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• How to calculate the normal of points on a 3D cubic Bézier curve given normals for its start and end points?

  - by Robert

  I'm trying to render a "3D ribbon" using a single 3D cubic Bézier curve to describe it (the width of the ribbon is some constant). The first and last control points have a normal vector associated with them (which are always perpendicular to the tangents at those points, and describe the surface normal of the ribbon at those points), and I'm trying to smoothly interpolate the normal vector over the course of the curve. For example, given a curve which forms the letter 'C', with the first and last control points both having surface normals pointing upwards, the ribbon should start flat, parallel to the ground, slowly turn, and then end flat again, facing the same way as the first control point. To do this "smoothly", it would have to face outwards half-way through the curve. At the moment (for this case), I've only been able to get all the surfaces facing upwards (and not outwards in the middle), which creates an ugly transition in the middle. It's quite hard to explain, I've attached some images below of this example with what it currently looks like (all surfaces facing upwards, sharp flip in the middle) and what it should look like (smooth transition, surfaces slowly rotate round). Silver faces represent the front, black faces the back. Incorrect, what it currently looks like: Correct, what it should look like: All I really need is to be able to calculate this "hybrid normal vector" for any point on the 3D cubic bézier curve, and I can generate the polygons no problem, but I can't work out how to get them to smoothly rotate round as depicted. Completely stuck as to how to proceed!

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• ASP.NET: I'm getting strange output when styling a Label control...

  - by pkiyan

  .labelOne { border-width:thin; border-style:solid; border-color:Red; background-color:Silver; } <asp:Label ID="Label1" runat="server" CssClass="labelOne"> <h1>Hello world</h1> </asp:Label> <br /><br /> <asp:Label ID="Label2" runat="server" BorderColor="Black" BorderStyle="Solid" BorderWidth="1px" BackColor="Silver"> <h1>Hello world</h1> </asp:Label> Hello. In the code sample above I have 2 Label controls with their contents set to an h1 header tag. The first Label is styled using css, and the second with the Label's inline properties (both Labels have identical styling). But the first Label doesn't output properly, it's border is broken. If I replace the first Label's markup with plain "Hello world" text it renders properly, but it breaks again when I use markup. Can someone explain why this is happening?

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• Windows Server 2008 R2 File Permissions

  - by Fly_Trap

  I’m having some problems understanding some particular file permissions behaviour. Here are the steps to reproduce: Log into the server using the default Administrator account Create a text file (testfile.txt) in C:\ProgramData containing some arbitrary text Create a new user account and make it a member of the Administrators group Log in using new account and open C:\ProgramData\testfile.txt Edit the text and try to save Upon clicking save I’m presented with the save as dialog, which indicates that i do not have the necessary permissions to edit the file. This seems odd considering that the new user account is a member of Administrators. When I view the permissions of the file I can see the there are three groups listed, System, Administrators and Users. SYSTEM and Administrators have full permissions, however, Users only has the Read & Execute and Read permissions checked. It would appear that when I open the testfile.txt from the new users account, it opens in the context of the Users group, despite being a member of Administrators, is this correct? It would certainly explain the behaviour. The reason that this is an issue for me is that if I deploy an application via 'Run as Administrator', will normal users be able to edit the text files I install to ProgramData. Is this behaviour confined to Windows server or is it the same in Vista and Win7.

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• accessing private variable from member function in PHP

  - by Carson Myers

  I have derived a class from Exception, basically like so: class MyException extends Exception { private $_type; public function type() { return $this->_type; //line 74 } public function __toString() { include "sometemplate.php"; return ""; } } Then, I derived from MyException like so: class SpecialException extends MyException { private $_type = "superspecial"; } If I throw new SpecialException("bla") from a function, catch it, and go echo $e, then the __toString function should load a template, display that, and then not actually return anything to echo. This is basically what's in the template file <div class="<?php echo $this->type(); ?>class"> <p> <?php echo $this->message; ?> </p> </div> in my mind, this should definitely work. However, I get the following error when an exception is thrown and I try to display it: Fatal error: Cannot access private property SpecialException::$_type in C:\path\to\exceptions.php on line 74 Can anyone explain why I am breaking the rules here? Am I doing something horribly witty with this code? Is there a much more idiomatic way to handle this situation? The point of the $_type variable is (as shown) that I want a different div class to be used depending on the type of exception caught.

