Search Results

Search found 13867 results on 555 pages for 'avoid learning'.

Page 479/555 | < Previous Page | 475 476 477 478 479 480 481 482 483 484 485 486  | Next Page >

  • Model-binding an object from the repository by several keys

    - by Anton
    Suppose the following route: {region}/{storehouse}/{controller}/{action} These two parameters region and storehouse altogether identify a single entity - a Storehouse. Thus, a bunch of controllers are being called in the context of some storehouse. And I'd like to write actions like this: public ActionResult SomeAction(Storehouse storehouse, ...) Here I can read your thoughts: "Write custom model binder, man". I do. However, the question is How to avoid magic strings within custom model binder? Here is my current code: public class StorehouseModelBinder : IModelBinder { readonly IStorehouseRepository repository; public StorehouseModelBinder(IStorehouseRepository repository) { this.repository = repository; } public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext) { var region = bindingContext.ValueProvider.GetValue("region").AttemptedValue; var storehouse = bindingContext.ValueProvider.GetValue("storehouse").AttemptedValue; return repository.GetByKey(region, storehouse); } } If there was a single key, bindingContext.ModelName could be used... Probably, there is another way to supply all the actions with a Storehouse object, i.e. declaring it as a property of the controller and populating it in the Controller.Initialize.

    Read the article

  • JDBC transaction dead-lock solution required?

    - by user49767
    It's a scenario described my friend and challenged to find solution. He is using Oracle database and JDBC connection with read committed as transaction isolation level. In one of the transaction, he updates a record and executes selects statement and commits the transaction. when everything happening within single thread, things are fine. But when multiple requests are handled, dead-lock happens. Thread-A updates a record. Thread B updates another record. Thread-A issues select statement and waits for Thread-B's transaction to complete the commit operation. Thread-B issues select statement and waits for Thread-A's transaction to complete the commit operation. Now above causes dead-lock. Since they use command pattern, the base framework allows to issue commit only once (at the end of all the db operation), so they are unable to issue commit immediately after select statement. My argument was Thread-A supposed to select all the records which are committed and hence should not be issue. But he said that Thread-A will surely wait till Thread-B commits the record. is that true? What are all the ways, to avoid the above issue? is it possible to change isolation-level? (without changing underlying java framework) Little information about base framework, it is something similar to Struts action, their each and every request handled by one action, transaction begins before execution and commits after execution.

    Read the article

  • Why am I getting a permission denied error on my public folder?

    - by Robin Fisher
    Hi all, This one has got me stumped. I'm deploying a Rails 3 app to Slicehost running Apache 2 and Passenger. My server is running Ruby 1.9.1 using RVM. I am receiving a permission denied error on the "public" folder in my app. My Virtual Host is setup as follows: <VirtualHost *:80> ServerName sharerplane.com ServerAlias www.sharerplane.com ServerAlias *.sharerplane.com DocumentRoot /home/robinjfisher/public_html/sharerplane.com/current/public/ <Directory "/home/robinjfisher/public_html/sharerplane.com/public/"> AllowOverride all Options -MultiViews Order allow,deny Allow from all </Directory> PassengerDefaultUser robinjfisher </VirtualHost> I've tried the following things: trailing slash on public; no trailing slash on public; PassengerUserSwitching on and off; PassengerDefaultUser set and not set; with and without the block. The public folder is owned by robinjfisher:www-data and Passenger is running as robinjfisher so I can't see why there are permission issues. Does anybody have any thoughts? Thanks Robin PS. Have disabled the site for the time being to avoid indexing so what is there currently is not the site in question.

    Read the article

  • A potentially dangerous Request.Form value was detected: Dealing with these errors proactively, or a

    - by Albert
    I'm noticing this error more and more in my error logs. I've read through the questions here talking about this error, but they don't address what I would like to do (see below). I'm considering three options, in the order of preference: 1) When submitting a form (I use formviews almost exclusively, if that helps), if potentially dangerous characters are detected, automatically strip them out and submit. 2) When submitting a form, if potentially dangerous characters are detected, alert the user and let them fix it before trying again. 3) After the exception is generated, deal with it and alert the user. I'm hoping one of the first two options might be able to do somewhat globally...I know for the 3rd I'd have to alter a TON of Try-Catch blocks I already have in place. Doable, but labor intensive. I'd rather be proactive about it if at all possible and avoid the exception all together. Perhaps one approach to #1 would be to write a block of code that could loop through all text entry fields in a formview, during the insert/update event, and strip the characters out. I'm ok with that, but I'd rather not have to heavily alter all my Insert/Update events to accomplish this. Or maybe I just create a different class to do the text checking/deleting, and only insert 1 line of code in each Insert/Update event. If anyone can come up with some example code of any of these approaches that would be a help. Thanks for any ideas or information. I'm definitely open to other solutions too; these are only the 3 that came to mind. I can say that I don't want to turn request validation off though.

