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  • Using PDO with MVC

    - by mister martin
    I asked this question at stackoverflow and received no response (closed as duplicate with no answer). I'm experimenting with OOP and I have the following basic MVC layout: class Model { // do database stuff } class View { public function load($filename, $data = array()) { if(!empty($data)) { extract($data); } require_once('views/header.php'); require_once("views/$filename"); require_once('views/footer.php'); } } class Controller { public $model; public $view; function __construct() { $this->model = new Model(); $this->view = new View(); // determine what page we're on $page = isset($_GET['view']) ? $_GET['view'] : 'home'; $this->display($page); } public function display($page) { switch($page) { case 'home': $this->view->load('home.php'); break; } } } These classes are brought together in my setup file: // start session session_start(); require_once('Model.php'); require_once('View.php'); require_once('Controller.php'); new Controller(); Now where do I place my database connection code and how do I pass the connection onto the model? try { $db = new PDO('mysql:host='.DB_HOST.';dbname='.DB_DATABASE.'', DB_USERNAME, DB_PASSWORD); $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); } catch(PDOException $err) { die($err->getMessage()); } I've read about Dependency Injection, factories and miscellaneous other design patterns talking about keeping SQL out of the model, but it's all over my head using abstract examples. Can someone please just show me a straight-forward practical example?

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  • If a library doesn't provide all my needs, how should I proceed?

    - by 9a3eedi
    I'm developing an application involving math and physics models, and I'd like to use a Math library for things like Matrices. I'm using C#, and so I was looking for some libraries and found Math.NET. I'm under the impression, from past experience, that for math, using a robust and industry-approved third party library is much better than writing your own code. It seems good for many purposes, but it does not provide support for Quaternions, which I need to use as a type. Also, I need some functions in Vector and Matrix that also aren't provided, such as rotation matrices and vector rotation functions, and calculating cross products. At the same time, it provides a lot of functions/classes that I simply do not need, which might mean a lot of unnecessary bloat and complexity. At this rate, should I even bother using the library? Should I write my own math library? Or is it a better idea to stick to the third party library and somehow wrap around it? Perhaps I should make a subclass of the Matrix and Vector type of the library? But isn't that considered bad style? I've also tried looking for other libraries but unfortunately I couldn't find anything suitable.

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  • Earmarks of a Professional PHP Programmer

    - by Scotty C.
    I'm a 19 year old student who really REALLY enjoys programming, and I'm hoping to glean from your years of experience here. At present, I'm studying PHP every chance I get, and have been for about 3 years, although I've never taken any formal classes. I'd love to some day be a programmer full time, and make a good career of it. My question to you is this: What do you consider to be the earmarks or traits of a professional programmer? Mainly in the field of PHP, but other, more generalized qualifications are also more than welcome, as I think PHP is more of a hobbyist language and may not be the language of choice in the eyes of potential employers. Please correct me if I'm wrong. Above all, I don't want to wast time on something that isn't worth while. I'm currently feeling pretty confident in my knowledge of PHP as a language, and I know that I could build just about anything I need and have it "work", but I feel sorely lacking in design concepts and code structure. I can even write object oriented code, but in my personal opinion, that isn't worth a hill of beans if it isn't organized well. For this reason, I bought Matt Zandstra's book "PHP Objects, Patterns, and Practice" and have been reading that a little every day. Anyway, I'm starting to digress a little here, so back to the original question. What advice would you give to an aspiring programmer who wants to make an impact in this field? Also, on a side note, I've been working on a project with a friend of mine that would give a fairly good idea of where I'm at coding wise. I'm gonna give a link, I don't want anyone to feel as though I'm pushing or spamming here, so don't click it if you don't want to. But if you are interested on giving some feedback there as well, you can see the code on github. I'm known as The Craw there. https://github.com/PureChat/PureChat--Beta-/tree/

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  • Designing a plug-in system

    - by madflame991
    I'm working on a Java project and I would like to add a plug-in system. More precisely, I would like to let the user design his own module, pack it into a jar, leave it in a "plugins/" subfolder of my application and be done with it. I've managed to get a child classloader to instantiate objects of classes located in external jars, but now I'm facing a design dilemma: Say Joe makes a plug-in and he packs it in joeplugin.jar. I would really like Joe to have a class named "instantiation.Factory" and I would also like everyone to have this class with this exact location and name. (This factory class obviously implements a interface that I provide and through it I get what I want from the plug-in.) If Joe wouldn't be restricted in this way I would have to look into his entire jar for some class that implements my factory interface and I don't want to imagine how complicated things get. So my question is: should I enforce a strict naming convention for this single class? I have no idea how plug-in systems work.

