Search Results

Search found 17921 results on 717 pages for 'cocoa design patterns'.

Page 281/717 | < Previous Page | 277 278 279 280 281 282 283 284 285 286 287 288  | Next Page >

• Drag and Drop Team Selection

  - by davidjwest

  I have a Fantasy F1 Website, currently users select their teams using dropdown menus. It works OK but isn't as user friendly as I would like. I would like to implement a drag and drop type of system, there's jQuery code out there that would go part of the way to allowing me to do this: http://jqueryui.com/demos/draggable/ But I am not sure about how to integrate that into PHP and MySQL, my jQuery skills are limited! I'd also need to stop them spending more than a certain amount of money, each driver has a value and the teams can only spend a certain amount of money. There's also limits for example you can only pick a driver once, but you can have three different drivers. Finally, how would you decide that the user had picked their team, I don't want a submit button as that kind of defeats the object of the exercise! Thanks for any advice, I don't expect anyone to write the code for me but some pointers would be greatly appreciated.

  Read the article

• PHP class data implementation

  - by Bakanyaka

  I'm studying OOP PHP and have watched two tutorials that implement user login\registration system as an example. But implementation varies. Which way will be more correct one to work with data such as this? Load all data retrieved from database as array into a property called something like _data on class creation and further methods operate with this property Create separate properties for each field retrieved from database, on class creation load all data fields into respective properties and operate with that properties separately? Then let's say I want to create a method that returns a list of all users with their data. Which way is better? Method that returns just an array of userdata like this: Array([0]=>array([id] => 1, [username] => 'John', ...), [1]=>array([id] => 2, [username] => 'Jack', ...), ...) Method that creates a new instance of it's class for each user and returns an array of objects

  Read the article

• Significant amount of the time, I can't think of a reason to have an object instead of a static class. Do objects have more benefits than I think?

  - by Prog

  I understand the concept of an object, and as a Java programmer I feel the OO paradigm comes rather naturally to me in practice. However recently I found myself thinking: Wait a second, what are actually the practical benefits of using an object over using a static class (with proper encapsulation and OO practices)? I could think of two benefits of using an object (both significant and powerful): Polymorphism: allows you to swap functionality dynamically and flexibly during runtime. Also allows to add new functionality 'parts' and alternatives to the system easily. For example if there's a Car class designed to work with Engine objects, and you want to add a new Engine to the system that the Car can use, you can create a new Engine subclass and simply pass an object of this class into the Car object, without having to change anything about Car. And you can decide to do so during runtime. Being able to 'pass functionality around': you can pass an object around the system dynamically. But are there any more advantages to objects over static classes? Often when I add new 'parts' to a system, I do so by creating a new class and instantiating objects from it. But recently when I stopped and thought about it, I realized that a static class would do just the same as an object, in a lot of the places where I normally use an object. For example, I'm working on adding a save/load-file mechanism to my app. With an object, the calling line of code will look like this: Thing thing = fileLoader.load(file); With a static class, it would look like this: Thing thing = FileLoader.load(file); What's the difference? Fairly often I just can't think of a reason to instantiate an object when a plain-old static-class would act just the same. But in OO systems, static classes are fairly rare. So I must be missing something. Are there any more advantages to objects other from the two that I listed? Please explain.

  Read the article

• What class structure allows for a base class and mix/match of subclasses? (Similar to Users w/ roles)

  - by cdeszaq

  I have a set of base characteristics, and then a number of sub-types. Each instance must be one of the sub-types, but can be multiple sub-types at once. The sub-types of each thing can change. In general, I don't care what subtype I have, but sometimes I do care. This is much like a Users-Roles sort of relationship where a User having a particular Role gives the user additional characteristics. Sort of like duck-typing (ie. If my Foo has a Bar, I can treat it like a ThingWithABar.) Straight inheritance doesn't work, since that doesn't allow mix/match of sub-types. (ie. no multi-inheritance). Straight composition doesn't work because I can't switch that up at runtime. How can I model this?

  Read the article

• Versioning Java APIs in a non-web context

  - by GAP

  I have modular java application which consists of 40 modules. Some of these modules needs to expose external APIs which other modules or any external integration should be using. The system runs as a desktop application and each module is bundled as a separate jar file. My plan is to bundle the external api as a separate jar. But now the question is: how can I maintain multiple versions of the same API to keep backward compatibility in cases where it can co-exist? Are there any de facto standards on handling APIs versioning out of a web context ?