    Read the article

  • Reordering methods in ComImport interfaces throws COMException (0x80041001)

    - by Ohad Schneider
    Consider the following code for COM interop with internet shortcuts: [ComImport] [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)] [Guid("CABB0DA0-DA57-11CF-9974-0020AFD79762")] public interface IUniformResourceLocatorW { void SetUrl([MarshalAs(UnmanagedType.LPWStr)] string pcszUrl, int dwInFlags); void GetUrl([MarshalAs(UnmanagedType.LPWStr)] out StringBuilder ppszUrl); void InvokeCommand(IntPtr purlici); } [ComImport] [Guid("FBF23B40-E3F0-101B-8488-00AA003E56F8")] public class InternetShortcut { } The following works as expected: var ishort = new InternetShortcut(); ((IPersistFile)ishort).Load("MyLink.url", 0); ((IUniformResourceLocatorW)ishort).GetUrl(out url); However: If I comment out IUniformResourceLocatorW.SetUrl (which I am not using), IUniformResourceLocatorW.GetUrl throws a COMException (HResult 0x80041001). If I switch between IUniformResourceLocatorW.SetUrl and IUniformResourceLocatorW.GetUrl (that is place the former below the latter) the same exception is thrown If I comment out IUniformResourceLocatorW.InvokeCommand the code runs fine. It's as if the order has to be preserved "up to" the invoked method. Is this behavior by design? documented somewhere? I'm asking because some COM interfaces are composed of many methods with possibly many supporting types and I'd rather avoid defining what I don't need if possible.

    Read the article

  • zoomfactor value in CGAffineTransformMakeScale in iPhone

    - by suse
    Hello, 1) I'm doing pinch zoom on the UIImageView , how should i decide upon the zoomfactor value, because when the zoomfactor value goes beyond 0[i.e negative value]the image is gettig tilted, which i dont want it to happen. how to avoid this situation. 2) Y is the flickring kind of rotationis happening, Y not the smooth rotation? ll this be taken care by CGAffineTransformMakeScale(zoomfactor,zoomfactor);method? This is what i'm doing in my code: zoomFactor = 0;// Initially zoomfactor is set to zero - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{ NSLog(@" Inside touchesBegan .................."); NSArray *twoTouches = [touches allObjects]; UITouch *first = [twoTouches objectAtIndex:0]; OPERATION = [self identifyOperation:touches :first]; NSLog(@"OPERATION : %d",OPERATION); if(OPERATION == OPERATION_PINCH){ //double touch pinch UITouch *second = [twoTouches objectAtIndex:1]; f_G_initialDistance = distanceBetweenPoints([first locationInView:self.view],[second locationInView:self.view]); } NSLog(@" leaving touchesBegan .................."); } - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { NSLog(@" Inside touchesMoved ................."); NSArray *twoTouchPoints = [touches allObjects]; if(OPERATION == OPERATION_PINCH){ CGFloat currentDistance = distanceBetweenPoints([[twoTouchPoints objectAtIndex:0] locationInView:self.view],[[twoTouchPoints objectAtIndex:1] locationInView:self.view]); int pinchOperation = [self identifyPinchOperation:f_G_initialDistance :currentDistance]; G_zoomFactor = [self calculateZoomFactor:pinchOperation :G_zoomFactor]; [uiImageView_G_obj setTransform:CGAffineTransformMakeScale(G_zoomFactor, G_zoomFactor)]; [self.view bringSubviewToFront:resetButton]; [self.view bringSubviewToFront:uiSlider_G_obj]; f_G_initialDistance = currentDistance; } NSLog(@" leaving touchesMoved .................."); } - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { NSLog(@" Inside touchesEnded .................."); NSArray *twoTouches = [touches allObjects]; UITouch *first = [twoTouches objectAtIndex:0]; if(OPERATION == OPERATION_PINCH){ //do nothing } NSLog(@" Leaving touchesEnded .................."); } Thank You.

    Read the article

  • The perfect web UI framework (with Microsoft stack?) - architecture question?

