Search Results

Search found 26104 results on 1045 pages for 'command pattern'.

Page 96/1045 | < Previous Page | 92 93 94 95 96 97 98 99 100 101 102 103  | Next Page >

• Strategy Pattern with Type Reflection affecting Performances ?

  - by Aurélien Ribon

  Hello ! I am building graphs. A graph consists of nodes linked each other with links (indeed my dear). In order to assign a given behavior to each node, I implemented the strategy pattern. class Node { public BaseNodeBehavior Behavior {get; set;} } As a result, in many parts of the application, I am extensively using type reflection to know which behavior a node is. if (node.Behavior is NodeDataOutputBehavior) workOnOutputNode(node) .... My graph can get thousands of nodes. Is type reflection greatly affecting performances ? Should I use something else than the strategy pattern ? I'm using strategy because I need behavior inheritance. For example, basically, a behavior can be Data or Operator, a Data behavior can IO, Const or Intermediate and finally an IO behavior can be Input or Output. So if I use an enumeration, I wont be able to test for a node behavior to be of data kind, I will need to test it to be [Input, Output, Const or Intermediate]. And if later I want to add another behavior of Data kind, I'm screwed, every data-testing method will need to be changed.

  Read the article

• Singleton Pattern combine with a Decorator

  - by Mike

  Attached is a classic Decorator pattern. My question is how would you modify the below code so that you can wrap zero or one of each topping on to the Pizza Right now I can have a Pepporini - Sausage -- Pepporini -- Pizza class driving the total cost up to $10, charging twice for Pepporini. I don't think I want to use the Chain of Responsibility pattern as order does not matter and not all toppings are used? Thank you namespace PizzaDecorator { public interface IPizza { double CalculateCost(); } public class Pizza: IPizza { public Pizza() { } public double CalculateCost() { return 8.00; } } public abstract class Topping : IPizza { protected IPizza _pizzaItem; public Topping(IPizza pizzaItem) { this._pizzaItem = pizzaItem; } public abstract double CalculateCost(); } public class Pepporini : Topping { public Pepporini(IPizza pizzaItem) : base(pizzaItem) { } public override double CalculateCost() { return this._pizzaItem.CalculateCost() + 0.50; } } public class Sausage : Topping { public Sausage(IPizza pizzaItem) : base(pizzaItem) { } public override double CalculateCost() { return this._pizzaItem.CalculateCost() + 1.00; } } public class Onions : Topping { public Onions(IPizza pizzaItem) : base(pizzaItem) { } public override double CalculateCost() { return this._pizzaItem.CalculateCost() + .25; } } }

  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

• What is the right pattern for a async data fetching method in .net async/await

  - by s093294

  Given a class with a method GetData. A few other clients call GetData, and instead of it fetching data each time, i would like to create a pattern where the first call starts the task to get the data, and the rest of the calls wait for the task to complete. private Task<string> _data; private async Task<string> _getdata() { return "my random data from the net"; //get_data_from_net() } public string GetData() { if(_data==null) _data=_getdata(); _data.wait(); //are there not a problem here. cant wait a task that is already completed ? if(_data.status != rantocompletion) _data.wait() is not any better, it might complete between the check and the _data.wait? return _data.Result; } How would i do the pattern correctly? (Solution) private static object _servertime_lock = new object(); private static Task<string> _servertime; private static async Task<string> servertime() { try { var thetvdb = new HttpClient(); thetvdb.Timeout = TimeSpan.FromSeconds(5); // var st = await thetvdb.GetStreamAsync("http://www.thetvdb.com/api/Updates.php?type=none"); var response = await thetvdb.GetAsync("http://www.thetvdb.com/api/Updates.php?type=none"); response.EnsureSuccessStatusCode(); Stream stream = await response.Content.ReadAsStreamAsync(); XDocument xdoc = XDocument.Load(stream); return xdoc.Descendants("Time").First().Value; } catch { return null; } } public static async Task<string> GetServerTime() { lock (_servertime_lock) { if (_servertime == null) _servertime = servertime(); } var time = await _servertime; if (time == null) _servertime = null; return time; }

  Read the article

• Is this a good decorator pattern for javascript?