  Read the article

• Greenspun's Tenth Rule, does every large project include a Lisp interpreter?

  - by casualcoder

  Greenspun's tenth rule (actually the only rule) states that: Any sufficiently complicated C or Fortran program contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Common Lisp. My memory is that there are some papers on the topic, perhaps for Borland's Quattro (spreadsheet) project and possibly others. Google is unhelpful, maybe the right search terms are not coming to mind. I am looking for papers or articles supporting this claim, if any.

  Read the article

• Is there such a concept as "pseudo implementation" in software development?

  - by MachuPichu

  I'm looking for a label to describe the practice of using human-based computation methods or other means of "faking" an algorithm for the sake of getting a product or demo off the ground quickly without spending the time to develop an technical/scalable/analytical solution? Eg: using Amazon Turk to count the number of empty tables in a restaurant. I'm also looking to learn more about this subject, but not sure what to search for. Human-based computation is only one method, I'm interested in the general idea of pseudo-implementation. Any ideas, recommended reading? Thanks

  Read the article

• Scene or Activity Animation

  - by Siddharth

  My game require an animation when one activity finishes and next started because I have develop game with multiple activity not as multiple scene per game. I have to show animation at the time of activity creation and activity destroy. I have trying to create basic animation that was supported by android. And all that xml file I have to post it into the anim folder but the loading of resource was so much high so any type of animation I provide using android method does not work for me it look weird. If scene class has some functionality for animation that please know me then I try to load different type of animation using scene. I have not create multiple scene because I have no awareness about how to manage multiple scene in andengine though I have a working experience of 8 months in andengine. So this help also provide me a great help. Basically I want to create animation like one activity slide out at the same time the other activity slide in. So at a time user can see the transition of activity. Thanks in advance.

  Read the article

• What makes Java so suitable for writing NoSQL Databases

  - by good_computer

  Looking at this page that aggregates the current NoSQL landscape, one can see that the majority of these projects are written in Java. Databases are complex systems software dealing with the file system, and so C/C++ would be a better choice than Java for this. (that's my thinking which might be flawed) Secondly, databases deal with transferring large amounts of data from disk to RAM -- which they call a working set. The JVM takes non-trivial amount of RAM for it's own purpose -- so it would be more efficient to use a platform that leaves lots of memory for data instead of hogging it for its own operations. The major relational databases are ALL written in C/C++ MySQL C, C++ Oracle Assembler, C, C++ SQL Server C++ PostgreSQL C SQLite C So what makes Java so popular in NoSQL world.

  Read the article

• What Technology to use to Interact with Codeigniter "Backend" [on hold]

  - by symlynk

  I am building an application that looks like this: Codeingiter App/MySQL DB <--> API (this is the "contract" between the two entities) <--> Web Frontend I want the web frontend to be able to interact with the MySQL DB by requesting JSON objects in a RESTful way. But I don't want the Web Frontend to expose the workings of the Codeigniter App (i.e. let the Web Frontend clients see the domain of the codeigniter app, including its controllers/functions). The Codeigniter App is for business clients, and needs to be "hidden" from the Web Frontend users. I want to use PHP or Javascript, and am considering node js's Express, Angular, and SLIM PHP. Any thoughts as to what technology would suit this purpose best? Thanks

  Read the article

• Architecture driven by users, or by actions/content?

  - by hugerth

  I have a question about designing MVC app architecture. Let's say our application has three main categories of views (items of type 1, items of type 2...). And we have three (or more in future) types of users - Admins, let's say Moderators and typical Users. And in the future there might be more of them. Admins have full access to app, Moderators can visit only 2/3 type of items, and Users can visit only basic type of items. Should I divide my controllers/views/whatever like this: Items "A", Items "B", Items "C", then make them 100% finished and at the end add access privileges? Pros: DRY option Cons Conditional expressions in views Or another options: Items "A" / Admin, Items "A" / Moderator / Items "B" Admin ...? Pros: Divided parts of application for specific user (is that pros?) Cons: A lot of repeated code I don't have great experience in planning such things so it would nice if you can give me some tips or links to learn something about it.

  Read the article

• How is this paradigm/style called?

