Search Results

Search found 11960 results on 479 pages for 'auto implemented propert'.

Page 432/479 | < Previous Page | 428 429 430 431 432 433 434 435 436 437 438 439  | Next Page >

• Which is the "best" data access framework/approach for C# and .NET?

  - by Frans

  (EDIT: I made it a community wiki as it is more suited to a collaborative format.) There are a plethora of ways to access SQL Server and other databases from .NET. All have their pros and cons and it will never be a simple question of which is "best" - the answer will always be "it depends". However, I am looking for a comparison at a high level of the different approaches and frameworks in the context of different levels of systems. For example, I would imagine that for a quick-and-dirty Web 2.0 application the answer would be very different from an in-house Enterprise-level CRUD application. I am aware that there are numerous questions on Stack Overflow dealing with subsets of this question, but I think it would be useful to try to build a summary comparison. I will endeavour to update the question with corrections and clarifications as we go. So far, this is my understanding at a high level - but I am sure it is wrong... I am primarily focusing on the Microsoft approaches to keep this focused. ADO.NET Entity Framework Database agnostic Good because it allows swapping backends in and out Bad because it can hit performance and database vendors are not too happy about it Seems to be MS's preferred route for the future Complicated to learn (though, see 267357) It is accessed through LINQ to Entities so provides ORM, thus allowing abstraction in your code LINQ to SQL Uncertain future (see Is LINQ to SQL truly dead?) Easy to learn (?) Only works with MS SQL Server See also Pros and cons of LINQ "Standard" ADO.NET No ORM No abstraction so you are back to "roll your own" and play with dynamically generated SQL Direct access, allows potentially better performance This ties in to the age-old debate of whether to focus on objects or relational data, to which the answer of course is "it depends on where the bulk of the work is" and since that is an unanswerable question hopefully we don't have to go in to that too much. IMHO, if your application is primarily manipulating large amounts of data, it does not make sense to abstract it too much into objects in the front-end code, you are better off using stored procedures and dynamic SQL to do as much of the work as possible on the back-end. Whereas, if you primarily have user interaction which causes database interaction at the level of tens or hundreds of rows then ORM makes complete sense. So, I guess my argument for good old-fashioned ADO.NET would be in the case where you manipulate and modify large datasets, in which case you will benefit from the direct access to the backend. Another case, of course, is where you have to access a legacy database that is already guarded by stored procedures. ASP.NET Data Source Controls Are these something altogether different or just a layer over standard ADO.NET? - Would you really use these if you had a DAL or if you implemented LINQ or Entities? NHibernate Seems to be a very powerful and powerful ORM? Open source Some other relevant links; NHibernate or LINQ to SQL Entity Framework vs LINQ to SQL

  Read the article

• Security review of an authenticated Diffie Hellman variant

  - by mtraut

  EDIT I'm still hoping for some advice on this, i tried to clarify my intentions... When i came upon device pairing in my mobile communication framework i studied a lot of papers on this topic and and also got some input from previous questions here. But, i didn't find a ready to implement protocol solution - so i invented a derivate and as i'm no crypto geek i'm not sure about the security caveats of the final solution: The main questions are Is SHA256 sufficient as a commit function? Is the addition of the shared secret as an authentication info in the commit string safe? What is the overall security of the 1024 bit group DH I assume at most 2^-24 bit probability of succesful MITM attack (because of 24 bit challenge). Is this plausible? What may be the most promising attack (besides ripping the device out off my numb, cold hands) This is the algorithm sketch For first time pairing, a solution proposed in "Key agreement in peer-to-peer wireless networks" (DH-SC) is implemented. I based it on a commitment derived from: A fix "UUID" for the communicating entity/role (128 bit, sent at protocol start, before commitment) The public DH key (192 bit private key, based on the 1024 bit Oakley group) A 24 bit random challenge Commit is computed using SHA256 c = sha256( UUID || DH pub || Chall) Both parties exchange this commitment, open and transfer the plain content of the above values. The 24 bit random is displayed to the user for manual authentication DH session key (128 bytes, see above) is computed When the user opts for persistent pairing, the session key is stored with the remote UUID as a shared secret Next time devices connect, commit is computed by additionally hashing the previous DH session key before the random challenge. For sure it is not transfered when opening. c = sha256( UUID || DH pub || DH sess || Chall) Now the user is not bothered authenticating when the local party can derive the same commitment using his own, stored previous DH session key. After succesful connection the new DH session key becomes the new shared secret. As this does not exactly fit the protocols i found so far (and as such their security proofs), i'd be very interested to get an opinion from some more crypto enabled guys here. BTW. i did read about the "EKE" protocol, but i'm not sure what the extra security level is.

  Read the article

• Is there a programming language with be semantics close to English ?

  - by ivo s

  Most languages allow to 'tweek' to certain extend parts of the syntax (C++,C#) and/or semantics that you will be using in your code (Katahdin, lua). But I have not heard of a language that can just completely define how your code will look like. So isn't there some language which already exists that has such capabilities to override all syntax & define semantics ? Example of what I want to do is basically from the C# code below: foreach(Fruit fruit in Fruits) { if(fruit is Apple) { fruit.Price = fruit.Price/2; } } I want do be able to to write the above code in my perfect language like this: Check if any fruits are Macintosh apples and discount the price by 50%. The advantages that come to my mind looking from a coder's perspective in this "imaginary" language are: It's very clear what is going on (self descriptive) - it's plain English after all even kid would understand my program Hides all complexities which I have to write in C#. But why should I care to learn that if statements, arithmetic operators etc since there are already implemented The disadvantages that I see for a coder who will maintain this program are: Maybe you would express this program differently from me so you may not get all the information that I've expressed in my sentence Programs can be quite verbose and hard to debug but if possible to even proximate this type of syntax above maybe more people would start programming right? That would be amazing I think. I can go to work and just write an essay to draw a square on a winform like this: Create a form called MyGreetingForm. Draw a square with in the middle of MyGreetingFormwith a side of 100 points. In the middle of the square write "Hello! Click here to continue" in Arial font. In the above code the parser must basically guess that I want to use the unnamed square from the previous sentence, it'd be hard to write such a smart parser I guess, yet it's so simple what I want to do. If the user clicks on square in the middle of MyGreetingForm show MyMainForm. In the above code 'basically' the compiler must: 1)generate an event handler 2) check if there is any square in the middle of the form and if there is - 3) hide the form and show another form It looks very hard to do but it doesn't look impossible IMO to me at least approximate this (I can personally generate a parser to perform the 3 steps above np & it's basically the same that it has to do any way when you add even in c# a.MyEvent=+handler; so I don't see a problem here) so I'm thinking maybe somebody already did something like this ? Or is there some practical burden of complexity to create such a 'essay style' programming language which I can't see ? I mean what's the worse that can happen if the parser is not that good? - your program will crash so you have to re-word it:)

  Read the article

• What the best approach to iterate and "store" files over a directory in C (Linux) ?