    - by Igorek
    I'm looking for suggestions for the following issue, and I realize there is really not going to be a perfect answer to my question: I have a UI built in WinForms.NET (v4.0 framework) with WCF back-end and EF4 model objects, that I am looking to port to the web. UI is not huge and is not super complex and is structured well. But it is not a super simple system either. I am looking to pick a technology stack for the web-frontend that will target desktop & partially mobile platforms, provide a good development platform to build on, and facilitate code reuse across UI and back-end tiers... I would rather avoid: custom coding of UI-centric scripts, because they are hard to debug, non-compiled, usually a maintenance nightmare, almost always start to contain business logic, and duplicate some of the logic that back-end tiers have (especially validation) custom-coding for Desktop Web and Mobile Web UI's separately (although I realize that mobile web UI will likely contain fewer of data-entry screens and more reporting screens) non-.NET technology stacks I would love to: target the reporting capabilities of the system toward mobile web browsers not have to write a single line of script (javascript, jquery, etc.) utilize a good collection of controls that produces an elegant UI use .NET for everything The way I see it right now, I need to re-write this app in Silverlight, utilize a 3rd party UI framework like Telerik, and re-do the reports UI again for mobile platforms separately. However, I'm rather concerned about the shelf-life of Silverlight and the needed to deploy a different architecture to deal with mobile platform. Is there an ASP.NET/MVC/Ajax architecture/framework/library that would allow me to get at the power of .NET and without painful (imho) client-side scripting, while providing a decent user experience Thank you

    Read the article

  • SVN 409 conflict on commits and updates

    - by bhefny
    We have been using SVN for the past year now and when we migrated to an online server we started getting this error: Commit: Commit failed (details follow): File or directory 'x.php' is out of date; try updating resource out of date; try updating CHECKOUT of '/!svn/ver/491/x.php': 409 Conflict (http://svn.example.com) We are currently using SmartSVN 6.5 and we have also tested with RapidSVN & Syncro (but we can't use tortoise as we have a lot of Ubunutu users) at the begining I though this How do you fix an SVN 409 Conflict Error would help, but it didn't we are still facing the same error and it's even more absurd now. the main problem is that after you get the error, you can't shake it of. Updating doesn't solve, reverting doesn't solve. You are just stuck with the error. The only thing that could work is removing the file from SVN and adding your version but that would be against why we are using SVN in the first place This is our apache config (and yes autoversioning is ON) <Location /> DAV svn SVNPath /home/example/svn SVNAutoversioning on AuthType Basic AuthName "Access Restricted" AuthUserFile /home/example/svn-auth-file Require valid-user </Location> <Directory /> <Files ~ "^\.ht"> Order allow,deny Allow from all Satisfy All </Files> <Files ~ "^error_log"> Order allow,deny Allow from all Satisfy All </Files> </Directory> And here are some observation: We don't receive conflicts anymore, we just get this 409 conflict you can somehow avoid the error if you always update before committing When committing a modified file + a newly added file, you get the error. As if the added file incremented the version by one and then you are committing another file with a older version. Please advise, we are about to go insane

    Read the article

  • Best practice to structure large html-based project

    - by AntonAL
    I develop Rails based website, enjoying using partials for some common "components" Recently, i faced a problem, that states with CSS interference. Styles for one component (described in css) override styles for another components. For example, one component has ... <ul class="items"> ... and another component has it too. But that ul's has different meaning in these two components. On the other hand, i want to "inherit" some styles for one component from another. For example: Let, we have one component, called "post" <div class="post"> <!-- post's stuff --> <ul class="items"> ... </ul> </div And another component, called "new-post": <div class="new-post"> <!-- post's stuff --> <ul class="items"> ... </ul> <!-- new-post's stuff --> <div class="tools">...</div> </div Post and new-post have something similar ("post's stuff") and i want to make CSS rules to handle both "post" and "new-post" New post has "subcomponents", for example - editing tools, that has also: <ul class="items"> This is where CSS rules starting to interfer - some rules, targeted for ul.items (in post and new-post) applies subcomponent of new-post, called "tools" On the one hand - i want to inherit some styles On the other hand, i want to get better incapsulation What are the best practices, to avoid such kind of problems ?

