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  • Alternatives to static methods on interfaces for enforcing consistency

    - by jayshao
    In Java, I'd like to be able to define marker interfaces, that forced implementations to provide static methods. For example, for simple text-serialization/deserialization I'd like to be able to define an interface that looked something like this: public interface TextTransformable<T>{ public static T fromText(String text); public String toText(); Since interfaces in Java can't contain static methods though (as noted in a number of other posts/threads: here, here, and here this code doesn't work. What I'm looking for however is some reasonable paradigm to express the same intent, namely symmetric methods, one of which is static, and enforced by the compiler. Right now the best we can come up with is some kind of static factory object or generic factory, neither of which is really satisfactory. Note: in our case our primary use-case is we have many, many "value-object" types - enums, or other objects that have a limited number of values, typically carry no state beyond their value, and which we parse/de-parse thousands of time a second, so actually do care about reusing instances (like Float, Integer, etc.) and its impact on memory consumption/g.c. Any thoughts?

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  • Indices instead of pointers in STL containers?

    - by zvrba
    Due to specific requirements [*], I need a singly-linked list implementation that uses integer indices instead of pointers to link nodes. The indices are always interpreted with respect to a vector containing the list nodes. I thought I might achieve this by defining my own allocator, but looking into the gcc's implementation of , they explicitly use pointers for the link fields in the list nodes (i.e., they do not use the pointer type provided by the allocator): struct _List_node_base { _List_node_base* _M_next; ///< Self-explanatory _List_node_base* _M_prev; ///< Self-explanatory ... } (For this purpose, the allocator interface is also deficient in that it does not define a dereference function; "dereferencing" an integer index always needs a pointer to the underlying storage.) Do you know a library of STL-like data structures (i am mostly in need of singly- and doubly-linked list) that use indices (wrt. a base vector) instead of pointers to link nodes? [*] Saving space: the lists will contain many 32-bit integers. With two pointers per node (STL list is doubly-linked), the overhead is 200%, or 400% on 64-bit platform, not counting the overhead of the default allocator.

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  • how to create static line in coreplot

    - by Rémi Bédard-Couture
    I am trying to make my control lines static so instead of being displayed as part of the graph(the control lines are moving with the graph), they would be displayed like an axis the app can only scroll horizontally i'm talking about the two red line and the green line(which i put over the x axis) this is how i do my lines: // Center line CPTScatterPlot *centerLinePlot = [[CPTScatterPlot alloc] init]; centerLinePlot.identifier = kCenterLine; CPTMutableLineStyle *lineStyle = [CPTMutableLineStyle lineStyle]; lineStyle.lineWidth = 2.0; lineStyle.lineColor = [CPTColor greenColor]; centerLinePlot.dataLineStyle = lineStyle; centerLinePlot.dataSource = self; [graph addPlot:centerLinePlot]; but maybe it has something to do with the displayed range: ////////ajuste la portion a voir if(data.Resultats.count>10) { plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble(data.Resultats.count - 10) length:CPTDecimalFromDouble(10)]; } plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble(RangeMin) length:CPTDecimalFromDouble(RangeMax-RangeMin)]; // Adjust visible ranges so plot symbols along the edges are not clipped CPTMutablePlotRange *xRange = [plotSpace.xRange mutableCopy]; CPTMutablePlotRange *yRange = [plotSpace.yRange mutableCopy]; //place l'axe x sur la ligne de controle pour voir les WorkOrders x.orthogonalCoordinateDecimal = CPTDecimalFromDouble(center); //x.orthogonalCoordinateDecimal = yRange.location; //y.orthogonalCoordinateDecimal = xRange.location; //x.visibleRange = xRange; //y.visibleRange = yRange; //x.gridLinesRange = yRange; //y.gridLinesRange = xRange; [xRange expandRangeByFactor:CPTDecimalFromDouble(1.15)];//1.05 [yRange expandRangeByFactor:CPTDecimalFromDouble(1.15)]; plotSpace.xRange = xRange; plotSpace.yRange = yRange;

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  • gpg error - connection already closed?