  - by McMannus

  I have the following situation: I'm developing an add-in for a UML modeling tool. The models that can be created by the user are stored inside the main application and a limited access to the models is given through its API. However, the add-in has a lot of callbacks for events that are triggered by the main application, when changes to the model occur by the user. Since the models are already stored once in the main application, I considered it not practicable to duplicate the models in the add-in, which leads to the fact that I have only behavior in the add-in, rather than having a state. This behavior is mainly expressed by static functions, that are organized in functional cohesive classes. The callbacks for the events have always references to the model elements relevant for the specifc event that ocurred. First, it seemed to me that this is a procedural style in general, but procedural style doesn't consider events/callbacks, so this boils down to the question. How is this programming style called?

  Read the article

• Any tips/tricks/resources on actually TEACHING a class on OOP? [closed]

  - by Sempus

  I may slowly be getting into teaching an Object-Orientated Programming class at my school in a year or two. I just graduated and work at my school as an Application Programmer. I'd first start off as a TA/grader and then slowly move into the Professor role. The class would be in Java. I always see resources on this fine site about HOW to program, but does anyone know any tips/tricks/resources on how to TEACH a programming class? It would be full of all different skills levels(but still semi-technical) so it would have to be a little more understandable than if it was just CS kids.

  Read the article

• how to stop enemies from moving to one point when lots of them are chasing one object [duplicate]

  - by BBgun

  This question already has an answer here: Is there a simple way to stop enemies standing in the same spot? 8 answers i am making a top down game which lots of enemies are chasing one guy. then,enemies would move to one point without any collision,they just overlay each other. so ,is there any simple way to make them feel more real? make them not overlay with each other? ================================= i have tried the solution using boundbox to check collision, but i still very puzzled about what to do with the collision. i have a bad solution.it doesn't work well. my solution in simple: foreach(around_enemy_arr in other) { vector a = normalize(self.positionvector - other.positionvector); self.move_vector = self.move_vector + a; } this can work,but when plenty of enemies come very close to each other,they would shake. i am sooooo confused. please help.

  Read the article

• User input and automated input separation

  - by tpaksu

  I have a MySQL database and an automation script which modifies the data inside once a day. And these columns may have changed by an user manually. What is the best approach to make the system only update the automated data, not the manually edited ones? I mean yes, flagging the cell which is manually edited is one way to do it, but I want to know if there's another way to accomplish this? Just curiosity. BTW, the question is about cell values, not rows.

  Read the article

• Do I need to add an index on a table with one row?

  - by briddums

  I'm creating a parameter table in our database. This table will have 1 row with values that are environment specific (production, development, etc). Is there any reason why I should define an index on this table? Update This table is a parameter table which will be used to drive our job queue system. The table will be defined like this: QueuePrm LogLvl integer ShowMs boolean Restart boolean This table will only ever have 1 row. No other table in our system will reference it.

  Read the article

• Characteristics, what's the inverse of (x*(x+1))/2? [closed]

  - by Valmond

  In my game you can spend points to upgrade characteristics. Each characteristic has a formula like: A) out = in : for one point spent, one pont gained (you spend 1 point on Force so your force goes from 5 to 6) B) out = last level (starting at 1) : so the first point spent earns you 1 point, the next point spent earns you an additional 2 and so on (+3,+4,+5...) C) The inverse of B) : You need to spend 1 point to earn one, then you need to spend 2 to earn another one and so on. I have already found the formula for calculating the actual level of B when points spent = x : charac = (x*(x+1))/2 But I'd like to know what the "reverse" version of B) (usable for C) is, ie. if I have spent x points, how many have I earned if 1 spent gives 1, 1+2=3 gives 2, 1+2+3=6 gives 3 and so on. I know I can just calculate the numbers but I'd like to have the formula because its neater and so that I can stick it in an excel sheet for example... Thanks! ps. I think I have nailed it down to something like charac = sqrt( x*m +k) but then I'm stuck doing number guessing for k and m and I feel I might be wrong anyway as I get close but never hits the spot.