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  • TechEd 2010 Day Four: Learning how to help others learn

    - by BuckWoody
    I do quite a few presentations, and teach at the University of Washington, and also teach other classes. But I'm always learning from others how to help others learn. At events like TechEd I have access to some of the best speakers around, so I try to find out what they do that works. I attended a great session by allen White, in which he demonstrated a set of PowerShell scripts. He said that Dan Jones of the Microsoft Manageability team told him while he demonstrated a script he needed to provide some visual way to represent the process. Allen used one of the oldest visualizations around - a flowchart. It was the first time I'd seen one used to illustrate a PowerShell script, and it was very effective. I'm totally stealing the idea. All of us are teachers - we help others on our team understand what we're up to. Make sure you make notes for what you find effective in dealing with you, and then meld that into your own way of teaching. Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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  • Why to say, my function is of IFly type rather than saying it's Airplane type

    - by Vishwas Gagrani
    Say, I have two classes: Airplane and Bird, both of them fly. Both implement the interface IFly. IFly declares a function StartFlying(). Thus both Airplane and Bird have to define the function, and use it as per their requirement. Now when I make a manual for class reference, what should I write for the function StartFlying? 1) StartFlying is a function of type IFly . 2) StartFlying is a function of type Airplane 3) StartFlying is a function of type Bird. My opinion is 2 and 3 are more informative. But what i see is that class references use the 1st one. They say what interface the function is declared in. Problem is, I really don't get any usable information from knowing StartFlying is IFly type. However, knowing that StartFlying is a function inside Airplane and Bird, is more informative, as I can decide which instance (Airplane or Bird ) to use. Any lights on this: how saying StartFlying is a function of type IFly, can help a programmer understanding how to use the function?

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  • Is this an acceptable approach to undo/redo in Python?

    - by Codemonkey
    I'm making an application (wxPython) to process some data from Excel documents. I want the user to be able to undo and redo actions, even gigantic actions like processing the contents of 10 000 cells simultaneously. I Googled the topic, and all the solutions I could find involves a lot of black magic or is overly complicated. Here is how I imagine my simple undo/redo scheme. I write two classes - one called ActionStack and an abstract one called Action. Every "undoable" operation must be a subclass of Action and define the methods do and undo. The Action subclass is passed the instance of the "document", or data model, and is responsible for committing the operation and remembering how to undo the change. Now, every document is associated with an instance of the ActionStack. The ActionStack maintains a stack of actions (surprise!). Every time actions are undone and new actions are performed, all undone actions are removed for ever. The ActionStack will also automatically remove the oldest Action when the stack reaches the configurable maximum amount. I imagine the workflow would produce code looking something like this: class TableDocument(object): def __init__(self, table): self.table = table self.action_stack = ActionStack(history_limit=50) # ... def delete_cells(self, cells): self.action_stack.push( DeleteAction(self, cells) ) def add_column(self, index, name=''): self.action_stack.push( AddColumnAction(self, index, name) ) # ... def undo(self, count=1): self.action_stack.undo(count) def redo(self, count=1): self.action_stack.redo(count) Given that none of the methods I've found are this simple, I thought I'd get the experts' opinion before I go ahead with this plan. More specifically, what I'm wondering about is - are there any glaring holes in this plan that I'm not seeing?

