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  • Effective handling of variables in non-object oriented programming

    - by srnka
    What is the best method to use and share variables between functions in non object-oriented program languages? Let's say that I use 10 parameters from DB, ID and 9 other values linked to it. I need to work with all 10 parameters in many functions. I can do it next ways: 1. call functions only with using ID and in every function get the other parameters from DB. Advantage: local variables are clear visible, there is only one input parameter to function Disadvantage: it's slow and there are the same rows for getting parameters in every function, which makes function longer and not so clear 2. call functions with all 10 parameters Advantage: working with local variables, clear function code Disadvantage: many input parameters, what is not nice 3. getting parameters as global variables once and using them everywhere Advantage - clearer code, shorter functions, faster processing Disadvantage - global variables - loosing control of them, possibility of unwanted overwriting (Especially when some functions should change their values) Maybe there is some another way how to implement this and make program cleaner and more effective. Can you say which way is the best for solving this issue?

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  • What is the best way to handle dynamic content?

    - by user1561753
    So we run a site where there are elements of the interface that could potentially be changed at any moment in the backend. Specifically we run a web service where certain functions are loaded dynamically. However, there are times where we remove certian functions and we want the experience to be as seamless for the user as possible. Now we've considered a few methods of solving this Ping the server every few seconds. If the functions are outdated/no longer available refresh the users page. While this would work the best, I feel like having that much IO can't be too good When the user clicks a function, if it's outdated/no longer available, alert them in the response and refresh the page. This would also work fairly well. I guess I'm more wondering how web apps like Google Docs work where you have content that has to be synced up across multiple users and that isn't more than a few seconds outdated Sorry if this isn't the best place to ask this. I figured this was more of a site architecture question and that this might be the place to ask it over SO.

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  • I have an MIS degree. How do I sell myself as a programmer?

    - by hydroparadise
    So, I graduated with a BSBA in Management Information Systems with honors almost 2 years ago which is more of a business degree. As of right now, I do have a job title of "Programmer", but it's more of a report writing position in an arbitrary, proprietary language called PowerOn with the occasional interesting project using more mainstream technologies like .Net and Java. I am also somewhat isoloated being the only programmer in the workplace, which I beleive is a detriment to my career path. The only people I have to bounce ideas against are those on the various SE sites. I don't regret going MIS, but over the past couple of years I have discovered my passion for coding, even though I have been doing some form of coding profesionally and as an enthusiast for years. I do want to persue my Masters in CS (at a later time), but I am not sure if I necessarily need a CS degree to get in with a team of programmers. In addition, I do have a number classes I have taken for different laguanges on the way (C++, Java, SQL, and VB.Net) I beleive my strength is in problem solving where code is just a tool to tackling to problem if needed. My question: How do I best sell myself as a programmer? Should I continue pounding out reports and wait till I have my masters in CS? Or am I viable to be a programmer as I stand?

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  • Looking for a better Factory pattern (Java)

    - by Sam Goldberg
    After doing a rough sketch of a high level object model, I am doing iterative TDD, and letting the other objects emerge as a refactoring of the code (as it increases in complexity). (That whole approach may be a discussion/argument for another day.) In any case, I am at the point where I am looking to refactor code blocks currently in an if-else blocks into separate objects. This is because there is another another value combination which creates new set of logical sub-branches. To be more specific, this is a trading system feature, where buy orders have different behavior than sell orders. Responses to the orders have a numeric indicator field which describes some event that occurred (e.g. fill, cancel). The combination of this numeric indicator field plus whether it is a buy or sell, require different processing buy the code. Creating a family of objects to separate the code for the unique handling each of the combinations of the 2 fields seems like a good choice at this point. The way I would normally do this, is to create some Factory object which when called with the 2 relevant parameters (indicator, buysell), would return the correct subclass of the object. Some times I do this pattern with a map, which allows to look up a live instance (or constructor to use via reflection), and sometimes I just hard code the cases in the Factory class. So - for some reason this feels like not good design (e.g. one object which knows all the subclasses of an interface or parent object), and a bit clumsy. Is there a better pattern for solving this kind of problem? And if this factory method approach makes sense, can anyone suggest a nicer design?

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  • Cron prepending filename to script output

    - by Caitifty
    I'm having an issue with unwanted lines being added to files output by a cron job. I have a script in /etc/cron.hourly which selects some data from a mysql database and saves it in a text file in /var/www. When I run the script as root, it does exactly what I expect it to do. When the script is executed by cron, it creates the same file, but prepends the following three lines at the top of the output file: :::::::::::::: /var/www/outputfilename :::::::::::::: I can't for the life of me work out how to stop this unwanted behavior. The line in /etc/crontab for cron.hourly is the default "44 * * * * root cd / && run-parts --report /etc/cron.hourly". If I use su to change to being root and do "cd / && run-parts --report /etc/cron.hourly" the script runs as expected and the output doesn't have the mysterious additional 3 lines. I've also tried removing the --report flag from the run-parts command in case that was somehow connected, but no joy. Finally, perusing the cron log output in /var/log/syslog just says cron.hourly ran without giving any additional information. Any suggestions on solving this weird problem most welcome..

