Search Results

Search found 6619 results on 265 pages for 'digital logic'.

Page 216/265 | < Previous Page | 212 213 214 215 216 217 218 219 220 221 222 223  | Next Page >

• javascript equivalent of ASP preInit event

  - by Pankaj Kumar

  Hi guys, searching for this has yielded no resuts.. i have a middle page that has an iframe and all the pages open in that iframe...i have to implement a chat system just like in Google and so to ensure that the chat windows did not close whwn the page would postback i am opening all pages in iframe.... this is a social networking site and user can have themes which have background images per theme now when i visit a friends profile the backgrounf image of the middle page should change... i have this code to find parent of iframe and change background image $(document).ready(function(){ var theme=document.getElementById("ctl00_decideFooterH").value; var t= parent.document.getElementsByTagName("body"); if(theme=='basicTheme'){ t[0].className="basic"; } else if(theme=='Tranquility') { t[0].className="Tranquility"; } else if(theme=='AbstractPink') { t[0].className="abstractPink"; } }); and this code is the master page that all child pages that would open in iframe would access..the trouble is that there is a lag between the theme application on server side(which happens at PreInit) and the background image change which is done by this document.ready that gets executed after the iframe has loaded.. so essentially i need a javascript function that would either execute parallel to PreInit or some other logic....so guys plz help its urgent

  Read the article

• On-Demand thumbnail creation with django and nginx

  - by sharjeel

  I want to generate thumbnails of images on the fly. My site is built with django and deployed using nginx which serves all the static content and communicates with django/apache using reverse proxy. Right now, for every image in my site, I generate all required sizes of thumbnails on-hand and deliver them when required. The problem is that whenever I change the size of a thumbnail, I have to regenerate all of them (and they are tons). However now I'd like to generate the thumbnail the first time it is accessed and later on nginx would deliver the same file over n over. If I delete that thumbnail file because of lesser accesses, it should get generated automatically the next time. Thumbnails in my case also have watermarks which require some computation logic of my application so a webserver thumbnail module might not work very well. The size of the thumbnail can be embedded in the URL. So http://www.example.com/thumbnail/abc_320x240.jpg gets the 320x240 size of the thumbnail. The approach I'm looking right now is to let nginx lookup the file and if it doesn't exist, forward the query to my django application which would create the thumbnail and send either the response or a redirect string. However I'm not sure about the concurrency issues and any other issues which might pop up later. What is the appropriate way to achieve this?

  Read the article

• ASP.NET MVC Authorize by Group

  - by Jimmo

  I have what seems like a common issue with SaaS applications, but have not seen this question on here anywhere. I am using ASP.NET MVC with Forms Authentication. I have implemented a custom membership provider to handle logic, but have one issue (perhaps the issue is in my mental picture of the system). As with many SaaS apps, Customers create accounts and use the app in a way that looks like they are the only ones present (they only see their items, users, etc.) In reality, there are generic controllers and views presenting data depending on their account. When calling something like ValidateUser, I have access to their affiliation in the User object - what I don't have is the context of the request to which to compare it. As an example, One company called ABC goes to abc.mysite.com Another company called XYZ goes to xyz.mysite.com When an ABC user calls http://abc.mysite.com/product/edit/12 I have an [Authorize] attribute on the Edit method in the ProductController to make sure he is signed in and has sufficient permission to do so. If that same ABC user tried to access http://xyz.mysite.com/product/edit/12 I would not want to validate him in the context of that call. In the ValidateUser of the MembershipProvider, I have the information about the user, but not about the request. I can tell that the user is from ABC, but I cannot tell that the request is for XYZ at that point in the code. How should I resolve this?

  Read the article

• "hour" int taken from NSDate not behaving as expected at midnight??

