the navigation stack, nothing happens. Below is the delegate method (from my list view controller) to handle the details disclosure button being tapped. I've set up break points, so I know the code is running. The navigation controller simply doesn't want to push the detailsController onto the stack (my guess is that I don't have a pointer to the correct UINavigationController). - (void)tableView:(UITableView *)tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath { if (detailController == nil) { detailController = [[DetailsViewController alloc] init]; } [self.navigationController pushViewController:detailController animated:YES]; } Assuming I was probably missing a pointer to the navigation controller, I exposed a UINavigation property on my list and map views (navigationController is readonly) and initialized them with a pointer to the navigation controller from my SwitchViewController (the view responsible for switching between list/map views when a user changes the value of the segmented control). Unfortunately, this did not solve the problem. Am I on the right track? If so, how do I see to it that my view has a pointer to the correct navigation controller? Should I add a delegate, which allows me to call a function in the SwitchViewController that transitions into the details view (this seems messy)?

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  • .NET port with Java's Map, Set, HashMap

    - by Nikos Baxevanis
    I am porting Java code in .NET and I am stuck in the following lines that (behave unexpectedly in .NET). Java: Map<Set<State>, Set<State>> sets = new HashMap<Set<State>, Set<State>>(); Set<State> p = new HashSet<State>(); if (!sets.containsKey(p)) { ... } The equivalent .NET code could possibly be: IDictionary<HashSet<State>, HashSet<State>> sets = new Dictionary<HashSet<State>, HashSet<State>>(); HashSet<State> p = new HashSet<State>(); if (!sets.containsKey(p)) { /* (Add to a list). Always get here in .NET (??) */ } However the code comparison fails, the program think that "sets" never contain Key "p" and eventually results in OutOfMemoryException. Perhaps I am missing something, object equality and identity might be different between Java and .NET. I tried implementing IComparable and IEquatable in class State but the results were the same. Edit: What the code does is: If the sets does not contain key "p" (which is a HashSet) it is going to add "p" at the end of a LinkedList. The State class (Java) is a simple class defined as: public class State implements Comparable<State> { boolean accept; Set<Transition> transitions; int number; int id; static int next_id; public State() { resetTransitions(); id = next_id++; } // ... public int compareTo(State s) { return s.id - id; } public boolean equals(Object obj) { return super.equals(obj); } public int hashCode() { return super.hashCode(); }

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  • What's a good way to write batch scripts in C#?

    - by Scott Bilas
    I would like to write simple scripts in C#. Stuff I would normally use .bat or 4NT .btm files for. Copying files, parsing text, asking user input, and so on. Fairly simple but doing this stuff right in a batch file is really hard (no exceptions for example). I'm familiar with command line "scripting" wrappers like AxScript so that gets me part of the way there. What I'm missing is the easy file-manipulation framework. I want to be able to do cd(".."), copy(srcFile, destFile) type functionality. Tools I have tried: NANT, which we use in our build process. Not a good scripting tool. Insanely verbose XML syntax and to add a simple function you must write an extension assembly. Can't do it inline. PowerShell. Looks great, but I just haven't been able to switch over to this as my primary shell. Too many differences from 4NT. Whatever I do needs to run from an ordinary command prompt and not require a special shell to run it through. Can PowerShell be used as a script executor? Perl/Python/Ruby. Really hate learning an entirely new language and framework just to do batch file operations. Haven't been able to dedicate the time I need to do this. Plus, we're a 99% .NET shop for our toolchain and I really want to leverage our existing experience and codebase. Are there frameworks out there that are trying to solve this problem of "make a batch file in C#" that you have used? I want the power of C#/.NET with the immediate-mode type functionality of a typical cmd.exe shell language. Am I alone in wanting something like this?

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  • Accessing vars from another clojure namespace?