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• jquery callback functions failing to finish execution

  - by calumbrodie

  I'm testing a jquery app i've written and have come across some unexpected behaviour $('button.clickme').live('click',function(){ //do x (takes 2 seconds) //do y (takes 4 seconds) //do z (takes 0.5 seconds) }) The event can be triggered by a number of buttons. What I'm finding is that when I click each button slowly (allowing 10 seconds between clicks) - my callback function executes correctly (actions x, y & z complete). However If I rapidly click buttons on my page it appears that the function sometimes only completes up to step x or y before terminating. My question: Is it the case that if this function is fired by a clicking second DOM element, while the first callback function is completing - will jQuery terminate the first callback and start over again? Do I have to write my callback function explicitly outside the event handler and then call it?? function doStuff() { //do x //do y //do z ( } $('button.clickme).live('click',doStuff()) If this is the case can someone explain why this is happening or give me a link to some advice on best practice on closures etc - I'd like to know the BEST way to write jQuery to improve performance etc. Thanks

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• Strange results from OdbcDataReader reading Sqlite DB

  - by stout

  This method returns some strange results, and was wondering if someone could explain why this is happening, and possibly a solution to get my desired results. Results: FileName = what I'd expect FileSize = what I'd expect Buffer = all bytes = 0 BytesRead = 0 BlobString = string of binary data FieldType = BLOB (what I'd expect) ColumnType = System.String Furthermore, if the file is greater than a few KB, the reader throws an exception stating the StringBuilder capacity argument must be greater than zero (presummably because the size is greater than Int32.MaxValue). I guess my question is how does one properly read large BLOBs from an OdbcDataReader? public static String SaveBinaryFile(String Key) { try { Connect(); OdbcCommand Command = new OdbcCommand("SELECT [_filename_],[_filesize_],[_content_] FROM [_sys_content] WHERE [_key_] = '" + Key + "';", Connection); OdbcDataReader Reader = Command.ExecuteReader(CommandBehavior.SequentialAccess); if (Reader.HasRows == false) return null; String FileName = Reader.GetString(0); int FileSize = int.Parse(Reader.GetString(1)); byte[] Buffer = new byte[FileSize]; long BytesRead = Reader.GetBytes(2, 0, Buffer, 0, FileSize); String BlobString = (String)Reader["_content_"]; String FieldType = Reader.GetDataTypeName(2); Type ColumnType = Reader.GetFieldType(2); return null; } catch (Exception ex) { Tools.ErrorHandler.Catch(ex); return null; } }

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• Long running method causing race condition

  - by keeleyt83

  Hi, I'm relatively new with hibernate so please be gentle. I'm having an issue with a long running method (~2 min long) and changing the value of a status field on an object stored in the DB. The pseudo-code below should help explain my issue. public foo(thing) { if (thing.getStatus() == "ready") { thing.setStatus("finished"); doSomethingAndTakeALongTime(); } else { // Thing already has a status of finished. Send the user back a message. } } The pseudo-code shouldn't take much explanation. I want doSomethingAndTakeALongTime() to run, but only if it has a status of "ready". My issue arises whenever it takes 2 minutes for doSomethingAndTakeALongTime() to finish and the change to thing's status field doesn't get persisted to the database until it leaves foo(). So another user can put in a request during those 2 minutes and the if statement will evaluate to true. I've already tried updating the field and flushing the session manually, but it didn't seem to work. I'm not sure what to do from here and would appreciate any help. PS: My hibernate session is managed by spring.