    Read the article

  • Django install on a shared host, .htaccess help

    - by redconservatory
    I am trying to install Django on a shared host using the following instructions: docs.google.com/View?docid=dhhpr5xs_463522g My problem is with the following line on my root .htaccess: RewriteRule ^(.*)$ /cgi-bin/wcgi.py/$1 [QSA,L] When I include this line I get a 500 error with almost all of my domains on this account. My cgi-bin directory is home/my-username/public_html/cgi-bin/ The wcgi.py file contains: #!/usr/local/bin/python import os, sys sys.path.insert(0, "/home/username/django/") sys.path.insert(0, "/home/username/django/projects") sys.path.insert(0, "/home/username/django/projects/newprojects") import django.core.handlers.wsgi os.chdir("/home/username/django/projects/newproject") # optional os.environ['DJANGO_SETTINGS_MODULE'] = "newproject.settings" def runcgi(): environ = dict(os.environ.items()) environ['wsgi.input'] = sys.stdin environ['wsgi.errors'] = sys.stderr environ['wsgi.version'] = (1,0) environ['wsgi.multithread'] = False environ['wsgi.multiprocess'] = True environ['wsgi.run_once'] = True application = django.core.handlers.wsgi.WSGIHandler() if environ.get('HTTPS','off') in ('on','1'): environ['wsgi.url_scheme'] = 'https' else: environ['wsgi.url_scheme'] = 'http' headers_set = [] headers_sent = [] def write(data): if not headers_set: raise AssertionError("write() before start_response()") elif not headers_sent: # Before the first output, send the stored headers status, response_headers = headers_sent[:] = headers_set sys.stdout.write('Status: %s\r\n' % status) for header in response_headers: sys.stdout.write('%s: %s\r\n' % header) sys.stdout.write('\r\n') sys.stdout.write(data) sys.stdout.flush() def start_response(status,response_headers,exc_info=None): if exc_info: try: if headers_sent: # Re-raise original exception if headers sent raise exc_info[0], exc_info[1], exc_info[2] finally: exc_info = None # avoid dangling circular ref elif headers_set: raise AssertionError("Headers already set!") headers_set[:] = [status,response_headers] return write result = application(environ, start_response) try: for data in result: if data: # don't send headers until body appears write(data) if not headers_sent: write('') # send headers now if body was empty finally: if hasattr(result,'close'): result.close() runcgi() Only I changed the "username" to my username...

    Read the article

  • Is it possible for a function called from within an object to have access to that object's scope?

    - by Elliot Bonneville
    I can't think of a way to explain what I'm after more than I've done in the title, so I'll repeat it. Is it possible for an anonymous function called from within an object to have access to that object's scope? The following code block should explain what I'm trying to do better than I can: function myObj(testFunc) { this.testFunc = testFunc; this.Foo = function Foo(test) { this.test = test; this.saySomething = function(text) { alert(text); }; }; var Foo = this.Foo; this.testFunc.apply(this); } var test = new myObj(function() { var test = new Foo(); test.saySomething("Hello world"); }); When I run this, I get an error: "Foo is not defined." How do I ensure that Foo will be defined when I call the anonymous function? Here's a jsFiddle for further experimentation. Edit: I am aware of the fact that adding the line var Foo = this.Foo; to the anonymous function I pass in to my instance of myObj will make this work. However, I'd like to avoid having to expose the variable inside the anonymous function--do I have any other options?.

    Read the article

  • caching images that are retrieved

    - by Rahul Varma
    Hi, I am retrieving a list of images and text from a web service. The images are getting displayed in the list view. But the problem is, when i scroll down the list the entire images are getting loaded once again. When i scroll twice or thrice there is a OutofMemory occuring... Can anyone tell me how to cache the images and also to avoid the loading of the images that are already loaded when i scroll down. I have tried to increase inSampleSize but it didnt work... Here's the code.... public static Bitmap loadImageFromUrl(String url) { InputStream inputStream; Bitmap b; try { inputStream = (InputStream) new URL(url).getContent(); BitmapFactory.Options bpo= new BitmapFactory.Options(); b=BitmapFactory.decodeStream(inputStream, null,bpo ); b.recycle(); bpo.inSampleSize=2; return b; } catch (IOException e) { throw new RuntimeException(e); } // return null; }

    Read the article

  • can javascript process binary data?

    - by Johnny
    admit me describe my questions in situation-oriented way: assume IE is still the dominate web browser(the firefox have document for binary processing): the XMLHttpRequest.responseText or XMLHttpRequest.responseXML in ie desire txt or xml/xhtml/html,but what about the server response the xmlHttprequest whith MIME TYPE application/octet ? would the response string all little than 256 ?(every char of that string < 256), thanks very much for a straight answer, i have no webserver env,so i don't know how to test it out. because use txt or xml have a issue of character set encode, and i don't know how to process #[[[CDDATA node of one encoded xml(ex : utf-8,ascii,gb18030) with javascript, when i getNodeText, does the docObj return me byte or decoded char ? if it was decoded char which according to the header indicated charSet in the httpresponse , it would be all wrong. to avoid mess up with charSet ,i would like the server to response octet data and force strings data to be encoded as utf-8 but another charSet in the binary format. if the response is octal, so i guess the browser would not try to decode the response"txt" does this weird? or miss understanding the fundamental things? EDIT: I believe the question is asking this: Can Javascript safely process strings that aren't encoded in Unicode? What are the problems with trying to do so? EDIT: no no no , i means if http-header: content-type is "application/octet" , would the ie try to decoded it as (16bits Unicode | ie local setting charset ) when i get XMLHttpRequestobj.responseText use javascript ? or it(ie) just wrap every single byte of the response body as a javascript string, then every char in that string little than or equal 256 (char<=256), am i talking Mars language? sadly, if i were Marsizen,i would come as tourist without fuzzy questions. however i am in a country which share at least one property with Mars : RED