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  • How should an undergraduate programmer organize his time learning the maximum possible?

    - by nischayn22
    I started programming lately(pre-final year of a CS degree) and now feel like there's a sea of uncovered treasure for me out there. So, I decided to cover as much as is possible before I look out for a job after graduation. So, I started to read books (The C++ Programming Language, Introduction to Algorithms, Cracking the Coding Interview, Programming Pearls,etc ) participate in StackExchange sites, solving problems (InterviewStreet and ProjectEuler), coding for open source, chatting to fellow programmers/mentors and try to learn more and more. Good,then what's the problem?? The problem is I am trying to do many things, but I am doubtful that I am still utilizing my time properly. I am reading many books and sometimes I just leave a book halfway (jumping from one book to another), sometimes I spend way too much time on chatting and also in getting lost somewhere in the huge internet world, and lastly the wasteful burden of attending classes (I don't think my teachers know good enough or I prefer learning on my own) May be some of you had similar situation. How did you organize your time? Or what do you think is the best way to organize it for an undergraduate? Also what mistakes am I making that you can warn me of

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  • Make Gameobject Stand On Surface Facing Certain Direction

    - by Julian
    I want to make a biped character stand on any surface I click on. Surfaces have up vectors of any of positive or negative X,Y,Z. So imagine a cube with each face being a gameobject whose up vector pointing directly away from the cube. If my character is facing "forward" and I click on a surface which is to the left or right of me ( left or right walls), I want my character to now be standing on that surface but still be facing in the direction he initially was. If I click on a wall which is in the forward path of my character i want him to now be standing on that surface and his forward to now be what was once "up" relative to my character. Here is the code I am working with now. void Update() { if (Input.GetMouseButtonUp (0)) { RaycastHit hit; var ray = Camera.main.ScreenPointToRay(Input.mousePosition); if (Physics.Raycast(ray, out hit)) { Vector3 upVectBefore = transform.up; Vector3 forwardVectBefore = transform.forward; Quaternion rotationVectBefore = transform.rotation; Vector3 hitPosition = hit.transform.position; transform.position = hitPosition; float lookDifference = Vector3.Distance(hit.transform.up, forwardVectBefore); if(Vector3.Distance(hit.transform.up, upVectBefore) < .23) //Same normal { transform.rotation = rotationVectBefore; } else if(lookDifference > 1.412 && lookDifference <= 1.70607) //side wall { transform.up = hit.transform.up; transform.forward = forwardVectBefore; } else //head on wall { transform.up = hit.transform.up; transform.forward = upVectBefore; } } } } The first case "Same normal" works fine, however the other two do not work as I would like them to. Sometimes my character is laying down on the surface or on the wrong side of the surface. Does anyone know nice way of solving this problem?

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  • FP for simulation and modelling

    - by heaptobesquare
    I'm about to start a simulation/modelling project. I already know that OOP is used for this kind of projects. However, studying Haskell made me consider using the FP paradigm for modelling a system of components. Let me elaborate: Let's say I have a component of type A, characterised by a set of data (a parameter like temperature or pressure,a PDE and some boundary conditions,etc.) and a component of type B, characterised by a different set of data(different or same parameter, different PDE and boundary conditions). Let's also assume that the functions/methods that are going to be applied on each component are the same (a Galerkin method for example). If I were to use an OOP approach, I would create two objects that would encapsulate each type's data, the methods for solving the PDE(inheritance would be used here for code reuse) and the solution to the PDE. On the other hand, if I were to use an FP approach, each component would be broken down to data parts and the functions that would act upon the data in order to get the solution for the PDE. This approach seems simpler to me assuming that linear operations on data would be trivial and that the parameters are constant. What if the parameters are not constant(for example, temperature increases suddenly and therefore cannot be immutable)? In OOP, the object's (mutable) state can be used. I know that Haskell has Monads for that. To conclude, would implementing the FP approach be actually simpler,less time consuming and easier to manage (add a different type of component or new method to solve the pde) compared to the OOP one? I come from a C++/Fortran background, plus I'm not a professional programmer, so correct me on anything that I've got wrong.

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  • I am not the most logically-organized person. Do I have any chance at being a good 'low-level' programmer?