    - by OopsForgotMyOtherUserName
    omg... hope someone can help me because I am so lost as to what to try next.... I don't know what is causing the error to happen, and I don't see how to figure it out... Keep going between the pgloader.conf examples and what I have, and I don't understand why I keep getting the 'connection already closed' error? The first few lines of my fr.conf is at the very end... I'd really appreciate / love some guidance here... Been trying to get this thing going all morning, and am even getting stuck just on this part... Running this command at the command line: /usr/bin/pgloader -c /var/mybin/pgconfs/fr.conf Yields this in the pgloader.log (with the process just hanging) more /tmp/pgloader.log 27-03-2010 12:22:53 pgloader INFO Logger initialized 27-03-2010 12:22:53 pgloader INFO Reformat path is ['/usr/share/python-support/pgloader/reformat'] 27-03-2010 12:22:53 pgloader INFO Will consider following sections: 27-03-2010 12:22:53 pgloader INFO fixed 27-03-2010 12:22:54 fixed INFO fixed processing 27-03-2010 12:22:54 pgloader INFO All threads are started, wait for them to terminate 27-03-2010 12:22:57 fixed ERROR connection already closed 27-03-2010 12:22:57 fixed INFO closing current database connection [pgsql] host = localhost port = 5432 base = frdb user = username pass = password [fixed] table = fr format = fixed filename = /var/www/fr.txt ...

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  • How To Deal With Exceptions In Large Code Bases

    - by peter
    Hi All, I have a large C# code base. It seems quite buggy at times, and I was wondering if there is a quick way to improve finding and diagnosing issues that are occuring on client PCs. The most pressing issue is that exceptions occur in the software, are caught, and even reported through to me. The problem is that by the time they are caught the original cause of the exception is lost. I.e. If an exception was caught in a specific method, but that method calls 20 other methods, and those methods each call 20 other methods. You get the picture, a null reference exception is impossible to figure out, especially if it occured on a client machine. I have currently found some places where I think errors are more likely to occur and wrapped these directly in their own try catch blocks. Is that the only solution? I could be here a long time. I don't care that the exception will bring down the current process (it is just a thread anyway - not the main application), but I care that the exceptions come back and don't help with troubleshooting. Any ideas? I am well aware that I am probably asking a question which sounds silly, and may not have a straightforward answer. All the same some discussion would be good.

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  • Can't access resource from Generic.xaml within the Custom Control constructor.

    - by myermian
    I'm not sure why this is doing this, but I can't access the resource from within my constructor. XTabItem.cs using System; using System.ComponentModel; using System.Windows; using System.Windows.Controls; using System.Windows.Media; namespace MyStuff { public class XTabItem : TabItem { public static readonly DependencyProperty XTabItemNormalBackgroundProperty; /// <summary> /// Visual Property: Normal Background /// </summary> [Description("Determines the visibility of the close button."), Category("XTabItem Visual")] public Brush XTabItemNormalBackground { get { return (Brush)GetValue(XTabItemNormalBackgroundProperty); } set { SetValue(XTabItemNormalBackgroundProperty, value); } } static XTabItem() { DefaultStyleKeyProperty.OverrideMetadata(typeof(XTabItem), new FrameworkPropertyMetadata(typeof(XTabItem))); XTabItemNormalBackgroundProperty = DependencyProperty.Register("XTabItemNormalBackground", typeof(Brush), typeof(XTabItem), new UIPropertyMetadata(null)); } public XTabItem() { //XTabItemNormalBackground = (Brush)this.TryFindResource("XTabItemNormalBackgroundBrush"); //THIS DOES NOT WORK?? } public override void OnApplyTemplate() { base.OnApplyTemplate(); } } } Generic.xaml <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="clr-namespace:MyStuff" xmlns:con="clr-namespace:MyStuff.Converters" > <SolidColorBrush x:Key="XTabItemNormalBackgroundBrush" Color="BlueViolet" /> <Style TargetType="{x:Type local:XTabItem}"> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="{x:Type local:XTabItem}"> <!-- CONTENT TEMPLATE --> <Grid SnapsToDevicePixels="True"> <Border x:Name="_Border" Background="{Binding Path=XTabItemNormalBackground, RelativeSource={RelativeSource Mode=TemplatedParent}}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="1,1,1,0"> ... </Border> </Grid> </Style> </ResourceDictionary>

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  • myXmlDataDoc.DataSet.ReadXml problem