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• Android: Adding header to dynamic listView

  - by cg5572

  I'm still pretty new to android coding, and trying to figure things out. I'm creating a listview dynamically as shown below (and then disabling items dynamically also) - you'll notice that there's no xml file for the activity itself, just for the listitem. What I'd like to do is add a static header to the page. Could someone explain to me how I can modify the code below to EITHER add this programatically within the java file, before the listView, OR edit the code below so that it targets a listView within an xml file! Help would be much appreciated!!! public class Start extends ListActivity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); DataBaseHelper myDbHelper = new DataBaseHelper(null); myDbHelper = new DataBaseHelper(this); try { myDbHelper.openDataBase(); }catch(SQLException sqle){ throw sqle; } ArrayList<String> categoryList = new ArrayList<String>(); Cursor cur = myDbHelper.getAllCategories(); cur.moveToFirst(); while (cur.isAfterLast() == false) { if (!categoryList.contains(cur.getString(1))) { categoryList.add(cur.getString(1)); } cur.moveToNext(); } cur.close(); Collections.sort(categoryList); setListAdapter(new ArrayAdapter<String>(this, R.layout.listitem, categoryList) { @Override public View getView(int position, View convertView, ViewGroup parent) { View view = super.getView(position, convertView, parent); if(Arrays.asList(checkArray3).contains(String.valueOf(position))){ view.setEnabled(false); } else { view.setEnabled(true); } return view; } }); } @Override protected void onListItemClick(ListView l, View v, int position, long id) { if(v.isEnabled()) { String clickedCat = l.getItemAtPosition(position).toString(); Toast.makeText(this, clickedCat, Toast.LENGTH_SHORT).show(); finish(); Intent myIntent = new Intent(getApplicationContext(), Questions.class); myIntent.putExtra("passedCategory", clickedCat); myIntent.putExtra("startTrigger", "go"); startActivity(myIntent); } } }

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• _beginthreadx and socket

  - by user638197

  hi, i have a question about the _beginthreadx function In the third and fourth parameter: if i have this line to create the thread hThread=(HANDLE)_beginthreadex(0,0, &RunThread, &m_socket,CREATE_SUSPENDED,&threadID ); m_socket is the socket that i want inside the thread (fourth parameter) and i have the RunThread function (third parameter) in this way static unsigned __stdcall RunThread (void* ptr) { return 0; } It is sufficient to create the thread independently if m_socket has something or not? Thanks in advance Thank you for the response Ciaran Keating helped me understand better the thread I'll explain a little more the situation I´m creating the tread in this function inside a class public: void getClientsConnection() { numberOfClients = 1; SOCKET temporalSocket = NULL; firstClient = NULL; secondClient = NULL; while (numberOfClients < 2) { temporalSocket = SOCKET_ERROR; while (temporalSocket == SOCKET_ERROR) { temporalSocket = accept(m_socket, NULL, NULL); //----------------------------------------------- HANDLE hThread; unsigned threadID; hThread=(HANDLE)_beginthreadex(0,0, &RunThread, &m_socket,CREATE_SUSPENDED,&threadID ); WaitForSingleObject( hThread, INFINITE ); if(!hThread) printf("ERROR AL CREAR EL HILO: %ld\n", WSAGetLastError()); //----------------------------------------------- } if(firstClient == NULL) { firstClient = temporalSocket; muebleC1 = temporalSocket; actionC1 = temporalSocket; ++numberOfClients; printf("CLIENTE 1 CONECTADO\n"); } else { secondClient = temporalSocket; muebleC2 = temporalSocket; actionC2 = temporalSocket; ++numberOfClients; printf("CLIENTE 2 CONECTADO\n"); } } } What i'm trying to do is to have the socket inside the thread while wait for a client connection Is this feasible as i have the code of the thread? I can change the state of the thread that is not a problem Thanks again

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• html doctype adds whitespace ??

  - by pstanton

  can someone please explain to me why having a doctype of <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> and <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"> render the following block differently under firefox? <table style="border-collapse:collapse; margin:0; padding:0;"> <tr> <td style="border:1px solid red; margin:0; padding:0;"><img src="http://images.smh.com.au/2010/06/01/1533814/th_park-90x60.jpg" style="border:none; padding:0; margin:0;" /></td> </tr> </table> using 'Transitional', there is no white space below the image, using 'Strict' there is! 2nd question, using strict, is it at all possible to remove this whitespace?