    Read the article

  • systematizing error codes for a web app in php?

    - by user151841
    I'm working on a class-based php web app. I have some places where objects are interacting, and I have certain situations where I'm using error codes to communicate to the end user -- typically when form values are missing or invalid. These are situations where exceptions are unwarranted ( and I'm not sure I could avoid the situations with exceptions anyways). In one object, I have some 20 code numbers, each of which correspond to a user-facing message, and a admin/developer-facing message, so both parties know what's going on. Now that I've worked over the code several times, I find that it's difficult to quickly figure out what code numbers in the series I've already used, so I accidentally create conflicting code numbers. For instance, I just did that today with 12, 13, 14 and 15. How can I better organize this so I don't create conflicting error codes? Should I create one singleton class, errorCodes, that has a master list of all error codes for all classes, systematizing them across the whole web app? Or should each object have its own set of error codes, when appropriate, and I just keep a list in the commentary of the object, to use and update that as I go along?

    Read the article

  • The CLR has been unable to transition from COM context [...] for 60 seconds

    - by BlueRaja The Green Unicorn
    I am getting this error on code that used to work. I have not changed the code. Here is the full error: The CLR has been unable to transition from COM context 0x3322d98 to COM context 0x3322f08 for 60 seconds. The thread that owns the destination context/apartment is most likely either doing a non pumping wait or processing a very long running operation without pumping Windows messages. This situation generally has a negative performance impact and may even lead to the application becoming non responsive or memory usage accumulating continually over time. To avoid this problem, all single threaded apartment (STA) threads should use pumping wait primitives (such as CoWaitForMultipleHandles) and routinely pump messages during long running operations. And here is the code that caused it: var openFileDialog1 = new System.Windows.Forms.OpenFileDialog(); openFileDialog1.DefaultExt = "mdb"; openFileDialog1.Filter = "Management Database (manage.mdb)|manage.mdb"; //Stalls indefinitely on the following line, then gives the CLR error //one minute later. The dialog never opens. if(openFileDialog1.ShowDialog() == DialogResult.OK) { .... } Yes, I am sure the dialog is not open in the background, and no, I don't have any explicit COM code or unmanaged marshalling or multithreading. I have no idea why the OpenFileDialog won't open - any ideas?

