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  • Why do we need serialization in web service

    - by Cloud2010
    I have one webservice: public class Product { public int ProductId { get; set; } public string ProductName { get; set; } } public class Service : System.Web.Services.WebService { public Service () { //Uncomment the following line if using designed components //InitializeComponent(); } [WebMethod] public List<Product> GetItems() { List<Product> productList = new List<Product>() { new Product{ProductId=1,ProductName="Pencil"}, new Product{ProductId=2,ProductName="Pen"} }; return productList; } and in a asp.net application I am consuming it like: localhost.Service s = new localhost.Service(); List<localhost.Product> k = new List<localhost.Product>(); k = s.GetItems().ToList(); // i am getting the values here. now my question is do I need to serialize my webmethod as i am returning custom types? when should we serialize ? is it necessary at all, if yes , then what are the conditions?

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  • How to make restrictions on XML Schema Complex type?

    - by chobo2
    Hi I am reading the tutorials on w3cschools ( http://www.w3schools.com/schema/schema_complex.asp ) but they don't seem to mention how you could add restrictions on complex types. Like for instance I have this schema. <xs:element name="employee"> <xs:complexType> <xs:sequence> <xs:element name="firstname" type="xs:string"/> <xs:element name="lastname" type="xs:string"/> </xs:sequence> </xs:complexType> </xs:element> now I want to make sure the firstname is no more then 10 characters long. How do I do this? I tried to put in the simple type for the firstname but it says I can't do that since I am using a complex type. So how do I put restrictions like that on the file so the people who I give the schema to don't try to make the firstname 100 characters.

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  • in haskell, why do I need to specify type constraints, why can't the compiler figure them out?

    - by Steve
    Consider the function, add a b = a + b This works: *Main> add 1 2 3 However, if I add a type signature specifying that I want to add things of the same type: add :: a -> a -> a add a b = a + b I get an error: test.hs:3:10: Could not deduce (Num a) from the context () arising from a use of `+' at test.hs:3:10-14 Possible fix: add (Num a) to the context of the type signature for `add' In the expression: a + b In the definition of `add': add a b = a + b So GHC clearly can deduce that I need the Num type constraint, since it just told me: add :: Num a => a -> a -> a add a b = a + b Works. Why does GHC require me to add the type constraint? If I'm doing generic programming, why can't it just work for anything that knows how to use the + operator? In C++ template programming, you can do this easily: #include <string> #include <cstdio> using namespace std; template<typename T> T add(T a, T b) { return a + b; } int main() { printf("%d, %f, %s\n", add(1, 2), add(1.0, 3.4), add(string("foo"), string("bar")).c_str()); return 0; } The compiler figures out the types of the arguments to add and generates a version of the function for that type. There seems to be a fundamental difference in Haskell's approach, can you describe it, and discuss the trade-offs? It seems to me like it would be resolved if GHC simply filled in the type constraint for me, since it obviously decided it was needed. Still, why the type constraint at all? Why not just compile successfully as long as the function is only used in a valid context where the arguments are in Num? Thank you.

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  • can I store an id value in array of float type ?

    - by srikanth rongali
    I used, for(id value in values) to get the value from an NSArray. Now I want to store it in 2 dimensional float array[][]. When I try to assign the values to array it is giving error:incompatible types in assignment. I tried to cast the value but I got error: pointer value used where a floating point value was expected. I need to store the values in an 2 dimensional array . How can I make it ? Thank You. @implementation fromFileRead1 NSString *fileNameString; int numberOfEnemies, numberOfValues; -(id)init { if( (self = [super init]) ) { NSString *path = @"/Users/sridhar/Desktop/Projects/exampleOnFile2/enemyDetals.txt"; NSString *contentsOfFile = [[NSString alloc] initWithContentsOfFile:path]; NSArray *lines = [contentsOfFile componentsSeparatedByString:@"\n"]; numberOfEnemies = [lines count]; NSLog(@"The number of Lines: %d", numberOfEnemies); for (id line in lines) { NSLog(@"Line %@", line ); NSString *string1 = line; NSArray *split1 = [string1 componentsSeparatedByString:@","]; numberOfValues = [split1 count]; NSLog(@"The number of values in Row: %d", numberOfValues); for (id value in split1) { NSLog(@"value %@", value); float value1; value1 = [split1 objectAtIndex:2]); NSLog(@"VAlue of Value1 at index 2: %f", value1 ); } } } return self; } @end In enemyDetal.txt I have 1,3,3 2,3,2.8 10,2,1.6

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  • Most Efficient way to deal with multiple CCSprites?