  - by Eric

  I feel like I've lost my mind. Can someone tell me what's going on here? Also, I'm sure there is a better way to do what I'm trying to do, but I'm not interested in that now. I'd just like to solve the mystery of why my ints are not responding to logic as expected. // Set "At: " field close to current time NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; [dateFormatter setDateFormat:@"HH"]; int hour = [[dateFormatter stringFromDate:[NSDate date]] intValue]; [dateFormatter setDateFormat:@"mm"]; int minute = [[dateFormatter stringFromDate:[NSDate date]] intValue]; NSLog(@"currently %i:%i",hour, minute); if(hour >= 12){ // convert to AM/PM selectedMeridiem = 1; if(hour != 12){ hour = hour - 12; } } else{ selectedMeridiem = 0; } selectedHour = hour - 1; if(selectedHour <= 0){ selectedHour = 11; } When I debug the above code with my clock set to 12:XX AM, the integer "hour" returned is 0. But then any if statements with the condition if(hour == 0) are not evaluated. Likewise, this would not be evaluated either: if(hour < 1). The code above puts the hour int into another int, selectedHour (don't worry about why I'm doing this for now), but selectedHour suffers from the same weird behavior; the if(selectedHour <= 0) line is never evaluated. Am I going crazy, or am I just an idiot? Maybe there's some behavior of 0 integers that I'm not aware of. All of my code runs fine as long as it's not 12:XX AM.

  Read the article

• What MS technology to use for HTTP service returning XML?

  - by Borek

  I need to create a service that: accepts HTTP requests (with query string or HTTP POST parameters) does some processing on the requests (checking if the request is valid, authentication etc.) reads data from a custom store (another HTTP call in our case) returns the result as custom XML (defined with XSD) I'm trying to think of various MS technologies that could help me and how good they would be for this scenario (pretty standard one I guess). The tasks above are relatively separate, this is what comes to mind: HTTP front-end: ASP.NET Web Forms ASP.NET MVC (seems more appropriate here as I won't need server controls, view state etc.) WCF? Don't know much about it or how well it would suit my task. Custom logic on the server: this will probably be a generic C# code in all cases (sometimes "plugged into" or called from MVC controllers or some equivalent place in other technologies) Reading data from internal data stores: As said, this is another HTTP server in our case. Options that come to mind: Just read the data using something like WebClient (Just theoretically) implement a LINQ provider (Just even more theoretically) implement an EF provider Output the data as custom XML: Linq2XML Serialization? Is it flexible enough? Does WCF provide some tools for this? Some "OXM" - Object/XML mapper if there is something like that for .NET I may be wrong in many of my assumptions, this is just a quick list that comes to mind after a quick research. Some general notes / questions: Testing is important Solution with a clear domain model would be much preferred over the one without Can Entity Framework actually help somewhere in my scenario? If so, where and how? Would WCF be an appropriate technology for this? I don't know much about it.

  Read the article

• Using SQL dB column as a lock for concurrent operations in Entity Framework

  - by Sid

  We have a long running user operation that is handled by a pool of worker processes. Data input and output is from Azure SQL. The master Azure SQL table structure columns are approximated to [UserId, col1, col2, ... , col N, beingProcessed, lastTimeProcessed ] beingProcessed is boolean and lastTimeProcessed is DateTime. The logic in every worker role is: public void WorkerRoleMain() { while(true) { try { dbContext db = new dbContext(); // Read foreach (UserProfile user in db.UserProfile .Where(u => DateTime.UtcNow.Subtract(u.lastTimeProcessed) > TimeSpan.FromHours(24) & u.beingProcessed == false)) { user.beingProcessed = true; // Modify db.SaveChanges(); // Write // Do some long drawn processing here ... ... ... user.lastTimeProcessed = DateTime.UtcNow; user.beingProcessed = false; db.SaveChanges(); } } catch(Exception ex) { LogException(ex); Sleep(TimeSpan.FromMinutes(5)); } } // while () } With multiple workers processing as above (each with their own Entity Framework layer), in essence beingProcessed is being used a lock for MutEx purposes Question: How can I deal with concurrency issues on the beingProcessed "lock" itself based on the above load? I think read-modify-write operation on the beingProcessed needs to be atomic but I'm open to other strategies. Open to other code refinements too.

  Read the article

• Servlet Mapping Help - Possible to Avoid Referencing Context Name?