  - by Andrei Ciobanu

  I have written a function that checks if to files are duplicates or not. This function signature is: int check_dup_memmap(char *f1_name, char *f2_name) It returns: (-1) - If something went wrong; (0) - If the two files are similar; (+1) - If the two files are different; The next step is to write a function that iterates through all the files in a certain directory,apply the previous function, and gives a report on every existing duplicates. Initially I've thought to write a function that generates a file with all the filenames in a certain directory and then, read that file again and gain and compare every two files. Here is that version of the function, that gets all the filenames in a certain directory. void *build_dir_tree(char *dirname, FILE *f) { DIR *cdir = NULL; struct dirent *ent = NULL; struct stat buf; if(f == NULL){ fprintf(stderr, "NULL file submitted. [build_dir_tree].\n"); exit(-1); } if(dirname == NULL){ fprintf(stderr, "NULL dirname submitted. [build_dir_tree].\n"); exit(-1); } if((cdir = opendir(dirname)) == NULL){ char emsg[MFILE_LEN]; sprintf(emsg, "Cannot open dir: %s [build_dir_tree]\t",dirname); perror(emsg); } chdir(dirname); while ((ent = readdir(cdir)) != NULL) { lstat(ent->d_name, &buf); if (S_ISDIR(buf.st_mode)) { if (strcmp(".", ent->d_name) == 0 || strcmp("..", ent->d_name) == 0) { continue; } build_dir_tree(ent->d_name, f); } else{ fprintf(f, "/%s/%s\n",util_get_cwd(),ent->d_name); } } chdir(".."); closedir(cdir); } Still I consider this approach a little inefficient, as I have to parse the file again and again. In your opinion what are other approaches should I follow: Write a datastructure and hold the files instead of writing them in the file ? I think for a directory with a lot of files, the memory will become very fragmented. Hold all the filenames in auto-expanding array, so that I can easy access every file by their index, because they will in a contiguous memory location. Map this file in memory using mmap() ? But mmap may fail, as the file gets to big. Any opinions on this. I want to choose the most efficient path, and access as few resources as possible. This is the requirement of the program... EDIT: Is there a way to get the numbers of files in a certain directory, without iterating through it ?

  Read the article

• Not allowing characters after Space. Mysql Insert With PHP

  - by Jake

  Ok so I think this is easy but I dont know (I'm a novice to PHP and MySQL). I have a select that is getting data from a table in the database. I am simply taking whatever options the user selects and putting it into a separate table with a php mysql insert statement. But I am having a problem. When I hit submit, everything is submitted properly except for any select options that have spaces don't submit after the first space. For example if the option was COMPUTER REPAIR, all that would get sent is COMPUTER. I will post code if needed, and any help would be greatly appreciated. Thanks! Ok here is my select code: <?php include("./config.php"); $query="SELECT id,name FROM category_names ORDER BY name"; $result = mysql_query ($query); echo"<div style='overflow:auto;width:100%'><label>Categories (Pick three that describe your business)</label><br/><select name='select1'><option value='0'>Please Select A Category</option>"; // printing the list box select command while($catinfo=mysql_fetch_array($result)){//Array or records stored in $nt echo "<option>$catinfo[name]</option><br/> "; } echo"</select></div>"; ?> And here is my insert code ( Just to let you know its got everything not just the select!) ?php require("./config.php"); $companyname = mysql_real_escape_string(addslashes(trim($_REQUEST['name']))); $phone = mysql_real_escape_string(addslashes($_REQUEST['phone'])); $zipcode = mysql_real_escape_string(addslashes($_REQUEST['zipcode'])); $city = mysql_real_escape_string(addslashes($_REQUEST['city'])); $description = mysql_real_escape_string(addslashes($_REQUEST['description'])); $website = mysql_real_escape_string(addslashes($_REQUEST['website'])); $address = mysql_real_escape_string(addslashes($_REQUEST['address'])); $other = mysql_real_escape_string(addslashes($_REQUEST['other'])); $payment = mysql_real_escape_string(addslashes($_REQUEST['payment'])); $products = mysql_real_escape_string(addslashes($_REQUEST['products'])); $email = mysql_real_escape_string(addslashes($_REQUEST['email'])); $select1 = mysql_real_escape_string(addslashes($_REQUEST['select1'])); $select2 = mysql_real_escape_string(addslashes($_REQUEST['select2'])); $select3 = mysql_real_escape_string(addslashes($_REQUEST['select3'])); $save=$_POST['save']; if(!empty($save)){ $sql="INSERT INTO gj (name, phone, city, zipcode, description, dateadded, website, address1, other2, payment_options, Products, email,cat1,cat2,cat3) VALUES ('$companyname','$phone','$city','$zipcode','$description',curdate(),'$website','$address','$other','$payment','$products','$email','$select1','$select2','$select3')"; if (!mysql_query($sql,$link)) { die('Error: ' . mysql_error()); } echo "<br/><h2><font color='green' style='font-size:15px'>1 business added</font></h2>"; mysql_close($link); } ?>

  Read the article

• How can a C/C++ program put itself into background?

  - by Larry Gritz

  What's the best way for a running C or C++ program that's been launched from the command line to put itself into the background, equivalent to if the user had launched from the unix shell with '&' at the end of the command? (But the user didn't.) It's a GUI app and doesn't need any shell I/O, so there's no reason to tie up the shell after launch. But I want a shell command launch to be auto-backgrounded without the '&' (or on Windows). Ideally, I want a solution that would work on any of Linux, OS X, and Windows. (Or separate solutions that I can select with #ifdef.) It's ok to assume that this should be done right at the beginning of execution, as opposed to somewhere in the middle. One solution is to have the main program be a script that launches the real binary, carefully putting it into the background. But it seems unsatisfying to need these coupled shell/binary pairs. Another solution is to immediately launch another executed version (with 'system' or CreateProcess), with the same command line arguments, but putting the child in the background and then having the parent exit. But this seems clunky compared to the process putting itself into background. Edited after a few answers: Yes, a fork() (or system(), or CreateProcess on Windows) is one way to sort of do this, that I hinted at in my original question. But all of these solutions make a SECOND process that is backgrounded, and then terminate the original process. I was wondering if there was a way to put the EXISTING process into the background. One difference is that if the app was launched from a script that recorded its process id (perhaps for later killing or other purpose), the newly forked or created process will have a different id and so will not be controllable by any launching script, if you see what I'm getting at. Edit #2: fork() isn't a good solution for OS X, where the man page for 'fork' says that it's unsafe if certain frameworks or libraries are being used. I tried it, and my app complains loudly at runtime: "The process has forked and you cannot use this CoreFoundation functionality safely. You MUST exec()." I was intrigued by daemon(), but when I tried it on OS X, it gave the same error message, so I assume that it's just a fancy wrapper for fork() and has the same restrictions. Excuse the OS X centrism, it just happens to be the system in front of me at the moment. But I am indeed looking for a solution to all three platforms.