    - by alex
    Hi: I am using myXmlDataDoc.DataSet.ReadXml(xml_file_name, XmlReadMode.InferSchema); to populate the tables within the dataset created by reading in a xml schema using: myStreamReader = new StreamReader(xsd_file_name); myXmlDataDoc.DataSet.ReadXmlSchema(myStreamReader); The problems I am facing is when it comes to read the xml tag: The readXml function puts the element in a different table and everything in the tables are 0s. Here is the print out of the datatable: TableName: test_data 100 2 1 TableName: parameters 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 10 0 11 0 12 0 In my xsd file, I represent an array using this: <xs:element name="test_data"> <xs:complexType> <xs:complexContent> <xs:extension base="test_base"> <xs:sequence> <xs:element name="a" type="xs:unsignedShort"/> <xs:element name="b" type="xs:unsignedShort"/> <xs:element name="c" type="xs:unsignedInt"/> <xs:element name="parameters" minOccurs="0" maxOccurs="12" type="xs:unsignedInt"/> </xs:sequence> </xs:extension> </xs:complexContent> </xs:complexType> And here is my xml file: 100 2 1 1 2 3 4 5 6 7 8 9 10 11 12 I am expecting after the readXml function call, the "parameters" is part of the test_data table. TableName: test_data 100 2 1 1 2 3 4 5 6 7 8 9 10 11 12 Does anyone knows what's wrong? Thanks

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  • How does one restrict xml with an XML Schema?

    - by John
    Hello, I want to restrict xml with a schema to a specific set. I read this tutorial http://www.w3schools.com/schema/schema_facets.asp This seems to be what I want. So, I'm using Qt to validate this xml <car>BMW</car> Here is the pertinent source code. QXmlSchema schema; schema.load( QUrl("file:///workspace/QtExamples/ValidateXSD/car.xsd") ); if ( schema.isValid() ) { QXmlSchemaValidator validator( schema ); if ( validator.validate( QUrl("file:///workspace/QtExamples/ValidateXSD/car.xml") ) ) { qDebug() << "instance is valid"; } else { qDebug() << "instance is invalid"; } } else { qDebug() << "schema is invalid"; } I expected the xml to match the schema definition. Unexpectedly, QxmlSchemaValidator complains. Error XSDError in file:///workspace/QtExamples/ValidateXSD/car.xml, at line 1, column 5: Content of element car does not match its type definition: String content is not listed in the enumeration facet.. instance is invalid I suspect this is a braino. How does one restrict xml with an XML Schema? Thanks for your time and consideration. Sincerely, -john Here is the xsd from the tutorial. <xs:element name="car"> <xs:simpleType> <xs:restriction base="xs:string"> <xs:enumeration value="Audi"/> <xs:enumeration value="Golf"/> <xs:enumeration value="BMW"/> </xs:restriction> </xs:simpleType> </xs:element>

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  • XSL Reuse? YES! But: Element must not contain an xsl:import element! :-(

    - by Fedor Steeman
    I am using a heavy stylesheet with a lot of recurring transformations, so I thought it would be smart to reuse the same chunks of code, so I would not need to make the same changes at a bunch of different places. So I discovered , but -alas- it won't allow me to do it. When trying to run it in Sonic Workbench I get the following error: An xsl:for-each element must not contain an xsl:import element This is my stylesheet code: <xsl:template match="/"> <InboundFargoMessage> <EdiSender> <xsl:value-of select="TransportInformationMessage/SenderId"/> </EdiSender> <EdiReceiver> <xsl:value-of select="TransportInformationMessage/RecipientId"/> </EdiReceiver> <EdiSource>PORLOGIS</EdiSource> <EdiDestination>FARGO</EdiDestination> <Transportations> <xsl:for-each select="TransportInformationMessage/TransportUnits/TransportUnit"> <xsl:import href="TransportCDMtoFDM_V0.6.xsl"/> </xsl:for-each> <xsl:for-each select="TransportInformationMessage/Waybill/TransportUnits/TransportUnit"> <xsl:import href="TransportCDMtoFDM_V0.6.xsl"/> </xsl:for-each> </Transportations> </InboundFargoMessage> </xsl:template> </xsl:stylesheet> I will leave out the child xsl-sheets for now, as the problem appears to be happening at the base. If I cannot use xsl:import, is there any option of reuse?