  Read the article

• VMware vSphere cluster design for site redundancy

  - by Stefan Radovanovici

  I have a question about the best design for site redudancy when using vSphere clusters. A bit of background info about our situation first though. We are a medium-sized company with two main offices, located in different countries. Our networks are linked by a Layer2 150Mbps leased line which is currently underused. We have a variety of services running for internal use within the company, some on physycal servers and some on existing vSphere clusters. In our department we also run several services (almost all running under various forms of Linux) like NTP, Syslog, jump servers, monitoring servers and so on. We have now the requirement that those servers need to be redundant within each location (which they are not at the moment) and also site redudant (which they are to some extent, the servers are duplicated in the 2nd location with configurations kept in sync via various methods at the application layer). There is no SAN available for us, at least not something that we can use at the moment. Cost is also an issue. While we do have some budget available for this, we can't afford to buy SANs for both locations for example. I looked at the VSA feature and it seems that this could be something for us but I am unsure how to solve the site-redudancy requirement. At the moment for testing purposes I am setting up in a lab a vSphere 5 with VSA on two ESXi hosts. I am currently using the Essentials Plus kit with VSA license, which allows me to build a VSA cluster on up to 3 hosts, together with a vCenter license to manage them. The hosts each have two dual-port network cards and two 600GB drives, running in Raid1. Hardware-wise this will be enough for us to run the all the services we need as VMs and will provide redundandcy within the site. At the moment I see only two option to have site redundancy: build an identical VSA cluter in the second location and keep the various services sync'ed at application layer (database sync, rsync and so on). simply move one of the hosts from the existing cluster to the second location, basically having the VSA cluster span the 150Mbps link between the sites. I would very much prefer the second option but I am unsure how well it'll work, if it can work at all. Technically it should, we can span the needed VLANs across the leased line and have them available in the second location. The advantage would be that we don't need to worry at all about sync'ing databases and the like. But I have the feeling that the bandwidth will not be enough, I have no way of knowing how much traffic will the VSA cluster generate between the hosts. I realize that this will most likely depend on the individual usage of the VMs but still, I have no idea how VSA replicates data between the ESXi hosts. Are these my only options or can my goals be achieved in some other way ? Is there perhaps a way to have some sort of "cold stand by" cluster in the second location where the VMs would be sync'ed once per night from the main location ? The idea is that in case the first site becomes unavailable, we would be able to bring all those VMs online there. We would be ok with the data being 1 day old. Any answers are appreciated. Best regards, Stefan

  Read the article

• Taking the data mapper approach in Zend Framework

  - by Seeker

  Let's assume the following tables setup for a Zend Framework app. user (id) groups (id) groups_users (id, user_id, group_id, join_date) I took the Data Mapper approach to models which basically gives me: Model_User, Model_UsersMapper, Model_DbTable_Users Model_Group, Model_GroupsMapper, Model_DbTable_Groups Model_GroupUser, Model_GroupsUsersMapper, Model_DbTable_GroupsUsers (for holding the relationships which can be seen as aentities; notice the "join_date" property) I'm defining the _referenceMap in Model_DbTable_GroupsUsers: protected $_referenceMap = array ( 'User' => array ( 'columns' => array('user_id'), 'refTableClass' => 'Model_DbTable_Users', 'refColumns' => array('id') ), 'App' => array ( 'columns' => array('group_id'), 'refTableClass' => 'Model_DbTable_Groups', 'refColumns' => array('id') ) ); I'm having these design problems in mind: 1) The Model_Group only mirrors the fields in the groups table. How can I return a collection of groups a user is a member of and also the date the user joined that group for every group? If I just added the property to the domain object, then I'd have to let the group mapper know about it, wouldn't I? 2) Let's say I need to fetch the groups a user belongs to. Where should I put this logic? Model_UsersMapper or Model_GroupsUsersMapper? I also want to make use of the referencing map (dependent tables) mechanism and probably use findManyToManyRowset or findDependentRowset, something like: $result = $this->getDbTable()->find($userId); $row = $result->current(); $groups = $row->findManyToManyRowset( 'Model_DbTable_Groups', 'Model_DbTable_GroupsUsers' ); This would produce two queries when I could have just written it in a single query. I will place this in the Model_GroupsUsersMapper class. An enhancement would be to add a getGroups method to the Model_User domain object which lazily loads the groups when needed by calling the appropriate method in the data mapper, which begs for the second question. Should I allow the domain object know about the data mapper?