    - by user217902
    Background: I am entering college next year. I really enjoy making stuff and solving logical problems, so I'm thinking of majoring in compsci and working in software development. I hope to have the kind of job where I can work with implementing / improving algorithms and data structures on a regular basis.. as opposed to, say, a job that's purely concerned with mashing different libraries together, or 'finding the right APIs for the job'. (Hence the word 'low-level' in the title. No, I don't wish to write assembly all day.) Thing is, I've never been the most logically-sharp person. Thus far I have only worked on hobby projects, but I find that I make the silliest of errors ever so often, and it can take me ages to find it. Like anywhere between three hours to a day to locate a simple segfault, off-by-one error, or other logical mistake. (Of course, I do other things in the meantime, like browsing SO, reddit, and the like..) It's not like I'm 'new' to programming either; I first tried C++ maybe five years ago. My question is: is this normal? Should a programmer with any talent solve it in less time? Having read Spolsky's Smart and gets things done, where he talks about the large variance in programming speed, am I near the bottom of the curve, and therefore destined to work in companies that cannot afford to hire quality programmers? I'd like to think that conceptually I'm okay -- I can grasp algorithms and concepts pretty well, I do fine in math and science, although I probably drop signs in my equations more often than the next guy. Still, grokking concepts makes me happy, and is the reason why I want to work with algorithms. I'm hoping to hear from those of you with real-world programming experience. TL;DR: I make many careless mistakes, should I not consider programming as a career?

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  • Algorithm for grouping friends at the cinema [closed]

    - by Tim Skauge
    I got a brain teaser for you - it's not as simple as it sounds so please read and try to solve the issue. Before you ask if it's homework - it's not! I just wish to see if there's an elegant way of solving this. Here's the issue: X-number of friends want's to go to the cinema and wish to be seated in the best available groups. Best case is that everyone sits together and worst case is that everyone sits alone. Fewer groups are preferred over more groups. Sitting alone is least preferred. Input is the number of people going to the cinema and output should be an array of integer arrays that contains: Ordered combinations (most preferred are first) Number of people in each group Below are some examples of number of people going to the cinema and a list of preferred combinations these people can be seated: 1 person: 1 2 persons: 2, 1+1 3 persons: 3, 2+1, 1+1+1 4 persons: 4, 2+2, 3+1, 2+1+1, 1+1+1+1 5 persons: 5, 3+2, 4+1, 2+2+1, 3+1+1, 2+1+1+1, 1+1+1+1+1 6 persons: 6, 3+3, 4+2, 2+2+2, 5+1, 3+2+1, 2+2+1+1, 2+1+1+1+1, 1+1+1+1+1+1 Example with more than 7 persons explodes in combinations but I think you get the point by now. Question is: What does an algorithm look like that solves this problem? My language by choice is C# so if you could give an answer in C# it would be fantastic!

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  • When is it too late to go back to coding from a management role? [closed]

    - by LeoLambrettra
    Problem solving keeps the mind sharp and if you are like me then it makes you happy. But what if you went from coding up to Team Lead and then to Project Manager? I have a team of 12 and on a good salary but lately have been thinking that the politics and admin tasks of being middle level management in an Investment Bank is not the right path to happiness. I used to be able to design and code as well as manage but lately it's all budgets, admin tasks and people problems. At 39 is it too late to go be a senior developer again? Basically - Team Lead in a flat structure with good people rocks. But if half your team is offshore then it loses something - There's a lot of politics in Project Management and so many meetings that even if you want to code you start letting your team down by missing deadlines and only suited for small units of work The coding skills haven't gone so to pick up WCF services it just takes a bit of reading and then playing around. I reckon I could switch to a Hedge Fund and go back to developing and be far happier and get more money. My 2 doubts though are 1. Mid life crisis in that I'd get bored with coding again 2. Or maybe I'd like it but there aren't many dev jobs for 40+ so I'd be throwing away a high level management role that took 7 years at thee one bank to get to0 Anybody else made to switch back and survived?

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  • Disable touchpad tap to click on Oneiric ocelot

    - by AWE
    You've heard this a million times but the "tap to click" is a pain in the behind and I want to disable it. There is no touchpad in gpointing-device-settings and neither in mouse and touchpad in system settings. I've tried some commands in terminal but it's all crap. Dconf-editor doesn't react. How about solving this once and for all? xinput list: ? Virtual core pointer id=2 [master pointer (3)] ? ? Virtual core XTEST pointer id=4 [slave pointer (2)] ? ? PS/2 Generic Mouse id=13 [slave pointer (2)] ? Virtual core keyboard id=3 [master keyboard (2)] ? Virtual core XTEST keyboard id=5 [slave keyboard (3)] ? Power Button id=6 [slave keyboard (3)] ? Video Bus id=7 [slave keyboard (3)] ? Video Bus id=8 [slave keyboard (3)] ? Power Button id=9 [slave keyboard (3)] ? Sleep Button id=10 [slave keyboard (3)] ? Laptop_Integrated_Webcam_HD id=11 [slave keyboard (3)] ? AT Translated Set 2 keyboard id=12 [slave keyboard (3)] ? Dell WMI hotkeys id=14 [slave keyboard (3)]

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  • Why does there seem to be a lot of fear in choosing the "wrong" language to learn?