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• Which function pair in QString to use for converting to/from std::string?

  - by Noah Roberts

  I'm working on a project that we want to use Unicode and could end up in countries like Japan, etc... We want to use std::string for the underlying type that holds string data in the data layer (see Qt, MSVC, and /Zc:wchar_t- == I want to blow up the world as to why). The problem is that I'm not completely sure which function pair (to/from) to use for this and be sure we're 100% compatible with anything the user might enter in the Qt layer. A look at to/fromStdString indicates that I'd have to use setCodecForCStrings. The documentation for that function though indicates that I wouldn't want to do this for things like Japanese. This is the set that I'd LIKE to use though. Does someone know enough to explain how I'd set this up if it's possible? The other option that looks like I could be pretty sure of it working is the to/fromUTF8 functions. Those would require a two step approach though so I'd prefer the other if possible. Is there anything I've missed?

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• Doubly Linked Lists Implementation

  - by user552127

  Hi All, I have looked at most threads here about Doubly linked lists but still unclear about the following. I am practicing the Goodrich and Tamassia book in Java. About doubly linked lists, please correct me if I am wrong, it is different from a singly linked list in that a node could be inserted anywhere, not just after the head or after the tail using both the next and prev nodes available, while in singly linked lists, this insertion anywhere in the list is not possible ? If one wants to insert a node in a doubly linked list, then the default argument should be either the node after the to-be inserted node or node before the to-be inserted node ? But if this is so, then I don't understand how to pass the node before or after. Should we be displaying all nodes that were inserted till now and ask the user to select the node before or after which some new node is to be inserted ? My doubt is how to pass this default node. Because I assume that will require the next and prev nodes of these nodes as well. For e.g, Head<-A<-B<-C<-D<-E<-tail If Z is the new node to be inserted after say D, then how should node D be passed ? I am confused with this though it seems pretty simple to most. But pl do explain. Thanks, Sanjay

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• How do virtual destructors work?

  - by Prabhu

  Few hours back I was fiddling with a Memory Leak issue and it turned out that I really got some basic stuff about virtual destructors wrong! Let me put explain my class design. class Base { virtual push_elements() {} }; class Derived:public Base { vector<int> x; public: void push_elements(){ for(int i=0;i <5;i++) x.push_back(i); } }; void main() { Base* b = new Derived(); b->push_elements(); delete b; } The bounds checker tool reported a memory leak in the derived class vector. And I figured out that the destructor is not virtual and the derived class destructor is not called. And it surprisingly got fixed when I made the destructor virtual. Isn't the vector deallocated automatically even if the derived class destructor is not called? Is that a quirk in BoundsChecker tool or is my understanding of virtual destructor wrong?

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• Accessing a struct collection property from within another collection

  - by paddyb

  I have a struct that I need to store in a collection. The struct has a property that returns a Dictionary. public struct Item { private IDictionary<string, string> values; public IDictionary<string, string> Values { get { return this.values ?? (this.values = new Dictionary<string, string>()); } } } public class ItemCollection : Collection<Item> {} When testing I've found that if I add the item to the collection and then try to access the dictionary the structs values property is never updated. var collection = new ItemCollection { new Item() }; // pre-loaded with an item collection[0].Values.Add("myKey", "myValue"); Trace.WriteLine(collection[0].Values["myKey"]); // KeyNotFoundException here However if I load up the item first and then add it to a collection the values field is maintained. var collection = new ItemCollection(); var item = new Item(); item.Values.Add("myKey", "myValue"); collection.Add(item); Trace.WriteLine(collection[0].Values["myKey"]); // ok I've already decided that a struct is the wrong option for this type, and when using a class the issue doesn't occur, but I'm curious what's different between the two methods. Can anybody explain what's happening?