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  • Ways to organize interface and implementation in C++

    - by Felix Dombek
    I've seen that there are several different paradigms in C++ concerning what goes into the header file and what to the cpp file. AFAIK, most people, especially those from a C background, do: foo.h class foo { private: int mem; int bar(); public: foo(); foo(const foo&); foo& operator=(foo); ~foo(); } foo.cpp #include foo.h foo::bar() { return mem; } foo::foo() { mem = 42; } foo::foo(const foo& f) { mem = f.mem; } foo::operator=(foo f) { mem = f.mem; } foo::~foo() {} int main(int argc, char *argv[]) { foo f; } However, my lecturers usually teach C++ to beginners like this: foo.h class foo { private: int mem; int bar() { return mem; } public: foo() { mem = 42; } foo(const foo& f) { mem = f.mem; } foo& operator=(foo f) { mem = f.mem; } ~foo() {} } foo.cpp #include foo.h int main(int argc, char* argv[]) { foo f; } // other global helper functions, DLL exports, and whatnot Originally coming from Java, I have also always stuck to this second way for several reasons, such as that I only have to change something in one place if the interface or method names change, that I like the different indentation of things in classes when I look at their implementation, and that I find names more readable as foo compared to foo::foo. I want to collect pro's and con's for either way. Maybe there are even still other ways? One disadvantage of my way is of course the need for occasional forward declarations.

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  • which style of member-access is preferable

    - by itwasntpete
    the purpose of oop using classes is to encapsulate members from the outer space. i always read that accessing members should be done by methods. for example: template<typename T> class foo_1 { T state_; public: // following below }; the most common doing that by my professor was to have a get and set method. // variant 1 T const& getState() { return state_; } void setState(T const& v) { state_ = v; } or like this: // variant 2 // in my opinion it is easier to read T const& state() { return state_; } void state(T const& v) { state_ = v; } assume the state_ is a variable, which is checked periodically and there is no need to ensure the value (state) is consistent. Is there any disadvantage of accessing the state by reference? for example: // variant 3 // do it by reference T& state() { return state_; } or even directly, if I declare the variable as public. template<typename T> class foo { public: // variant 4 T state; }; In variant 4 I could even ensure consistence by using c++11 atomic. So my question is, which one should I prefer?, Is there any coding standard which would decline one of these pattern? for some code see here

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  • Loose typing not applied to objects

    - by TecBrat
    I have very little experience working with classes and object. I work in a loosely typed language, PHP. I was working with a SimpleXML object and ran into a problem where I was trying to do math with an element of that object like $results->ProductDetail->{'Net'.$i}; If I echoed that value, I'd get 0.53 but when I tried to do math with it, it was converted to 0 Is there a reason that a loosely typed language would not recognize that as a float and handle it as such? Why would "echo" handle it as a string but the math fail to convert it? Example: $xml='<?xml version="1.0" encoding="UTF-8" ?>'; $xml.='<Test> <Item> <Price>0.53</Price> </Item> </Test>'; $result=simplexml_load_string($xml); var_dump($result->Item->Price); echo '<br>'; echo $result->Item->Price; echo '<br>'; echo 1+$result->Item->Price; echo '<br>'; echo 1+(float)$result->Item->Price; Output: object(SimpleXMLElement)#4 (1) { [0]=> string(4) "0.53" } 0.53 1 1.53

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  • Go/Obj-C style interfaces with ability to extend compiled objects after initial release

    - by Skrylar
    I have a conceptual model for an object system which involves combining Go/Obj-C interfaces/protocols with being able to add virtual methods from any unit, not just the one which defines a class. The idea of this is to allow Ruby-ish open classes so you can take a minimalist approach to library development, and attach on small pieces of functionality as is actually needed by the whole program. Implementation of this involves a table of methods marked virtual in an RTTI table, which system functions are allowed to add to during module initialization. Upon typecasting an object to an interface, a Go-style lookup is done to create a vtable for that particular mapping and pass it off so you can have comparable performance to C/C++. In this case, methods may be added /afterwards/ which were not previously known and these new methods allow newer interfaces to be satisfied; while I like this idea because it seems like it would be very flexible (disregarding the potential for spaghetti code, which can happen with just about any model you use regardless). By wrapping the system calls for binding methods up in a set of clean C-compatible calls, one would also be able to integrate code with shared libraries and retain a decent amount of performance (Go does not do shared linking, and Objective-C does a dynamic lookup on each call.) Is there a valid use-case for this model that would make it worth the extra background plumbing? As much as this Dylan-style extensibility would be nice to have access to, I can't quite bring myself to a use case that would justify the overhead other than "it could make some kinds of code more extensible in future scenarios."