  - by AJ

  Hi all, I am working on a Spring application and trying to get my URL mapping correct. What I would like to have work is the following: http://localhost:8080/idptest -> doesn't work But instead, I have to reference the context name in my URL in order to resolve the mapping: http://localhost:8080/<context_name>/idptest -> works How can I avoid the requirement of referencing the context name in my URL without using a rewrite/proxy engine e.g. Apache? Here is the servlet definition and mapping from my web.xml: <servlet> <servlet-name>idptest</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/conf/idptest.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>idptest</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> Here's the outline of my controller (showing annotations for request mappings): @Controller @RequestMapping("/idptest") public class MyController { @RequestMapping(method=RequestMethod.GET) public String setupForm(Model model){ MyObject someObject = new MyObject(); model.addAttribute("someObject", someObject); return "myform"; } @RequestMapping(method = RequestMethod.POST) public String processSubmit(@ModelAttribute("someObject") MyObject someObject) throws Exception { // POST logic... } } Thanks!

  Read the article

• PHP Overloading, singleton instance

  - by jamalali81

  I've sort of created my own MVC framework and am curious as to how other frameworks can send properties from the "controller" to the "view". Zend does something along the lines of $this->view->name = 'value'; My code is: file: services_hosting.php class services_hosting extends controller { function __construct($sMvcName) { parent::__construct($sMvcName); $this->setViewSettings(); } public function setViewSettings() { $p = new property; $p->banner = '/path/to/banners/home.jpg'; } } file: controller.php class controller { public $sMvcName = "home"; function __construct($sMvcName) { if ($sMvcName) { $this->sMvcName = $sMvcName; } include('path/to/views/view.phtml'); } public function renderContent() { include('path/to/views/'.$this->sMvcName.'.phtml'); } } file: property.php class property { private $data = array(); protected static $_instance = null; public static function getInstance() { if (null === self::$_instance) { self::$_instance = new self(); } return self::$_instance; } public function __set($name, $value) { $this->data[$name] = $value; } public function __get($name) { if (array_key_exists($name, $this->data)) { return $this->data[$name]; } } public function __isset($name) { return isset($this->data[$name]); } public function __unset($name) { unset($this->data[$name]); } } In my services_hosting.phtml "view" file I have: <img src="<?php echo $this->p->banner ?>" /> This just does not work. Am I doing something fundamentally wrong or is my logic incorrect? I seem to be going round in circles at the moment. Any help would be very much appreciated.

  Read the article

• Managing logs/warnings in Python extensions

  - by Dimitri Tcaciuc

  TL;DR version: What do you use for configurable (and preferably captured) logging inside your C++ bits in a Python project? Details follow. Say you have a a few compiled .so modules that may need to do some error checking and warn user of (partially) incorrect data. Currently I'm having a pretty simplistic setup where I'm using logging framework from Python code and log4cxx library from C/C++. log4cxx log level is defined in a file (log4cxx.properties) and is currently fixed and I'm thinking how to make it more flexible. Couple of choices that I see: One way to control it would be to have a module-wide configuration call. # foo/__init__.py import sys from _foo import import bar, baz, configure_log configure_log(sys.stdout, WARNING) # tests/test_foo.py def test_foo(): # Maybe a custom context to change the logfile for # the module and restore it at the end. with CaptureLog(foo) as log: assert foo.bar() == 5 assert log.read() == "124.24 - foo - INFO - Bar returning 5" Have every compiled function that does logging accept optional log parameters. # foo.c int bar(PyObject* x, PyObject* logfile, PyObject* loglevel) { LoggerPtr logger = default_logger("foo"); if (logfile != Py_None) logger = file_logger(logfile, loglevel); ... } # tests/test_foo.py def test_foo(): with TemporaryFile() as logfile: assert foo.bar(logfile=logfile, loglevel=DEBUG) == 5 assert logfile.read() == "124.24 - foo - INFO - Bar returning 5" Some other way? Second one seems to be somewhat cleaner, but it requires function signature alteration (or using kwargs and parsing them). First one is.. probably somewhat awkward but sets up entire module in one go and removes logic from each individual function. What are your thoughts on this? I'm all ears to alternative solutions as well. Thanks,

