Search Results

Search found 13469 results on 539 pages for 'avoid trouble'.

Page 459/539 | < Previous Page | 455 456 457 458 459 460 461 462 463 464 465 466  | Next Page >

• Testing approach for multi-threaded software

  - by Shane MacLaughlin

  I have a piece of mature geospatial software that has recently had areas rewritten to take better advantage of the multiple processors available in modern PCs. Specifically, display, GUI, spatial searching, and main processing have all been hived off to seperate threads. The software has a pretty sizeable GUI automation suite for functional regression, and another smaller one for performance regression. While all automated tests are passing, I'm not convinced that they provide nearly enough coverage in terms of finding bugs relating race conditions, deadlocks, and other nasties associated with multi-threading. What techniques would you use to see if such bugs exist? What techniques would you advocate for rooting them out, assuming there are some in there to root out? What I'm doing so far is running the GUI functional automation on the app running under a debugger, such that I can break out of deadlocks and catch crashes, and plan to make a bounds checker build and repeat the tests against that version. I've also carried out a static analysis of the source via PC-Lint with the hope of locating potential dead locks, but not had any worthwhile results. The application is C++, MFC, mulitple document/view, with a number of threads per doc. The locking mechanism I'm using is based on an object that includes a pointer to a CMutex, which is locked in the ctor and freed in the dtor. I use local variables of this object to lock various bits of code as required, and my mutex has a time out that fires my a warning if the timeout is reached. I avoid locking where possible, using resource copies where possible instead. What other tests would you carry out?

  Read the article

• Block facebook from my website

  - by Joseph Szymborski

  I have a secure link direction service I'm running (expiringlinks.co). If I change the headers in php to redirect my visitors, then facebook is able to show a preview of the website I'm redirecting to when users send links to one another via facebook. I wish to avoid this. Right now, I'm using an AJAX call to get the URL and javascript to redirect, but it's causing problems for users who don't use javascript. Here are a number of ways I'd like to block facebook, but I can't seem to get working: I've tried blocking the facebook bot (facebookexternalhit/1.0 and facebookexternalhit/1.1) but it's not working, I don't think they're using them for this functionality. I'm thinking of blocking the facebook IP addresses, but I can't find all of them, and I don't think it'll work unless I get all of them. I've thought of using a CAPTCHA or even a button, but I can't bring myself to do that to my visitors. Not to mention I don't think anyone would use the site. I've searched the facebook docs for meta tags that would "opt-me out", but haven't found one, and doubt that I would trust it if I had. Any creative ideas or any idea how to implement the ones above? Thank you so much in advance!

  Read the article

• Http authentication with apache httpcomponents

  - by matdan

  Hi, I am trying to develop a java http client with apache httpcomponents 4.0.1. This client calls the page "https://myHost/myPage". This page is protected on the server by a JNDIRealm with a login form authentication, so when I try to get https://myHost/myPage I get a login page. I tried to bypass it unsuccessfully with the following code : //I set my proxy HttpHost proxy = new HttpHost("myProxyHost", myProxyPort); //I add supported schemes SchemeRegistry supportedSchemes = new SchemeRegistry(); supportedSchemes.register(new Scheme("http", PlainSocketFactory .getSocketFactory(), 80)); supportedSchemes.register(new Scheme("https", SSLSocketFactory .getSocketFactory(), 443)); // prepare parameters HttpParams params = new BasicHttpParams(); HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1); HttpProtocolParams.setContentCharset(params, "UTF-8"); HttpProtocolParams.setUseExpectContinue(params, true); ClientConnectionManager ccm = new ThreadSafeClientConnManager(params, supportedSchemes); DefaultHttpClient httpclient = new DefaultHttpClient(ccm, params); httpclient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy); //I add my authentication information httpclient.getCredentialsProvider().setCredentials( new AuthScope("myHost/myPage", 443), new UsernamePasswordCredentials("username", "password")); HttpHost host = new HttpHost("myHost", 443, "https"); HttpGet req = new HttpGet("/myPage"); //show the page ResponseHandler<String> responseHandler = new BasicResponseHandler(); String rsp = httpClient.execute(host, req, responseHandler); System.out.println(rsp); When I run this code, I always get the login page, not myPage. How can I apply my credential parameters to avoid this login form? Any help would be fantastic

  Read the article

• Visitor Pattern can be replaced with Callback functions?