    Read the article

  • Android ListActivity with Bitmaps and Garbage Collection issue

    - by chis54
    I have a ListActivity and in it I set my list items with a class that extends SimpleCursorAdapter. I'm overriding bindView to set my Views. I have some TextViews and ImageViews. This is how I set my list items in my cursor adapter: String variableName = "drawable/q" + num + "_200px"; int imageResource = context.getResources().getIdentifier(variableName, "drawable", context.getPackageName()); if (imageResource != 0 ) { // The drawable exists Bitmap b = BitmapFactory.decodeResource(context.getResources(), imageResource); width = b.getWidth(); height = b.getHeight(); imageView.getLayoutParams().width = (int) (width); imageView.getLayoutParams().height = (int) (height); imageView.setImageResource(imageResource); } else { imageView.setImageResource(R.drawable.25trans_200px); } The problem I'm having is whenever I update my list with setListAdapter I get a large amount of garbage collection: D/dalvikvm(18637): GC_EXTERNAL_ALLOC freed 125K, 51% free 2710K/5447K, external 2022K/2137K, paused 75ms D/dalvikvm(18637): GC_EXTERNAL_ALLOC freed 30K, 51% free 2701K/5447K, external 2669K/2972K, paused 64ms D/dalvikvm(18637): GC_EXTERNAL_ALLOC freed 23K, 51% free 2713K/5447K, external 3479K/3579K, paused 53ms D/dalvikvm(18637): GC_EXTERNAL_ALLOC freed 22K, 51% free 2706K/5447K, external 3303K/3352K, paused 64ms D/dalvikvm(18637): GC_EXTERNAL_ALLOC freed 21K, 51% free 2722K/5447K, external 3569K/3685K, paused 102ms D/dalvikvm(18637): GC_EXTERNAL_ALLOC freed 23K, 50% free 2755K/5447K, external 3499K/3605K, paused 65ms D/dalvikvm(18637): GC_EXTERNAL_ALLOC freed 23K, 50% free 2771K/5447K, external 4213K/4488K, paused 53ms D/dalvikvm(18637): GC_EXTERNAL_ALLOC freed 18K, 49% free 2796K/5447K, external 5057K/5343K, paused 75ms D/dalvikvm(18637): GC_EXTERNAL_ALLOC freed 28K, 49% free 2803K/5447K, external 5944K/5976K, paused 53ms D/dalvikvm( 435): GC_EXPLICIT freed 6K, 54% free 2544K/5511K, external 1625K/2137K, paused 50ms D/dalvikvm( 165): GC_EXPLICIT freed 85K, 52% free 2946K/6087K, external 4838K/5980K, paused 111ms D/dalvikvm( 448): GC_EXPLICIT freed 1K, 54% free 2540K/5511K, external 1625K/2137K, paused 50ms D/dalvikvm( 294): GC_EXPLICIT freed 8K, 55% free 2598K/5703K, external 1625K/2137K, paused 64ms What can I do to avoid this? It's causing my UI to be sluggish and when I scroll, too.

    Read the article

  • GWT: Populating a page from datastore using RPC is too slow

    - by Ilya Boyandin
    Is there a way to speed up the population of a page with GWT's UI elements which are generated from data loaded from the datastore? Can I avoid making the unnecessary RPC call when the page is loaded? More details about the problem I am experiencing: There is a page on which I generate a table with names and buttons for a list of entities loaded from the datastore. There is an EntryPoint for the page and in its onModuleLoad() I do something like this: final FlexTable table = new FlexTable(); rpcAsyncService.getAllCandidates(new AsyncCallback<List<Candidate>>() { public void onSuccess(List<Candidate> candidates) { int row = 0; for (Candidate person : candidates) { table.setText(row, 0, person.getName()); table.setWidget(row, 1, new ToggleButton("Yes")); table.setWidget(row, 2, new ToggleButton("No")); row++; } } ... }); This works, but takes more than 30 seconds to load the page with buttons for 300 candidates. This is unacceptable. The app is running on Google App Engine and using the app engine's datastore.

    Read the article

  • C++ - passing references to boost::shared_ptr

    - by abigagli
    If I have a function that needs to work with a shared_ptr, wouldn't it be more efficient to pass it a reference to it (so to avoid copying the shared_ptr object)? What are the possible bad side effects? I envision two possible cases: 1) inside the function a copy is made of the argument, like in ClassA::take_copy_of_sp(boost::shared_ptr<foo> &sp) { ... m_sp_member=sp; //This will copy the object, incrementing refcount ... } 2) inside the function the argument is only used, like in Class::only_work_with_sp(boost::shared_ptr<foo> &sp) //Again, no copy here { ... sp->do_something(); ... } I can't see in both cases a good reason to pass the boost::shared_ptr by value instead of by reference. Passing by value would only "temporarily" increment the reference count due to the copying, and then decrement it when exiting the function scope. Am I overlooking something? Andrea. EDIT: Just to clarify, after reading several answers : I perfectly agree on the premature-optimization concerns, and I alwasy try to first-profile-then-work-on-the-hotspots. My question was more from a purely technical code-point-of-view, if you know what I mean.

    Read the article

  • Which languages and techniques can I use to improve my coding practices?

    - by Danjah
    I've been offered the opportunity upskill through study, while at work which is great. My background I am mostly self-taught, but have worked with many excellent people over the years - both self-taught and fully educated, and on many decent projects. I have mild experience in Actionscript, I'm getting better every day with my Javascript, and my CSS is angled at best practice, but needs a bit of modernising. I'm a traditional interface developer, I'm not stupid and I like a challenge. My goal I need to start seeing ways of applying better logic, optimising code, refactoring, different styles of development (agile, others?), and.. well I need to try and start thinking like.. a more solid programmer. Its hard to describe, I have good solutions and I'm efficient - but I KNOW that there's a bunch I am missing. I am already employed with a solid career, but I feel the need to fill gaps. My question/s Are there a set of guiding principles you can recommend I focus on to improve the points above? Are there particular programming languages which I might focus on to get a broader overview? Do you think I should avoid particular styles of development, or even languages, while solidifying what might end up being part 'the basics' but hopefully 'advanced programming'? -- Sorry if this appears off topic or something but I figure you're probably some of the best people to ask.