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  • Why is there no facility to overload static properties in PHP?

    - by Jon
    Intro PHP allows you to overload method calls and property accesses by declaring magic methods in classes. This enables code such as: class Foo { public function __get($name) { return 42; } } $foo = new Foo; echo $foo->missingProperty; // prints "42" Apart from overloading instance properties and methods, since PHP 5.3.0 we can also overload static methods calls by overriding the magic method __callStatic. Something missing What is conspicuously missing from the available functionality is the ability to overload static properties, for example: echo Foo::$missingProperty; // fatal error: access to undeclared static property This limitation is clearly documented: Property overloading only works in object context. These magic methods will not be triggered in static context. Therefore these methods should not be declared static. As of PHP 5.3.0, a warning is issued if one of the magic overloading methods is declared static. But why? My questions are: Is there a technical reason that this functionality is not currently supported? Or perhaps a (shudder) political reason? Have there been any aborted attempts to add this functionality in the past? Most importantly, the question is not "how can I have dynamic static properties in userland PHP?". That said, if you know of an especially cute implementation based on __callStatic that you want to share then by all means do so.

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  • I need some career/education advice regarding computer science [on hold]

    - by user2521987
    So I'm a senior mathematics major this fall and I have only taken three CS classes (Java I, Java II, and C++). This summer, I am participating in a mathematics REU (Research Experience for Undergraduates), and I program in C++ about 8 hours a day...and I find that I absolutely love it. I love using programming to solve math problems in my research. I think I want to pursue a career in programming. I have a few options Stay at my university an extra 1-1.5 years (beyond the 4) and do a double major in Math/CS. This will put me in up to around 7-10k in debt (currently I have no debt and am scheduled to graduate debt free). Then apply to a masters in CS. Apply directly to a masters in CS from a math undergraduate degree. I don't like this idea because I likely won't get into a good program or funded with such little background. Go to graduate school, funded, in applied mathematics and try to further my knowledge in computer science while there. Then apply to a masters in CS. I'm not sure if 1 or 3 would be better. My end goal would be to go to a top 20-30 CS graduate program and to get a cool, good job. What would you recommend?

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  • Is there a better way to consume an ASP.NET Web API call in an MVC controller?

    - by davidisawesome
    In a new project I am creating for my work I am creating a fairly large ASP.NET Web API. The api will be in a separate visual studio solution that also contains all of my business logic and database interactions, Model classes as well. In the test application I am creating (which is asp.net mvc4), I want to be able to hit an api url I defined from the control and cast the return JSON to a Model class. The reason behind this is that I want to take advantage of strongly typing my views to a Model. This is all still in a proof of concept stage, so I have not done any performance testing on it, but I am curious if what I am doing is a good practice, or if I am crazy for even going down this route. Here is the code on the client controller: public class HomeController : Controller { protected string dashboardUrlBase = "http://localhost/webapi/api/StudentDashboard/"; public ActionResult Index() //This view is strongly typed against User { //testing against Joe Bob string adSAMName = "jBob"; WebClient client = new WebClient(); string url = dashboardUrlBase + "GetUserRecord?userName=" + adSAMName; //'User' is a Model class that I have defined. User result = JsonConvert.DeserializeObject<User>(client.DownloadString(url)); return View(result); } . . . } If I choose to go this route another thing to note is I am loading several partial views in this page (as I will also do in subsequent pages). The partial views are loaded via an $.ajax call that hits this controller and does basically the same thing as the code above: Instantiate a new WebClient Define the Url to hit Deserialize the result and cast it to a Model Class. So it is possible (and likely) I could be performing the same actions 4-5 times for a single page. Is there a better method to do this that will: Let me keep strongly typed views. Do my work on the server rather than on the client (this is just a preference since I can write C# faster than I can write javascript).