    - by nardsurfer
    I have four different types of objects within my environment(box2d), each type of object having multiple instances of itself, and would like to find the most efficient way to deal with adding and manipulating all the CCSprites. The sprites are all from different files, so would it be best to create each sprite and add it to a data structure (NSMutableArray) or would I use a CCSpriteBatchNode even though each CCSprite file is different (for each type of object)? Thanks. @interface LevelScene : CCLayer { b2World* world; GLESDebugDraw *m_debugDraw; CCSpriteBatchNode *ballBatch; CCSpriteBatchNode *blockBatch; CCSpriteBatchNode *springBatch; CCSprite *goal; } +(id) scene; // adds a new sprite at a given coordinate -(void) addNewBallWithCoords:(CGPoint)p; // loads the objects (blocks, springs, and the goal), returns the Level Object -(Level) loadLevel:(int)level; @end or using NSMutableArray objects within the Level object... @interface zLevel : zThing { NSMutableArray *springs; NSMutableArray *blocks; NSMutableArray *balls; zGoal *goal; int levelNumber; } @property(nonatomic,retain)NSMutableArray *springs; @property(nonatomic,retain)NSMutableArray *blocks; @property(nonatomic,retain)NSMutableArray *balls; @property(nonatomic,retain)zGoal *goal; @property(nonatomic,assign)int levelNumber; -(void)initWithLevel:(int)level; -(void)loadLevelThings; @end

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  • Switching Between Cards in a CardLayout using getParent()

    - by plutoisaplanet
    Hey everyone, I am writing an application where I am using the CardLayout to swap between two panels that are placed right on top of one another. There's a JPanel called Top, and it's layout is the CardLayout. Inside this JPanel is a JPanel called CMatch. Whenever the user clicks the submit button in the CMatch panel, I want a new JPanel added to Top that is custom built based on what the user types in, and it will be shown instead of the original CMatch panel. All of this done using the CardLayout. These are all different classes in different files, however (the panel Top with CardLayout, the panel CMatch that is inside the Top panel, and the custom built panel). So i tried using the following to add the new panel to the Top panel and then have it shown: (this code takes place in the CMatch class): private void submitButtionActionPerformed(ActionEvent e) { CardLayout cl = (CardLayout)(this.getParent().getLayout()); cl.addLayoutComponent(new CChoice(), "college_choices"); cl.show(this.getParent(), "college_choices"); } However, this didn't work. So i was wondering, what am I doing wrong? Any advice is greatly appreciated, thanks!

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  • Accessing both stored procedure output parameters AND the result set in Entity Framework?

    - by MS.
    Is there any way of accessing both a result set and output parameters from a stored procedure added in as a function import in an Entity Framework model? I am finding that if I set the return type to "None" such that the designer generated code ends up calling base.ExecuteFunction(...) that I can access the output parameters fine after calling the function (but of course not the result set). Conversely if I set the return type in the designer to a collection of complex types then the designer generated code calls base.ExecuteFunction<T>(...) and the result set is returned as ObjectResult<T> but then the value property for the ObjectParameter instances is NULL rather than containing the proper value that I can see being passed back in Profiler. I speculate the second method is perhaps calling a DataReader and not closing it. Is this a known issue? Any work arounds or alternative approaches? Edit My code currently looks like public IEnumerable<FooBar> GetFooBars( int? param1, string param2, DateTime from, DateTime to, out DateTime? createdDate, out DateTime? deletedDate) { var createdDateParam = new ObjectParameter("CreatedDate", typeof(DateTime)); var deletedDateParam = new ObjectParameter("DeletedDate", typeof(DateTime)); var fooBars = MyContext.GetFooBars(param1, param2, from, to, createdDateParam, deletedDateParam); createdDate = (DateTime?)(createdDateParam.Value == DBNull.Value ? null : createdDateParam.Value); deletedDate = (DateTime?)(deletedDateParam.Value == DBNull.Value ? null : deletedDateParam.Value); return fooBars; }