  Read the article

• Naming convention for non-virtual and abstract methods

  - by eagle

  I frequently find myself creating classes which use this form (A): abstract class Animal { public void Walk() { // TODO: do something before walking // custom logic implemented by each subclass WalkInternal(); // TODO: do something after walking } protected abstract void WalkInternal(); } class Dog : Animal { protected override void WalkInternal() { // TODO: walk with 4 legs } } class Bird : Animal { protected override void WalkInternal() { // TODO: walk with 2 legs } } Rather than this form (B): abstract class Animal { public abstract void Walk(); } class Dog : Animal { public override void Walk() { // TODO: do something before walking // custom logic implemented by each subclass // TODO: walk with 4 legs // TODO: do something after walking } } class Bird : Animal { public override void Walk() { // TODO: do something before walking // custom logic implemented by each subclass // TODO: walk with 2 legs // TODO: do something after walking } } As you can see, the nice thing about form A is that every time you implement a subclass, you don't need to remember to include the initialization and finalization logic. This is much less error prone than form B. What's a standard convention for naming these methods? I like naming the public method Walk since then I can call Dog.Walk() which looks better than something like Dog.WalkExternal(). However, I don't like my solution of adding the suffix "Internal" for the protected method. I'm looking for a more standardized name. Btw, is there a name for this design pattern?

  Read the article

• HTML Submit button vs AJAX based Post (ASP.NET MVC)

  - by Graham

  I'm after some design advice. I'm working on an application with a fellow developer. I'm from the Webforms world and he's done a lot with jQuery and AJAX stuff. We're collaborating on a new ASP.MVC 1.0 app. He's done some pretty amazing stuff that I'm just getting my head around, and used some 3rd party tools etc. for datagrids etc. but... He rarely uses Submit buttons whereas I use them most of the time. He uses a button but then attaches Javascript to it that calls an MVC action which returns a JSON object. He then parses the object to update the datagrid. I'm not sure how he deals with server-side validation - I think he adds a message property to the JSON object. A sample scenario would be to "Save" a new record that then gets added to the gridview. The user doesn't see a postback as such, so he uses jQuery to disable the UI whilst the controller action is running. TBH, it looks pretty cool. However, the way I'd do it would be to use a Submit button to postback, let the ModelBinder populate a typed model class, parse that in my controller Action method, update the model (and apply any validation against the model), update it with the new record, then send it back to be rendered by the View. Unlike him, I don't return a JSON object, I let the View (and datagrid) bind to the new model data. Both solutions "work" but we're obviously taking the application down different paths so one of us has to re-work our code... and we don't mind whose has to be done. What I'd prefer though is that we adopt the "industry-standard" way of doing this. I'm unsure as to whether my WebForms background is influencing the fact that his way just "doesn't feel right", in that a "submit" is meant to submit data to the server. Any advice at all please - many thanks.

  Read the article

• dynamical binding or switch/case?

  - by kingkai

  A scene like this: I've different of objects do the similar operation as respective func() implements. There're 2 kinds of solution for func_manager() to call func() according to different objects Solution 1: Use virtual function character specified in c++. func_manager works differently accroding to different object point pass in. class Object{ virtual void func() = 0; } class Object_A : public Object{ void func() {}; } class Object_B : public Object{ void func() {}; } void func_manager(Object* a) { a->func(); } Solution 2: Use plain switch/case. func_manager works differently accroding to different type pass in typedef _type_t { TYPE_A, TYPE_B }type_t; void func_by_a() { // do as func() in Object_A } void func_by_b() { // do as func() in Object_A } void func_manager(type_t type) { switch(type){ case TYPE_A: func_by_a(); break; case TYPE_B: func_by_b(); default: break; } } My Question are 2: 1. at the view point of DESIGN PATTERN, which one is better? 2. at the view point of RUNTIME EFFCIENCE, which one is better? Especailly as the kinds of Object increases, may be up to 10-15 total, which one's overhead oversteps the other? I don't know how switch/case implements innerly, just a bunch of if/else? Thanks very much!