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  • How to keep track of previous scenes and return to them in libgdx

    - by MxyL
    I have three scenes: SceneTitle, SceneMenu, SceneLoad. (The difference between the title scene and the menu scene is that the title scene is what you see when you first turn on the game, and the menu scene is what you can access during the game. During the game, meaning, after you've hit "play!" in the title scene.) I provide the ability to save progress and consequently load a particular game. An issue that I've run into is being able to easily keep track of the previous scene. For example, if you enter the load scene and then decide to change your mind, the game needs to go back to where you were before; this isn't something that can be hardcoded. Now, an easy solution off the top of my head is to simply maintain a scene stack, which basically keeps track of history for me. A simple transaction would be as follows I'm currently in the menu scene, so the top of the stack is SceneMenu I go to the load scene, so the game pushes SceneLoad onto the stack. When I return from the load scene, the game pops SceneLoad off the stack and initializes the scene that's currently at the top, which is SceneMenu I'm coding in Java, so I can't simply pass around Classes as if they were objects, so I've decided implemented as enum for eac scene and put that on the stack and then have my scene managing class go through a list of if conditions to return the appropriate instance of the class. How can I implement my scene stack without having to do too much work maintaining it?

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  • Mocking concrete class - Not recommended

    - by Mik378
    I've just read an excerpt of "Growing Object-Oriented Software" book which explains some reasons why mocking concrete class is not recommended. Here some sample code of a unit-test for the MusicCentre class: public class MusicCentreTest { @Test public void startsCdPlayerAtTimeRequested() { final MutableTime scheduledTime = new MutableTime(); CdPlayer player = new CdPlayer() { @Override public void scheduleToStartAt(Time startTime) { scheduledTime.set(startTime); } } MusicCentre centre = new MusicCentre(player); centre.startMediaAt(LATER); assertEquals(LATER, scheduledTime.get()); } } And his first explanation: The problem with this approach is that it leaves the relationship between the objects implicit. I hope we've made clear by now that the intention of Test-Driven Development with Mock Objects is to discover relationships between objects. If I subclass, there's nothing in the domain code to make such a relationship visible, just methods on an object. This makes it harder to see if the service that supports this relationship might be relevant elsewhere and I'll have to do the analysis again next time I work with the class. I can't figure out exactly what he means when he says: This makes it harder to see if the service that supports this relationship might be relevant elsewhere and I'll have to do the analysis again next time I work with the class. I understand that the service corresponds to MusicCentre's method called startMediaAt. What does he mean by "elsewhere"? The complete excerpt is here: http://www.mockobjects.com/2007/04/test-smell-mocking-concrete-classes.html

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  • The Correct Usage of DLLs with a DirectX Game?

    - by smoth190
    I'm using DirectX 10 (in C++) to make a game engine, and a test driver program on top of it. Now that I've written many messy rough drafts of an engine, I want to make the final (or sorta final) clean version. I choose to follow how I've seen other engines do it, and that's to have all the core nasty messy crap in a DLL, and then you can create games with just a few functions (well, not really :D). However, I'm unsure of what nasty messy crap to put in that DLL. I don't know about speed restrictions with DLLs. What I've done is put my winproc in the DLL, and have a class that takes the messages, and sends them through to the program using the DLL. Then that program does what it needs to do, and calls a rendering functions back in the DLL that renders everything. Only problem is it gets very low FPS (2, to be exact...). I've looked through everything, and I don't know if the way I'm using DLLs in causing this, or its something different. Whether it's the DLLs or not, I still want to know how to use a DLL correctly with a game engine. I like being neat, I hate having to see all those long names of DirectX classes. I use typedef a lot.