  Read the article

• How can I order by the result of a recursive SQL query

  - by Tony

  I have the following method I need to ORDER BY: def has_attachments? attachments.size > 0 || (!parent.nil? && parent.has_attachments?) end I have gotten this far: ORDER BY CASE WHEN attachments.size > 0 THEN 1 ELSE (CASE WHEN parent_id IS NULL THEN 0 ELSE (CASE message.parent ...what goes here ) END END END I may be looking at this wrong because I don't have experience with recursive SQL. Essentially I want to ORDER by whether a message or any of its parents has attachments. If it's attachment size is 0, I can stop and return a 1. If the message has an attachment size of 0, I now check to see if it has a parent. If it has no parent then there is no attachment, however if it does have a parent then I essentially have to do the same query case logic for the parent. UPDATE The table looks like this +---------------------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------------------+--------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | message_type_id | int(11) | NO | MUL | | | | message_priority_id | int(11) | NO | MUL | | | | message_status_id | int(11) | NO | MUL | | | | message_subject_id | int(11) | NO | MUL | | | | from_user_id | int(11) | YES | MUL | NULL | | | parent_id | int(11) | YES | MUL | NULL | | | expires_at | datetime | YES | MUL | NULL | | | subject_other | varchar(255) | YES | | NULL | | | body | text | YES | | NULL | | | created_at | datetime | NO | MUL | | | | updated_at | datetime | NO | | | | | lock_version | int(11) | NO | | 0 | | +---------------------+--------------+------+-----+---------+----------------+ Where the parent_id refers to the parent message, if it exists. Thanks!

  Read the article

• Understanding sql queries formulation methodoloy. How do you think while formulating Sql Queries

  - by Shantanu Gupta

  I have been working on sql server and front end coding and have usually faced problem formulating queries. I do understand most of the concepts of sql that are needed in formulating queries but whenever some new functionality comes into the picture that can be dont using sql query, i do usually fails resolving them. I am very comfortable with select queries using joins and all such things but when it comes to DML operation i usually fails For every query that i never done before I usually finds uncomfortable with that while creating them. Whenever I goes for an interview I usually faces this problem. Is it their some concept behind approaching on formulating sql queries. Eg. I need to create an sql query such that A table contain single column having duplicate record. I need to remove duplicate records. I know i can find the solution to this query very easily on Googling, but I want to know how everyone comes to the desired result. Is it something like Practice Makes Man Perfect i.e. once you did it, next time you will be able to formulate or their is some logic or concept behind.

  Read the article

• Dependency Property ListBox

  - by developer

  Hi All, I want to use a dependency property, so that my label displays values selected in the listbox. This is just to more clearly understand the working of a dependency property. <Window x:Class="WpfApplication1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:WPFToolkit="clr-namespace:Microsoft.Windows.Controls;assembly=WPFToolkit" xmlns:local="clr-namespace:WpfApplication1" x:Name="MyWindow" Height="200" Width="300" > <StackPanel> <ListBox x:Name="lbColor" Width="248" Height="56" ItemsSource="{Binding TestColor}"/> <StackPanel> <Label Content="{Binding Path=Test, ElementName=lbColor}" /> </StackPanel> </StackPanel> </Window> Code Behind, namespace WpfApplication1 { /// <summary> /// Interaction logic for Window1.xaml /// </summary> public partial class Window1 : Window { public ObservableCollection<string> TestColor { get; set; } public String Test { get { return (String)GetValue(TestProperty); } set { SetValue(TestProperty, value); } } // Using a DependencyProperty as the backing store for Title. This enables animation, styling, binding, etc... public static readonly DependencyProperty TestProperty = DependencyProperty.Register("Test", typeof(String), typeof(ListBox), new UIPropertyMetadata("Test1")); public Window1() { InitializeComponent(); TestColor = new ObservableCollection<string>(); DataContext = this; TestColor.Add("Red"); TestColor.Add("Orange"); TestColor.Add("Yellow"); TestColor.Add("Green"); TestColor.Add("Blue"); } } } Can anyone explain me how will I accompalish this using a dependency property. Somehow I am very confused with the Dependency Property concept, and I just wanted to see a working example for that.

  Read the article

• Parallel.Foreach loop creating multiple db connections throws connection errors?