  Read the article

• Make text in a <div> wrap around a child element.

  - by John

  In Word you can place an image on a page and have the text flow nicely around it. I was wondering how far one can get towards this using CSS, noting that is has to work in IE6. I already have something sort of close using float, but the floated child-element still 'blocks' text above it. So it partially wraps. Is it possible to put a child div at some arbitrary position in the parent, and have text flow around it freely? The actual use-case here is to put illustrations inside the main content , where each illustration is implemented inside a child . I repeat, it has to work on IE6. And I don't want to get too involved in browser-specific hacks... floating the child at least works on IE6 with no tweaking. Currently I have like this: <div> <div class="illustration"> <img src="image1.png" /> <p>Illustration caption</p> </div> <p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. Atvero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. </p> </div> div.illustration { float:right; border-top: 1px solid #505050; border-left: 1px solid #505050; border-right: 1px solid #505050; border-bottom: 1px solid #505050; margin-right:30px; margin-top:100px; text-align:center; padding:2px; background: #96C3FF; } div.illustration p { margin:0; font-size:small; font-style:italic; padding:0; }

  Read the article

• Bind Icon depending on Enum in WPF Treeview

  - by phenevo

  Hi, I have at treeeview TextBox, and I want convert my Enum: <TextBlock TextAlignment="Justify" VerticalAlignment="Center" Text="{Binding Path=AcceptationStatusGlobalFlag}" /> public enum AcceptationStatusGlobalFlag { NotReady = 0, Ready = 1, AcceptedByAdmin=2 } To Icons. There will be 3 icons, let say ready.jpg, notready.jpg and AcceptedByAdmin.jpg Country and Region has pool AcceptationStatusGlobalFlag and on both I want to display this enum/Icon <TreeView Name="structureTree" SelectedItemChanged="structureTree_SelectedItemChanged" Grid.Row="0" Grid.Column="0" ItemsSource="{Binding}" Height="413" ScrollViewer.VerticalScrollBarVisibility="Visible" ScrollViewer.HorizontalScrollBarVisibility="Visible" Width="Auto" PreviewMouseRightButtonUp="structureTree_PreviewMouseRightButtonUp" FontFamily="Verdana" FontSize="12"> <TreeView.Resources> <HierarchicalDataTemplate DataType="{x:Type ServiceMy:Country}" ItemsSource="{Binding Path=ListOfRegions}"> <StackPanel Orientation="Horizontal"> <TextBlock TextAlignment="Justify" VerticalAlignment="Center" Text="{Binding Path=Name}"/> <TextBlock TextAlignment="Justify" VerticalAlignment="Center" Text=" H:"/> <TextBlock TextAlignment="Justify" VerticalAlignment="Center" Text="{Binding Path=NumberOfHotels}"/> <TextBlock TextAlignment="Justify" VerticalAlignment="Center" Text=" "/> <TextBlock TextAlignment="Justify" VerticalAlignment="Center" Text=" FG:"/> <TextBlock TextAlignment="Justify" VerticalAlignment="Center" Text="{Binding Path=AcceptationStatusGlobalFlag}" /> <!--<Button Name="BTNAddRegion" Height="20" Content="+" Click="BTNAddRegion_Click"></Button>--> </StackPanel> </HierarchicalDataTemplate> <HierarchicalDataTemplate DataType="{x:Type ServiceMy:Region}" ItemsSource="{Binding Path=ListOfProvinces}"> <StackPanel Orientation="Horizontal"> <TextBlock TextAlignment="Justify" VerticalAlignment="Center" Text="{Binding Path=Name}"/> <TextBlock TextAlignment="Justify" VerticalAlignment="Center" Text=" H:"/> <TextBlock TextAlignment="Justify" VerticalAlignment="Center" Text="{Binding Path=NumberOfHotels}"/> <TextBlock TextAlignment="Justify" VerticalAlignment="Center" Text=" "/> <!--<Button Name="BTNAddProvince" Height="20" Content="+" Click="BTNAddProvince_Click"></Button>--> </StackPanel> </DataTemplate> </TreeView.Resources> </TreeView> </GroupBox> </StackPanel> </Grid>

  Read the article

• HttpWebRequest possibly slowing website

  - by Steven Smith

  Using Visual studio 2012, C#.net 4.5 , SQL Server 2008, Feefo, Nopcommerce Hey guys I have Recently implemented a new review service into a current site we have. When the change went live the first day all worked fine. Since then though the sending of sales to Feefo hasnt been working, There are no logs either of anything going wrong. In the OrderProcessingService.cs in Nop Commerce's Service, i call a HttpWebrequest when an order has been confirmed as completed. Here is the code. var email = HttpUtility.UrlEncode(order.Customer.Email.ToString()); var name = HttpUtility.UrlEncode(order.Customer.GetFullName().ToString()); var description = HttpUtility.UrlEncode(productVariant.ProductVariant.Product.MetaDescription != null ? productVariant.ProductVariant.Product.MetaDescription.ToString() : "product"); var orderRef = HttpUtility.UrlEncode(order.Id.ToString()); var productLink = HttpUtility.UrlEncode(string.Format("myurl/p/{0}/{1}", productVariant.ProductVariant.ProductId, productVariant.ProductVariant.Name.Replace(" ", "-"))); string itemRef = ""; try { itemRef = HttpUtility.UrlEncode(productVariant.ProductVariant.ProductId.ToString()); } catch { itemRef = "0"; } var url = string.Format("feefo Url", login, password,email,name,description,orderRef,productLink,itemRef); var request = (HttpWebRequest)WebRequest.Create(url); request.KeepAlive = false; request.Timeout = 5000; request.Proxy = null; using (var response = (HttpWebResponse)request.GetResponse()) { if (response.StatusDescription == "OK") { var stream = response.GetResponseStream(); if(stream != null) { using (var reader = new StreamReader(stream)) { var content = reader.ReadToEnd(); } } } } So as you can see its a simple webrequest that is processed on an order, and all product variants are sent to feefo. Now: this hasnt been happening all week since the 15th (day of the implementation) the site has been grinding to a halt recently. The stream and reader in the the var content is there for debugging. Im wondering does the code redflag anything to you that could relate to the process of website? Also note i have run some SQL statements to see if there is any deadlocks or large escalations, so far seems fine, Logs have also been fine just the usual logging of Bots. Any help would be much appreciated! EDIT: also note that this code is in a method that is called and wrapped in A try catch UPDATE: well forget about the "not sending", thats because i was just told my code was rolled back last week