  - by getit

  Is there any significant benefit to using either technique? In case there are variations, the Visitor Pattern I mean is this: http://en.wikipedia.org/wiki/Visitor_pattern And below is an example of using a delegate to achieve the same effect (at least I think it is the same) Say there is a collection of nested elements: Schools contain Departments which contain Students Instead of using the Visitor pattern to perform something on each collection item, why not use a simple callback (Action delegate in C#) Say something like this class Department { List Students; } class School { List Departments; VisitStudents(Action<Student> actionDelegate) { foreach(var dep in this.Departments) { foreach(var stu in dep.Students) { actionDelegate(stu); } } } } School A = new School(); ...//populate collections A.Visit((student)=> { ...Do Something with student... }); *EDIT Example with delegate accepting multiple params Say I wanted to pass both the student and department, I could modify the Action definition like so: Action class School { List Departments; VisitStudents(Action<Student, Department> actionDelegate, Action<Department> d2) { foreach(var dep in this.Departments) { d2(dep); //This performs a different process. //Using Visitor pattern would avoid having to keep adding new delegates. //This looks like the main benefit so far foreach(var stu in dep.Students) { actionDelegate(stu, dep); } } } }

  Read the article

• ReaderWriterLockSlim and Pulse/Wait

  - by Jono

  Is there an equivalent of Monitor.Pulse and Monitor.Wait that I can use in conjunction with a ReaderWriterLockSlim? I have a class where I've encapsulated multi-threaded access to an underlying queue. To enqueue something, I acquire a lock that protects the underlying queue (and a couple of other objects) then add the item and Monitor.Pulse the locked object to signal that something was added to the queue. public void Enqueue(ITask task) { lock (mutex) { underlying.Enqueue(task); Monitor.Pulse(mutex); } } On the other end of the queue, I have a single background thread that continuously processes messages as they arrive on the queue. It uses Monitor.Wait when there are no items in the queue, to avoid unnecessary polling. (I consider this to be good design, but any flames (within reason) are welcome if they help me learn otherwise.) private void DequeueForProcessing(object state) { while (true) { ITask task; lock (mutex) { while (underlying.Count == 0) { Monitor.Wait(mutex); } task = underlying.Dequeue(); } Process(task); } } As more operations are added to this class (requiring read-only access to the lock protected underlying), someone suggested using ReaderWriterLockSlim. I've never used the class before, and assuming it can offer some performance benefit, I'm not against it, but only if I can keep the Pulse/Wait design.

  Read the article

• HTTP Compression problems on IIS7

  - by Jonathan Wood

  I've spent quite a bit of time on this but seem to be going nowhere. I have a large page that I really want to speed up. The obvious place to start seems to be HTTP compression, but I just can't seem to get it to work for me. After considerable searching, I've tried several variations of the code below. It kind of works, but after refreshing the browser, the results seem to fall apart. They were turning to garbage when the page used caching. If I turn off caching, then the page seems right but I lose my CSS formatting (stored in a separate file) and get an error that an included JS file contains invalid characters. Most of the resources I've found on the Web were either very old or focused on accessing IIS directly. My page is running on a shared hosting account and I do not have direct access to IIS7, which it's running on. protected void Application_BeginRequest(object sender, EventArgs e) { // Implement HTTP compression if (Request["HTTP_X_MICROSOFTAJAX"] == null) // Avoid compressing AJAX calls { // Retrieve accepted encodings string encodings = Request.Headers.Get("Accept-Encoding"); if (encodings != null) { // Verify support for or gzip (deflate takes preference) encodings = encodings.ToLower(); if (encodings.Contains("gzip") || encodings == "*") { Response.Filter = new GZipStream(Response.Filter, CompressionMode.Compress); Response.AppendHeader("Content-Encoding", "gzip"); Response.Cache.VaryByHeaders["Accept-encoding"] = true; } else if (encodings.Contains("deflate")) { Response.Filter = new DeflateStream(Response.Filter, CompressionMode.Compress); Response.AppendHeader("Content-Encoding", "deflate"); Response.Cache.VaryByHeaders["Accept-encoding"] = true; } } } } Is anyone having better success with this?