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  • BCM2046B1 Bluetooth Dongle connection problem

    - by Andfoy
    Well i have a Blueooth dongle with an BCM2046 IC intrregated, my problem is that when i connect it, Ubuntu recognize it, but it don't work whe i try to scan or scan the PC from other device, i replaced the default Gnome Bluetooth manager and i installed Blueman, but the problem presists. The Bluetooth LED indicator appears to be "working". I'm using 11.10 Oneiric Ocelot hcitool dev: Devices: hci0 89:21:XX:XX:XX:XX lsusb: Bus 002 Device 003: ID 0a5c:4500 Broadcom Corp. BCM2046B1 USB 2.0 Hub (part of BCM2046 Bluetooth) Bus 002 Device 004: ID 0a5c:2100 Broadcom Corp. Bluetooth 2.0+eDR dongle hciconfig -a: hci0: Type: BR/EDR Bus: USB BD Address: 89:21:XX:XX:XX:XX ACL MTU: 1017:8 SCO MTU: 64:0 UP RUNNING PSCAN ISCAN RX bytes:1329 acl:0 sco:0 events:40 errors:0 TX bytes:671 acl:0 sco:0 commands:35 errors:0 Features: 0xff 0xff 0x8d 0xfe 0x9b 0xf9 0x00 0x80 Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3 Link policy: RSWITCH HOLD SNIFF PARK Link mode: SLAVE ACCEPT Name: 'ubuntu-0' Class: 0x4a0100 Service Classes: Networking, Capturing, Telephony Device Class: Computer, Uncategorized HCI Version: 2.0 (0x3) Revision: 0x4000 LMP Version: 2.0 (0x3) Subversion: 0x430e Manufacturer: Broadcom Corporation (15) Sorry for my English and thanks for any hints.

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  • Parallel Class/Interface Hierarchy with the Facade Design Pattern?

    - by Mike G
    About a third of my code is wrapped inside a Facade class. Note that this isn't a "God" class, but actually represents a single thing (called a Line). Naturally, it delegates responsibilities to the subsystem behind it. What ends up happening is that two of the subsystem classes (Output and Timeline) have all of their methods duplicated in the Line class, which effectively makes Line both an Output and a Timeline. It seems to make sense to make Output and Timeline interfaces, so that the Line class can implement them both. At the same time, I'm worried about creating parallel class and interface structures. You see, there are different types of lines AudioLine, VideoLine, which all use the same type of Timeline, but different types of Output (AudioOutput and VideoOutput, respectively). So that would mean that I'd have to create an AudioOutputInterface and VideoOutputInterface as well. So not only would I have to have parallel class hierarchy, but there would be a parallel interface hierarchy as well. Is there any solution to this design flaw? Here's an image of the basic structure (minus the Timeline class, though know that each Line has-a Timeline): NOTE: I just realized that the word 'line' in Timeline might make is sound like is does a similar function as the Line class. They don't, just to clarify.

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  • What alternative is better to diagram this scenario?

    - by Mosty Mostacho
    I was creating and discussing a class diagram with a partner of mine. To simplify things, I've modify the real domain we're working on and made up the following diagram: Basically, a company works on constructions that are quite different one from each other but are still constructions. Note I've added one field for each class but there should be many more. Now, I thought this was the way to go but my partner told me that if in the future new construction classes appear we would have to modify the Company class, which is correct. So the new proposed class diagram would be this: Now I've been wondering: Should the fact that in no place of the application will there be mixed lists of planes and bridges affect the design in any way? When we have to list only planes for a company, how are we supposed to distinguish them from the other elements in the list without checking for their class names? Related to the previous question, is it correct to assume that this type of diagram should be high-level and this is something it shouldn't matter at this stage but rather be thought and decided at implementation time? Any comment will be appreciated.

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  • Should components have sub-components in a component-based system like Artemis?

    - by Daniel Ingraham
    I am designing a game using Artemis, although this is more of philosophical question about component-based design in general. Let's say I have non-primitive data which applies to a given component (a Component "animal" may have qualities such as "teeth" or "diet"). There are three ways to approach this in data-driven design, as I see it: 1) Generate classes for these qualities using "traditional" OOP. I imagine this has negative implications for performance, as systems then must be made aware of these qualities in order to process them. It also seems counter to the overall philosophy of data-driven design. 2) Include these qualities as sub-components. This seems off, in that we are now confusing the role of components with that of entities. Moreover out of the box Artemis isn't capable of mapping these subcomponents onto their parent components. 3) Add "teeth", "diet", etc. as components to the overall entity alongside "animal". While this feels odd hierarchically, it may simply be a peculiarity of component-based systems. I suspect 3 is the correct way to think about things, but I was curious about other ideas.