  Read the article

• ACL implementation

  - by Kirzilla

  First question Please, could you explain me how simpliest ACL could be implemented in MVC. Here is the first approach of using Acl in Controller... <?php class MyController extends Controller { public function myMethod() { //It is just abstract code $acl = new Acl(); $acl->setController('MyController'); $acl->setMethod('myMethod'); $acl->getRole(); if (!$acl->allowed()) die("You're not allowed to do it!"); ... } } ?> It is very bad approach, and it's minus is that we have to add Acl piece of code into each controller's method, but we don't need any additional dependencies! Next approach is to make all controller's methods private and add ACL code into controller's __call method. <?php class MyController extends Controller { private function myMethod() { ... } public function __call($name, $params) { //It is just abstract code $acl = new Acl(); $acl->setController(__CLASS__); $acl->setMethod($name); $acl->getRole(); if (!$acl->allowed()) die("You're not allowed to do it!"); ... } } ?> It is better than previous code, but main minuses are... All controller's methods should be private We have to add ACL code into each controller's __call method. The next approach is to put Acl code into parent Controller, but we still need to keep all child controller's methods private. What is the solution? And what is the best practice? Where should I call Acl functions to decide allow or disallow method to be executed. Second question Second question is about getting role using Acl. Let's imagine that we have guests, users and user's friends. User have restricted access to viewing his profile that only friends can view it. All guests can't view this user's profile. So, here is the logic.. we have to ensure that method being called is profile we have to detect owner of this profile we have to detect is viewer is owner of this profile or no we have to read restriction rules about this profile we have to decide execute or not execute profile method The main question is about detecting owner of profile. We can detect who is owner of profile only executing model's method $model-getOwner(), but Acl do not have access to model. How can we implement this? I hope that my thoughts are clear. Sorry for my English. Thank you.

  Read the article

• Fast response on first Socket I/O request but slow every other time when communicating with remote serial port

  - by GreenGodot

  I'm using sockets to pass Serial commands to a remote device. And the response to that request is sent back and printed out. However, I am having a problem in that the first time it is instant but the rest of the time it can take up to 20 seconds to receive a reply. I think the problem is with my attempt at threading but I am not entirely sure. new Thread() { @Override public void run() { System.out.println("opened"); try { isSocketRetrieving.setText("Opening Socket"); socket = new Socket(getAddress(), getRemotePort())); DataOutput = new DataOutputStream(socket .getOutputStream()); inFromServer = new BufferedReader( new InputStreamReader(socket .getInputStream())); String line = ""; isSocketRetrieving.setText("Reading Stream......"); while ((line = inFromServer.readLine()) != null) { System.out.println(line); if (line.contains(getHandshakeRequest())) { DataOutput.write((getHandshakeResponse()toString() + "\r").getBytes()); DataOutput.flush(); DataOutput .write((getCommand().toString() + "\r").getBytes()); DataOutput.flush(); int pause = (line.length()*8*1000)/getBaud(); sleep(pause); } else if (line.contains(readingObject .getExpected())) { System.out.println(line); textArea.append("value = " + line + "\n"); textAreaScroll.revalidate(); System.out.println("Got Value"); break; } } System.out.println("Ended"); try { inFromServer.close(); DataOutput.close(); socket.close(); isSocketRetrieving.setText("Socket is inactive..."); rs232Table.addMouseListener(listener); interrupt(); join(); } catch (IOException e) { e.printStackTrace(); } catch (InterruptedException e) { System.out.println("Thread exited"); } } catch (NumberFormatException e1) { e1.printStackTrace(); } catch (UnknownHostException e1) { e1.printStackTrace(); } catch (IOException e1) { e1.printStackTrace(); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }.start();

  Read the article

• JAXB doesn't unmarshal list of interfaces

  - by Joker_vD

  It seems JAXB can't read what it writes. Consider the following code: interface IFoo { void jump(); } @XmlRootElement class Bar implements IFoo { @XmlElement public String y; public Bar() { y = ""; } public Bar(String y) { this.y = y; } @Override public void jump() { System.out.println(y); } } @XmlRootElement class Baz implements IFoo { @XmlElement public int x; public Baz() { x = 0; } public Baz(int x) { this.x = x; } @Override public void jump() { System.out.println(x); } } @XmlRootElement public class Holder { private List<IFoo> things; public Holder() { things = new ArrayList<>(); } @XmlElementWrapper @XmlAnyElement public List<IFoo> getThings() { return things; } public void addThing(IFoo thing) { things.add(thing); } } // ... try { JAXBContext context = JAXBContext.newInstance(Holder.class, Bar.class, Baz.class); Holder holder = new Holder(); holder.addThing(new Bar("1")); holder.addThing(new Baz(2)); holder.addThing(new Baz(3)); for (IFoo thing : holder.getThings()) { thing.jump(); } StringWriter s = new StringWriter(); context.createMarshaller().marshal(holder, s); String data = s.toString(); System.out.println(data); StringReader t = new StringReader(data); Holder holder2 = (Holder)context.createUnmarshaller().unmarshal(t); for (IFoo thing : holder2.getThings()) { thing.jump(); } } catch (Exception e) { System.err.println(e.getMessage()); } It's a simplified example, of course. The point is that I have to store two very differently implemented classes, Bar and Baz, in one collection. Well, I observed that they have pretty similar public interface, so I created an interface IFoo and made them two to implement it. Now, I want to have tools to save and load this collection to/from XML. Unfortunately, this code doesn't quite work: the collection is saved, but then it cannot be loaded! The intended output is 1 2 3 some xml 1 2 3 But unfortunately, the actual output is 1 2 3 some xml com.sun.org.apache.xerces.internal.dom.ElementNSImpl cannot be cast to testapplication1.IFoo Apparently, I need to use the annotations in a different way? Or to give up on JAXB and look for something else? I, well, can write "XMLNode toXML()" method for all classes I wan't to (de)marshal, but...

  Read the article

• Java: file write on finalize method

  - by sowrov

  In my understanding a singleton object will destroy only when the application is about to terminate. So in C++ I write a Singleton class to log my application and in that Singleton logger's destructor I log the time when my application was terminated. Things worked perfectly in C++. Now I want to have that same logger in Java, as in java there is no destructor so I implemented the finalize method for that singleton logger. But it seem that finalize method actually never get called. So, I add that System.runFinalizersOnExit(true); line, somewhere in my code (though I know it is deprecated) and that finalize method get called every time before termination of the app. But still there is a problem! If I try to write anything on file in that finalize method, It does not work, though System.out work without any problem! :( Can you guys help me on this problem? Here is a sample code of what I am try to do: Singleton Logger Class: public class MyLogger { FileWriter writer; private MyLogger() { try { this.writer = new FileWriter("log.txt"); } catch (IOException ex) { } } public static MyLogger getInstance() { return MyLoggerHolder.INSTANCE; } private static class MyLoggerHolder { private static final MyLogger INSTANCE = new MyLogger(); } @Override protected void finalize () { try { super.finalize(); System.out.println("Here"); //worked correctly. this.writer.write(new Date().toString()+System.getProperty("line.separator")); this.writer.write("End"); this.writer.flush(); //does not work! this.writer.close(); } catch (Throwable ex) { } } public synchronized void log(String str) { try { this.writer.write(new Date().toString()+System.getProperty("line.separator")); this.writer.write(str+"\n"); this.writer.flush(); } catch (IOException ex) { } } } Main: public class Main { public static void main(String[] args) { System.runFinalizersOnExit(true); MyLogger logger = MyLogger.getInstance(); logger.log("test"); } }

  Read the article

• How do I change the visual style of a listitem based on its bound value?

