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  • Default value for hidden field in Django model

    - by Daniel Garcia
    I have this Model: class Occurrence(models.Model): id = models.AutoField(primary_key=True, null=True) reference = models.IntegerField(null=True, editable=False) def save(self): self.collection = self.id super(Occurrence, self).save() I want for the reference field to be hidden and at the same time have the same value as id. This code works if the editable=True but if i want to hide it it doesnt change the value of reference. how can i fix that?

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  • Core Plot never stops asking for data, hangs device

    - by Ben Collins
    I'm trying to set up a core plot that looks somewhat like the AAPLot example on the core-plot wiki. I have set up my plot like this: - (void)initGraph:(CPXYGraph*)graph forDays:(NSUInteger)numDays { self.cplhView.hostedLayer = graph; graph.paddingLeft = 30.0; graph.paddingTop = 20.0; graph.paddingRight = 30.0; graph.paddingBottom = 20.0; CPXYPlotSpace *plotSpace = (CPXYPlotSpace*)graph.defaultPlotSpace; plotSpace.xRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromFloat(0) length:CPDecimalFromFloat(numDays)]; plotSpace.yRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromFloat(0) length:CPDecimalFromFloat(1)]; CPLineStyle *lineStyle = [CPLineStyle lineStyle]; lineStyle.lineColor = [CPColor blackColor]; lineStyle.lineWidth = 2.0f; // Axes NSLog(@"Setting up axes"); CPXYAxisSet *xyAxisSet = (id)graph.axisSet; CPXYAxis *xAxis = xyAxisSet.xAxis; // xAxis.majorIntervalLength = CPDecimalFromFloat(7); // xAxis.minorTicksPerInterval = 7; CPXYAxis *yAxis = xyAxisSet.yAxis; // yAxis.majorIntervalLength = CPDecimalFromFloat(0.1); // Line plot with gradient fill NSLog(@"Setting up line plot"); CPScatterPlot *dataSourceLinePlot = [[[CPScatterPlot alloc] initWithFrame:graph.bounds] autorelease]; dataSourceLinePlot.identifier = @"Data Source Plot"; dataSourceLinePlot.dataLineStyle = nil; dataSourceLinePlot.dataSource = self; [graph addPlot:dataSourceLinePlot]; CPColor *areaColor = [CPColor colorWithComponentRed:1.0 green:1.0 blue:1.0 alpha:0.6]; CPGradient *areaGradient = [CPGradient gradientWithBeginningColor:areaColor endingColor:[CPColor clearColor]]; areaGradient.angle = -90.0f; CPFill *areaGradientFill = [CPFill fillWithGradient:areaGradient]; dataSourceLinePlot.areaFill = areaGradientFill; dataSourceLinePlot.areaBaseValue = CPDecimalFromString(@"320.0"); // OHLC plot NSLog(@"OHLC Plot"); CPLineStyle *whiteLineStyle = [CPLineStyle lineStyle]; whiteLineStyle.lineColor = [CPColor whiteColor]; whiteLineStyle.lineWidth = 1.0f; CPTradingRangePlot *ohlcPlot = [[[CPTradingRangePlot alloc] initWithFrame:graph.bounds] autorelease]; ohlcPlot.identifier = @"OHLC"; ohlcPlot.lineStyle = whiteLineStyle; ohlcPlot.stickLength = 2.0f; ohlcPlot.plotStyle = CPTradingRangePlotStyleOHLC; ohlcPlot.dataSource = self; NSLog(@"Data source set, adding plot"); [graph addPlot:ohlcPlot]; } And my delegate methods like this: #pragma mark - #pragma mark CPPlotdataSource Methods - (NSUInteger)numberOfRecordsForPlot:(CPPlot *)plot { NSUInteger maxCount = 0; NSLog(@"Getting number of records."); if (self.data1 && [self.data1 count] > maxCount) { maxCount = [self.data1 count]; } if (self.data2 && [self.data2 count] > maxCount) { maxCount = [self.data2 count]; } if (self.data3 && [self.data3 count] > maxCount) { maxCount = [self.data3 count]; } NSLog(@"%u records", maxCount); return maxCount; } - (NSNumber *)numberForPlot:(CPPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index { NSLog(@"Getting record @ idx %u", index); return [NSNumber numberWithInt:index]; } All the code above is in the view controller for the view hosting the plot, and when initGraph is called, numDays is 30. I realize of course that this plot, if it even worked, would look nothing like the AAPLot example. The problem I'm having is that the view is never shown. It finished loading because viewDidLoad is the method that calls initGraph above, and the NSLog statements indicate that initGraph finishes. What's strange is that I return a value of 54 from numberOfRecordsForPlot, but the plot asks for more than 54 data points. in fact, it never stops asking. The NSLog statement in numberForPlot:field:recordIndex prints forever, going from 0 to 54 and then looping back around and continuing. What's going on? Why won't the plot stop asking for data and draw itself?