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  • VB.NET Button Issue

    - by Michael
    I am having problem with a button the code of my button is. Private Sub btnCalculateCosts_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCalculateCosts.Click it handles: ' This Calculate Costs button click event handler edits the ' registration(costs) form to ensure it contains valid data. ' Then, after passing control to the business class, it ' displays the registration cost. Dim objCourse As Course Dim objCourseCostsFile As Course Dim InputError As Boolean = False ' Is student ID entered properly If Me.txtCorporateID.MaskFull = False Then MessageBox.Show("Enter your Corporate ID in the Corporate ID box", _ "Error") Me.txtCorporateID.Clear() Me.txtCorporateID.Focus() InputError = True ' Is student name entered properly ElseIf Me.txtFirstName.TextLength < 1 Or _ Me.txtFirstName.Text < "A" Then MessageBox.Show("Please enter your first name in the First Name box", "Error") Me.txtFirstName.Clear() Me.txtFirstName.Focus() InputError = True ' Is number of units entered properly ElseIf Me.txtLastName.TextLength < 1 Or _ Me.txtLastName.Text < "A" Then MessageBox.Show("Please enter your last name in the Last Name box", "Error") Me.txtLastName.Clear() Me.txtLastName.Focus() InputError = True ' Is number of units entered properly ElseIf Not IsNumeric(Me.txtNumberOfDays.Text) Then MessageBox.Show("Enter the units in the Number of Units box", _ "Error") Me.txtNumberOfDays.Clear() Me.txtNumberOfDays.Focus() InputError = True ' Has 1-4 units been entered ElseIf Convert.ToInt32(Me.txtNumberOfDays.Text) < 1 _ Or Convert.ToInt32(Me.txtNumberOfDays.Text) > 4 Then MessageBox.Show("Units must be 1 - 4", "Error") Me.txtNumberOfDays.Clear() Me.txtNumberOfDays.Focus() InputError = True End If ' If no input error, process the registration costs If Not InputError Then If Me.radPreConferenceCourse.Checked = False Then objCourse = New Course(txtCorporateID.Text, txtFirstName.Text, txtLastName.Text, txtNumberOfDays.Text) Me.lblCosts.Visible = True Me.lblCosts.Text = "Total Conference Costs Are: " _ & (objCourse.ComputeCosts()).ToString("C2") Else objCourse = New Course(txtCorporateID.Text, txtFirstName.Text, txtLastName.Text, txtNumberOfDays.Text, g) Me.lblCosts.Visible = True Me.lblCosts.Text = "Total Conference Costs Are: " _ & (objCourse.ComputeCosts()).ToString("C2") Receiving the error: Handles clause requrieres a WithEvents variable defined in the containing type or one of its base types.

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  • Vector Usage in MPI(C++)

    - by lsk1985
    I am new to MPI programming,stiil learning , i was successful till creating the Derived data-types by defining the structures . Now i want to include Vector in my structure and want to send the data across the Process. for ex: struct Structure{ //Constructor Structure(): X(nodes),mass(nodes),ac(nodes) { //code to calculate the mass and accelerations } //Destructor Structure() {} //Variables double radius; double volume; vector<double> mass; vector<double> area; //and some other variables //Methods to calculate some physical properties Now using MPI i want to sent the data in the structure across the processes. Is it possible for me to create the MPI_type_struct vectors included and send the data? I tried reading through forums, but i am not able to get the clear picture from the responses given there. Hope i would be able to get a clear idea or approach to send the data PS: i can send the data individually , but its an overhead of sending the data using may MPI_Send/Recieve if we consider the domain very large(say 10000*10000)

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  • "Find all tiles connected to this one" project

    - by Omega
    Remember MS Paint? The bucket tool? If you used it and clicked on a pixel, all pixels connected to this pixel that are the same are affected. The theory is, I suppose, to check if there is any pixel adjacent to the selected one. If such pixel is the same type as the selected one, check for more adjacent pixels in this one, and so on. I want to implement something similar in VB.NET. Basically I have a 2D array map which represents the map. Let's assume there are only two types of tile: 0 and 1. Now, I got pretty much everything ready: I got my 2d map and I can tell which tile is clicked and tell what array indexes are the ones that represent such tile. Now for the "painting" process. Whenever I think about it, I can't figure a convenient way to execute such iteration. Can someone help me choosing a correct design/way/tip to achieve this?