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  • Can higher-order functions in FP be interpreted as some kind of dependency injection?

    - by Giorgio
    According to this article, in object-oriented programming / design dependency injection involves a dependent consumer, a declaration of a component's dependencies, defined as interface contracts, an injector that creates instances of classes that implement a given dependency interface on request. Let us now consider a higher-order function in a functional programming language, e.g. the Haskell function filter :: (a -> Bool) -> [a] -> [a] from Data.List. This function transforms a list into another list and, in order to perform its job, it uses (consumes) an external predicate function that must be provided by its caller, e.g. the expression filter (\x -> (mod x 2) == 0) [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] selects all even numbers from the input list. But isn't this construction very similar to the pattern illustrated above, where the filter function is the dependent consumer, the signature (a -> Bool) of the function argument is the interface contract, the expression that uses the higher-order is the injector that, in this particular case, injects the implementation (\x -> (mod x 2) == 0) of the contract. More in general, can one relate higher-order functions and their usage pattern in functional programming to the dependency injection pattern in object-oriented languages? Or in the inverse direction, can dependency injection be compared to using some kind of higher-order function?

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  • TechEd 2010 Day Four: Learning how to help others learn

    - by BuckWoody
    I do quite a few presentations, and teach at the University of Washington, and also teach other classes. But I'm always learning from others how to help others learn. At events like TechEd I have access to some of the best speakers around, so I try to find out what they do that works. I attended a great session by allen White, in which he demonstrated a set of PowerShell scripts. He said that Dan Jones of the Microsoft Manageability team told him while he demonstrated a script he needed to provide some visual way to represent the process. Allen used one of the oldest visualizations around - a flowchart. It was the first time I'd seen one used to illustrate a PowerShell script, and it was very effective. I'm totally stealing the idea. All of us are teachers - we help others on our team understand what we're up to. Make sure you make notes for what you find effective in dealing with you, and then meld that into your own way of teaching. Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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  • Standards & compliances for secure web application development?

    - by MarkusK
    I am working with developers right now that write code the way they want and when i tell them to do it other way they respond that its just matter of preference how to do it and they have their way and i have mine. I am not talking about the formatting of code, but rather of way site is organized in classes and the way the utilize them. and the way they create functions and process forms etc. Their coding does not match my standards, but again they argue that its matter of preference and as long as goal achieved the can be different way's to do it. I agree but their way is proven to have bugs and we spend a lot of time going back and forth with them to fix all problems security or functionality, yet they still write same code no matter how many times i asked them to stop doing certain things. Now i am ready to dismiss them but friend of mine told me that he has same exact problem with freelance developers he work with. So i don't want to trade one bad apple for another. Question is is there some world wide (or at least europe and usa) accepted standard or compliance on how write secure web based applications. What application architecture should be for maintainable application. Is there are some general standard that can be used for any language ruby php or java govern security and functionality and quality of code? Or at least for PHP and MySQL i use for my website. So i can make them follow this strict standard and stop making excuses.

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  • Implementing a ILogger interface to log data

    - by Jon
    I have a need to write data to file in one of my classes. Obviously I will pass an interface into my class to decouple it. I was thinking this interface will be used for testing and also in other projects. This is my interface: //This could be used by filesystem, webservice public interface ILogger { List<string> PreviousLogRecords {get;set;} void Log(string Data); } public interface IFileLogger : ILogger { string FilePath; bool ValidFileName; } public class MyClassUnderTest { public MyClassUnderTest(IFileLogger logger) {....} } [Test] public void TestLogger() { var mock = new Mock<IFileLogger>(); mock.Setup(x => x.Log(Is.Any<string>).AddsDataToList()); //Is this possible?? var myClass = new MyClassUnderTest(mock.Object); myClass.DoSomethingThatWillSplitThisAndLog3Times("1,2,3"); Assert.AreEqual(3,mock.PreviousLogRecords.Count); } This won't work I don't believe as nothing is storing the items so is this possible using Moq and also what do you think of the design of the interface?

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