    Read the article

  • Classic ASP application-wide initializations and object caching

    - by slack3r
    In classic ASP (which I am forced to use), I have a few factory functions, that is, functions that return classes. I use JScript. In one include file I use these factory functions to create some classes that are used throughout the application. This include file is included with the #include directive in all pages. These factory functions do some "heavy lifting" and I don't want them to be executed on every page load. So, to make this clear I have something like this: // factory.inc function make_class(arg1, arg2) { function klass() { //... } // ... Some heavy stuff return klass; } // init.inc, included everywhere <!-- #include FILE="factory.inc" --> // ... MyClass1 = make_class(myarg01, myarg02); MyClass2 = make_class(myarg11, myarg12); //... How can I achieve the same effect without calling make_class on every page load? I know that I can't cache the classes in the Application object I can't use the Application_OnStart hook in Global.asa I could probably create a scripting component, but I really don't want to do that So, is there something else I can do? Maybe some way to achieve caching of these classes, which are really objects in JScript. PS: [further clarification] In the above code "heavy stuff" is not so heavy, but I just want to know if there's a way to avoid it being executed all the time. It reads database meta information, builds a table of the primary keys in the database and another table that resolves strings to classes, etc.

    Read the article

  • IndexOutofRangeException while using WriteLine in nested Parallel.For loops

    - by Umar Asif
    I am trying to write kinect depth data to a text file using nested Parallel.For loops with the following code. However, it gives IndexOutofRangeException. The code works perfect if using simple for loops but it hangs the UI since the depth format is set to 640x480 causing the loops to write 307200 lines in the text file at 30fps. Therefore, I switched to Parallel. For scheme. If I omit the writeLine command from the nested loops, the code works fine, which indicates that the IndexOutofRangeException is arising at the writeline command. I do not know how to troubleshoot this. Please advise. Any better workarounds to avoid UI freezing? Thanks. using (DepthImageFrame depthImageframe = d.OpenDepthImageFrame()) { if (depthImageframe == null) return; depthImageframe.CopyPixelDataTo(depthPixelData); swDepth = new StreamWriter(@"E:\depthData.txt", false); int i = 0; Parallel.For(0, depthImageframe.Width, delegate(int x) { Parallel.For(0, depthImageframe.Height, delegate(int y) { p[i] = sensor.MapDepthToSkeletonPoint(depthImageframe.Format, x, y, depthPixelData[x + depthImageframe.Width * y]); swDepth.WriteLine(i + "," + p[k].X + "," + p[k].Y + "," + p[k].Z); i++; }); }); swDepth.Close(); } }

    Read the article

  • Passing information safely between Wicket and Hibernate in long running conversations

    - by Peter Tillemans
    We are using Wicket with Hibernate in the background. As part of out UI we have quite long running conversations spanning multiple requests before the updated information is written back to the database. To avoid getting hibernate errors with detached objects we are now using value objects to transfer info from the service layer to Wicket. However we now end up with an explosion of almost the same objects : e.g. Answer (mapped entity saved in hibernate) AnswerVO (immutable value object) AnswerModel (A mutable bean in the session domain) IModel wrapped Wicket Model and usually this gets wrapped in a CompoundPropertyModel This plumbing becomes exponentially worse when collections to other objects are involved in the objects. There has to be a better way to organize this. Can anyone share tips to make this less onerous? Maybe make the value objects mutable so we can remove the need for a seaprate backing bean in Wicket? Use the entity beans but absolutely make dead-certain they are detached from hibernate. (easier said than done)? Some other tricks or patterns?

    Read the article

  • C++: parsing with simple regular expression or shoud I use sscanf?