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  • Using maven to distribute a swing application that can have each dependency individually tracked

    - by tms
    I'm moving my project to Maven and eventually OSGi. I currently distribute the project is a large Zip file with all the dependencies. Although my projects code is only 20% of the total package I have to redistribute all the dependency. With smaller independent modules this may be even less. Looking here on stack overflow it seems that to keep my current plan the maven-assembly-plugin should do the trick. I was considering having a base installer that would look at a XML manifest, then collect all the libraries that needed to be updated. This would mean that libraries that change occasionally would be downloaded less often. This also makes since for something like OSGi plugins (which could have independent release schedules). In essence I want my software to look and manage individual libraries, and download on demand (based on the manifest). I was wondering if there is a "maven way" of generating this Manifest and publishing all the libraries to a website? I believe the deploy life-cycle would do the second step. As an alternative, is there a OpenSource Java library that does this type of deployment? I don't want to embed Maven or something larger with the distributed code. The application is not for coders, the simpler the better, and the smaller the installer the better.

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  • Simplifying for-if messes with better structure?

    - by HH
    # Description: you are given a bitwise pattern and a string # you need to find the number of times the pattern matches in the string # any one liner or simple pythonic solution? import random def matchIt(yourString, yourPattern): """find the number of times yourPattern occurs in yourString""" count = 0 matchTimes = 0 # How can you simplify the for-if structures? for coin in yourString: #return to base if count == len(pattern): matchTimes = matchTimes + 1 count = 0 #special case to return to 2, there could be more this type of conditions #so this type of if-conditionals are screaming for a havoc if count == 2 and pattern[count] == 1: count = count - 1 #the work horse #it could be simpler by breaking the intial string of lenght 'l' #to blocks of pattern-length, the number of them is 'l - len(pattern)-1' if coin == pattern[count]: count=count+1 average = len(yourString)/matchTimes return [average, matchTimes] # Generates the list myString =[] for x in range(10000): myString= myString + [int(random.random()*2)] pattern = [1,0,0] result = matchIt(myString, pattern) print("The sample had "+str(result[1])+" matches and its size was "+str(len(myString))+".\n" + "So it took "+str(result[0])+" steps in average.\n" + "RESULT: "+str([a for a in "FAILURE" if result[0] != 8])) # Sample Output # # The sample had 1656 matches and its size was 10000. # So it took 6 steps in average. # RESULT: ['F', 'A', 'I', 'L', 'U', 'R', 'E']

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  • Concept: Is mongo right for applying schemas?

    - by Jan
    I am currently in charge of checking wether it is valuable for one of our upcoming products to be developed on mongo. Without going too much into detail, I'll try to explain, what the app does. The app simply has "entities". These entities are technical stuff, like cell phones, TVs, Laptops, tablet pcs, and so forth. Of course, a cell phone has other attributes than a Tablet PCs and a Laptop has even other attributes, like RAM, CPU, display size and so on. Now I want to have something that we wanna call a scheme: We define that we need to have saved the display size, amount of ram size of flash devices, processor type, processor speed and so on for tablet pcs. For cell phone we might save display size, GSM, Edge, 3g, 4g, processor, ram, touch screen technology, bla bla bla. I think you got it :) What I want to realize is, that each "category" has a schema and when one of the system's users enters a new product (let's say the new iphone 4), the app constructs the form to be filled out with the appropriate attributes. So far it sounds nice and should not be a problem with mongo. But now the tough for which I could not find a clean solution.... An attribute modeled in mongo looks like: { _id: 1234456, name: "Attribute name", type: 0, "description" } But what to do, if i need this attribute in several languages, like: { en: {name: "Attribute name", type: 0, "description"}, de: {name: "Name des Attributs, type: 0, "Beschreibung"} } I also need to ensure that the german attribute gets updated as soon as the english gets updated, for instance when type changes from 0 to 1. Any ideas on that?