  - by Kucebe

  I need some simple objects that could become more complex later, with many different properties, so i thought to decorator pattern. I made this looking at Crockford's power constructor and object augmentation: //add property to object Object.prototype.addProperty = function(name, func){ for(propertyName in this){ if(propertyName == name){ throw new Error(propertyName + " is already defined"); } } this[name] = func; }; //constructor of base object var BaseConstructor = function(param){ var _privateVar = param; return{ getPrivateVar: function(){ return _privateVar; } }; }; //a simple decorator, adds one private attribute and one privileged method var simpleDecorator = function(obj, param){ var _privateVar = param; var privilegedMethod1 = function(){ return "privateVar of decorator is: " + _privateVar; }; obj.addProperty("privilegedMethod1", privilegedMethod1); return obj; } //a more complex decorator, adds public and private properties var complexDecorator = function(obj, param1, param2){ //private properties var _privateVar = param1; var _privateMethod = function(x){ for(var i=0; i<x; i++){ _privateVar += x; } return _privateVar; }; //public properties var publicVar = "I'm public"; obj.addProperty("publicVar", publicVar); var privilegedMethod2 = function(){ return _privateMethod(param2); }; obj.addProperty("privilegedMethod2", privilegedMethod2); var publicMethod = function(){ var temp = this.privilegedMethod2(); return "do something: " + temp + " - publicVar is: " + this.publicVar; }; obj.addProperty("publicMethod", publicMethod); return obj; } //new basic object var myObj = BaseConstructor("obj1"); //the basic object will be decorated var myObj = simpleDecorator(obj, "aParam"); //the basic object will be decorated with other properties var myObj = complexDecorator(obj, 2, 3); Is this a good way to have Decorator Pattern in javascript? Are there other better ways to do this?

  Read the article

• PHP OOP: Avoid Singleton/Static Methods in Domain Model Pattern

  - by sunwukung

  I understand the importance of Dependency Injection and its role in Unit testing, which is why the following issue is giving me pause: One area where I struggle not to use the Singleton is the Identity Map/Unit of Work pattern (Which keeps tabs on Domain Object state). //Not actual code, but it should demonstrate the point class Monitor{//singleton construction omitted for brevity static $members = array();//keeps record of all objects static $dirty = array();//keeps record of all modified objects static $clean = array();//keeps record of all clean objects } class Mapper{//queries database, maps values to object fields public function find($id){ if(isset(Monitor::members[$id]){ return Monitor::members[$id]; } $values = $this->selectStmt($id); //field mapping process omitted for brevity $Object = new Object($values); Monitor::new[$id]=$Object return $Object; } $User = $UserMapper->find(1);//domain object is registered in Id Map $User->changePropertyX();//object is marked "dirty" in UoW // at this point, I can save by passing the Domain Object back to the Mapper $UserMapper->save($User);//object is marked clean in UoW //but a nicer API would be something like this $User->save(); //but if I want to do this - it has to make a call to the mapper/db somehow $User->getBlogPosts(); //or else have to generate specific collection/object graphing methods in the mapper $UserPosts = $UserMapper->getBlogPosts(); $User->setPosts($UserPosts); Any advice on how you might handle this situation? I would be loathe to pass/generate instances of the mapper/database access into the Domain Object itself to satisfy DI - At the same time, avoiding that results in lots of calls within the Domain Object to external static methods. Although I guess if I want "save" to be part of its behaviour then a facility to do so is required in its construction. Perhaps it's a problem with responsibility, the Domain Object shouldn't be burdened with saving. It's just quite a neat feature from the Active Record pattern - it would be nice to implement it in some way.

  Read the article

• Abstract factory pattern on top of IoC?

  - by Sergei

  I have decided to use IoC principles on a bigger project. However, i would like to get something straight that's been bothering me for a long time. The conclusion that i have come up with is that an IoC container is an architectural pattern, not a design pattern. In other words, no class should be aware of its presence and the container itself should be used at the application layer to stitch up all components. Essentially, it becomes an option, on top of a well designed object-oriented model. Having said that, how is it possible to access resolved types without sprinkling IoC containers all over the place (regardless of whether they are abstracted or not)? The only option i see here is to utilize abstract factories which use an IoC container to resolve concrete types. This should be easy enough to swap out for a set of standard factories. Is this a good approach? Has anyone on here used it and how well did it work for you? Is there anything else available? Thanks!

  Read the article

• Communication with different social networks, strategy pattern?