  - by shawn.mek

  Login failed. The login is from an untrusted domain and cannot be used with Windows authentication I wanted to get my code running in parallel, so I changed my foreach loop to a parallel foreach loop. It seemed simple enough. Each loop connects to the database, looks up some stuff, performs some logic, adds some stuff, closes the connection. But I get the above error? I'm using my local sql server and entity framework (each loop uses it's own context). Is there some problem with connecting multiple times using the same local login or something? How did I get around this? I have (before trying to covert to a parallel.foreach loop) split my list of objects that I am foreach looping through into four groups (separate csv files) and run four concurrent instances of my program (which ran faster overall than just one, thus the idea for parallel). So it seems connecting to the db shouldn't be a problem? Any ideas? EDIT: Here's before var gtgGenerator = new CustomGtgGenerator(); var connectionString = ConfigurationManager.ConnectionStrings["BioEntities"].ConnectionString; var allAccessionsFromObs = _GetAccessionListFromDataFiles(collectionId); ForEach(cloneIdAndAccessions in allAccessionsFromObs) DoWork(gtgGenerator, taxonId, organismId, cloneIdAndAccessions, connectionString)); after var gtgGenerator = new CustomGtgGenerator(); var connectionString = ConfigurationManager.ConnectionStrings["BioEntities"].ConnectionString; var allAccessionsFromObs = _GetAccessionListFromDataFiles(collectionId); Parallel.ForEach(allAccessionsFromObs, cloneIdAndAccessions => DoWork(gtgGenerator, taxonId, organismId, cloneIdAndAccessions, connectionString)); Inside the DoWork I use the BioEntities using (var bioEntities = new BioEntities(connectionString)) {...}

  Read the article

• Data Annotations on ViewModels or Domain Objects

  - by Ahmad

  Where would data annotations be more suitable: ViewModels or Domain Objects or Both I am struggling to decide where these will be more suited. I have not as yet fully utilized them but this question came to mind. From most of the examples I have seen, they are generally placed on Models and simply use the required attributes for validation using ModelState.IsValid. I have also seen another question on SO where the use of data annotations alone is not sufficient and advocate. Option 1 - I will still need to validate again in my service layer. ( I think that my service layer should be complete and this include validation, since its planned to be used elsewhere) Option 2 - How will I then get the benefits of the built in validation both client and server side. Option 3 - there will be a repetition of validation logic, however I was wondering if one could use a MetaData class approach that can be used for both ViewModels and Domain Objects. ( This is completely of the top of my head, so it may be nonsensical) I wonder if this question even makes sense. If not, can someone please help in understanding this better. Have I completely misunderstood the use of data annotations?

  Read the article

• Passing filtering functions to Where() in LINQ-to-SQL

  - by Daniel

  I'm trying to write a set of filtering functions that can be chained together to progressively filter a data set. What's tricky about this is that I want to be able to define the filters in a different context from that in which they'll be used. I've gotten as far as being able to pass a very basic function to the Where() clause in a LINQ statement: filters file: Func<item, bool> returnTrue = (i) => true; repository file: public IQueryable<item> getItems() { return DataContext.Items.Where(returnTrue); } This works. However, as soon as I try to use more complicated logic, the trouble begins: filters file: Func<item, bool> isAssignedToUser = (i) => i.assignedUserId == userId; repository file: public IQueryable<item> getItemsAssignedToUser(int userId) { return DataContext.Items.Where(isAssignedToUser); } This won't even build because userId isn't in the same scope as isAssignedToUser(). I've also tried declaring a function that takes the userId as a parameter: Func<item, int, bool> isAssignedToUser = (i, userId) => i.assignedUserId == userId; The problem with this is that it doesn't fit the function signature that Where() is expecting: Func<item, bool> There must be a way to do this, but I'm at a loss for how. I don't feel like I'm explaining this very well, but hopefully you get the gist. Thanks, Daniel