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  • JavaScript cookie value can't be retrieved in Django

    - by Boris Rusev
    I am trying to build a web site in both English and Bulgarian using the Django framework. My idea is the user should click on a button, the page will reload and the language will be changed. This is how I am trying to do it: In my html I hava a the button tag <button id='btn' onclick="changeLanguage();" type="button"> ... </button> An excerpt from cookies.js: function changeLanguage() { if (getCookie('language') == 'EN') { document.getElementById('btn').innerHTML = getCookie('language'); setCookie("language", 'BG'); } else { document.getElementById('btn').innerHTML = getCookie('language'); setCookie("language", 'EN'); } } function setCookie(sName, sValue, oExpires, sPath, sDomain, bSecure) { var sCookie = sName + "=" + encodeURIComponent(sValue); if (oExpires) { sCookie += "; expires=" + oExpires.toGMTString(); } if (sPath) { sCookie += "; path=" + sPath; } if (sDomain) { sCookie += "; domain=" + sDomain; } if (bSecure) { sCookie += "; secure"; } document.cookie = sCookie; } And in my views.py file this is the situation @base def index(request): if request.session['language'] == 'EN': return """<b>%s</b>""" % "Home" else request.session['language'] == 'BG': return """<b>%s</b>""" % "??????" So I know that my JS changes the value of the language cookie but I think Django doesn't get that. On the other hand when I set and get the cookie in my Python code again the cookie is set. My question is whether there is a way to make JS and Django work together - JavaScript sets the cookie value and Python only reads it when asked and takes adequate actions? Thank you.

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  • using STI and ActiveRecordBase<> with full FindAll

    - by oillio
    Is it possible to use generic support with single table inheritance, and still be able to FindAll of the base class? As a bonus question, will I be able to use ActiveRecordLinqBase< as well? I do love those queries. More detail: Say I have the following classes defined: public interface ICompany { int ID { get; set; } string Name { get; set; } } [ActiveRecord("companies", DiscriminatorColumn="type", DiscriminatorType="String", DiscriminatorValue="NA")] public abstract class Company<T> : ActiveRecordBase<T>, ICompany { [PrimaryKey] private int Id { get; set; } [Property] public String Name { get; set; } } [ActiveRecord(DiscriminatorValue="firm")] public class Firm : Company<Firm> { [Property] public string Description { get; set; } } [ActiveRecord(DiscriminatorValue="client")] public class Client : Company<Client> { [Property] public int ChargeRate { get; set; } } This works fine for most cases. I can do things like: var x = Client.FindAll(); But sometimes I want all of the companies. If I was not using generics I could do: var x = (Company[]) FindAll(Company); Client a = (Client)x[0]; Firm b = (Firm)x[1]; Is there a way to write a FindAll that returns an array of ICompany's that can then be typecast into their respective types? Something like: var x = (ICompany[]) FindAll(Company<ICompany>); Client a = (Client)x[0]; Or maybe I am going about implementing the generic support all wrong?

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  • Improve Efficiency in Array comparison in Ruby

    - by user2985025
    Hi I am working on Ruby /cucumber and have an requirement to develop a comparison module/program to compare two files. Below are the requirements The project is a migration project . Data from one application is moved to another Need to compare the data from the existing application against the new ones. Solution : I have developed a comparison engine in Ruby for the above requirement. a) Get the data, de duplicated and sorted from both the DB's b) Put the data in a text file with "||" as delimiter c) Use the key columns (number) that provides a unique record in the db to compare the two files For ex File1 has 1,2,3,4,5,6 and file2 has 1,2,3,4,5,7 and the columns 1,2,3,4,5 are key columns. I use these key columns and compare 6 and 7 which results in a fail. Issue : The major issue we are facing here is if the mismatches are more than 70% for 100,000 records or more the comparison time is large. If the mismatches are less than 40% then comparison time is ok. Diff and Diff -LCS will not work in this case because we need key columns to arrive at accurate data comparison between two applications. Is there any other method to efficiently reduce the time if the mismatches are more thatn 70% for 100,000 records or more. Thanks

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  • Where to define a filter function for a form field in my Joomla component's preferences

    - by Herman
    I am creating a component in Joomla 2.5. This component has some options that are defined in its config.xml, so they can be set in the preferences of the component. Now I would like to apply a filter to one of these option fields, using the attribute filter="my_filter". In the source code of JForm I saw the following lines at the very end of the implementation of JForm::filterField(): if (strpos($filter, '::') !== false && is_callable(explode('::', $filter))) { $return = call_user_func(explode('::', $filter), $value); } elseif (function_exists($filter)) { $return = call_user_func($filter, $value); } That's what I needed for using a filter function defined by myself! I managed to do this for form fields used in the views of my component. I defined the filter function as MyComponentHelper::my_filter(), where MyComponentHelper is a helper class which I always load in the very base of my component. And in the form's xml I added filter="MyComponentHelper::my_filter" to the fields that have to be filtered. However... when I am trying to apply the filter function to a form field in my component's preferences, I am not in my own component, but in com_config instead, so my helper class is not available! So, therefore, my question: where to define my own filter function in such a way that it can be found and called by JForm::filterField() in com_config?? Help is very much appreciated.