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  • UIButtons work when rotated right, but not when rotated left. Huh?

    - by Ben Collins
    I have a view that is added to the current view when the device is rotated to a LandscapeLeft or LandscapeRight orientation. This view has 4 buttons on it that are all connected to outlets and each have the "touch up inside" event hooked up to the same action. If rotated to a LandscapeLeft orientation, I transform my added view to rotate -90 degrees, and everything works fine. If rotated to a LandscapeRight orientation, I transform the added view to rotate 90 degrees, and the buttons don't work! Highlighting doesn't happen, and the action isn't called. I am at a bit of a loss as to why this might be. Any ideas?

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  • Referencing Entity from external data model - Core Data

    - by Ben Reeves
    I have a external library which includes a core data model, I would like to add a new entity to this model which has a relationship with one of the entities from the library. I know I could modify the original, but is there a way to without needing to pollute the library? I tried just creating a new model with an entity named the same, but that doesn't work: * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Can't merge models with two different entities named 'Host''

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  • iPhone SDK - Comparing characters in string

    - by Karl Daniel
    Basically what I'm trying to do is compare 2 strings one from a plist and one from the user's input. I use a while loop to step through each character and compare it and if true then I increase an integer then once the loop has finished I work out the percentage correct / similarity of the plist answer and the user's answer. I seem to be having a problem however as the only return I'm getting is 0. Below is the code I'm using... The code below is all functioning and the question no longer requires answering... Working code... answerLength = boxAnswer.length; //Gets number of characters of first string. plistLength = plistAnswer.length; //Gets number of characters of second string. characterRange = 0; //Sets the variable for which character to look at. charactersCorrect = 0; //Sets the variable of number of matching characters. unichar answerCharacter; //Declares a unichar for the first string. unichar plistCharacter; //Declares a unichar for the second string. while (answerLength > 0 && plistLength > 0) { answerCharacter = [boxAnswer characterAtIndex:characterRange]; //Gets character of first string at the index of the range integer. plistCharacter = [plistAnswer characterAtIndex:characterRange]; //Gets character of second string at the index of the range integer. answerLength--; //Reduces number of characters left to compare. plistLength--; characterRange++; //Increases integer to tell it to look at next character in string. if (answerCharacter == plistCharacter) { //Checks to see if character of first string and character of second string match. charactersCorrect++; //If true increases the number correct. } } //Works out percentage of matching characters out of the total string. totalChar = plistAnswer.length; totalPercentage = (charactersCorrect/totalChar)*100; percentageCorrect.text = [NSString stringWithFormat:@"%i%%",totalPercentage]; Variable Declarations... int answerLength; int plistLength; int characterRange; double totalChar; double charactersCorrect; int totalPercentage;

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  • Importing already existing git repo with multiple branches and tags into gerrit

    - by Daniel
    I'm trying to import an already existing git repository with multiple branches and tags into gerrit. I'm following the official guide at https://gerrit-review.googlesource.com/Documentation/install-quick.html#_already_existing_project. However, when issuing the push command all the branches and tags, except "master" which I'm currently in, are "prohibited by Gerrit". The output is something like this: user@host:~/my-project$ git push ssh://user@localhost:29418/demo-project *:* [....] * [new branch] master -> master ! [remote rejected] origin/Branch1 -> origin/Branch1 (prohibited by Gerrit) ! [remote rejected] origin/Branch2 -> origin/Branch2 (prohibited by Gerrit) [....] ! [remote rejected] Tag1 -> Tag1 (prohibited by Gerrit) ! [remote rejected] Tag2 -> Tag2 (prohibited by Gerrit) [....] I'm administrator so it shouldn't be an access rights issue.