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  • Troubleshooting multiple GET variables In PHP

    - by V413HAV
    This may be a very simple question but I don't what's the wrong thing am doing here... To explain you clearly, I've set a real simple example below: <ul> <li><a href="test.php?link1=true">Link 1</a></li> <li><a href="test.php?link2=true">Link 2</a></li> <li><a href="test.php?link3=true">Link 3</a></li> </ul> <?php if(isset($_GET['link1'])) { if(($_GET['link1']) == 'true') { echo 'This Is Link 1'; } } if(isset($_GET['link2'])) { if(($_GET['link2']) == 'true') { echo 'This Is Link 2'; } } if(isset($_GET['link3'])) { if(($_GET['link3']) == 'true') { echo 'This Is Link 3'; } } ?> This is a test.php page, here I've set 3 different arguments for $_GET, and show contents accordingly, now everything works perfect, the only thing am not understanding is how to block this kind of url say if user clicks on link 1 the url will be : http://localhost/test.php?link1=true And the Output of this url is This is Link 1 Now if I change this url to : http://localhost/test.php?link3=true&link2=true&link1=true And the Output what I get is This Is Link 1This Is Link 2This Is Link 3 Now this is ok here, but it's very annoying if someone types this and see's forms one below the other, any way I can stop this tampering?

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  • Memory allocation patterns in C++

    - by Mahatma
    I am confused about the memory allocation in C++ in terms of the memory areas such as Const data area, Stack, Heap, Freestore, Heap and Global/Static area. I would like to understand the memory allocation pattern in the following snippet. Can anyone help me to understand this. If there any thing more apart from the variable types mentioned in the example to help understand the concept better please alter the example. class FooBar { int n; //Stored in stack? public: int pubVar; //stored in stack? void foo(int param) //param stored in stack { int *pp = new int; //int is allocated on heap. n = param; static int nStat; //Stored in static area of memory int nLoc; //stored in stack? string str = "mystring"; //stored in stack? .. if(CONDITION) { static int nSIf; //stored in static area of memory int loopvar; //stored in stack .. } } } int main(int) { Foobar bar; //bar stored in stack? or a part of it? Foobar *pBar; //pBar is stored in stack pBar = new Foobar(); //the object is created in heap? What part of the object is stored on heap } EDIT: What confuses me is, if pBar = new Foobar(); stores the object on the heap, how come int nLoc; and int pubVar;, that are components of the object stored on stack? Sounds contradictory to me. Shouldn't the lifetime of pubvar and pBar be the same?

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  • Prevent coersion to a single type in unlist() or c(); passing arguments to wrapper functions

    - by Leo Alekseyev
    Is there a simple way to flatten a list while retaining the original types of list constituents?.. Is there a way to programmatically construct a heterogeneous list?.. For instance, I want to create a simple wrapper for functions like png(filename,width,height) that would take device name, file name, and a list of options. The naive approach would be something like my.wrapper <- function(dev,name,opts) { do.call(dev,c(filename=name,opts)) } or similar code with unlist(list(...)). This doesn't work because opts gets coerced to character, and the resulting call is e.g. png(filename,width="500",height="500"). If there's no straightforward way to create heterogeneous lists like that, is there a standard idiomatic way to splice arguments into functions without naming them explicitly (e.g. do.call(dev,list(filename=name,width=opts["width"]))? -- Edit -- Gavin Simpson answered both questions below in his discussion about constructing wrapper functions. Let me give a summary of the answer to the title question: It is possible to construct a heterogeneous list with c() provided the arguments to c() are lists. To wit: > foo <- c("a","b"); bar <- 1:3 > c(foo,bar) [1] "a" "b" "1" "2" "3" > c(list(foo),list(bar)) [[1]] [1] "a" "b" [[2]] [1] 1 2 3 > c(as.list(foo),as.list(bar)) ## this creates a flattened heterogeneous list [[1]] [1] "a" [[2]] [1] "b" [[3]] [1] 1 [[4]] [1] 2 [[5]] [1] 3

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  • "pseudo-atomic" operations in C++