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  • Determine target architecture of binary file in Linux (library or executable)

    - by Fernando Miguélez
    We have an issue related to a Java application running under a (rather old) FC3 on a Advantech POS board with a Via C3 processor. The java application has several compiled shared libs that are accessed via JNI. Via C3 processor is suppossed to be i686 compatible. Some time ago after installing Ubuntu 6.10 on a MiniItx board with the same processor I found out that the previous statement is not 100% true. The Ubuntu kernel hanged on startup due to the lack of some specific and optional instructions of the i686 set in the C3 processor. These instructions missing in C3 implementation of i686 set are used by default by GCC compiler when using i686 optimizations. The solution in this case was to go with a i386 compiled version of Ubuntu distribution. The base problem with the Java application is that the FC3 distribution was installed on the HD by cloning from an image of the HD of another PC, this time an Intel P4. Afterwards the distribution needed some hacking to have it running such as replacing some packages (such as the kernel one) with the i383 compiled version. The problem is that after working for a while the system completely hangs without a trace. I am afraid that some i686 code is left somewhere in the system and could be executed randomly at any time (for example after recovering from suspend mode or something like that). My question is: Is there any tool or way to find out at what specific architecture is an binary file (executable or library) aimed provided that "file" does not give so much information?

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  • rails2 and aws-simple (simpledb): data cannot be deleted from amazon simpledb?

    - by z3cko
    i am developing a ruby on rails (2.3.8) application with data storage amazon simpledb. i am using the aws-sdb gem in the version aws-sdb (0.3.1) there are a few bugs, but the problems are outlined in the comments of this tutorial from amazon: http://developer.amazonwebservices.com/connect/entry.jspa?externalID=1242 i am wondering if it is a bug of the gem or maybe a proxy issue, but i cannot delete any data from simpledb. anyone else experienced this or has a clue? >> t=Team.find(:first) => #<Team:0x329f718 @prefix_options={}, @attributes={"updated_at"=>Fri May 28 16:33:17 UTC 2010, "id"=>0}> >> t.destroy => #<Net::HTTPOK 200 OK readbody=true> >> t=Team.find(:first) => #<Team:0x321ad38 @prefix_options={}, @attributes={"updated_at"=>Fri May 28 16:33:17 UTC 2010, "id"=>0}> the team model is a normal ActiveResource Model, according to said tutorial. class Team < ActiveResource::Base self.site = "http://localhost:8888" # Proxy host + port self.prefix = "/fb2010_dev/" # SDB domain end

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  • How to enforce users to create objects of class derived from mine with "new" only?

    - by sharptooth
    To implement reference counting we use an IUnknown-like interface and a smart pointer template class. The interface has implementation for all the reference-count methods, including Release(): void IUnknownLike::Release() { if( --refCount == 0 ) { delete this; } } The smart pointer template class has a copy constructor and an assignment operator both accepting raw pointers. So users can do the following: class Class : public IUnknownLike { }; void someFunction( CSmartPointer<Class> object ); //whatever function Class object; someFunction( &object ); and the program runs into undefined behavior - the object is created with reference count zero, the smart pointer is constructed and bumps it to one, then the function returns, smart pointer is destroyed, calls Release() which leads to delete of a stack-allocated variable. Users can as well do the following: struct COuter { //whatever else; Class inner;// IUnknownLike descendant }; COuter object; somefunction( &object.Inner ); and again an object not created with new is deleted. Undefined behavior at its best. Is there any way to change the IUnknownLike interface so that the user is forced to use new for creating all objects derived from IUnknownLike - both directly derived and indirectly derived (with classes in between the most derived and the base)?