    - by erikcw
    In my main namespace, I have a top level var named "settings" which is initialized as an empty {}. My -main fn sets the contents of settings using def and conj based on some command line args (different database hosts for production/development, etc). I'm trying to access the contents of this map from another namespace to pull out some of the settings. When I try to compile with lein into an uberjar, I get a traceback saying "No such var: lb/settings". What am I missing? Is there a more idiomatic way to handle app wide settings such as these? Is it safe to use "def" inside of -main like I am, or should I be use an atom or ref to make this threadsafe? Thanks! (ns main (:use ...) (:gen-class)) (def settings {}) (defn -main [& args] (with-command-line-args... ;set devel? based on args (if (true? devel?) (def settings (conj settings {:mongodb {:host "127.0.0.1"} :memcached {:host "127.0.0.1"}})) (def settings (conj settings {:mongodb {:host "PRODUCTION_IP"} :memcached {:host "PRODUCTION_IP"}}))) ;file2.clj (ns some-other-namespace (:require [main :as lb] ...) ;configure MongoDB (congo/mongo! :db "dbname" :host (:host (mongodb lb/settings)))) ...

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  • Basic problems (type inference or something else?) in Objective-C/Cocoa.

    - by Matt
    Hi, Apologies for how basic these questions are to some. Just started learning Cocoa, working through Hillegass' book, and am trying to write my first program (a GUI Cocoa app that counts the number of characters in a string). I tried this: NSString *string = [textField stringValue]; NSUInteger *stringLength = [string length]; NSString *countString = (@"There are %u characters",stringLength); [label setStringValue:countString]; But I'm getting errors like: Incompatible pointer conversion initializing 'NSUInteger' (aka 'unsigned long'), expected 'NSUInteger *'[-pedantic] for the first line, and this for the second line: Incompatible pointer types initializing 'NSUInteger *', expected 'NSString *' [-pedantic] I did try this first, but it didn't work either: [label setStringValue:[NSString stringWithFormat:@"There are %u characters",[[textField stringValue] length]]] On a similar note, I've only written in easy scripting languages before now, and I'm not sure when I should be allocing/initing objects and when I shouldn't. For example, when is it okay to do this: NSString *myString = @"foo"; or int *length = 5; instead of this: NSString *myString = [[NSString alloc] initWithString:"foo"]; And which ones should I be putting into the header files? I did check Apple's documentation, and CocoaDev, and the book I'm working for but without luck. Maybe I'm looking in the wrong places.. Thanks to anyone who takes the time to reply this: it's appreciated, and thanks for being patient with a beginner. We all start somewhere. EDIT Okay, I tried the following again: [label setStringValue:[NSString stringWithFormat:@"There are %u characters",[[textField stringValue] length]]] And it actually worked this time. Not sure why it didn't the first time, though I think I might have typed %d instead of %u by mistake. However I still don't understand why the code I posted at the top of my original post doesn't work, and I have no idea what the errors mean, and I'd very much like to know because it seems like I'm missing something important there.

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  • Processing a database queue across multiple threads - design advice

    - by rwmnau
    I have a SQL Server table full of orders that my program needs to "follow up" on (call a webservice to see if something has been done with them). My application is multi-threaded, and could have instances running on multiple servers. Currently, every so often (on a Threading timer), the process selects 100 rows, at random (ORDER BY NEWID()), from the list of "unconfirmed" orders and checks them, marking off any that come back successfully. The problem is that there's a lot of overlap between the threads, and between the different processes, and their's no guarantee that a new order will get checked any time soon. Also, some orders will never be "confirmed" and are dead, which means that they get in the way of orders that need to be confirmed, slowing the process down if I keep selecting them over and over. What I'd prefer is that all outstanding orders get checked, systematically. I can think of two easy ways do this: The application fetches one order to check at a time, passing in the last order it checked as a parameter, and SQL Server hands back the next order that's unconfirmed. More database calls, but this ensures that every order is checked in a reasonable timeframe. However, different servers may re-check the same order in succession, needlessly. The SQL Server keeps track of the last order it asked a process to check up on, maybe in a table, and gives a unique order to every request, incrementing its counter. This involves storing the last order somewhere in SQL, which I wanted to avoid, but it also ensures that threads won't needlessly check the same orders at the same time Are there any other ideas I'm missing? Does this even make sense? Let me know if I need some clarification.