  Read the article

• Why does Android allocate more memory than needed when loading images

  - by Simon

  Folks, I don't think that this is a duplicate and is NOT one of those how do I avoid OOMs questions. This is a genuine quest for knowledge so hold off on those down votes please... Imagine I have a JPEG of 500x500 pixels. I load it as ARGB_8888 which is as "bad as it gets". I would expect Android to allocate 500x500x4 bytes = a little under 1MB however, look at a heap dump and you will see that Android allocates significantly more, often factors of 5-10 times greater. You frequently see questions on here about OOMS where the stack trace shows a heap request of say 15MB and it is ALWAYS much larger than is required simply to hold the bytes of the image. The OP usually catches some downvotes then is bombarded with stock answers and comments about using less memory (thanks Romain!) and in scaling. I think there is more than meets the eye here. Anybody know why this is? If there is no apparent answer, I will put together an SSCCE if it helps. PS. I assume that JPEG vs PNG etc is irrelevant since we're talking about the memory usage of the backing bitmap which is simply x times y times BPP - or am I being slow?

  Read the article

• Initialize Static Array of Structs in C

  - by russell_h

  I implementing a card game in C. There are lots of types of cards and each has a bunch of information, including some actions that will need to be individually scripted associated with it. Given a struct like this (and I'm not certain I have the syntax right for the function pointer) struct CARD { int value; int cost; // This is a pointer to a function that carries out actions unique // to this card int (*do_actions) (struct GAME_STATE *state, int choice1, int choice2); }; I would like to initialize a static array of these, one for each card. I'm guessing this would look something like this int do_card0(struct GAME_STATE *state, int choice1, int choice2) { // Operate on state here } int do_card1(struct GAME_STATE *state, int choice1, int choice2) { // Operate on state here } extern static struct cardDefinitions[] = { {0, 1, do_card0}, {1, 3, do_card1} }; Will this work, and am I going about this the right way at all? I'm trying to avoid huge numbers of switch statements. Do I need to define the 'do_cardN' functions ahead of time, or is there some way to define them inline in the initialization of the struct (something like a lambda function in python)? I'll need read-only access to cardDefinitions from a different file - is 'extern static' correct for that? I know this is a lot of questions rolled into one but I'm really a bit vague about how to go about this. Thanks.

  Read the article

• Is unnecessary error handling recommended in business logic? eg. Null check/Percentage limit check etc

  - by novice_at_work

  We usually put unnecessary checks in our business logic to avoid failures. Eg. 1. public ObjectABC funcABC(){ ObjectABC obj = new ObjectABC; .......... .......... //its never set to null here. .......... return obj; } ObjectABC o = funABC(); if(o!=null){ //do something } Why do we need this null check if we are sure that it will never be null? Is it a good practice or not? 2. int pplReached = funA(..,..,..); int totalPpl = funB(..,..,..); funA() just puts a few more restriction over result of funB(). Double percentage = (totalPpl==0||totalPpl<pplReached) ? 0.0 : pplReached/totalPpl; Do we again need this check? The questions is: Aren't we swallowing some fundamental issue by putting such checks? Issues which should be shown ideally, are avoided by putting these checks. What is the recommended way?