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  • Multi-level inheritance with Implements on properties in VB.NET vs C#

    - by Ben McCormack
    Let's say I have 2 interfaces defined like so: public interface ISkuItem { public string SKU { get; set; } } public interface ICartItem : ISkuItem { public int Quantity { get; set; } public bool IsDiscountable { get; set; } } When I go to implement the interface in C#, VS produces the following templated code: public class CartItem : ICartItem { #region ICartItem Members public int Quantity { get {...} set {...} } public bool IsDiscountable { get {...} set {...} } #endregion #region ISkuItem Members public string SKU { get {...} set {...} } #endregion } In VB.NET, the same class is built out like so: Public Class CartItem Implements ICartItem Public Property IsDiscountable As Boolean Implements ICartItem.IsDiscountable 'GET SET' End Property Public Property Quantity As Integer Implements ICartItem.Quantity 'GET SET' End Property Public Property SKU As String Implements ISkuItem.SKU 'GET SET' End Property End Class VB.NET explicitly requires you to add Implements IInterfaceName.PropertyName after each property that gets implemented whereas C# simply uses regions to indicate which properties and methods belong to the interface. Interestingly in VB.NET, on the SKU property, I can specify either Implements ISkuItem.SKU or Implements ICartItem.SKU. Although the template built by VS defaults to ISkuItem, I can also specify ICartItem if I want. Oddly, because C# only uses regions to block out inherited properties, it seems that I can't explicitly specify the implementing interface of SKU in C# like I can in VB.NET. My question is: Is there any importance behind being able to specify one interface or another to implement properites in VB.NET, and if so, is there a way to mimic this functionality in C#?

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  • Is this a memory leak?

    - by Ben
    char *pointer1; char *pointer2; pointer1 = new char[256]; pointer2 = pointer1; delete [] pointer1; In other words, do I have to do delete [] pointer2 as well? Thanks!

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  • JQuery - Ajax saving sortables in connected lists when sortable item is moved

    - by Ben Sinclair
    I have multiple JQuery sortable lists that connect with each other... They allow you to assign users to certain roles. Basically what I want to do is when a user is dragged from one list to another, I want JQuery to pick up the first list that the user was moved from so that I can send an AJAX request to delete it from that list in my database. I tried the following but every time you move the user over a list and haven't even dropped it within a list, it sends this request which means I'll be sending multiple AJAX requests... Does that make sense? $( ".selector" ).sortable({ out: function(event, ui) { ... } }); From my testing, I can use the following code to just update the list that user has been moved to so I've got the second half covered: $( ".selector" ).sortable({ receive: function(event, ui) { ... } }); Hopefully I am making sense :)

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  • Is there any way to optimize this LINQ where clause that searches for multiple keywords on multiple

    - by Daniel T.
    I have a LINQ query that searches for multiple keywords on multiple columns. The intention is that the user can search for multiple keywords and it will search for the keywords on every property in my Media entity. Here is a simplified example: var result = repository.GetAll<Media>().Where(x => x.Title.Contains("Apples") || x.Description.Contains("Apples") || x.Tags.Contains("Apples") || x.Title.Contains("Oranges") || x.Description.Contains("Oranges") || x.Tags.Contains("Oranges") || x.Title.Contains("Pears") || x.Description.Contains("Pears") || x.Tags.Contains("Pears") ); In other words, I want to search for the keywords Apples, Oranges, and Pears on the columns Title, Description, and Tags. The outputted SQL looks like this: SELECT * FROM Media this_ WHERE (((((((( this_.Title like '%Apples%' or this_.Description like '%Apples%') or this_.Tags like '%Apples%') or this_.Title like '%Oranges%') or this_.Description like '%Oranges%') or this_.Tags like '%Oranges%') or this_.Title like '%Pears%') or this_.Description like '%Pears%') or this_.Tags like '%Pears%') Is this the most optimal SQL in this case? If not, how do I rewrite the LINQ query to create the most optimal SQL statement? I'm using SQLite for testing and SQL Server for actual deployment.

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  • Memory dump much smaller than available memory

    - by Daniel
    I have a Tomcat Application Server that is configured to create a memory dump on OOM, and it is started with -Xmx1024M, so a Gigabyte should be available to him. Now I found one such dump and it contains only 260MB of unretained memory. How is it possible that the dump is so much smaller than the size he should have available?