  - by Rodd

  I have a listbox (here's the xaml): <ListBox MinWidth="300" ItemsSource="{Binding Relationships, Mode=OneWay}" SelectedItem="{Binding SelectedRelationship, Mode=TwoWay}" SelectionMode="Single" HorizontalAlignment="Left" > <ListBox.ItemTemplate> <DataTemplate> <Grid> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto"/> <ColumnDefinition/> </Grid.ColumnDefinitions> <Grid.RowDefinitions> <RowDefinition/> <RowDefinition/> <RowDefinition/> <RowDefinition/> <RowDefinition/> <RowDefinition/> </Grid.RowDefinitions> <CheckBox IsChecked = "{Binding IsPrimary}" IsHitTestVisible="False" /> <StackPanel Orientation="Horizontal" Grid.Column="1"> <TextBlock Text="{Binding RelationshipType}" FontWeight="Bold" Margin="0,0,5,0" /> <TextBlock Text="{Binding Status}" FontStyle="Italic" /> </StackPanel> <TextBlock Text="{Binding UnitName}" Grid.Row="1" Grid.Column="1" /> <TextBlock Text="{Binding StartDate, Converter={StaticResource DateConverter}}" Grid.Row="2" Grid.Column="1"/> <TextBlock Text="{Binding RetireDate}" Grid.Row="3" Grid.Column="1" /> <TextBlock Text="{Binding EndDate}" Grid.Row="4" Grid.Column="1" /> <TextBlock Text="{Binding ReasonForLeaving}" Grid.Row="5" Grid.Column="1" /> </Grid> </DataTemplate> </ListBox.ItemTemplate> </ListBox> What I want to do is have each item in the listbox have one of 3 backgrounds (green if the value of IsPrimary = true, Orange if the EndDate value is empty and grey if the EndDate value is not empty. Is there a way to template the listbox items so that they evaluate bound items to determine a view state or to have each listbox item bind to a value that I can set for each item in my viewmodel? Thanks for your help.

  Read the article

• getting Cannot identify image file when trying to create thumbnail in django

  - by Mo J. Mughrabi

  Am trying to create a thumbnail in django, am trying to build a custom class specifically to be used for generating thumbnails. As following from StringIO import StringIO from PIL import Image class Thumbnail(object): source = '' size = (50, 50) output = '' def __init__(self): pass @staticmethod def load(src): self = Thumbnail() self.source = src return self def generate(self, size=(50, 50)): if not isinstance(size, tuple): raise Exception('Thumbnail class: The size parameter must be an instance of a tuple.') self.size = size # resize properties box = self.size factor = 1 fit = True image = Image.open(self.source) # Convert to RGB if necessary if image.mode not in ('L', 'RGB'): image = image.convert('RGB') while image.size[0]/factor > 2*box[0] and image.size[1]*2/factor > 2*box[1]: factor *=2 if factor > 1: image.thumbnail((image.size[0]/factor, image.size[1]/factor), Image.NEAREST) #calculate the cropping box and get the cropped part if fit: x1 = y1 = 0 x2, y2 = image.size wRatio = 1.0 * x2/box[0] hRatio = 1.0 * y2/box[1] if hRatio > wRatio: y1 = int(y2/2-box[1]*wRatio/2) y2 = int(y2/2+box[1]*wRatio/2) else: x1 = int(x2/2-box[0]*hRatio/2) x2 = int(x2/2+box[0]*hRatio/2) image = image.crop((x1,y1,x2,y2)) #Resize the image with best quality algorithm ANTI-ALIAS image.thumbnail(box, Image.ANTIALIAS) # save image to memory temp_handle = StringIO() image.save(temp_handle, 'png') temp_handle.seek(0) self.output = temp_handle return self def get_output(self): return self.output.read() the purpose of the class is so i can use it inside different locations to generate thumbnails on the fly. The class works perfectly, I've tested it directly under a view.. I've implemented the thumbnail class inside the save method of the forms to resize the original images on saving. in my design, I have two fields for thumbnails. I was able to generate one thumbnail, if I try to generate two it crashes and I've been stuck for hours not sure whats the problem. Here is my model class Image(models.Model): article = models.ForeignKey(Article) title = models.CharField(max_length=100, null=True, blank=True) src = models.ImageField(upload_to='publication/image/') r128 = models.ImageField(upload_to='publication/image/128/', blank=True, null=True) r200 = models.ImageField(upload_to='publication/image/200/', blank=True, null=True) uploaded_at = models.DateTimeField(auto_now=True) Here is my forms class ImageForm(models.ModelForm): """ """ class Meta: model = Image fields = ('src',) def save(self, commit=True): instance = super(ImageForm, self).save(commit=True) file = Thumbnail.load(instance.src) instance.r128 = SimpleUploadedFile( instance.src.name, file.generate((128, 128)).get_output(), content_type='image/png' ) instance.r200 = SimpleUploadedFile( instance.src.name, file.generate((200, 200)).get_output(), content_type='image/png' ) if commit: instance.save() return instance the strange part is, when i remove the line which contains instance.r200 in the form save. It works fine, and it does the thumbnail and stores it successfully. Once I add the second thumbnail it fails.. Any ideas what am doing wrong here? Thanks Update: I tried earlier doing the following but I still got the same error class ImageForm(models.ModelForm): """ """ class Meta: model = Image fields = ('src',) def save(self, commit=True): instance = super(ImageForm, self).save(commit=True) instance.r128 = SimpleUploadedFile( instance.src.name, Thumbnail.load(instance.src).generate((128, 128)).get_output(), content_type='image/png' ) instance.r200 = SimpleUploadedFile( instance.src.name, Thumbnail.load(instance.src).generate((200, 200)).get_output(), content_type='image/png' ) if commit: instance.save() return instance

  Read the article

• How do I map a one-to-one value type association in an joined-subclass?