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• When I Add <DIV> Bottom Scroll Bar Appears, Even Though It Is Not Greater Than The Page Width

  - by Clay Dempsey

  I have searched for this with no answer. My page loads up perfectly when I load the header, navigation and then center image...all 3 different divs. However I have more I need to add and the div tags change the size of the page even though the css I'm using isn't larger than the page. I have no idea what is happening. Here's the code page where everything is fine: http://www.thehdmgroup.com/midwaymissionary/test.php When I add the below div tag with the below css I get a bottom scrollbar on the page and I don't know why. Can someone please explain it to me? #middleTextBox1 { position: absolute; top:507px; left:172px; width:180px; height:180px; background-color:#411b42; border: 1px solid #434343; padding:10px; color: #FFFFFF; font-size: 10px; font-family: Arial, Helvetica, sans-serif; } <div id="middleTextBox1"> <h3 align="center">Mission:</h3> Words </div> I really have no idea why this is happening, could someone please help me out? Thanks for your time.

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• Why is Func<T> ambiguous with Func<IEnumerable<T>>?

  - by Matt Hamilton

  This one's got me flummoxed, so I thought I'd ask here in the hope that a C# guru can explain it to me. Why does this code generate an error? class Program { static void Main(string[] args) { Foo(X); // the error is on this line } static String X() { return "Test"; } static void Foo(Func<IEnumerable<String>> x) { } static void Foo(Func<String> x) { } } The error in question: Error 1 The call is ambiguous between the following methods or properties: 'ConsoleApplication1.Program.Foo(System.Func<System.Collections.Generic.IEnumerable<string>>)' and 'ConsoleApplication1.Program.Foo(System.Func<string>)' C:\Users\mabster\AppData\Local\Temporary Projects\ConsoleApplication1\Program.cs 12 13 ConsoleApplication1 It doesn't matter what type I use - if you replace the "String" declarations with "int" in that code you'll get the same sort of error. It's like the compiler can't tell the difference between Func<T> and Func<IEnumerable<T>>. Can someone shed some light on this?

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• Get settings through a button action

  - by Russ Knudsen

  I am looking for a way to access user settings (I assume, NSUserDefaults?) through a button action. Let me back up and explain. What I have right now are 2 TextFields a label and a button. The user will type in measurements in the 2 TextFields. When they hit the button the label displays the volume of the measured object in Gallons. That part of it works great. Then I wanted to give the user options to output the volume in Liters instead of gallons. I would also like to give the user options to type in the measurements in Centimeters. So I setup a 'Settings.Bundle' and configured it with 2 'Multi Value' cells (Measurement units and Volumetric Units). Each Multi Value cell has its own list of different units the user can pick from. My main issue is I don't know how to access these settings through the button action. I may be thinking of this wrong, but what I'm looking for is something like; Button Action If settings key = 0 Then do the math in Inches, Display in Gallons If settings key = 1 Then do the math in Centimeters, Display in Gallons If settings key = 2 Then do the math in Inches, Display in Liters If settings key = 3 Then do the math in Centimeters, Display in Liters Etc... Is this possible? Am I thinking of this in the wrong way? What's the best way to do this?

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• Need an advice for unit testing using mock object

  - by Andree

  Hi there, I just recently read about "Mocking objects" for unit testing and currently I'm having a difficulties implementing this approach in my application. Please let me explain my problem. I have a User model class, which is dependent on 2 data sources (database and facebook web service). The controller class simply use this User model as an interface to access data and it doesn't care about where the data came from. Currently I never done any unit test to this User model because it is dependent on an external web service. But just a while ago, I read about object mocking and now I know that it is a common approach to unit test a class that depends on external resources (like in my case). Now I want to create a unit test for the User model, but then I encountered a design issue: In order for the User model to use a mocked Facebook SDK, I have to inject this mocked Facebook SDK to the User object (probably using a setter). Therefore I can't construct the Facebook SDK inside the User object. I have to construct it outside the User object, and inject the SDK into the User object. The real client of my User model is the application's controller. Therefore I have to construct the Facebook SDK inside the controller and inject it to the user object. Well, this is a problem because I want my controller to be as clean as possible. I want my controller to be ignorant about the application's data source. I'm not good at explaining something systematically, so you'll probably sleeping before reading this last paragraph. But anyway, I want to ask if anyone here ever encountered the same problem as mine? How do you solve this problem? Regards, Andree