    - by dan
    So I'm aware that nothing is atomic in C++. But I'm trying to figure out if there are any "pseudo-atomic" assumptions I can make. The reason is that I want to avoid using mutexes in some simple situations where I only need very weak guarantees. 1) Suppose I have globally defined volatile bool b, which initially I set true. Then I launch a thread which executes a loop while(b) doSomething(); Meanwhile, in another thread, I execute b=true. Can I assume that the first thread will continue to execute? In other words, if b starts out as true, and the first thread checks the value of b at the same time as the second thread assigns b=true, can I assume that the first thread will read the value of b as true? Or is it possible that at some intermediate point of the assignment b=true, the value of b might be read as false? 2) Now suppose that b is initially false. Then the first thread executes bool b1=b; bool b2=b; if(b1 && !b2) bad(); while the second thread executes b=true. Can I assume that bad() never gets called? 3) What about an int or other builtin types: suppose I have volatile int i, which is initially (say) 7, and then I assign i=7. Can I assume that, at any time during this operation, from any thread, the value of i will be equal to 7? 4) I have volatile int i=7, and then I execute i++ from some thread, and all other threads only read the value of i. Can I assume that i never has any value, in any thread, except for either 7 or 8? 5) I have volatile int i, from one thread I execute i=7, and from another I execute i=8. Afterwards, is i guaranteed to be either 7 or 8 (or whatever two values I have chosen to assign)?

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  • Using MPI_Type_Vector and MPI_Gather, in C.

    - by Goloneg
    Hi, I am trying to multiply square matrices in parallele with MPI. I use a MPI_Type_vector to send square submatrixes (arrays of float) to the processes, so they can calculate subproducts. Then, for the next iterations, these submatrices are send to neighbours processes as MPI_Type_contiguous (the whole submatrix is sent). This part is working as expected, and local results are corrects. Then, I use MPI_Gather with the contiguous types to send all local results back to the root process. The problem is, the final matrix is build (obviously, by this method) line by line instead of submatrix by submatrix. I wrote an ugly procedure rearranging the final matrix, but I would like to know if there is a direct way of performing the "inverse" operation of sending MPI_Type_vectors (i.e., sending an array of values and directly arranging it in a subarray form in the receiving array). An example, to try and clarify my long text : A[16] and B[16] are 4x4 matrices to be multiplied ; C[16] will contain the result ; 4 processes are used (Pi with i from 0 to 3) : Pi gets two 2x2 submatrices : subAi[4] and subBi[4] ; their product is stored locally in subCi[4]. For instance, P0 gets : subA0[4] containing A[0], A[1], A[4] and A[5] ; subB0[4] containing B[0], B[1], B[4] and B[5]. After everything is calculed, root process gathers all subCi[4]. Then C[16] contains : [ subC0[0], subC0[1], subC0[2], subC0[3], subC1[0], subC1[1], subC1[2], subC1[3], subC2[0], subC2[1], subC2[2], subC2[3], subC3[0], subC3[1], subC3[2], subC3[3]] and I would like it to be : [ subC0[0], subC0[1], subC1[0], subC1[1], subC0[2], subC0[3], subC1[2], subC1[3], subC2[0], subC2[1], subC3[0], subC3[1], subC2[2], subC2[3], subC3[2], subC3[3]] without further operation. Does someone know a way ? Thanks for your advices.

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  • Alternative to Altova's MissionKit

    - by nomad311
    Anyone know of any good alternatives (other than those listed below which really are only good at specific XML development tasks)? The Why (if you're interested): I've been doing XML development on and off for years now, but someone brought XMLSpy to my attention recently, and it is awesome - the price isn't. Lately I've been using a combination of: Notepad++ (modifying XML) EditX (validating/debugging XML) Eclipse (designing schemas) and MS Visual Studio (validating schemas) ...based on which makes the task(s) easiest. But, I've just found out that we will be using XSL transformations to generate XML in the future. I've never used mission kit before, but I'm just short of positive XMLSpy replaces all the above mentioned tool for XML development. And if their XSL tools are anywhere near the caliber of XMLSpy ...simply put I need it. I don't believe that I can convince the budgeting types to buy licenses for MissionKit at $1000 each (won't stop me from trying). In the mean while some research on alternatives won't hurt, but a few Google queries has only revealed that not many people pay for Altova's (overpriced?) software as there are mostly links to P2P sites for downloading a more free-like version of MissionKit.