  - by bclaessens

  Hi For the last few days I've been thinking how I can solve the following programming problem and find the ideal, flexible programming structure. (note: I'm using Flash as my platform technology but that shouldn't matter since I'm just looking for the ideal design pattern). Our Flash website has multiple situations in which it has to communicate with different social networks (Facebook, Netlog and Skyrock). Now, the communication strategy doesn't have to change multiple times over one "run". The strategy should be picked once (at launch time) for that session. The real problem is the way the communication works between each social network and our website. Some networks force us to ask for a token, others force us to use a webservice, yet another forces us to set up its communication through javascript. The problem becomes more complicated when our website has to run in each network's canvas. Which results in even more (different) ways of communicating. To sum up, our website has to work in the following cases: standalone on the campaign website url (user chooses their favourite network) communicate with netlog OR communicate with facebook OR communicate with skyrock run in a netlog canvas and log in automatically (website checks for netlog parameters) run in a facebook canvas and log in automatically (website checks for facebook params) run in a skyrock canvas and log in automatically (website checks for skyrock params) As you can see, our website needs 6 different ways to communicate with a social network. To be honest, the actual significant difference between all communication strategies is the way they have to connect to their individual network (as stated above in my example). Posting an image, make a comment, ... is the same whether it runs standalone or in the canvas url. WARNING: posting an image, posting a comment DOES differ from network to network. Should I use the strategy pattern and make 6 different communication strategies or is there a better way? An example would be great but isn't required ;) Thanks in advance

  Read the article

• Problem accessing private variables in jQuery like chainable design pattern

  - by novogeek

  Hi folks, I'm trying to create my custom toolbox which imitates jQuery's design pattern. Basically, the idea is somewhat derived from this post: http://stackoverflow.com/questions/2061501/jquery-plugin-design-pattern-common-practice-for-dealing-with-private-function (Check the answer given by "David"). So here is my toolbox function: (function(window){ var mySpace=function(){ return new PrivateSpace(); } var PrivateSpace=function(){ var testCache={}; }; PrivateSpace.prototype={ init:function(){ console.log('init this:', this); return this; }, ajax:function(){ console.log('make ajax calls here'); return this; }, cache:function(key,selector){ console.log('cache selectors here'); testCache[key]=selector; console.log('cached selector: ',testCache); return this; } } window.hmis=window.m$=mySpace(); })(window) Now, if I execute this function like: console.log(m$.cache('firstname','#FirstNameTextbox')); I get an error 'testCache' is not defined. I'm not able to access the variable "testCache" inside my cache function of the prototype. How should I access it? Basically, what I want to do is, I want to cache all my jQuery selectors into an object and use this object in the future.

  Read the article

• Design Pattern for Changing Object

  - by user210757

  Is there a Design Pattern for supporting different permutations object? Version 1 public class myOjbect { public string field1 { get; set; } /* requirements: max length 20 */ public int field2 { get; set; } . . . public decimal field200 { get; set; } } Version 2 public class myObject { public string field1 { get; set; } /* requirements: max length 40 */ public int field2 { get; set; } . . . public double field200 { get; set; } /* changed data types */ . . ./* 10 new properties */ public double field210 { get; set; } } of course I could just have separate objects, but thought there might be a good pattern for this sort of thing.

  Read the article

• Performance difference between functions and pattern matching in Mathematica

  - by Samsdram

  So Mathematica is different from other dialects of lisp because it blurs the lines between functions and macros. In Mathematica if a user wanted to write a mathematical function they would likely use pattern matching like f[x_]:= x*x instead of f=Function[{x},x*x] though both would return the same result when called with f[x]. My understanding is that the first approach is something equivalent to a lisp macro and in my experience is favored because of the more concise syntax. So I have two questions, is there a performance difference between executing functions versus the pattern matching/macro approach? Though part of me wouldn't be surprised if functions were actually transformed into some version of macros to allow features like Listable to be implemented. The reason I care about this question is because of the recent set of questions (1) (2) about trying to catch Mathematica errors in large programs. If most of the computations were defined in terms of Functions, it seems to me that keeping track of the order of evaluation and where the error originated would be easier than trying to catch the error after the input has been rewritten by the successive application of macros/patterns.