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  • Why does DeviceIoControl throw error 21 (Device Not Ready) from C# when the equivalent in C works fine?

    - by Ragesh
    I'm trying to send an IOCTL_SERVICE_REFRESH command to the GPS Intermediate Driver service using C# like this: handle = CreateFile("GPD0:", GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE, IntPtr.Zero, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, IntPtr.Zero); if (handle.ToInt32() == INVALID_HANDLE_VALUE) { rc = Marshal.GetLastWin32Error(); return rc; } int numBytesReturned = 0; rc = DeviceIoControl( handle, IOCTL_SERVICE_REFRESH, null, 0, null, 0, ref numBytesReturned, IntPtr.Zero); int error = Marshal.GetLastWin32Error(); GetLastWin32Error always gives me error 21 (device not ready). However, the equivalent call when made from C++ works fine: HANDLE hGPS = CreateFile(L"GPD0:", GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0); if (hGPS != INVALID_HANDLE_VALUE) { BOOL ret = DeviceIoControl(hGPS,IOCTL_SERVICE_REFRESH,0,0,0,0,0,0); DWORD err = GetLastError(); } I suspected a problem with the PInvoke signatures, but I can't seem to find anything wrong here: [DllImport("coredll.dll", EntryPoint = "DeviceIoControl", SetLastError = true)] public static extern int DeviceIoControl( IntPtr hDevice, uint dwIoControlCode, byte[] lpInBuffer, int nInBufferSize, byte[] lpOutBuffer, int nOutBufferSize, ref int lpBytesReturned, IntPtr lpOverlapped); [DllImport("coredll.dll", SetLastError = true)] public static extern IntPtr CreateFile( String lpFileName, uint dwDesiredAccess, uint dwShareMode, IntPtr attr, uint dwCreationDisposition, uint dwFlagsAndAttributes, IntPtr hTemplateFile); What am I missing here?

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  • Continuous build infrastructure recommendations for primarily C++; GreenHills Integrity

    - by andersoj
    I need your recommendations for continuous build products for a large (1-2MLOC) software development project. Characteristics: ClearCase revision control Approx 80% C++; 15% Java; 5% script or low-level Compiles for Green Hills Integrity OS, but also some windows and JVM chunks Mostly an embedded system; also includes some UI pieces and some development support (simulation tools, config tools, etc...) Each notional "version" of the deliverable includes deployment images for a number of boards, UI machines, etc... (~10 separate images; 5 distinct operating systems) Need to maintain/track many simultaneous versions which, notably, are built for a variety of different board support packages Build cycle time is a major issue on the project, need support for whatever features help address this (mostly need to manage a large farm of build machines, I guess..) Operates in a secure environment (this is a gov't program) (Edited to add: This is a classified program; outsourcing the build infrastructure is a non-starter.) Interested in any best practices or peripheral guidance you might offer. The build automation issues is one of several overlapping best practices that appear to be missing on the program, but try to keep your answers focused on build infrastructure piece and observations directly related. Cost is not an object. Scalability and ease of retrofitting onto an existing infrastructure are key. JA

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  • Problem shrinking with StretchBlt()

    - by SparkyNZ
    Hi. I have some code that paints my own rectangular buttons based on a source bitmap. Most of the time the destination buttons are bigger than my source bitmap image and StretchBlt works fine. However, when the destination is smaller than the source image, StretchBlt refuses to fill the entire destination area. I know StretchBlt isn't great on quality when it comes to scaling down images but I'm not too concerned about that. I just don't want missing pixels. Here a link with the source image at the top and destination at the bottom: link text Note, I am actually shrinking parts of the source image into the destination. I am not shrinking the entire image down. So for example, I copy the corners size for size with BitBlt() then I stretch (squash) the horizontal pixel data between the corners from the source image into the destination DC. There is no fault with my source and destination coordinates. If I change from SRCCOPY to WHITENESS, the entire area fills with white as you'd expect. There is no grey bar where pixels haven't copied as you see in the Broken.bmp image above. Has anyone had this problem before, and if so, can somebody please suggest a solution? Cheers

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  • implement AOP for Controllers in Spring 3