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  • Are there any other ways to iterate through the attributes of a custom class, excluding the in-built ones?

    - by Ricardo Altamirano
    Is there another way to iterate through only the attributes of a custom class that are not in-built (e.g. __dict__, __module__, etc.)? For example, in this code: class Terrain: WATER = -1 GRASS = 0 HILL = 1 MOUNTAIN = 2 I can iterate through all of these attributes like this: for key, value in Terrain.__dict__.items(): print("{: <11}".format(key), " --> ", value) which outputs: MOUNTAIN --> 2 __module__ --> __main__ WATER --> -1 HILL --> 1 __dict__ --> <attribute '__dict__' of 'Terrain' objects> GRASS --> 0 __weakref__ --> <attribute '__weakref__' of 'Terrain' objects> __doc__ --> None If I just want the integer arguments (a rudimentary version of an enumerated type), I can use this: for key, value in Terrain.__dict__.items(): if type(value) is int: # type(value) == int print("{: <11}".format(key), " --> ", value) this gives the expected result: MOUNTAIN --> 2 WATER --> -1 HILL --> 1 GRASS --> 0 Is it possible to iterate through only the non-in-built attributes of a custom class independent of type, e.g. if the attributes are not all integral. Presumably I could expand the conditional to include more types, but I want to know if there are other ways I'm missing.

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  • .htaccess trickery multi-language website

    - by user1658741
    I have a website right now that uses two languages (french and english) The way it works right now is that if someone goes to mysite.com/folder/file.php for example, file.php is simply a script that figures out which language to use, get's it's own path and filename(file.php) and serves up mysite.com/en/folder/file.php (if the language is english). However what shows up in the URL is still mysite.com/folder/file.php. For any folder and any file the same script is used. If I want to add a new file I have to add the file to the folder the user types into the browser as well to the en and fr folders. Could I do some .htaccess trickery so that whatever URL is typed, one .php file gets open that checks the language and what folder/file was requested and then serves up the correct language file? here's the php file that is served up for any files in the URL. <?php // Get current document path which is mirrored in the language folders $docpath = $_SERVER['PHP_SELF']; // Get current document name (Used when switching languages so that the same current page is shown when language is changed) $docname = GetDocName(); //call up lang.php which handles display of appropriate language webpage. //lang.php uses $docpath and $docname to give out the proper $langfile. //$docpath/$docname is mirrored in the /lang/en and /lang/fr folders $langfile = GetDocRoot()."/lang/lang.php"; include("$langfile"); //Call up the proper language file to display function GetDocRoot() { $temp = getenv("SCRIPT_NAME"); $localpath=realpath(basename(getenv("SCRIPT_NAME"))); $localpath=str_replace("\\","/",$localpath); $docroot=substr($localpath,0, strpos($localpath,$temp)); return $docroot; } function GetDocName() { $currentFile = $_SERVER["SCRIPT_NAME"]; $parts = Explode('/', $currentFile); $dn = $parts[count($parts) - 1]; return $dn; } ?>

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  • Best practice when removing entity regarding mappedBy collections?

    - by Daniel Bleisteiner
    I'm still kind of undecided which is the best practice to handle em.remove(entity) with this entity being in several collections mapped using mappedBy in JPA. Consider an entity like a Property that references three other entities: a Descriptor, a BusinessObject and a Level entity. The mapping is defined using @ManyToOne in the Property entity and using @OneToMany(mappedBy...) in the other three objects. That inverse mapping is defined because there are some situations where I need to access those collections. Whenever I remove a Property using em.remove(prop) this element is not automatically removed from managed entities of the other three types. If I don't care about that and the following page load (webapp) doesn't reload those entities the Property is still found and some decisions might be taken that are no longer true. The inverse mappings may become quite large and though I don't want to use something like descriptor.getProperties().remove(prop) because it will load all those properties that might have been lazy loaded until then. So my currently preferred way is to refresh the entity if it is managed: if (em.contains(descriptor)) em.refresh(descriptor) - which unloads a possibly loaded collection and triggers a reload upon the next access. Is there another feasible way to handle all those mappedBy collections of already loaded entites?