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  • Django make model field name a link

    - by Daniel Garcia
    what Im looking to do is to have a link on the name of a field of a model. So when im filling the form using the admin interface i can access some information. I know this doesn't work but shows what i want to do class A(models.Model): item_type = models.CharField(max_length=100, choices=ITEMTYPE_CHOICES, verbose_name="<a href='http://www.quackit.com/html/codes'>Item Type</a>") Other option would be to put a description next to the field. Im not even sure where to start from.

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  • Aborting jQuery().load()

    - by Daniel I-S
    The .load() function of the jQuery library allows you to selectively load elements from another page (subject to certain rules). I would like to know whether it is possible to abort the load process. In our application, a user can browse a list of items. They may choose to click a button which loads and displays additional information about an item from another document (which can take some time). If they choose a different item in the list whilst a .load() is still happening, I would like the loading to be aborted. Is this possible? Is it even worth it? Any ideas? Dan

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  • How can I read a textfile into matlab and make it a list?

    - by Ben Fossen
    I have a textfile that has the format gene complement(22995..24539) /gene="ppp" /locus_tag="MRA_0020" CDS complement(22995..24539) /gene="ppp" /locus_tag="MRA_0020" /codon_start=1 /transl_table=11 /product="putative serine/threonine phosphatase Ppp" /protein_id="ABQ71738.1" /db_xref="GI:148503929" gene complement(24628..25095) /locus_tag="MRA_0021" CDS complement(24628..25095) /locus_tag="MRA_0021" /codon_start=1 /transl_table=11 /product="hypothetical protein" /protein_id="ABQ71739.1" /db_xref="GI:148503930" gene complement(25219..26802) /locus_tag="MRA_0022" CDS complement(25219..26802) /locus_tag="MRA_0022" /codon_start=1 /transl_table=11 /product="hypothetical protein" /protein_id="ABQ71740.1" /db_xref="GI:148503931" I would like to read the textfile into Matlab and make a list with the information from the line gene as the starting point for each item in the list. So for this example there will be 3 items in the list. I have tried a few things and cannot get this to work. Anyone have any ideas of what I can do?

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  • How can I add HTML formating to 'Swift Mail tutorial based' PHP email?

    - by Daniel
    Hello, I have developed a competition page for a client, and they wish for the email the customer receives be more than simply text. The tutorial I used only provided simple text, within the 'send body message'. I am required to add html to thank the customer for entering, with introducing images to this email. The code is: //send the welcome letter function send_email($info){ //format each email $body = format_email($info,'html'); $body_plain_txt = format_email($info,'txt'); //setup the mailer $transport = Swift_MailTransport::newInstance(); $mailer = Swift_Mailer::newInstance($transport); $message = Swift_Message::newInstance(); $message ->setSubject('Thanks for entering the competition'); $message ->setFrom(array('[email protected]' => 'FromEmailExample')); $message ->setTo(array($info['email'] => $info['name'])); $message ->setBody('Thanks for entering the competition, we will be in touch if you are a lucky winner.'); $result = $mailer->send($message); return $result; } This function.php sheet is working and the customer is recieving their email ok, I just need to change the ('Thanks for entering the competition, we will be in touch if you are a lucky winner.') to have HTML instead... Please, if you can, provide me with an example of how I can integrate HTML into this function. Cheers in advance. :-)

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  • NHibernate with Framework .NET Framework 2