  Read the article

• flash creates more than one http request

  - by MilanAleksic

  We are facing one issue directly connected with our Flash API we've given to a 3rd party flash vendor. To make a long story short, our API basically wraps domain logic on client and creates a single POST request towards the server in JSON format. All will be ok except in combination MacOS + Safari we receive double requests on server (?). Even more interesting, we are receiving different agent names - one is expected name/decriptor of the browser and system, other is "CFNetwork". POST /RuntimeDelegate.ashx - 80 Mozilla/5.0+(Macintosh;+U;+Intel+Mac+OS+X+10_4_11;+fr)+AppleWebKit/531.22.7+(KHTML,+like+Gecko)+Version/4.0.5+Safari/531.22.7 200 0 0 POST /RuntimeDelegate.ashx - 80 CFNetwork/129.24 200 0 0 POST /RuntimeDelegate.ashx - 80 Mozilla/5.0+(Macintosh;+U;+Intel+Mac+OS+X+10_4_11;+fr)+AppleWebKit/531.22.7+(KHTML,+like+Gecko)+Version/4.0.5+Safari/531.22.7 200 0 0 POST /RuntimeDelegate.ashx - 80 Mozilla/5.0+(Macintosh;+U;+Intel+Mac+OS+X+10_4_11;+fr)+AppleWebKit/531.22.7+(KHTML,+like+Gecko)+Version/4.0.5+Safari/531.22.7 200 0 0 POST /RuntimeDelegate.ashx - 80 CFNetwork/129.24 200 0 0 POST /RuntimeDelegate.ashx - 80 Mozilla/5.0+(Macintosh;+U;+Intel+Mac+OS+X+10_4_11;+fr)+AppleWebKit/531.22.7+(KHTML,+like+Gecko)+Version/4.0.5+Safari/531.22.7 200 0 0 POST /RuntimeDelegate.ashx - 80 CFNetwork/129.24 200 0 0 POST /RuntimeDelegate.ashx - 80 CFNetwork/129.24 200 0 0 Has anyone encounter anything like this before?

  Read the article

• How to load entities into readonly collections using the entity framework

  - by Anton P

  I have a POCO domain model which is wired up to the entity framework using the new ObjectContext class. public class Product { private ICollection<Photo> _photos; public Product() { _photos = new Collection<Photo>(); } public int Id { get; set; } public string Name { get; set; } public virtual IEnumerable<Photo> Photos { get { return _photos; } } public void AddPhoto(Photo photo) { //Some biz logic //... _photos.Add(photo); } } In the above example i have set the Photos collection type to IEnumerable as this will make it read only. The only way to add/remove photos is through the public methods. The problem with this is that the Entity Framework cannot load the Photo entities into the IEnumerable collection as it's not of type ICollection. By changing the type to ICollection will allow callers to call the Add mentod on the collection itself which is not good. What are my options?

  Read the article

• Returning true or error message in Ruby

  - by seaneshbaugh

  I'm wondering if writing functions like this is considered good or bad form. def test(x) if x == 1 return true else return "Error: x is not equal to one." end end And then to use it we do something like this: result = test(1) if result != true puts result end result = test(2) if result != true puts result end Which just displays the error message for the second call to test. I'm considering doing this because in a rails project I'm working on inside my controller code I make calls to a model's instance methods and if something goes wrong I want the model to return the error message to the controller and the controller takes that error message and puts it in the flash and redirects. Kinda like this def create @item = Item.new(params[:item]) if [email protected]? result = @item.save_image(params[:attachment][:file]) if result != true flash[:notice] = result redirect_to(new_item_url) and return end #and so on... That way I'm not constructing the error messages in the controller, merely passing them along, because I really don't want the controller to be concerned with what the save_image method itself does just whether or not it worked. It makes sense to me, but I'm curious as to whether or not this is considered a good or bad way of writing methods. Keep in mind I'm asking this in the most general sense pertaining mostly to ruby, it just happens that I'm doing this in a rails project, the actual logic of the controller really isn't my concern.

  Read the article

• Is there a language with native pass-by-reference/pass-by-name semantics, which could be used in mod

  - by Bubba88

  Hi! This is a reopened question. I look for a language and supporting platform for it, where the language could have pass-by-reference or pass-by-name semantics by default. I know the history a little, that there were Algol, Fortran and there still is C++ which could make it possible; but, basically, what I look for is something more modern and where the mentioned value pass methodology is preferred and by default (implicitly assumed). I ask this question, because, to my mind, some of the advantages of pass-by-ref/name seem kind of obvious. For example when it is used in a standalone agent, where copyiong of values is not necessary (to some extent) and performance wouldn't be downgraded much in that case. So, I could employ it in e.g. rich client app or some game-style or standalone service-kind application. The main advantage to me is the clear separation between identity of a symbol, and its current value. I mean when there is no reduntant copying, you know that you're working with the exact symbol/path you have queried/received. And intristing boxing of values will not interfere with the actual logic of program. I know that there is C# ref keyword, but it's something not so intristic, though acceptable. Equally, I realize that pass-by-reference semantics could be simulated in virtually any language (Java as an instant example) and so on.. not sure about pass by name :) What would you recommend - create a something like DSL for such needs wherever it be appropriate; or use some languages that I already know? Maybe, there is something that I'm missing? Thank you!