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  • problem with a string's format in c++ while doing tcp communication

    - by james t
    hi, i am building a simple c++ client, i am splitting the info i get from the server to frames, and pass each frame to a function that processes it, i split the frame into lines using Poco::StringTokenizer tokenizer(frame, "\n"); i take the first line of the tokenizer which represents the type of frame StmpCommand command(tokenizer[0]); a StmpCommand is an enum with the different types of messages and the constructor works as follows : StmpCommand(std::string command): commandType_() { bool x=command=="CONNECTED"; std::cout<<x<<std::endl; if ("SUBSCRIBE" == command) commandType_ = SUBSCRIBE; else if ("UNSUBSCRIBE" == command) commandType_ = UNSUBSCRIBE; else if ("SEND" == command) commandType_ = SEND; else if ("BEGIN" == command) commandType_ = BEGIN; else if ("COMMIT" == command) commandType_ = COMMIT; else if ("CONNECT" == command) commandType_ = CONNECT; else if ("MESSAGE" == command) commandType_ = MESSAGE; else if ("RECEIPT" == command) commandType_ = RECEIPT; else if ("CONNECTED" == command) commandType_ = CONNECTED; else if ("DISCONNECT" == command) commandType_ = DISCONNECT; else if ("ERROR" == command) commandType_ = ERROR; else { std::cerr<<"Error in building StmpCommand object, unknown type - "<<command<<std::endl; } } the first frame i am trying to proccess is a CONNECTED frame therefor i try to create a StmpCommand with CONNECTED as the constructor's only argument and for some reason i am getting an : Error in building StmpCommand object, unknown type - CONNECTED i am clearly passing a string containing CONNECTED but i'm guessing there is something else there that isn't allowing the condition else if ("CONNECTED" == command) to hap

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  • Is this a good way to generically deserialize objects?

    - by Damien Wildfire
    I have a stream onto which serialized objects representing messages are dumped periodically. The objects are one of a very limited number of types, and other than the actual sequence of bytes that arrives, I have no way of knowing what type of message it is. I would like to simply try to deserialize it as an object of a particular type, and if an exception is thrown, try again with the next type. I have an interface that looks like this: public interface IMessageHandler<T> where T : class, IMessage { T Handle(string message); } // elsewhere: // (These are all xsd.exe-generated classes from an XML schema.) public class AppleMessage : IMessage { ... } public class BananaMessage : IMessage { ... } public class CoconutMessage : IMessage { ... } Then I wrote a GenericHandler<T> that looks like this: public class GenericHandler<T> : IMessageHandler<T> where T: class, IMessage { public class MessageHandler : IMessageHandler { T IMessageHandler.Handle(string message) { T result = default(T); try { // This utility method tries to deserialize the object with an // XmlSerializer as if it were an object of type T. result = Utils.SerializationHelper.Deserialize<T>(message); } catch (InvalidCastException e) { result = default(T); } return result; } } } Two questions: Using my GenericHandler<T> (or something similar to it), I'd now like to populate a collection with handlers that each handle a different type. Then I want to invoke each handler's Handle method on a particular message to see if it can be deserialized. If I get a null result, move onto the next handler; otherwise, the message has been deserialized. Can this be done? Is there a better way to deserialize data of unknown (but restricted) type?

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  • Nginx Rails app can't deploy