    - by Daniel Dolz
    Hi. I can not make NHibernate 2.1 work in machines without framework 3.X (basically, windows 2000 SP4, although it happens with XP too). NHibernate doc do no mention this. Maybe you can help? I NEED to make NHibernate 2.1 work in Windows 2000 PCs, so you think this can be done? Thanks! PD: DataBase is SQL 2000/2005. Error is: NHibernate.MappingException: Could not compile the mapping document: Datos.NH_VEN_ComprobanteBF.hbm.xml ---> NHibernate.HibernateException: Could not instantiate dialect class NHibernate.Dialect.MsSql2000Dialect ---> System.Reflection.TargetInvocationException: Se produjo una excepción en el destino de la invocación. ---> System.TypeInitializationException: Se produjo una excepción en el inicializador de tipo de 'NHibernate.NHibernateUtil'. ---> System.TypeLoadException: No se puede cargar el tipo 'System.DateTimeOffset' del ensamblado'mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'. en NHibernate.Type.DateTimeOffsetType.get_ReturnedClass() en NHibernate.NHibernateUtil..cctor() --- Fin del seguimiento de la pila de la excepción interna --- en NHibernate.Dialect.Dialect..ctor() en NHibernate.Dialect.MsSql2000Dialect..ctor() --- Fin del seguimiento de la pila de la excepción interna --- en System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandle& ctor, Boolean& bNeedSecurityCheck) en System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean fillCache) en System.RuntimeType.CreateInstanceImpl(Boolean publicOnly, Boolean skipVisibilityChecks, Boolean fillCache) en System.Activator.CreateInstance(Type type, Boolean nonPublic) en NHibernate.Bytecode.ActivatorObjectsFactory.CreateInstance(Type type) en NHibernate.Dialect.Dialect.InstantiateDialect(String dialectName) --- Fin del seguimiento de la pila de la excepción interna --- en NHibernate.Dialect.Dialect.InstantiateDialect(String dialectName) en NHibernate.Dialect.Dialect.GetDialect(IDictionary`2 props) en NHibernate.Cfg.Configuration.AddValidatedDocument(NamedXmlDocument doc) --- Fin del seguimiento de la pila de la excepción interna --- en NHibernate.Cfg.Configuration.LogAndThrow(Exception exception) en NHibernate.Cfg.Configuration.AddValidatedDocument(NamedXmlDocument doc) en NHibernate.Cfg.Configuration.ProcessMappingsQueue() and continues...

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  • trying to draw scaled UIImage in custom view, but nothing's rendering

    - by Ben Collins
    I've created a custom view class and right now just want to draw an image scaled to fit the view, given a UIImage. I tried just drawing the UIImage.CGImage, but as others have attested to on this site (and in the docs), that renders the image upside down. So, at the suggestion of an answer I found to another question, I'm trying to draw it directly, but nothing is rendering in the view and I'm not sure why. Here's my drawing code: - (void)drawRect:(CGRect)rect { // Drawing code [super drawRect:rect]; if (self.originalImage) { [self drawImage]; } } - (void) drawImage { if (CGSizeEqualToSize(originalImage.size, self.frame.size) == NO) { CGFloat scaleFactor = 1.0; CGFloat scaledWidth = 0.0; CGFloat scaledHeight = 0.0; CGPoint thumbPoint = CGPointMake(0.0, 0.0); CGFloat widthFactor = self.frame.size.width / originalImage.size.width; CGFloat heightFactor = self.frame.size.height / originalImage.size.height; if (widthFactor < heightFactor) { scaleFactor = widthFactor; } else { scaleFactor = heightFactor; } scaledWidth = originalImage.size.width * scaleFactor; scaledHeight = originalImage.size.height * scaleFactor; if (widthFactor < heightFactor) { thumbPoint.y = (self.frame.size.height - scaledHeight) * 0.5; } else if (widthFactor > heightFactor) { thumbPoint.x = (self.frame.size.width - scaledWidth) * 0.5; } UIGraphicsBeginImageContext(self.frame.size); CGRect thumbRect = CGRectZero; thumbRect.origin = thumbPoint; thumbRect.size.width = scaledWidth; thumbRect.size.height = scaledHeight; [originalImage drawInRect:thumbRect]; self.scaledImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); } else { self.scaledImage = originalImage; } } My understanding (after studying this a bit) is that the UIGraphicsBeginImageContext function creates an offscreen for me to draw into, so now how do I render that context on top of the original one?

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  • Is this slow WPF TextBlock performance expected?

    - by Ben Schoepke
    Hi, I am doing some benchmarking to determine if I can use WPF for a new product. However, early performance results are disappointing. I made a quick app that uses data binding to display a bunch of random text inside of a list box every 100 ms and it was eating up ~15% CPU. So I made another quick app that skipped the data binding/data template scheme and does nothing but update 10 TextBlocks that are inside of a ListBox every 100 ms (the actual product wouldn't require 100 ms updates, more like 500 ms max, but this is a stress test). I'm still seeing ~10-15% CPU usage. Why is this so high? Is it because of all the garbage strings? Here's the XAML: <Grid> <ListBox x:Name="numericsListBox"> <ListBox.Resources> <Style TargetType="TextBlock"> <Setter Property="FontSize" Value="48"/> <Setter Property="Width" Value="300"/> </Style> </ListBox.Resources> <TextBlock/> <TextBlock/> <TextBlock/> <TextBlock/> <TextBlock/> <TextBlock/> <TextBlock/> <TextBlock/> <TextBlock/> <TextBlock/> </ListBox> </Grid> Here's the code behind: public partial class Window1 : Window { private int _count = 0; public Window1() { InitializeComponent(); } private void OnLoad(object sender, RoutedEventArgs e) { var t = new DispatcherTimer(TimeSpan.FromSeconds(0.1), DispatcherPriority.Normal, UpdateNumerics, Dispatcher); t.Start(); } private void UpdateNumerics(object sender, EventArgs e) { ++_count; foreach (object textBlock in numericsListBox.Items) { var t = textBlock as TextBlock; if (t != null) t.Text = _count.ToString(); } } } Any ideas for a better way to quickly render text? My computer: XP SP3, 2.26 GHz Core 2 Duo, 4 GB RAM, Intel 4500 HD integrated graphics. And that is an order of magnitude beefier than the hardware I'd need to develop for in the real product.