  Read the article

• C# delegate or Func for 'all methods'?

  - by Michel

  Hi, i've read something about Func's and delegates and that they can help you to pass a method as a parameter. Now i have a cachingservice, and it has this declaration: public static void AddToCache<T>(T model, double millisecs, string cacheId) where T : class public static T GetFromCache<T>(string cacheId) where T : class So in a place where i want to cache some data, i check if it exists in the cache (with GetFromCache) and if not, get the data from somewhere, and the add it to the cache (with AddToCache) Now i want to extend the AddToCache method with a parameter, which is the class+method to call to get the data Then the declaration would be like this public static void AddToCache<T>(T model, double millisecs, string cacheId, Func/Delegate methode) where T : class Then this method could check wether the cache has data or not, and if not, get the data itself via the method it got provided. Then in the calling code i could say: AddToCache<Person>(p, 10000, "Person", new PersonService().GetPersonById(1)); AddToCache<Advert>(a, 100000, "Advert", new AdvertService().GetAdverts(3)); What i want to achieve is that the 'if cache is empty get data and add to cache' logic is placed on only one place. I hope this makes sense :) Oh, by the way, the question is: is this possible?

  Read the article

• Cookie not working after mod rewrite rule

  - by moonwalker

  Hi all, I have a simple Cookie to set the chosen language: $lang = $_GET['lang']; $myLang = $_COOKIE["myLang"]; if (!isset($_COOKIE["myLang"])){ setcookie("myLang", "en", $expire); include "languages/en.php"; $myLang = "en"; }else{ include "languages/$myLang.php"; } // One year to expire $expire = time()+60*60*24*30*365; // Put $languages in a common header file. $languages = array('en' => 1, 'fr' => 2, 'nl' => 3); if (array_key_exists($lang, $languages)) { include "languages/{$lang}.php"; setcookie("myLang", $lang, $expire); $myLang = $lang; } After using some rewrite rules, it just doesn't work anymore. I tried the following: setcookie("myLang", "en", $expire, "/" , false); No luck at all. This is my .htaccess file: <IfModule mod_rewrite.c> Options +FollowSymLinks Options +Indexes RewriteEngine On RewriteBase / RewriteRule ^sort/([^/]*)/([^/]*)$ /3arsi2/sort.php?mode=$1&cat=$2 [L] RewriteRule ^category/([^/]*)$ /3arsi2/category.php?cat=$1 [L] RewriteRule ^category/([^/]*)/([^/]*)$ /3arsi2/category.php?cat=$1&lang=$2 [L] RewriteRule ^search/([^/]*)$ /3arsi2/search.php?mode=$1 [L] RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^u/([^/]+)/?$ 3arsi2/user.php?user=$1 [NC,L] RewriteRule ^u/([^/]+)/(images|videos|music)/?$ 3arsi2/user.php?user=$1&page=$2 [NC,L] RewriteRule ^([^\.]+)$ 3arsi2/$1.php [NC,L] </IfModule> Any idea how to solve this? I'm still new to the mod rewrite thing, so I still don't really understand the logic behind it all. Thanks for any help you can provide.

  Read the article

• ADO.NET Multiple simultaneous reads from an open database.

  - by Deverill

  Answer not needed - my logic was wrong and this question is invalid. Charles helped me see where I went off-tracks. Thanks I have a utility that moves data from one source to another. In the process of writing the record I check to see if it exists and do an update/insert as necessary. The difficulty I have is that as I'm writing the main record info there is a 2nd table for "custom data" that I have to check to see if it exists and do an update/insert for that as well. Example: I may be loading a pencil sharpener that may or may not exist. While I'm writing it into destination it has characteristics such as style, color, etc. and each of them may or may not exist. As written I seem to need to have 2 DataReaders open, one for the sharpener and one to check for and update color. I am new to ADO.NET, but not to programming and it's more complicated than I listed but for sanity's sake I didn't put all the details. My question is: What am I missing? You can't have 2 readers open at the same time on a connection, yet I can't close the first if I'm stepping through all products. It seems inefficient to have 2 connections, readers, etc. for this. Is there a feature of ADO.NET DBs that I'm missing? How would you do it? Thanks!