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  • Creating a Linq->HQL provider

    - by Mike Q
    Hi all, I have a client application that connects to a server. The server uses hibernate for persistence and querying so it has a set of annotated hibernate objects for persistence. The client sends HQL queries to the server and gets responses back. The client has an auto-generated set of objects that match the server hibernate objects for query results and basic persistence. I would like to support using Linq to query as well as Hql as it makes the queries typesafe and quicker to build (no more typos in HQL string queries). I've looked around at the following but I can't see how to get them to fit with what I have. NHibernate's Linq provider - requires using NHibernate ISession and ISessionFactory, which I don't have LinqExtender - requires a lot of annotations on the objects and extending a base type, too invasive What I really want is something that will generate give me a nice easy to process structure to build the HQL queries from. I've read most of a 15 page article written by one of the C# developers on how to create custom providers and it's pretty fraught, mainly because of the complexity of the expression tree. Can anyone suggest an approach for implementing Linq - HQL translation? Perhaps a library that will the cleanup of the expression tree into something more SQL/HQLish. I would like to support select/from/where/group by/order by/joins. Not too worried about subqueries.

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  • Problems with overriding OnPaint and grabbing mouse events in C# UserControl containing other controls

    - by MoreThanChaos
    I've made a control which contains few other controls like PictureBox, Label and TextBox. But I'm having two problems: 1. I tried to paint some things on top of my control and when I'm overriding OnPaint, it results that things I try to draw are under controls that my control contains. Areas on which I would like to draw intersect with controls in ways that are not easy to predict. I mean that it includes something drawn on controls inside as well as on base of control. Is there a simple way to draw something on top of all contents of my control? Setting ForeColor to Transparent isn't a solution that would help me much. 2. I have a problem with grabbing mouse click events when I place my control on a form and add click event handling. It only works when I click on an area not occupied by controls inside. I would like the whole control to react to clicks and other actions like it was one consistent control. How can I redirect/handle these clicks to make them work the way I want? Thanks in advance for any tips

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  • Best way to migrate export/import from SQL Server to oracle

    - by matao
    Hi guys! I'm faced with needing access for reporting to some data that lives in Oracle and other data that lives in a SQL Server 2000 database. For various reasons these live on different sides of a firewall. Now we're looking at doing an export/import from sql server to oracle and I'd like some advice on the best way to go about it... The procedure will need to be fully automated and run nightly, so that excludes using the SQL developer tools. I also can't make a live link between databases from our (oracle) side as the firewall is in the way. The data needs to be transformed in the process from a star schema to a de-normalised table ready for reporting. What I'm thinking about is writing a monster query for SQL Server (which I mostly have already) that will denormalise and read out the data from SQL Server into a flat file using the sql server equivalent of sqlplus as a scheduled task, dump into a Well Known Location, then on the oracle side have a cron job that copies down the file and loads it with sql loader and rebuilds indexes etc. This is all doable, but very manual. Is there one or a combination of FOSS or standard oracle/SQL Server tools that could automate this for me? the Irreducible complexity is the query on one side and building indexes on the other, but I would love to not have to write the CSV dumping detail or the SQL loader script, just say dump this view out to CSV on one side, and on the other truncate and insert into this table from CSV and not worry about mapping column names and all other arcane sqlldr voodoo... best practices? thoughts? comments? edit: I have about 50+ columns all of varying types and lengths in my dataset, which is why I'd prefer to not have to write out how to generate and map each single column...

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  • How to mimic polymorphism in classes with template methods (c++)?

    - by davide
    in the problem i am facing i need something which works more or less like a polymorphic class, but which would allow for virtual template methods. the point is, i would like to create an array of subproblems, each one being solved by a different technique implemented in a different class, but holding the same interface, then pass a set of parameters (which are functions/functors - this is where templates jump up) to all the subproblems and get back a solution. if the parameters would be, e.g., ints, this would be something like: struct subproblem { ... virtual void solve (double& solution, double parameter)=0; } struct subproblem0: public subproblem { ... virtual void solve (double& solution, double parameter){...}; } struct subproblem1: public subproblem { ... virtual void solve (double* solution, double parameter){...}; } int main{ subproblem problem[2]; subproblem[0] = new subproblem0(); subproblem[1] = new subproblem1(); double argument0(0), argument1(1), sol0[2], sol1[2]; for(unsigned int i(0);i<2;++i) { problem[i]->solve( &(sol0[i]) , argument0); problem[i]->solve( &(sol1[i]) , argument1); } return 0; } but the problem is, i need the arguments to be something like Arg<T1,T2> argument0(f1,f2) and thus the solve method to be something of the likes of template<T1,T2> solve (double* solution, Arg<T1,T2> parameter) which cant obviously be declared virtual ( so cant be called from a pointer to the base class)... now i'm pretty stuck and don't know how to procede...