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  • Best practices: Sending email on behalf of users

    - by Ben Doom
    The company I work for provides testing services for the healthcare industry. As part of our services, we need to send email to our clients' employees. Typically, these are temp, part-time, or contract employees, and so have private email addresses (eg Hotmail, GMail, Yahoo!, etc). Up to now, we've been sending from an internal address, but this means that replies come back to us when employees aren't paying attention or don't know to send queries to our clients. I'd like to change this, so that the person who requests that the email is sent is the person that is replied to. We've used reply-to: in the past, but it seemed to cause additional mail to be trapped by spam filters. I've been reading about sender: and on-behalf-of: headers, and was wondering what the current best-practice was for sending email in a scenario where we need to send email such that the reply goes to a domain we don't control.

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  • Dynamically creating a TreeViewin HTML with indent lines in ASP.NET

    - by Ben
    Hi, i'm quite new to HTML, and am trying to create a professional looking TreeView. I can not use the in built TreeView in ASP.NET as i need to point the target of the selection to another frame (I have tried, and this doesn't seem possible). My TreeView is built up as follows: Folder1 ChildOne ChildTwo ChildThree Folder2 ChildOne ChildTwo ChildThree I have the collapsing of the folders working, but would like to know how to format this TreeView so it has dotted lines down to the child nodes (as most TreeViews tend to have). How would i go about this? Cheers.

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  • Reference-type conversion operators: asking for trouble?

    - by Ben
    When I compile the following code using g++ class A {}; void foo(A&) {} int main() { foo(A()); return 0; } I get the following error messages: > g++ test.cpp -o test test.cpp: In function ‘int main()’: test.cpp:10: error: invalid initialization of non-const reference of type ‘A&’ from a temporary of type ‘A’ test.cpp:6: error: in passing argument 1 of ‘void foo(A&)’ After some reflection, these errors make plenty of sense to me. A() is just a temporary value, not an assignable location on the stack, so it wouldn't seem to have an address. If it doesn't have an address, then I can't hold a reference to it. Okay, fine. But wait! If I add the following conversion operator to the class A class A { public: operator A&() { return *this; } }; then all is well! My question is whether this even remotely safe. What exactly does this point to when A() is constructed as a temporary value? I am given some confidence by the fact that void foo(const A&) {} can accept temporary values according to g++ and all other compilers I've used. The const keyword can always be cast away, so it would surprise me if there were any actual semantic differences between a const A& parameter and an A& parameter. So I guess that's another way of asking my question: why is a const reference to a temporary value considered safe by the compiler whereas a non-const reference is not?

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  • Is there a standard mapping between JSON and Protocol Buffers?

    - by Daniel Earwicker
    From a comment on the announcement blog post: Regarding JSON: JSON is structured similarly to Protocol Buffers, but protocol buffer binary format is still smaller and faster to encode. JSON makes a great text encoding for protocol buffers, though -- it's trivial to write an encoder/decoder that converts arbitrary protocol messages to and from JSON, using protobuf reflection. This is a good way to communicate with AJAX apps, since making the user download a full protobuf decoder when they visit your page might be too much. It may be trivial to cook up a mapping, but is there a single "obvious" mapping between the two that any two separate dev teams would naturally settle on? If two products supported PB data and could interoperate because they shared the same .proto spec, I wonder if they would still be able to interoperate if they independently introduced a JSON reflection of the same spec. There might be some arbitrary decisions to be made, e.g. should enum values be represented by a string (to be human-readable a la typical JSON) or by their integer value? So is there an established mapping, and any open source implementations for generating JSON encoder/decoders from .proto specs?

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