    - by tommy
    How do I implement AOP with an annotated Controller? I've search and found two previous posts regarding the problem, but can't seem to get the solutions to work. posted solution 1 posted solution 2 Here's what I have: Dispatch Servlet: <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd"> <context:annotation-config/> <context:component-scan base-package="com.foo.controller"/> <bean id="fooAspect" class="com.foo.aop.FooAspect" /> <aop:aspectj-autoproxy> <aop:include name="fooAspect" /> </aop:aspectj-autoproxy> </beans> Controller: @Controller public class FooController { @RequestMapping(value="/index.htm", method=RequestMethod.GET) public String showIndex(Model model){ return "index"; } } Aspect: @Aspect public class FooAspect { @Pointcut("@target(org.springframework.stereotype.Controller)") public void controllerPointcutter() {} @Pointcut("execution(* *(..))") public void methodPointcutter() {} @Before("controllerPointcutter()") public void beforeMethodInController(JoinPoint jp){ System.out.println("### before controller call..."); } @AfterReturning("controllerPointcutter() && methodPointcutter() ") public void afterMethodInController(JoinPoin jp) { System.out.println("### after returning..."); } @Before("methodPointcutter()") public void beforeAnyMethod(JoinPoint jp){ System.out.println("### before any call..."); } } The beforeAnyMethod() works for methods NOT in a controller; I cannot get anything to execute on calls to controllers. Am I missing something?

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  • How To Run MSBuild scripts in .wixproj?

    - by hisoka21
    Im trying to learn to make a web installer using Windows Installer XML (WIX 3.5). I found this blog about using msbuild in .wixproj files to avoid the scenario where the installer ends up dropping the web project assemblies right in the root of the app instead of keeping them in the bin folder like they're supposed to be. Here is the link to that: <http://www.paraesthesia.com/archive/2010/07/30/how-to-consume-msdeploy-staged-web-site-output-in-a.aspx But after adding the MSBuild scripts in the .wixproj file, I don't know what to do anymore. According to the instruction after adding the MSBuild script: "When that target runs, you'll see a .wxs file pop out in the .wixproj project folder. Add the generated .wxs to your .wixproj project so it knows to include it in the build." I really don7t know what this means. How can I run the target? I tried to build it but there was no .wxs file generated in the .wixproj folder. Am I missing something? Please help...

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  • Selectively search and replace certain lines using a regular expression

    - by eneveu
    I have a file containing a lot of SQL statements, such as: CREATE TABLE "USER" ( "ID" INTEGER PRIMARY KEY, "NAME" CHARACTER VARYING(50) NOT NULL, "AGE" INTEGER NOT NULL ); COPY "USER" (id, name, age) FROM stdin; 1 Skywalker 19 2 Kenobi 57 I want the column names in the COPY statements to be uppercased and quoted: COPY "USER" ("ID", "NAME", "AGE") FROM stdin; Using sed, I found the following regexp: sed -r 's/([( ])(\w+)([,)])/\1"\U\2\E"\3/g' It does replace the column names, but it is not selective enough, and replaces other words in the file: ~/test]$sed -r 's/([( ])(\w+)([,)])/\1"\U\2\E"\3/g' star_wars_example CREATE TABLE "USER" ( "ID" INTEGER PRIMARY "KEY", "NAME" CHARACTER VARYING("50")NOT "NULL", "AGE" INTEGER NOT NULL ); COPY "USER" ("ID", "NAME", "AGE") FROM stdin; 1 Skywalker 19 2 Kenobi 57 To avoid this problem, I want sed to only apply my regexp to the lines starting with COPY and ending with FROM stdin;. I have looked into lookahead / lookbehind, but they are not supported in sed. They seem to be supported in super-sed, but I am currently using Cygwin (Windows is mandatory here...) and it does not seem available in the package list. Is there a way to force sed to only consider specific line? I've considered piping my file through grep before applying sed, but other lines will then disappear from the output. Am I missing something obvious? It would be great if the answer was easily applicable on a default Cygwin install. I guess I could try installing super-sed on cygwin, but I'd like to know if there are more obvious ideas

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