  - by David Rubin

  I've got a class hierarchy mapped using table-per-subclass, and it's been working out great: class BasicReport { ... } class SpecificReport : BasicReport { ... } With mappings: <class name="BasicReport" table="reports"> <id name="Id" column="id">...</id> <!-- some common properties --> </class> <joined-subclass name="SpecificReport" table="specificReports" extends="BasicReport"> <key column="id"/> <!-- some special properties --> </joined-subclass> So far, so good. The problem I'm struggling with is how to add a property to one of my subclasses that's both a value type for which I have an IUserType implemented and also mapped via an association: class OtherReport : BasicReport { public SpecialValue V { get; set; } } class SpecialValueUserType : IUserType { ... } What I'd like to do is: <joined-subclass name="OtherReport" table="otherReports" extends="BasicReport"> <key column="id"/> <join table="rptValues" fetch="join"> <key column="rptId"/> <property name="V" column="value" type="SpecialValueUserType"/> </join> </joined-subclass> This accurately reflects the intent, and the pre-existing database schema I'm tied to: the SpecialValue instance is a property of the OtherReport, but is stored in a separate table ("rptValues"). Unfortunately, it seems as though I can't do this, because <join> elements can't be used in <joined-subclass> mappings. <one-to-one> would require creating a class mapping for SpecialValue, which doesn't make any sense given that SpecialValue is just a meaningful scalar. So what can I do? Do I have any options? Right now I'm playing a game with sets: class OtherReport : BasicReport { public SpecialValue V { get { return _values.Count() > 0 ? _values.First() : null; } set { _values.Clear(); _values.Add(value); } } private ICollection<SpecialValue> _values; } With mapping: <joined-subclass name="OtherReport" table="otherReports" extends="BasicReport"> <key column="id"/> <set name="_values" access="field" table="rptValues" cascade="all-delete-orphan"> <key column="rptId" /> <element column="value" type="SpecialValueUserType"/> </set> </joined-subclass> Thanks in advance for the help! I've been banging my head into my desk for several days now.

  Read the article

• RaphaelJS HTML5 Library pathIntersection() bug or alternative optimisation (screenshots)

  - by user1236048

  I have a chart generated using RaphaelJS library. It is just on long path: M 50 122 L 63.230769230769226 130 L 76.46153846153845 130 L 89.6923076923077 128 L 102.92307692307692 56 L 116.15384615384615 106 L 129.3846153846154 88 L 142.6153846153846 114 L 155.84615384615384 52 L 169.07692307692307 30 L 182.3076923076923 62 L 195.53846153846152 130 L 208.76923076923077 74 L 222 130 L 235.23076923076923 66 L 248.46153846153845 102 L 261.6923076923077 32 L 274.9230769230769 130 L 288.15384615384613 130 L 301.38461538461536 32 L 314.6153846153846 86 L 327.8461538461538 130 L 341.07692307692304 70 L 354.30769230769226 130 L 367.53846153846155 102 L 380.7692307692308 120 L 394 112 L 407.2307692307692 68 L 420.46153846153845 48 L 433.6923076923077 92 L 446.9230769230769 128 L 460.15384615384613 110 L 473.38461538461536 78 L 486.6153846153846 130 L 499.8461538461538 56 L 513.0769230769231 116 L 526.3076923076923 80 L 539.5384615384614 58 L 552.7692307692307 40 L 566 130 L 579.2307692307692 94 L 592.4615384615385 64 L 605.6923076923076 122 L 618.9230769230769 98 L 632.1538461538461 120 L 645.3846153846154 70 L 658.6153846153845 82 L 671.8461538461538 76 L 685.0769230769231 124 L 698.3076923076923 110 L 711.5384615384615 94 L 724.7692307692307 130 L 738 130 L 751.2307692307692 66 L 764.4615384615385 118 L 777.6923076923076 70 L 790.9230769230769 130 L 804.1538461538461 44 L 817.3846153846154 130 L 830.6153846153845 36 L 843.8461538461538 92 L 857.076923076923 130 L 870.3076923076923 76 L 883.5384615384614 130 L 896.7692307692307 60 L 910 88 Also below these chart I have a jqueryUI slider of the same width (860px) and centered with the chart. I want when I move the slider to move a dot on the chart accordingly with the slider position. See attached screenshot: As you can see it seems to work fine. I've implemented this behaviour using the pathIntersection() method. On the slide event at each ui.value (x coordinate) I intersect my chartPath (the one from above) with a vertical straight line at the x coordinate. But still there are some problems. One of them is that it runs very hard, and it kinda freezes sometimes.. and very weird sometimes it doesn't seem to intersect at all even it should.. I'll example below 2 cases I identified: M 499.8461538461538 0 L 499.8461538461538 140 M 910 0 L 910 140 Could you please explain why this intersect behaviour happens (it should return a dot).. and the worst part it seems like it happens randomly.. if I use another chartdata. Also if you can identify another (better) solution to syncronise the slider position with the dot on the chart.. would be perfect. I thought about using Element.getPointAtLength(length), but I don't know how. I think I should save the pathSegments and for each to compute the start Length and the finish Length.

  Read the article

• What web platform is right for me?

  - by egervari

  I've been looking at web frameworks like Rails, Grails, etc. I'm used to doing applications in Spring Framework with Hibernate... and I want something more productive. One of the things I realized is that while some of the things in Grails is sexy, there are some serious problems with it. Grails' controllers: 1) are implemented awfully. They don't seem to be able to extend from super classes at runtime. I tried this to add base actions and helper methods, and this seems to cause grails to blow up. 2) are based on an obsolete request parameters model (rather than form backing objects, which are much nicer). 3) are hard to test. Command objects are treated totally differently... and it's actually MUCH harder to write the test than it is to write the controller code. 4) Command objects operate totally differently. They are pre-validated and bound, which causes a lot of inconsistencies than basic parameter model. 5) Command objects are not reusable, and it's a pain in the rear to reuse most of the stuff from the domain classes, like constraints and fields. This is TRIVIAL to do in basic Spring. Why the hell was it not trivial to do in Grails? 6) The scaffolding that is generated is pure crap. It doesn't generalize inserts and updates... and it actually copy/pastes a pile of code in two views: create.gsp and edit.gsp. The views themselves are gargantuan piles of doggie do-do. This is further compounded by the fact that it uses low-level parameters and not objects. Integration tests are 30x slower than a Spring integration test. It is disgusting. Some mocking tests are so hard to write and aren't guaranteed to work when it's deployed, that I think it discourages fast, tdd test cycles. Most things seem to screw up grails while it's running, like adding a taglib, or anything really. The server restart problem wasn't solved at all. I'm starting to think going with Spring/Hibernate/Java is the only way to go. While there is a pretty big cost at startup, I know it'll eventually smooth out. It sucks I can't use a language like Scala... because idiomatically, it is so incompatible with Hibernate. This app is also not a run-of-the-mill UI over a database. It's got some of that, but it's not going to be a slouch. I am deathly scared of Grails now because of how crap it is in the Controller layer. Suggestions on what I can do?