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• Best practice- How to team-split a django project while still allowing code reusal

  - by Infinity

  I know this sounds kind of vague, but please let me explain- I'm starting work on a brand new project, it will have two main components: "ACME PRODUCT" (think Gmail, Meebo, etc), and "THE SITE" (help, information, marketing stuff, promotional landing pages, etc lots of marketing-induced cruft). So basically the url /acme/* will load stuff in the uber cool ajaxy application, and every other URI will load stuff in the other site. Problem: "THE SITE" component is out of my hands, and will be handled by a consultants team that will work closely with marketing, And I and my team will work solely on the ACME PRODUCT. Question: How to set up the django project in such a way that we can have: Seperate releases. (They can push new marketing pages and functionality without having to worry about the state of our code. Maybe even separate Subversion "projects") Minimize impact (on our product) of whatever flying-unicorns-hocus-pocus the other team codes into the site. Still allow some code reusal. My main concern is that the ACME product needs to be rock solid, and therefore needs to be somewhat isolated of whatever mistakes/code bloopers the consultants make in their marketing side of the site. How have you handled this? Any ideas? Thanks!

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• what is meant by normalization in huge pointers

  - by wrapperm

  Hi, I have a lot of confusion on understanding the difference between a "far" pointer and "huge" pointer, searched for it all over in google for a solution, couldnot find one. Can any one explain me the difference between the two. Also, what is the exact normalization concept related to huge pointers. Please donot give me the following or any similar answers: "The only difference between a far pointer and a huge pointer is that a huge pointer is normalized by the compiler. A normalized pointer is one that has as much of the address as possible in the segment, meaning that the offset is never larger than 15. A huge pointer is normalized only when pointer arithmetic is performed on it. It is not normalized when an assignment is made. You can cause it to be normalized without changing the value by incrementing and then decrementing it. The offset must be less than 16 because the segment can represent any value greater than or equal to 16 (e.g. Absolute address 0x17 in a normalized form would be 0001:0001. While a far pointer could address the absolute address 0x17 with 0000:0017, this is not a valid huge (normalized) pointer because the offset is greater than 0000F.). Huge pointers can also be incremented and decremented using arithmetic operators, but since they are normalized they will not wrap like far pointers." Here the normalization concept is not very well explained, or may be I'm unable to understand it very well. Can anyone try explaining this concept from a beginners point of view. Thanks, Rahamath

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• Developping an online music store

  - by Simon

  We need to develop an application to sell music online. No need to specify that all will be done quite legally and in so doing, we have to plan an interface to pay artists. However, we are confronted with a question: What is the best way to store music on the server? Should we save it on server's disk from a HTTP fileupload? Should we save via FTP or would it be wiser to save it in the database? No need to say that we need it to be the most safiest as possible. So maybe an https is required here. But, we what you think is the best way? Maybe other idea? Because in all HTTP case, upload songs (for administration) is quite long and boring, but easly linkable to a song that admin create in his web application comparativly to an FTP application to upload song on server and then list directory in admin part to link the correct uploaded song to the song informations in database. I know that its maybe not quite clear, it's because i'm french but tell me and I will try to explain part that you don't understand.

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• Validation problem with a 'JotForm' template

  - by Thomas

  A client sent me a form template they had created using jotform.com to implement on their wordpress site. The form template is supposed to hide part of the form until the user clicks the 'next' button. At which point a script is supposed to validate all of the input fields the user has presumably filled out and then display the rest of the form. While I have successfully managed to get the form to display the next part of the form when the user clicks 'next', it fails to validate the input fields. Its kind of difficult to explain without a huge block of text so it is probably easier to show you: The original working template that the customer sent me: http://www.loftist.com/jotform/List_Your_Loft.html The problem child: http://www.loftist.com/?page_id=78 If you just click on one of the input fields and then click elsewhere on the page, the input fields successfully return a validation error message and prevent the user from clicking on the 'next' button. However, if you simply click on the next button than the next set of fields get displayed. Any thoughts? What am I doing wrong here? Im convinced this must be a really simple problem but Im not sure what it could be....