    - by Helltone
    I need to parse a string like func1(arg1, arg2); func2(arg3, arg4);. It's not a very complex parsing problem, so I would prefer to avoid resorting to flex/bison or similar utilities. My first approch was to try to use POSIX C regcomp/regexec or Boost implementation of C++ std::regex. I wrote the following regular expression, which does not work (I'll explain why further on). "^" "[ ;\t\n]*" "(" // (1) identifier "[a-zA-Z_][a-zA-Z0-9_]*" ")" "[ \t\n]*" "(" // (2) non-marking "\[" "(" // (3) non-marking "[ \t]*" "(" // (4..n-1) argument "[a-zA-Z0-9_]+" ")" "[ \t\n]*" "," ")*" "[ \t\n]*" "(" // (n) last argument "[a-zA-Z0-9_]+" ")" "]" ")?" "[ \t\n]*" ";" Note that the group 1 captures the identifier and groups 4..n-1 are intended to capture arguments except the last, which is captured by group n. When I apply this regex to, say func(arg1, arg2, arg3) the result I get is an array {func, arg2, arg3}. This is wrong because arg1 is not in it! The problem is that in the standard regex libraries, submarkings only capture the last match. In other words, if you have for instance the regex "((a*|b*))*" applied on "babb", the results of the inner match will be bb and all previous captures will have been forgotten. Another thing that annoys me here is that in case of error there is no way to know which character was not recognized as these functions provide very little information about the state of the parser when the input is rejected. So I don't know if I'm missing something here... In this case should I use sscanf or similar instead? Note that I prefer to use C/C++ standard libraries (and maybe boost).

    Read the article

  • jQuery & Prototype Conflict

    - by DPereyra
    Hi, I am using the jQuery AutoComplete plugin in an html page where I also have an accordion menu which uses prototype. They both work perfectly separately but when I tried to implement both components in a single page I get an error that I have not been able to understand. uncaught exception: [Exception... "Component returned failure code: 0x80004005 (NS_ERROR_FAILURE) [nsIDOMViewCSS.getComputedStyle]" nsresult: "0x80004005 (NS_ERROR_FAILURE)" location: "JS frame :: file:///C:/Documents and Settings/Administrator/Desktop/website/js/jquery-1.2.6.pack.js :: anonymous :: line 11" data: no] I found out the file conflicting with jQuery is 'effects.js' which is used by the accordion menu. I tried replacing this file with a newer version but newer seems to break the accordion behavior. My guess is that the 'effects.js' file used in the accordion was modified to obtain the accordion demo output. I also tried using the overriding methods jQuery needs to avoid conflict with other libraries and that did not work. I obtained the accordion demo from the following site: http://www.stickmanlabs.com/accordion/ And the jQuery AutoComplete can be obtained from: http://docs.jquery.com/Plugins/Autocomplete#Setup Has any one else experienced this issue? Thanks.

    Read the article

  • how to use a parameterized function for the Default Binding of a Sql Server column

    - by Walt Gaber
    I have a table that catalogs selected files from multiple sources. I want to record whether a file is a duplicate of a previously cataloged file at the time the new file is cataloged. I have a column in my table (“primary_duplicate”) to record each entry as ‘P’ (primary) or ‘D’ (duplicate). I would like to provide a Default Binding for this column that would check for other occurrences of this file (i.e. name, length, timestamp) at the time the new file is being recorded. I have created a function that performs this check (see “GetPrimaryDuplicate” below). But I don’t know how to bind this function which requires three parameters to the table’s “primary_duplicate” column as its Default Binding. I would like to avoid using a trigger. I currently have a stored procedure used to insert new records that performs this check. But I would like to ensure that the flag is set correctly if an insert is performed outside of this stored procedure. How can I call this function with values from the row that is being inserted? USE [MyDatabase] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[FileCatalog]( [id] [uniqueidentifier] NOT NULL, [catalog_timestamp] [datetime] NOT NULL, [primary_duplicate] nchar NOT NULL, [name] nvarchar NULL, [length] [bigint] NULL, [timestamp] [datetime] NULL ) ON [PRIMARY] GO ALTER TABLE [dbo].[FileCatalog] ADD CONSTRAINT [DF_FileCatalog_id] DEFAULT (newid()) FOR [id] GO ALTER TABLE [dbo].[FileCatalog] ADD CONSTRAINT [DF_FileCatalog_catalog_timestamp] DEFAULT (getdate()) FOR [catalog_timestamp] GO ALTER TABLE [dbo].[FileCatalog] ADD CONSTRAINT [DF_FileCatalog_primary_duplicate] DEFAULT (N'GetPrimaryDuplicate(name, length, timestamp)') FOR [primary_duplicate] GO USE [MyDatabase] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE FUNCTION [dbo].[GetPrimaryDuplicate] ( @name nvarchar(255), @length bigint, @timestamp datetime ) RETURNS nchar(1) AS BEGIN DECLARE @c int SELECT @c = COUNT(*) FROM FileCatalog WHERE name=@name and length=@length and timestamp=@timestamp and primary_duplicate = 'P' IF @c > 0 RETURN 'D' -- Duplicate RETURN 'P' -- Primary END GO

    Read the article

< Previous Page | 475 476 477 478 479 480 481 482 483 484 485 486  | Next Page >