  Read the article

• Adding Insert Row in tableView

  - by user333624

  Hello everyone, I have a tableView that loads its data directly from a Core Data table with a NSFetchedResultsController. I'm not using an intermediate NSMutableArray to store the objects from the fetch results; I basically implemented inside my UITableViewController the protocol method numberOfRowsInSection and it returns the numberOfObjects inside a NSFetchedResultsSectionInfo. id <NSFetchedResultsSectionInfo> sectionInfo = [[fetchedResultsController sections] objectAtIndex:section]; and then I configure the cell content by implementing configureCell:atIndexPath and retrieving object info from the fetchedResultController but right now I have a generic configuration for any object (to avoid complications) cell.textLabel.text = @"categoria"; I also have a NavigationBar with a custom edit button at the right that loads my own selector called customSetEditing. What I'm trying to accomplish is to load an "Insert Cell" at the beginning of the tableView so when I tap it, it creates a new record. This last part is easy to implement the problem is that I dont's seem to be able to load the insert row or any row when I tap on the navigation bar edit button. this is the code for my customSetEditing: - (void) customSetEditing { [super setEditing:YES animated:YES]; [self.tableView setEditing:YES animated:YES]; [[self tableView] beginUpdates]; //[[self tableView] beginUpdates]; UIBarButtonItem *customDoneButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(customDone)]; [self.navigationItem.rightBarButtonItem release]; self.navigationItem.rightBarButtonItem = customDoneButtonItem; //[categoriasArray insertObject:[NSNull null] atIndex:0]; NSMutableArray *indexPaths = [[NSMutableArray alloc] initWithObjects:[NSIndexPath indexPathForRow:0 inSection:0],nil ]; [self.tableView insertRowsAtIndexPaths:indexPaths withRowAnimation:UITableViewRowAnimationTop]; //[indexPaths release]; [self.tableView reloadData];} Before adding the:[self.tableView reloadData]; I was getting an out of bounds error plus a program crash and although the program is not crashing it is not loading anything. I have seen many examples of similar situations in stackoverflow (by the way is an excellent forum with very helpful and nice people) none of the examples seems to work for me. Any ideas?

  Read the article

• Advice on "Invalid Pointer Operation" when using complex records

  - by Xaz

  Env: Delphi 2007 <JustificationI tend to use complex records quite frequently as they offer almost all of the advantages of classes but with much simpler handling.</Justification Anyhoo, one particularly complex record I have just implemented is trashing memory (later leading to an "Invalid Pointer Operation" error). This is an example of the memory trashing code: sSignature := gProfiles.Profile[_stPrimary].Signature.Formatted(True); On the second time i call it i get "Invalid Pointer Operation" It works OK if i call it like this: AProfile := gProfiles.Profile[_stPrimary]; ASignature := AProfile.Signature; sSignature := ASignature.Formatted(True); Background Code: gProfiles: TProfiles; TProfiles = Record private FPrimaryProfileID: Integer; FCachedProfile: TProfile; ... public < much code removed > property Profile[ProfileType: TProfileType]: TProfile Read GetProfile; end; function TProfiles.GetProfile(ProfileType: TProfileType): TProfile; begin case ProfileType of _stPrimary : Result := ProfileByID(FPrimaryProfileID); ... end; end; function TProfiles.ProfileByID(iID: Integer): TProfile; begin <snip> if LoadProfileOfID(iID, FCachedProfile) then begin Result := FCachedProfile; end else ... end; TProfile = Record private ... public ... Signature: TSignature; ... end; TSignature = Record private public PlainTextFormat : string; HTMLFormat : string; // The text to insert into a message when using this profile function Formatted(bHTML: boolean): string; end; function TSignature.Formatted(bHTML: boolean): string; begin if bHTML then result := HTMLFormat else result := PlainTextFormat; < SNIP MUCH CODE > end; OK, so I have a record within a record within a record, which is approaching Inception level confusion and I'm the first to admit is not really a good model. Clearly i am going to have to restructure it. What I would like from you gurus is a better understanding of why it is trashing the memory (something to do with the string object that is created then freed...) so that i can avoid making these kinds of errors in future. Thanks

  Read the article

• UITableViewCell separator line disappears on scroll

  - by iconso

  I'm trying to have a separator cell with a custom image. I did try something like that: In my cellForRowAtIndexPath: NSString *cellIdentifier = [NSString stringWithFormat:@"identifier"]; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier]; if (cell == nil) { cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:cellIdentifier]; } cell.textLabel.font = [UIFont fontWithName:@"Helvetica" size:19]; cell.textLabel.text = [self.menuItems objectAtIndex:indexPath.row]; cell.textLabel.textColor = [UIColor colorWithRed:128/255.0f green:129/255.0f blue:132/255.0f alpha:1.0f]; cell.backgroundColor = [UIColor whiteColor]; UIImageView *imagView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"reaL.png"]]; imagView.frame = CGRectMake(0, cellHeight, cellWidth, 1); [cell.contentView addSubview:imagView]; switch (indexPath.row) { case 0: cell.imageView.image = [self imageWithImage:[UIImage imageNamed:@"img1.png"] scaledToSize:CGSizeMake(27, 27)]; cell.imageView.highlightedImage = [self imageWithImage:[UIImage imageNamed:@"route.png"] scaledToSize:CGSizeMake(27, 27)]; break; case 1: cell.imageView.image = [self imageWithImage:[UIImage imageNamed:@"img.png"] scaledToSize:CGSizeMake(27, 27)]; cell.imageView.highlightedImage = [self imageWithImage:[UIImage imageNamed:@"money.png"] scaledToSize:CGSizeMake(27, 27)]; break; case 2: cell.imageView.image = [self imageWithImage:[UIImage imageNamed:@"auto.png"] scaledToSize:CGSizeMake(27, 27)]; cell.imageView.highlightedImage = [self imageWithImage:[UIImage imageNamed:@"cars.png"] scaledToSize:CGSizeMake(27, 27)]; break; case 3: cell.imageView.image = [self imageWithImage:[UIImage imageNamed:@"impostazioni.png"] scaledToSize:CGSizeMake(27, 27)]; cell.imageView.highlightedImage = [self imageWithImage:[UIImage imageNamed:@"impostazioni.png"] scaledToSize:CGSizeMake(27, 27)]; // cell.imageView.contentMode = UIViewContentModeScaleAspectFill; break; case 4: cell.imageView.image = [self imageWithImage:[UIImage imageNamed:@"info.png"] scaledToSize:CGSizeMake(27, 27)]; cell.imageView.highlightedImage = [self imageWithImage:[UIImage imageNamed:@"info.png"] scaledToSize:CGSizeMake(27, 27)]; break; default: break; } return cell; When I lunch the app everything is good, but when I scroll the the table, or when I select a cell the separator lines disappear. How I can have a permanent custom line separator?