  Read the article

• (nested) user controls within a mvp pattern causing sporadic problems

  - by LLEA

  hi everyone, I have a serious problem with nested user controls (UCs) in WinForms while trying to implement the mvp pattern (passive view). The project consists of one model (designed as a singleton) and a set of different presenters with corresponding view interfaces. To avoid one huge view interface and therefore an overloaded main UI, I decided to make use of a set of different UCs. Each UC has one view interface and one presenter that can access the model. But there are nested UCs: meaning that one specialised UC implements sort of a basic UC. The main UI just represents a container for all those UCs. So far, so good (if not, please ask)?! There are two problems that I am facing now (but I guess both are of the same origin): From time to time it is not possible anymore to load the UCs and test them within the Visual Studio 2008 User Control Test Container. The error message just says that a project with an output type of class library cannot be started directly etc. I can "handle" that by unloading all UC projects and reloading them afterwards. (I guess the references to all mvp components and other UCs are then updated). Assuming that the implementation of my mvp pattern is okay and all those UCs are testable within the VS Test Container at a certain time - there is the biggest problem still left: I am not able to add any UC (even the basic and unnested ones) to a simple Form (UI). The error message: error message.jpg Could it be that my basic UC causes all these Problems?! It consists of two simple ComboBoxes and implements a basic presenter and basic view interface. Whenever I add this UC to a different UC the VS designer adds two references to the public getter methods of the UC as resources. I then manually remove those resources from the resx-file and commend the corresponding lines in the designer file. thx in advance

  Read the article

• Read whole ASCII file into C++ std::string

  - by Arrieta

  Hello, I need to read a whole file into memory and place it in a C++ std::string. If I were to read it into a char, the answer would be very simple: std::ifstream t; int lenght; t.open("file.txt", "r"); // open input file t.seekg(0, std::ios::end); // go to the end length = t.tellg(); // report location (this is the lenght) t.seekg(0, std::ios::beg); // go back to the beginning buffer = new char[length]; // allocate memory for a buffer of appropriate dimension t.read(buffer, length); // read the whole file into the buffer t.close(); // close file handle // ... do stuff with buffer here ... Now, I want to do the exact same thing, but using a std::string instead of a char. I want to avoid loops, i. e., I don't want to: std::ifstream t; t.open("file.txt", "r"); std::string buffer; std::string line; while(t){ std::getline(t, line); // ... append line to buffer and go on } t.close() any ideas?

  Read the article

• How to process XML sernt via POST?

  - by John Conde

  I'm receiving XML sent via POST. Naturally I need to parse this XML to get at the goodies it holds for me. However, when I receive the XML is seems that PHP is parsing it like a query string. For example, this xml: <?xml version="1.0" encoding="utf-8"?> <ForgotPassword> <version>1.0</version> <authentication> <login>myresllerid</login> <apikey>1234567890abcdef</apikey> </authentication> <parameters> <emailAddress>[email protected]</emailAddress> </parameters> </ForgotPassword> Becomes this (from print_r($_REQUEST)): Array ( [ <?xml_version] => "1.0" encoding="utf-8"?> <IDCForgotPassword> <version>1.0</version> <authentication> <login>myresllerid</login> <apikey>1234567890abcdef</apikey> </authentication> <parameters> <emailAddress>[email protected]</emailAddress> </parameters> </IDCForgotPassword> ) You can see the XML is being broken up at the first equals sign (=) in the XML into a key/value pair. How do I avoid this?

  Read the article

• UITableViewCell Problem....