    - by user3596718
    I have an issue with my rails application running with passenger and nginx hosted in Ubuntu 12.04. In the nginx.conf file below, my "example.com" (Regular HTML) and "redmine.example.com" (Rails app) are working perfectly, but my "crete.example.com" (Another Rails app) is showing "502 bad gateway". I have them both hosted in /var/data with the same permissions and ownerships, also tried different ports, I can't think of something else to try. worker_processes 1; events { worker_connections 1024; } http { passenger_root /usr/lib/ruby/vendor_ruby/phusion_passenger/locations.ini; include mime.types; default_type application/octet-stream; sendfile on; keepalive_timeout 65; server{ listen 80; server_name example.com; root /opt/nginx/html; } server{ server_name redmine.example.com; root /var/data/redmine/public; passenger_enabled on; location ~ ^/<SUBURI>(/.*|$){ alias /var/data/redmine/public$1; passenger_base_uri /redmine; passenger_app_root /var/data/redmine; passenger_document_root /var/data/redmine/public; passenger_enabled on;} } server{ server_name crete.example.com; root /var/data/crete/public; passenger_enabled on; location ~ ^/<SUBURI>(/.*|$){ alias /var/data/crete/public$1; passenger_base_uri /crete; passenger_app_root /var/data/crete; passenger_document_root /var/data/crete/public; passenger_enabled on;} } } This are my Ruby and Rails versions: ruby 2.0.0p451 (2014-02-24 revision 45167) [x86_64-linux] Rails 4.1.0 My nginx error.log 2014/05/02 12:29:50 [error] 3343#0: *4 upstream prematurely closed connection while reading response header from upstream, client: xxx.xx.xx.xx, server: crete.example.com, request: "GET / HTTP/1.1", upstream: "passenger:/tmp/passenger.1.0.3 323/generation-0/request:", host: "crete.example.com" Any other conf file you might need to solve this don't hesitate to ask.

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  • Designing a database for a user/points system? (in Django)

    - by AP257
    First of all, sorry if this isn't an appropriate question for StackOverflow. I've tried to make it as generalisable as possible. I want to create a database (MySQL, site running Django) that has users, who can be allocated a certain number of points for various types of action - it's a collaborative game. My requirements are to obtain: the number of points a user has the user's ranking compared to all other users and the overall leaderboard (i.e. all users ranked in order of points) This is what I have so far, in my Django models.py file: class SiteUser(models.Model): name = models.CharField(max_length=250 ) email = models.EmailField(max_length=250 ) date_added = models.DateTimeField(auto_now_add=True) def points_total(self): points_added = PointsAdded.objects.filter(user=self) points_total = 0 for point in points_added: points_total += point.points return points_total class PointsAdded(models.Model): user = models.ForeignKey('SiteUser') action = models.ForeignKey('Action') date_added = models.DateTimeField(auto_now_add=True) def points(self): points = Action.objects.filter(action=self.action) return points class Action(models.Model): points = models.IntegerField() action = models.CharField(max_length=36) However it's rapidly becoming clear to me that it's actually quite complex (in Django query terms at least) to figure out the user's ranking and return the leaderboard of users. At least, I'm finding it tough. Is there a more elegant way to do something like this? This question seems to suggest that I shouldn't even have a separate points table - what do people think? It feels more robust to have separate tables, but I don't have much experience of database design.

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  • C++ traits question

    - by duli
    I have a templated class template <typename Data> class C { ..... } In most situations, I depend on the compiler to let me substitute types for Data. I call methods foo(), goo() on objects of type Data, so what I substitute needs to provide that. I now need to substitute int and string for my Data type. I do not want to specialize because the class is already too big and would require specializing each method (with only small code change). My options (please tell me if there are more) 1) I can provide wrapper classes around int and string which implement the methods foo(), goo() etc 2) provide a traits class traits that calls foo() or goo() on objects of classes that provide foo(),goo() (these are my present substitutable classes) and specialize these classes for int and string. Questions 1) what are the relative merits of 1 vs 2? 2) My traits classes will have static methods. Can a traits class have non-static methods as well? I see most traits classes define constants in the STL. 3) Do I make the traits classes global or should I pass them in as a template parameter for class C?

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  • Getting the current item number or index when using will_paginate in rails app

    - by Rich
    I have a rails app that stores movies watched, books read, etc. The index page for each type lists paged collections of all its items, using will_paginate to bring back 50 items per page. When I output the items I want to display a number to indicate what item in the total collection it is. The numbering should be reversed as the collection is displayed with most recent first. This might not relate to will_paginate but rather some other method of calculation. I will be using the same ordering in multiple types so it will need to be reusable. As an example, say I have 51 movies. The first item of the first page should display: Fight Club - Watched: 30th Dec 2010 Whilst the last item on the page should display: The Matrix - Watched: 3rd Jan 2010 The paged collection is available as an instance variable e.g. @movies, and @movies.count will display the number of items in the paged collection. So if we're on page 1, movies.count == 50, whilst on page 2 @movies.count == 1. Using Movie.count would give 51. If the page number and page size can be accessed the number could be calculated so how can they be returned? Though I'm hopeful there is something that already exists to handle this calculation!

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