  Read the article

• [NHibernate and ASP.NET MVC] How can I implement a robust session-per-request pattern in my project,

  - by Guillaume Gervais

  I'm currently building an ASP.NET MVC project, with NHibernate as its persistance layer. For now, some functionnalities have been implemented, but only use local NHibernate sessions: each method that accessed the database (read or write) needs to instanciate its own NHibernate session, with the "using()" directive. The problem is that I want to leverage NHibernate's Lazy-Loading capabilities to improve the performance of my project. This implies an open NHibernate session per request until the view is rendered. Furthermore, simultaneous request must be supported (multiple Sessions at the same time). How can I achieve that as cleanly as possible? I searched the Web a little bit and learned about the session-per-request pattern. Most of the implementations I saw used some sort of Http* (HttpContext, etc.) object to store the session. Also, using the Application_BeginRequest/Application_EndRequest functions is complicated, since they get fired for each HTTP request (aspx files, css files, js files, etc.), when I only want to instanciate a session once per request. The concern that I have is that I don't want my views or controllers to have access to NHibernate sessions (or, more generally, NHibernate namespaces and code). That means that I do not want to handle sessions at the controller level nor the view one. I have a few options in mind. Which one seems the best ? Use interceptors (like in GRAILS) that get triggered before and after the controller action. These would open and close sessions/transactions. Is it possible in the ASP.NET MVC world? Use the CurrentSessionContext Singleton provided by NHibernate in a Web context. Using this page as an example, I think this is quite promising, but that still requires filters at the controller level. Use the HttpContext.Current.Items to store the request session. This, coupled with a few lines of code in Global.asax.cs, can easily provide me with a session on the request level. However, it means that dependencies will be injected between NHibernate and my views (HttpContext). Thank you very much!

  Read the article

• Writing a mini-language with haskell, trouble with "while" statements and blocks { }

  - by Nibirue

  EDIT: problem partially solved, skip to the bottom for update. I'm writing a small language using haskell, and I've made a lot of progress, but I am having trouble implementing statements that use blocks, like "{ ... }". I've implemented support for If statements like so in my parser file: stmt = skip +++ ifstmt +++ assignment +++ whilestmt ifstmt = symbol "if" >> parens expr >>= \c -> stmt >>= \t -> symbol "else" >> stmt >>= \e -> return $ If c t e whilestmt = symbol "while" >> parens expr >>= \c -> symbol "\n" >> symbol "{" >> stmt >>= \t -> symbol "}" >> return $ While c t expr = composite +++ atomic And in the Syntax file: class PP a where pp :: Int -> a -> String instance PP Stmt where pp ind (If c t e) = indent ind ++ "if (" ++ show c ++ ") \n" ++ pp (ind + 2) t ++ indent ind ++ "else\n" ++ pp (ind + 2) e pp ind (While c t) = indent ind ++ "while (" ++ show c ++") \n" ++ "{" ++ pp (ind + 2) t ++ "}" ++ indent ind Something is wrong with the while statement, and I don't understand what. The logic seems correct, but when I run the code I get the following error: EDIT: Fixed the first problem based on the first reply, now it is not recognizing my while statment which I assume comes from this: exec :: Env -> Stmt -> Env exec env (If c t e) = exec env ( if eval env c == BoolLit True then t else e ) exec env (While c t) = exec env ( if eval env c == BoolLit True then t ) The file being read from looks like this: x = 1; c = 0; if (x < 2) c = c + 1; else ; -- SEPARATE FILES FOR EACH x = 1; c = 1; while (x < 10) { c = c * x; x = x + 1; } c I've tried to understand the error report but nothing I've tried solves the problem.

  Read the article

• CSS Ease-in-out to full screen

  - by Aditya Singh

  I have a black background div of a size which contains an image. <div id="Banner"> <img onclick="expand();" src="hola.jpg"> </div> #Banner { position:relative; height:50px; width:50px; margin:0 auto; background-color:#000000; -webkit-transition: all 0.5s ease-in-out 0.5s; -moz-transition: all 0.5s ease-in-out 0.5s; -o-transition: all 0.5s ease-in-out 0.5s; transition: all 0.5s ease-in-out 0.5s; } <script type="text/javascript"> function expand(){ document.getElementById('Banner').style['height'] = '250'; document.getElementById('Banner').style['width'] = '250'; } </script> So when the user clicks on the image, the div transitions to 250, 250. My problem is that, i want it to to transition to full screen. The following javascript function does expand to fullscreen but the transition effect doesn't come. I need to do it from a javascript code without jquery. function expand(){ document.getElementById('Banner').style['position'] = 'absolute'; document.getElementById('Banner').style['height'] = '100%'; document.getElementById('Banner').style['width'] = '100%'; document.getElementById('Banner').style['top'] = '0'; document.getElementById('Banner').style['left'] = '0'; } Please advice. Update : Solution Roger below has provided with an alternative solution. This takes care if the document has already been scrolled and is another place. Will expand the div to full browser screen. sz=getSize(); //function returns screen width and height in pixels currentWidth=200; currentHeight=200; scalex=sz.W/currentWidth; scaley=sz.H/currentHeight; transx=0-((expandingDiv.offsetLeft+(currentWidth/2))-(sz.W/2))+document.body.scrollLeft; transy=0-((expandingDiv.offsetTop+(cuttentHeight/2))-(sz.H/2))+document.body.scrollTop; transx = transx.toString(); transy = transy.toString(); document.getElementById("Banner").style['-webkit-transform'] = 'translate('+transx+'px,'+transy+'px) scale('+scalex+','+scaley+')';

  Read the article

• circles and triangles problem

  - by Faken

  Hello everyone, I have an interesting problem here I've been trying to solve for the last little while: I have 3 circles on a 2D xy plane, each with the same known radius. I know the coordinates of each of the three centers (they are arbitrary and can be anywhere). What is the largest triangle that can be drawn such that each vertice of the triangle sits on a separate circle, what are the coordinates of those verticies? I've been looking at this problem for hours and asked a bunch of people but so far only one person has been able to suggest a plausible solution (though i have no way of proving it). The solution that we have come up with involves first creating a triangle about the three circle centers. Next we look at each circle individually and calculate the equation of a line that passes through the circle's center and is perpendicular to the opposite edge. We then calculate two intersection points of the circle. This is then done for the next two circles with a result of 6 points. We iterate over the 8 possible 3 point triangles that these 6 points create (the restriction is that each point of the big triangle must be on a separate circle) and find the maximum size. The results look reasonable (at least when drawn out on paper) and it passes the special case of when the centers of the circles all fall on a straight line (gives a known largest triangle). Unfortunate i have no way of proving this is correct or not. I'm wondering if anyone has encountered a problem similar to this and if so, how did you solve it? Note: I understand that this is mostly a math question and not programming, however it is going to be implemented in code and it must be optimized to run very fast and efficient. In fact, I already have the above solution in code and tested to be working, if you would like to take a look, please let me know, i chose not to post it because its all in vector form and pretty much impossible to figure out exactly what is going on (because it's been condensed to be more efficient). Lastly, yes this is for school work, though it is NOT a homework question/assignment/project. It's part of my graduate thesis (abet a very very small part, but still technically is part of it). Thanks for your help.

  Read the article

< Previous Page | 428 429 430 431 432 433 434 435 436 437 438 439  | Next Page >