  - by balu

  Hi friends... i am creating a Custom reusable UITableViewCell with Three labels and one imageView,and i am removing them in cell's dealloc method... all is working fine but the problem is the text in cell getting Dark while selected... it and it is kind of overlapping on each other help me to avoid that problem... - (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier { if (self = [super initWithStyle:style reuseIdentifier:reuseIdentifier]) { NSLog(@"Address for cel called"); NameLbl = [[UILabel alloc] initWithFrame:CGRectMake(5,5,140,20)]; [self.contentView addSubview:NameLbl]; NameLbl.font =[UIFont fontWithName:@"Times New Roman" size:15]; NameLbl.font = [UIFont boldSystemFontOfSize:15]; NameLbl.opaque=YES; NameLbl.tag = 1001; AddressLbl = [[UILabel alloc] initWithFrame:CGRectMake(5,25,140,20)]; [self.contentView addSubview:AddressLbl]; AddressLbl.font =[UIFont fontWithName:@"Times New Roman" size:15]; AddressLbl.opaque=YES; AddressLbl.tag = 1002; CityStateZipLbl = [[UILabel alloc] initWithFrame:CGRectMake(5,50,150,20)]; [self.contentView addSubview:CityStateZipLbl]; CityStateZipLbl.opaque=YES; CityStateZipLbl.tag = 1003; CityStateZipLbl.font =[UIFont fontWithName:@"Times New Roman" size:15]; } return self; } - (void)dealloc { [CityStateZipLbl release]; [NameLbl release]; [AddressLbl release]; [super dealloc]; }

  Read the article

• How to check for mip-map availability in OpenGL?

  - by Xavier Ho

  Recently I bumped into a problem where my OpenGL program would not render textures correctly on a 2-year-old Lenovo laptop with an nVidia Quadro 140 card. It runs OpenGL 2.1.2, and GLSL 1.20, but when I turned on mip-mapping, the whole screen is black, with no warnings or errors. This is my texture filter code: glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_TRUE); After 40 minutes of fiddling around, I found out mip-mapping was the problem. Turning it off fixed it: // glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); // glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_TRUE); I get a lot of aliasing, but at least the program is visible and runs fine. Finally, two questions: What's the best or standard way to check if mip-mapping is available on a machine, aside from checking OpenGL versions? If mip-mapping is not available, what's the best work-around to avoid aliasing?

  Read the article

• Wait until image loads before performing function

  - by Steven

  I'm trying to create a simple portfolio page. I have a list of thumbs and an image. When you click on a thumb, the image will change. When a thumbnail is clicked, I'd like to have the image fade out, wait until the image is loaded, then fade back in. The problem I have right now is that some of the images are pretty big, so it fades out, then fades back in immediately, sometimes while the image is still loading. I'd like to avoid using setTimeout, since sometimes an image will load faster or slower than the time I set. Here's my code: $(function() { $('img#image').attr("src", $('ul#thumbs li:first img').attr("src")); $('ul#thumbs li img').click(function() { $('img#image').fadeOut(700); var src = $(this).attr("src"); $('img#image').attr("src", src); $('img#image').fadeIn(700); }); }); <img id="image" src="" alt="" /> <ul id="thumbs"> <li><img src="/images/thumb1.png" /></li> <li><img src="/images/thumb2.png" /></li> <li><img src="/images/thumb3.png" /></li> </ul>

  Read the article

• Vim: Making Auto-Completion Smarter

  - by Rafid K. Abdullah

  I use ctags, taglist, etc., to have auto completion in Vim. However, it is very limited compared to Visual Studio intellisense or Eclipse auto-completion. I am wondering whether it is possible to tune Vim to: Show auto-completion whenever . or - are typed. But only after some text that might be a variable (e.g. avoid showing auto completion after a number). Show function parameters when ( is typed. Stop removing the auto completion list when some delete all characters after . or -: When I enter a variable name, then press . or - to search for a certain member, I frequently have to delete all the characters I type after the . or -, but this makes Vim hide the auto completion list. I would like to keep it visible unless I press Esc. Showing related auto completion: When I type a variable and press ^X ^O, it usually shows me all the tags in the ctags file. I would like to have it showing only the tags related to the variable. Thanks for the help. EDIT: Some people are voting for this question, but no body seems to know the answer. So just wanted to mention that you don't have to provide a complete answer; partial answers to any of the mentioned points would be good also.

  Read the article

• Client-server synchronization pattern / algorithm?