  Read the article

• Abstract Design Pattern implementation

  - by Pathachiever11

  I started learning design patterns a while ago (only covered facade and abstract so far, but am enjoying it). I'm looking to apply the Abstract pattern to a problem I have. The problem is: Supporting various Database systems using one abstract class and a set of methods and properties, which then the underlying concrete classes (inheriting from abstract class) would be implementing. I have created a DatabaseWrapper abstract class and have create SqlClientData and MSAccessData concrete class that inherit from the DatabaseWrapper. However, I'm still a bit confused about how the pattern goes as far as implementing these classes on the Client. Would I do the following?: DatabaseWrapper sqlClient = new SqlClientData(connectionString); This is what I saw in an example, but that is not what I'm looking for because I want to encapsulate the concrete classes; I only want the Client to use the abstract class. This is so I can support for more database systems in the future with minimal changes to the Client, and creating a new concrete class for the implementations. I'm still learning, so there might be a lot of things wrong here. Please tell me how I can encapsulate all the concrete classes, and if there is anything wrong with my approach. Many Thanks! PS: I'm very excited to get into software architecture, but still am a beginner, so take it easy on me. :)

  Read the article

• free open-source linux screenshot & ocr tool

  - by Gryllida

  I'm looking for a tool which would be able to capture a screen region, pass it to OCR and put the result into clipboard. "import ppm:- | gocr -i - | xclip -selection c" works, but gocr is unreliable: simple text on a webpage has errors. It is a clear font but the OCR tool always misses "r" and replaces it with underscore. "import ppm:- | ocrad -i - | xclip -selection c" says "ocrad: maxval 255 in ppm "P6" file." tesseract needs an image file and does not accept piping input to it. xfce4-screenshooter does not do OCR. ABBYY Screenshot Reader is proprietary. tessnet2 is freeware running on a proprietary platform. Google Docs can OCR screenshots in a batch. But my data is confidential and better not put online. Graphical interface solutions would be acceptable for this question, too. There is a number of existing SuperUser questions about OCR. They fall in several categories. Questions just about OCR without the "screenshot taking" part. Open Source OCR for linux Free OCR for Arabic text Looking for recommendations on OCR problem - tabular numeric data Which has better OCR applications: Ubuntu, or Mac/iPad, or Windows? How can I preform OCR from the command line? OCR solution on linux machine from command line (duplicate) Free OCR software OCR for Sanskrit ( OR devanagari) Copy image and paste to OCR (windows) File processing OCR instead of screenshot. Online OCR website for processing an entire pdf file at one time? Practical OCR solution for converting a large book to a digital format? How to extract text with OCR from a PDF on Linux? Batch-OCR many PDFs OCR Image based PDF Copy image and paste to OCR Extract OCR text from Evernote OCR in Word 2013 Replace (OCR) garbled text in PDF? Process files prior to running OCR. How can I make OCR recognize my documents' text better? Tesseract OCR recognition bilingual document. mistakes tolerance level setup OCR for low quality images How do I get the best quality screenshot for OCR (Optical Character Recognition) and what tool would be the best for screenshots? OCR training. Training Tesseract-OCR for english language fonts None of them answer this question.

  Read the article

• Autologin on Ubuntu Server

  - by hekevintran

  I have a machine running Ubuntu Server. It has only a command-line interface. How can I make the system login with a specific user automatically (I don't want to type the username/password). I know that this is insecure and I don't care.

  Read the article

• Trace linux bash call

  - by jex

  I was wondering if there is a way to trace where a command was run from in Linux. For example, if I call a script, is there any way to trace where it was called from, like started from a program or another bash script.

  Read the article

• List full timestamps of files in a tarball

  - by Mechanical snail

  I have a large tar archive and want to see the exact (nanosecond) timestamps that are stored for each file in the archive. In case it's relevant, the tarball is in POSIX-2001 format (tar --format=posix). tar --list --verbose displays the timestamps rounded off to the minute. For comparison, ls --full-time does what I want, but I'd rather not have to extract everything first because it's huge. For my purposes, command-line and GUI tools are both fine.

  Read the article

• > /dev/null for Windows

  - by Sridhar Ratnakumar

  If I want to ignore stdout of a command, I do this on *nix: myprog > /dev/null How do I achieve the same on Windows (.cmd/.bat)?

  Read the article

• Rotate a 3gp video file 90 degrees using ubuntu and free tools

  - by justinhj

  I want to use ubuntu and preferably standard packages such as ffmpeg to rotate a 3gp video by 90 degrees in any direction. Preferably a command line or python script.

  Read the article

• Where does $PATH get set in OS X 10.6 Snow Leopard?

  - by Andrew

  I type echo $PATH on the command line and get /opt/local/bin:/opt/local/sbin:/Users/andrew/bin:/usr/local/bin:/usr/local/mysql/bin:/usr/local/pear/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin:/opt/local/bin:/usr/local/git/bin I'm wondering where this is getting set since my .bash_login file is empty. I'm particularly concerned that, after installing MacPorts, it installed a bunch of junk in /opt. I don't think that directory even exists in a normal Mac OS X install. Update: Thanks to jtimberman for correcting my echo $PATH statement

  Read the article

• How do I detect if uTorrent is downloading?