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• Managing libraries and imports in a programming language

  - by sub

  I've created an interpreter for a stupid programming language in C++ and the whole core structure is finished (Tokenizer, Parser, Interpreter including Symbol tables, core functions, etc.). Now I have a problem with creating and managing the function libraries for this interpreter (I'll explain what I mean with that later) So currently my core function handler is horrible: // Simplified version myLangResult SystemFunction( name, argc, argv ) { if ( name == "print" ) { if( argc < 1 ) { Error('blah'); } cout << argv[ 0 ]; } else if ( name == "input" ) { if( argc < 1 ) { Error('blah'); } string res; getline( cin, res ); SetVariable( argv[ 0 ], res ); } else if ( name == "exit ) { exit( 0 ); } And now think of each else if being 10 times more complicated and there being 25 more system functions. Unmaintainable, feels horrible, is horrible. So I thought: How to create some sort of libraries that contain all the functions and if they are imported initialize themselves and add their functions to the symbol table of the running interpreter. However this is the point where I don't really know how to go on. What I wanted to achieve is that there is e.g.: an (extern?) string library for my language, e.g.: string, and it is imported from within a program in that language, example: import string myString = "abcde" print string.at( myString, 2 ) # output: c My problems: How to separate the function libs from the core interpreter and load them? How to get all their functions into a list and add it to the symbol table when needed? What I was thinking to do: At the start of the interpreter, as all libraries are compiled with it, every single function calls something like RegisterFunction( string namespace, myLangResult (*functionPtr) ); which adds itself to a list. When import X is then called from within the language, the list built with RegisterFunction is then added to the symbol table. Disadvantages that spring to mind: All libraries are directly in the interpreter core, size grows and it will definitely slow it down.

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• C# Interface Method calls from a controller

  - by ArjaaAine

  I was just working on some application architecture and this may sound like a stupid question but please explain to me how the following works: Interface: public interface IMatterDAL { IEnumerable<Matter> GetMattersByCode(string input); IEnumerable<Matter> GetMattersBySearch(string input); } Class: public class MatterDAL : IMatterDAL { private readonly Database _db; public MatterDAL(Database db) { _db = db; LoadAll(); //Private Method } public virtual IEnumerable<Matter> GetMattersBySearch(string input) { //CODE return result; } public virtual IEnumerable<Matter> GetMattersByCode(string input) { //CODE return results; } Controller: public class MatterController : ApiController { private readonly IMatterDAL _publishedData; public MatterController(IMatterDAL publishedData) { _publishedData = publishedData; } [ValidateInput(false)] public JsonResult SearchByCode(string id) { var searchText = id; //better name for this var results = _publishedData.GetMattersBySearch(searchText).Select( matter => new { MatterCode = matter.Code, MatterName = matter.Name, matter.ClientCode, matter.ClientName }); return Json(results); } This works, when I call my controller method from jquery and step into it, the call to the _publishedData method, goes into the class MatterDAL. I want to know how does my controller know to go to the MatterDAL implementation of the Interface IMatterDAL. What if I have another class called MatterDAL2 which is based on the interface. How will my controller know then to call the right method? I am sorry if this is a stupid question, this is baffling me.

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• Looking for Opinions and Sugestions on my Website. (General Question)

  - by MrEnder

  I am looking for general opinions and suggestions about the site in whole. Its ok I don't mind hearing where I went wrong on anything. I'm still learning. All tips and pointers on any subject relating are highly welcome. If you are going to make a suggestion and post a snippet or code please explain how it works in detail. The site was design as a interface to display the labs I have to do in my college (the labs are all basic things that I'm way beyond). So I decided to take it all to the next level with this. The link is http://opentech.durhamcollege.ca/~intn2201/brittains/labs/ It is 100% designed by me with the exception of the icons. (I could not think of anything better to draw) There is no specific area of the site I want suggestions or opinions on this is a general question. You may answer about the site in whole or an area of the coding just please specify. If you have any questions related to my site or code you may ask them as well. Thank you for your time and any comments Shelby

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