  - by tm_lv

  I have a feeling that there must be client-server synchronization patterns out there. But i totally failed to google up one. Situation is quite simple - server is the central node, that multiple clients connect to and manipulate same data. Data can be split in atoms, in case of conflict, whatever is on server, has priority (to avoid getting user into conflict solving). Partial synchronization is preferred due to potentially large amounts of data. Are there any patterns / good practices for such situation, or if you don't know of any - what would be your approach? Below is how i now think to solve it: Parallel to data, a modification journal will be held, having all transactions timestamped. When client connects, it receives all changes since last check, in consolidated form (server goes through lists and removes additions that are followed by deletions, merges updates for each atom, etc.). Et voila, we are up to date. Alternative would be keeping modification date for each record, and instead of performing data deletes, just mark them as deleted. Any thoughts?

  Read the article

• Ember Data Sycn - LocalStorage+REST+RealTime+Online/Offline

  - by Miguel Madero

  We have a combination of requirements in terms o data access. Pre-load some reference data. We need reference data to survive browser restarts instead of just living in memory to avoid loading it all the time. I'm currently using the LocalStorageAdapter for that. Once we have it, we would like to sync changes (polling or using Socket.IO in the background and updating the LocalStorage could do the trick) There're other models that are more transactional, where we would need to directly go to the Server and get/save them. It would be nice to use something like the RESTAdapter for that. Lastly, there're some operations that should work off-line and changes should be synced later. To make it more concrete: * We pre-load vendor and "favorite products" into Local Storage. We work offline with those. * We need to sync server changes to vendor and product information. * If they search the full catalog, that requires them to be online. * When offline, we need to allow users to add something to their cart or even submit and order. We would like to queue this action and submit it when they have an Internet Connection. So a few questions are derived from this: * Is there a way to user RESTAdapter in combination with LocalStorage? * Is there some Socket.IO support? (Happy to do this part manually) * Is there Queueing support? Ideally at the Ember-Data level. I know we will have to do a lot of this manually and pull together the different lego pieces, but I wanted to ask for some perspective from experience Ember devs.

  Read the article

• Scala implicit dynamic casting

  - by weakwire

  I whould like to create a scala Views helper for Android Using this combination of trait and class class ScalaView(view: View) { def onClick(action: View => Any) = view.setOnClickListener(new OnClickListener { def onClick(view: View) { action(view) } }) } trait ScalaViewTrait { implicit def view2ScalaView(view: View) = new ScalaView(view) } I'm able to write onClick() like so class MainActivity extends Activity with ScalaViewTrait { //.... val textView = new TextView(this) textView.onClick(v => v.asInstanceOf[TextView] setText ("asdas")) } My concern is that i want to avoid casting v to TextView v will always be TextView if is applied to a TextView LinearLayout if applied to LinearLayout and so on. Is there any way that v gets dynamic casted to whatever view is applied? Just started with Scala and i need your help with this. UPDATE With the help of generics the above get's like this class ScalaView[T](view: View) { def onClick(action: T => Any) = view.setOnClickListener(new OnClickListener { def onClick(view: View) { action(view.asInstanceOf[T]) } }) } trait ScalaViewTrait { implicit def view2ScalaView[T](view: View) = new ScalaView[T](view) } i can write onClick like this view2ScalaView[TextView](textView) .onClick(v => v.setText("asdas")) but is obvious that i don't have any help from explicit and i moved the problem instead or removing it