  - by Richard

  I need to write a script that determines whether or not uTorrent is currently downloading something. I'd rather it just be downloading, but if I cannot differentiate between downloading and uploading then it would be better than nothing. One possible way would be check the whether any files ending in .!ut are locked - but I'm hoping for something a little more elegant. My weapon of choice is VBScript but I'm happy to use the command line if needs be.

  Read the article

• I used route delete 0.0.0.0 in Windows 7 and now i can't connect to my adsl internet

  - by Santiago Sanchez

  I was looking for a way to portfoward 0.0.0.0 default gateways and I found in a Microsoft page that I had to try the command route delete 0.0.0.0, my internet disconnected and I couldn't connect to the internet anymore... Does anyone have a solution? It's an ADSL Modem. I have: Windows 7 x32 4 GB ram A kanji modem that has this problem too... It's like Windows doesn't detect the wireless adapter, so it won't connect to the internet.

  Read the article

• stsadm -o. What does the -o mean?

  - by ddono25

  I am working on a large SharePoint farm, mainly with the backend SQL Servers. We have always used stsadm -o for all stsadm functions, but no one seems to know why. I can't seem to find the info specific for stsadm, would it be general Windows command-line sytax?

  Read the article

• How can I see Bash history from more than one terminal session in Ubuntu?

  - by Sanoj

  I use Ubuntu 9.10 and I would like to be able to see my bash history for more than one terminal sessions. I.e. my last 200 commands or so, even if I have been logged out in between. When I use the history I just see all commands from my actual terminal session. How can I see more command history from Bash? Is there any specific settings for bash that I should change from the default values in Ubuntu?

  Read the article

• How to upgrade XBMC Live from 9.04.1 to 9.11?

  - by sunpech

  I've been unable to do a fresh install of XBMC Live 9.11 to my hard drive. Everytime it fails at the Install System step. But I am able to get XBMC Live 9.04.1 to install successfully. How do I upgrade XBMC Live 9.04.1 to 9.11? I understand that Ctrl+Shift+F2 brings up the command line, but what are the next set of commands to run?

  Read the article

• Configuring gmail for use on mailing lists

  - by reemrevnivek

  This is really two questions in one. First, are nettiquette guidelines still accurate in their restrictions on ASCII vs. HTML, posting style, and line length? (Here's a recent metafilter discussion of the topic.) Second, If they are not, should these guidelines be respected? If they are (or if they should still be respected), how can modern mail programs be configured to work properly with them? Most mailing list etiquette statements appear to have been written by sysadmins who loved their command lines, and refuse to change anything. Many still reference rfc1855, written in 1995. Just reading that paginated TXT should give you an idea of the climate at the time. Here's a short, fairly random list of mailing list etiquette statements with some extracted formatting guidelines: Mozilla - HTML discouraged, interleaved posting. FreeBSD - No HTML, don't top post, line length at 75 characters. Fedora - No HTML, bottom-post. You get the idea. You've all seen etiquette statements before. So, assuming that the rules should be obeyed (Usually a good idea), what can be done to allow me to still use a modern mail program, and exchange mail with friends who use the same programs? We like to format our mail. Bold headings, code snippets (sometimes syntax highlighted, if the copy-paste pulls RTF text as from XCOde and Eclipse), free line breaks determined by your browser width, and the (very) occasional image make the message easier to read. Threaded conversations are a wonderful thing. Broadband connections are, I'm sure, the rule for most of the users of SU and of developer mailing lists, disk space is cheap, and so the overhead of HTML is laughable. However, I don't want to post a question to a mailing list and have the guru who can answer my question automatically delete it, or come off as uncaring. Until I hear otherwise, I'll continue to respect the rules as best I can. For a common example of the problem, Gmail, by default, sends HTML formatted messages with bottom-posted quotes (which are folded in, just read the last message immediately above), and uses the frame width to wrap lines, rather than a character count. ASCII can be selected, and quotes can be moved and reversed, but line wraps of quotes don't work, line breaks are tedious to add (and more tedious to read, if they're super small in comparison to the width of the frame). Is there a forwarding, free mail program which can help with this exercise? Should an "RFC1855 mode" lab be written? Or do I have to go to the command line for my mailing lists, and gmail for my other mail?

  Read the article

< Previous Page | 92 93 94 95 96 97 98 99 100 101 102 103  | Next Page >