  Read the article

• Problem in filtering records using Dataview (C#3.0)

  - by Newbie

  I have a data table . The data table is basically getting populated from excel sheet. And there are many excel sheets. Henceforth, I have written a utility method for accomplishing the same. Now in some of the excel sheets, there are date columns and in some it is not(only text/string). My function is populating the values properly into the datatable from the excell sheet. But there are many blank rows in the excel sheets some are filled with NULL , some with " ". So I need to filter those records (which are NULL or " " ) first before further processing. What I am after is to use a dataview and apply the filter over there. DataView dv = dataTable.DefaultView; dv.RowFilter = ColumnName + " <> ''"; Well by using metedata (GetOleDbSchemaTable(OleDbSchemaGuid.Columns, restrection)) I was able to get the column names from the excel sheet , so getting the column names is not an issue. But the problem is as I said in some Excel sheet there are date fileds some are not. So the Filter condition of the Dataview needs to be proper. If I apply the above logic, and if it encounters a Datafield, it is throwing error Cannot perform '<' operation on System.DateTime and System.String. Could you people please help me out? I need to filter columns(not known at compile time + their data types) which can have NULL and " " I am using C#3.0 Thanks

  Read the article

• What does this structure actually do?

  - by LGTrader

  I found this structure code in a Julia Set example from a book on CUDA. I'm a newbie C programmer and cannot get my head around what it's doing, nor have I found the right thing to read on the web to clear it up. Here's the structure: struct cuComplex { float r; float i; cuComplex( float a, float b ) : r(a), i(b) {} float magnitude2( void ) { return r * r + i * i; } cuComplex operator*(const cuComplex& a) { return cuComplex(r*a.r - i*a.i, i*a.r + r*a.i); } cuComplex operator+(const cuComplex& a) { return cuComplex(r+a.r, i+a.i); } }; and it's called very simply like this: cuComplex c(-0.8, 0.156); cuComplex a(jx, jy); int i = 0; for (i=0; i<200; i++) { a = a * a + c; if (a.magnitude2() > 1000) return 0; } return 1; So, the code did what? Defined something of structure type 'cuComplex' giving the real and imaginary parts of a number. (-0.8 & 0.156) What is getting returned? (Or placed in the structure?) How do I work through the logic of the operator stuff in the struct to understand what is actually calculated and held there? I think that it's probably doing recursive calls back into the stucture float magnitude2 (void) { return return r * r + i * i; } probably calls the '*' operator for r and again for i, and then the results of those two operations call the '+' operator? Is this correct and what gets returned at each step? Just plain confused. Thanks!

  Read the article

• SQL - Multiple join conditions using OR?

  - by Brandi

  I have a query that is using multiple joins. The goal is to say "Out of table A, give me all the customer numbers in which you can match table A's EmailAddress with either email_to or email_from of table B. Ignore nulls, internal emails, etc.". It seems like it would be better to use an or condition in the join than multiple joins since it is the same table. When I try to use AND/OR it does not give the behaviour I expect... AND finishes in a reasonable time, but yields no results (I know that there are matches, so it must be some flaw in my logic) and OR never finishes (I have to kill it). Here is example code to illustrate the question: --my original query SELECT DISTINCT a.CustomerNo FROM A a WITH (NOLOCK) LEFT JOIN B e WITH (NOLOCK) ON a.EmailAddress = e.email_from RIGHT JOIN B f WITH (NOLOCK) ON a.EmailAddress = f.email_to WHERE a.EmailAddress NOT LIKE '%@mydomain.___' AND a.EmailAddress IS NOT NULL AND (e.email_from IS NOT NULL OR f.email_to IS NOT NULL) Here is what I tried, (I am attempting logical equivalence): SELECT DISTINCT a.CustomerNo FROM A a WITH (NOLOCK) LEFT JOIN B e WITH (NOLOCK) ON a.EmailAddress = e.email_from OR a.EmailAddress = e.email_to WHERE a.EmailAddress NOT LIKE '%@mydomain.___' AND a.EmailAddress IS NOT NULL AND (e.email_from IS NOT NULL OR e.email_to IS NOT NULL) So my question is two-fold: Why does having AND in the above query work in a few seconds and OR goes for minutes and never completes? What am I missing to make a logically equivalent statement that has only one join?

  Read the article

< Previous Page | 212 213 214 215 216 217 218 219 220 221 222 223  | Next Page >