  Read the article

• Applying the Decorator Pattern to Forms

  - by devoured elysium

  I am trying to apply the Decorator Design Pattern to the following situation: I have 3 different kind of forms: Green, Yellow, Red. Now, each of those forms can have different set of attributes. They can have a minimize box disabled, a maximized box disabled and they can be always on top. I tried to model this the following way: Form <---------------------------------------FormDecorator /\ /\ |---------|-----------| |----------------------|-----------------| GreenForm YellowForm RedForm MinimizeButtonDisabled MaximizedButtonDisabled AlwaysOnTop Here is my GreenForm code: public class GreenForm : Form { public GreenForm() { this.BackColor = Color.GreenYellow; } public override sealed Color BackColor { get { return base.BackColor; } set { base.BackColor = value; } } } FormDecorator: public abstract class FormDecorator : Form { private Form _decoratorForm; protected FormDecorator(Form decoratorForm) { this._decoratorForm = decoratorForm; } } and finally NoMaximizeDecorator: public class NoMaximizeDecorator : FormDecorator { public NoMaximizeDecorator(Form decoratorForm) : base(decoratorForm) { this.MaximizeBox = false; } } So here is the running code: static void Main() { Application.EnableVisualStyles(); Application.SetCompatibleTextRenderingDefault(false); Application.Run(CreateForm()); } static Form CreateForm() { Form form = new GreenForm(); form = new NoMaximizeDecorator(form); form = new NoMinimizeDecorator(form); return form; } The problem is that I get a form that isn't green and that still allows me to maximize it. It is only taking in consideration the NoMinimizeDecorator form. I do comprehend why this happens but I'm having trouble understanding how to make this work with this Pattern. I know probably there are better ways of achieving what I want. I made this example as an attempt to apply the Decorator Pattern to something. Maybe this wasn't the best pattern I could have used(if one, at all) to this kind of scenario. Is there any other pattern more suitable than the Decorator to accomplish this? Am I doing something wrong when trying to implement the Decorator Pattern? Thanks

  Read the article

• Structuring the UI code of a single-page EXTjs Web app using Rails?

  - by Daniel Beardsley

  I’m in the process of creating a large single-page web-app using ext-js for the UI components with Rails on the backend. I’ve come to good solutions for transferring data using Whorm gem and Rails support of RESTful Resources. What I haven’t come to a conclusion on is how to structure the UI and business logic aspects of the application. I’ve had a look at a few options, including Netzke but haven’t seen anything that I really think fits my needs. How should a web-application that uses ext-js components, layouts, and controls in the browser and Rails on the server best implement UI component re-use, good organization, and maintainability while maintaining a flexible layout design. Specifically I’m looking for best-practice suggestions for structuring the code that creates and configures UI components (many UI config options will be based on user data) Should EXT classes be extended in static JS for often re-used customizations and then instantiated with various configuration options by generated JS within html partials? Should partials create javascript blocks that instantiate EXT components? Should partials call helpers that return ruby hashes for EXT component config which is then dumped to Json? Something else entirely? There are many options and I'd love to hear from people who've been down this road and found some methodology that worked for them.

  Read the article

• How to properly implement the Strategy pattern in a web MVC framework?

  - by jboxer

  In my Django app, I have a model (lets call it Foo) with a field called "type". I'd like to use Foo.type to indicate what type the specific instance of Foo is (possible choices are "Number", "Date", "Single Line of Text", "Multiple Lines of Text", and a few others). There are two things I'd like the "type" field to end up affecting; the way a value is converted from its normal type to text (for example, in "Date", it may be str(the_date.isoformat())), and the way a value is converted from text to the specified type (in "Date", it may be datetime.date.fromtimestamp(the_text)). To me, this seems like the Strategy pattern (I may be completely wrong, and feel free to correct me if I am). My question is, what's the proper way to code this in a web MVC framework? In a client-side app, I'd create a Type class with abstract methods "serialize()" and "unserialize()", override those methods in subclasses of Type (such as NumberType and DateType), and dynamically set the "type" field of a newly-instantiated Foo to the appropriate Type subclass at runtime. In a web framework, it's not quite as straightforward for me. Right now, the way that makes the most sense is to define Foo.type as a Small Integer field and define a limited set of choices (0 = "Number", 1 = "Date", 2 = "Single Line of Text", etc.) in the code. Then, when a Foo object is instantiated, use a Factory method to look at the value of the instance's "type" field and plug in the correct Type subclass (as described in the paragraph above). Foo would also have serialize() and unserialize() methods, which would delegate directly to the plugged-in Type subclass. How does this design sound? I've never run into this issue before, so I'd really like to know if other people have, and how they've solved it.

  Read the article

< Previous Page | 277 278 279 280 281 282 283 284 285 286 287 288  | Next Page >