  Read the article

• Alternative for table mark-up in ASP.NET not working properly

  - by yetanothercoder

  Using Visual WebDeveloper 2010 Express and ASP.NET 4.0 Don't know whether its relevant but the whole thing is in a ContentPlaceHolder and inside an UpdatePanel. To avoid using the old table tr td model, I have created a simple form like this <div class="admin-form"> <asp:Label ID="UserNameLabel" runat="server" CssClass="form-label" Text="User Name" /> <asp:TextBox ID="UserNameText" runat="server" Width="200px"/> <br /> <asp:Label ID="PasswordLabel" runat="server" CssClass="form-label" Text="Password" /> <asp:TextBox ID="PasswordText" runat="server" TextMode="Password" Width="200px"/> <br /> <asp:Label ID="ConfirmPasswordLabel" runat="server" CssClass="form-label" Text="Confirm Password" /> <asp:TextBox ID="ConfirmPasswordText" runat="server" TextMode="Password" Width="200px"/> <br /> <asp:Label ID="EmailLabel" runat="server" CssClass="form-label" Text="Email" /> <asp:TextBox ID="EmailText" runat="server" Width="200px"/> <br /> <br /> <br /> <span class="form-label"></span> <asp:Button ID="CreateUserButton" runat="server" CssClass="button blue" Text="Create New User"/> </div> And the CSS .form-label { width: 300px !important; } This renders incorrectly as I would like to have all textboxes vertically lined after taking 300px. What is wrong? P.S: I cannot use HTML Controls like label as I have resx for globalization

  Read the article

• How to easily map c++ enums to strings

  - by Roddy

  I have a bunch of enum types in some library header files that I'm using, and I want to have a way of converting enum values to user strings - and vice-versa. RTTI won't do it for me, because the 'user strings' need to be a bit more readable than the enumerations. A brute force solution would be a bunch of functions like this, but I feel that's a bit too C-like. enum MyEnum {VAL1, VAL2,VAL3}; String getStringFromEnum(MyEnum e) { switch e { case VAL1: return "Value 1"; case VAL2: return "Value 2"; case VAL1: return "Value 3"; default: throw Exception("Bad MyEnum"); } } I have a gut feeling that there's an elegant solution using templates, but I can't quite get my head round it yet. UPDATE: Thanks for suggestions - I should have made clear that the enums are defined in a third-party library header, so I don't want to have to change the definition of them. My gut feeling now is to avoid templates and do something like this: char * MyGetValue(int v, char *tmp); // implementation is trivial #define ENUM_MAP(type, strings) char * getStringValue(const type &T) \ { \ return MyGetValue((int)T, strings); \ } ; enum eee {AA,BB,CC}; - exists in library header file ; enum fff {DD,GG,HH}; ENUM_MAP(eee,"AA|BB|CC") ENUM_MAP(fff,"DD|GG|HH") // To use... eee e; fff f; std::cout<< getStringValue(e); std::cout<< getStringValue(f);

  Read the article

• Trie Backtracking in Recursion

  - by Darksky

  I am building a tree for a spell checker with suggestions. Each node contains a key (a letter) and a value (array of letters down that path). So assume the following sub-trie in my big trie: W / \ a e | | k k | | is word--> e e | ... This is just a subpath of a sub-trie. W is a node and a and e are two nodes in its value array etc... At each node, I check if the next letter in the word is a value of the node. I am trying to support mistyped vowels for now. So 'weke' will yield 'wake' as a suggestion. Here's my searchWord function in my trie: def searchWord(self, word, path=""): if len(word) > 0: key = word[0] word = word[1:] if self.values.has_key(key): path = path + key nextNode = self.values[key] return nextNode.searchWord(word, path) else: # check here if key is a vowel. If it is, check for other vowel substitutes else: if self.isWord: return path # this is the word found else: return None Given 'weke', at the end when word is of length zero and path is 'weke', my code will hit the second big else block. weke is not marked as a word and so it will return with None. This will return out of searchWord with None. To avoid this, at each stack unwind or recursion backtrack, I need to check if a letter is a vowel and if it is, do the checking again. I changed the if self.values.has_key(key) loop to the following: if self.values.has_key(key): path = path + key nextNode = self.values[key] ret = nextNode.searchWord(word, path) if ret == None: # check if key == vowel and replace path # return nextNode.searchWord(... return ret What am I doing wrong here? What can I do when backtracking to achieve what I'm trying to do?