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  • Mysql - Operand should contain 1 column(s) : What's wrong with the query...?

    - by SpikETidE
    Hi everybody.... I am trying to query a database to find the following If a customer searches for a hotel in a city between dates A and B, find and return the hotels in which rooms are free between the two dates. There will be more than one room in each room type(i.e. 5 Rooms in type A, 10 rooms in Type B etc) and we have to query the db to find only those hotels in which there is atleast one room free in atleast one type. This is my table structure.... **Structure for table 'reservations'** reservation_id hotel_id room_id customer_id payment_id no_of_rooms check_in_date check_out_date reservation_date **Structure for table 'hotels'** hotel_id hotel_name hotel_description hotel_address hotel_location hotel_country hotel_city hotel_type hotel_stars hotel_image hotel_deleted **Structure for table 'rooms'** room_id hotel_id room_name max_persons total_rooms room_price room_image agent_commision room_facilities service_tax vat city_tax room_description room_deleted And this is my query $city_search = '15'; $check_in_date = '29-03-2010'; $check_out_date = '31-03-2010'; $dateFormat_check_in = "DATE_FORMAT('$reservations.check_in_date','%d-%m-%Y')"; $dateFormat_check_out = "DATE_FORMAT('$reservations.check_out_date','%d-%m-%Y')"; $dateCheck = "$dateFormat_check_in >= '$check_in_date' AND $dateFormat_check_out <= '$check_out_date'"; $query = "SELECT $rooms.room_id, $rooms.room_name, $rooms.max_persons, $rooms.room_price, $hotels.hotel_id, $hotels.hotel_name, $hotels.hotel_stars, $hotels.hotel_type FROM $hotels,$rooms,$reservations WHERE $hotels.hotel_city = '$city_search' AND $hotels.hotel_id = $rooms.hotel_id AND $hotels.hotel_deleted = '0' AND $rooms.room_deleted = '0' AND $rooms.total_rooms - (SELECT SUM($reservations.no_of_rooms) as tot, $rooms.room_id as id FROM $reservations,$rooms WHERE $dateCheck GROUP BY $reservations.room_id) > '0'"; The number of rooms already reserved in each room type in each hotel will be stored in the reservations table... The query returns the error : Operand should contain 1 column(s) I tried running the sub-query alone but i don't get any result... And i have lost quite some amount of hair trying to de-bug this query from yesterday... What's wrong with this...? Or is there a better way to do what i mentioned above...? Thanks for your time...

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  • How can I embed images within my application and use them in HTML control?

    - by Atara
    Is there any way I can embed the images within my exe (as resource?) and use it in generated HTML ? Here are the requirements: A. I want to show dynamic HTML content (e.g. using webBrowser control, VS 2008, VB .Net, winForm desktop application) B. I want to generate the HTML on-the-fly using XML and XSL (file1.xml or file2.xml transformed by my.xsl) C. The HTML may contain IMG tags (file1.gif and or file2.gif according to the xml+xsl transformation) and here comes the complicated one: D. All these files (file1.xml, file2.xml, my.xsl, file1.gif, file2.gif) should be embedded in one exe file. I guess the XML and XSL can be embedded resources, and I can read them as stream, but what ways do I have to reference the image within the HTML ? <IMG src="???" /> I do not want to use absolute path and external files. If the image files are resources, can I use relative path? Relative to what? (I can use BASE tag, and then what?) Can I use stream as in email messages? If so, where can I find the format I need to use? http://www.websiteoptimization.com/speed/tweak/inline-images/ are browser dependent. What is the browser used by webBrowser control? IE? what version? Does it matter if I use GIF or JPG or BMP (or any other image format) for the images? Does it matter if I use mshtml library and not the regular webBrowser control? (currently I use http://www.itwriting.com/htmleditor/index.php ) Does it matter if I upgrade to VS 2010 ? Thanks, Atara

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