  Read the article

• Give More Prominence To DIV or <P> That Is After Floating DIV

  - by Aahan Krish

  Consider this HTML: <div id="entry-content"> <div id="my-300px-ad">AD CODE HERE</div> <p><img src="file.jpg" alt="file" /></p> <p>SOME TEXT</p> <p>SOME MORE TEXT</p> </div> Now, consider that the div#my-300px-ad is floating right. Would it be possible for me to have the image in the next paragraph show up before the ad so that the TEXT in its following paragraphs can wrap around the ad? For example, like this: Why so...? The thing is, due to various reasons (including Google) I want to avoid placing an ad in BETWEEN the post's content. CSS only I am sure that something like this would be possible with some JavaScript code. But I am looking for a CSS-based solution only. (Cross-browser compatibility, = IE8) Please note that ONLY the CSS of div#my-300px-ad can be changed. Nothing else should be touched as this is not a static HTML page, besides they are articles. PS: It was hard to frame a one-line question for this. Please feel free to edit the question's title if it can be made more clear.

  Read the article

• CFfile -- value is not set to the queried data

  - by user494901

  I have this add user form, it also doubles as a edit user form by querying the data and setting the value="#query.xvalue#". If the user exists (eg, you're editing a user, it loads in the users data from the database. When doing this on the <cffile field it does not load in the data, then when the insert goes to insert data it overrights the database values with a blank string (If a user does not input a new file). How do I avoid this? Code: Form: <br/>Digital Copy<br/> <!--- If null, set a default if not, set the default to database default ---> <cfif len(Trim(certificationsList.cprAdultImage)) EQ 0> <cfinput type="file" required="no" name="cprAdultImage" value="" > <cfelse> File Exists: <cfoutput><a href="#certificationsList.cprAdultImage#">View File</a></cfoutput> <cfinput type="file" required="no" name="cprAdultImage" value="#certificationsList.cprAdultImage#"> </cfif> Form Processor: <!--- Has a file been specificed? ---> <cfif not len(Trim(form.cprAdultImage)) EQ 0> <cffile action="upload" filefield="cprAdultImage" destination="#destination#" nameConflict="makeUnique"> <cfinvokeargument name="cprAdultImage" value="#pathOfFile##cffile.serverFile#"> <cfelse> <cfinvokeargument name="cprAdultImage" value=""> </cfif> CFC ARGS: <cfargument name="cprAdultExp" required="NO"> <cfargument name="cprAdultCompany" type="string" required="no"> <cfargument name="cprAdultImage" type="string" required="no"> <cfargument name="cprAdultOnFile" type="boolean" required="no"> Query: UPDATE mod_StudentCertifications SET cprAdultExp='#DateFormat(ARGUMENTS.cprAdultExp, "mm/dd/yyyy")#', cprAdultCompany='#Trim(ARGUMENTS.cprAdultCompany)#', cprAdultImage='#Trim(ARGUMENTS.cprAdultImage)#', cprAdultOnFile='#Trim(ARGUMENTS.cprAdultOnFile)#' INSERT INTO mod_StudentCertifications( cprAdultExp, cprAdultcompany, cprAdultImage, cprAdultOnFile

  Read the article

• How to check for a null object reference when validating forms in MVC

  - by quakkels

  Hello SO, I'm experimenting with validating forms in the asp.net MVC framework. I'm focusing on server side validation for the time being. I've come across an error that I'm not sure how to rectify. System.NullReferenceException: Object reference not set to an instance of an object. The code that throws the error is: [AcceptVerbs(HttpVerbs.Post)] public ActionResult Create([Bind(Exclude="ID")] MembersCreate mc ) { mc.Modules = ModuleListDataContext.GetModuleList(); ViewData.Model = mc; //Validation using ModelState // // //line below errors when form field is empty // if ((string)mc.Member.Username.Trim() == "") ModelState.AddModelError("Member.Username", "Username is required."); if (!ModelState.IsValid) return View(); try { // TODO: Add insert logic here return RedirectToAction("Index","Home"); } catch { return View(); } } When I put spaces in the field it performs exactly as i want, but if I leave the field blank and press submit I get the error. What's the best way to avoid this error and still validate blank form fields? Thanks all -

  Read the article

< Previous Page | 455 456 457 458 459 460 461 462 463 464 465 466  | Next Page >