    - by Shewbox
    Perhaps its just me, but as a current CS student I have already come across many questions on this site and elsewhere about not just "Which language should I use for x?" but also "Does anyone still use language Y?" My first CS class was taught in Scheme, which, if I'm not mistaken, isn't used widely (at least in comparison to languages like Java, PHP, Python, etc). Many of my classmates balked at the idea of having to learn a language they would never have to use again, but I don't quite understand where so much of this fear of learning less popular languages comes from. No, I may not use Scheme in any job I get, but I certainly don't regret having learned to use it (albeit in a very beginner, not very in-depth manner in that one semester). I am taking a search engines class this semester, which is done in Perl and again I am seeing classmates complaining about the language choice. I can understand having a favorite language and disliking others but why do some get worked up over learning it in the first place? Can you really learn the "wrong" language? Isn't learning something like Scheme or Haskell good mental exercise if nothing else, and useful at least to exposure to different ways of solving problems?

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  • Working with volonteers

    - by JavaCecilia
    I've been engaged as a scout leader in the Scout movement since 1993, working on a local and national level, leading both kids and other scout leaders.Last year, the Swedish Scout Association invited 40000 scouts aged 14-17 years old from 150 countries around the world to go camping for 10 days. I was on the planning team with a couple of hundreds of my closest scout friends and during a couple of years we spent our spare time planning logistics, food, program, etc to give these youths an experience of a life time. It was a big and complex project; different languages, religion (Ramadan was celebrated during the camp) and the Swedish weather were some of the factors we had to take into account. The camp was a huge success, the daily wow factor was measured and people truly had fun and got to know each other. I learnt a lot and got friends around the globe - looking back at the pictures it feels unreal that we managed it.The Java platform as OpenJDK and its' future is a similar project in my mind. With 9 million developers and being installed on 3 bn devices, the platform touches a lot of users and businesses. There's a strong community taking Java into the future, making sure it stays relevant. Finding ways to collaborate in a scalable way is the key to success here. We have the bylaws directing how decisions are made, roles are appointed and how to "level" within the community. Using these, we can then make contributions according to our competence and interest and innovate taking our platform into the future.If you find a way to organize volunteers towards a common goal, solving conflicts, making decisions, dividing the work into manageable chunks and having fun while doing it - there's no end to what you can achieve.

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  • Subdomain takes the position of main site in Google search result

    - by user3578586
    We have one domain and one sub-domain. Until last week both of them appear in first page of Google search for very important keyword. Unfortunately Google dropped our main domain from search results. our main site has been in first page for 5 years! About one year ago we build this sub-domain. It simply has been redirected to one of pages of main domain. For solving problem we upload a independent site for sub-domain because we guessed that Google think this is our main page of our site. But problem did not solved. What should we do? our main site offer main services and we we want that will be on first page. Shout down sub-domain? Redirect to main site? Put the link of our main site in sub-domain? (About one year ago we put link of this sub-domain to our main site. Google indexed it and continuously bring that to top.) changing in robots.txt ....

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  • Artificial Intelligence ... how to make an object roam freely/avoid other objects, and model consciousness? [on hold]

    - by help bonafide pigeons
    Say a simple free roam battle scene in which a player runs around freely and engages in battle with other enemies/objects, as shown below: The dragon/dinosaur (or whatever that thing I drew appears to be) will, by some measure, try and avoid attacks so it is modeled to appear to have a conscious desire to avoid pain. My question is ... since this is very complex, many possible strategies for solving this, algorithms, etc., what is the basic idea behind how this would be accomplished in any sort? Like, we can assume the enemy in the picture is not just going to aimlessly hop around and avoid, but freely be modeled to behave as if it were really exploring/fighting. For the best example I can give, witness the behavior of the enemies in Final Fantasy 12 in this video: http://www.youtube.com/watch?v=mO0TkmhiQ6w How do the pros, or how would anyone attempt solve/implement this? PS: I have tried several times to give an image the "illusion" that is has a conciousness, but aside from emulating a real animal's consciousness in complete, I fall short and get choppy moving images that follow predictable patterns, error-prone movements, and the worst imaginable scenario of a battle engagement.

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  • How do I find actors in an area on a poly-precise basis?

    - by Almo
    Ok, I've been asking various questions and getting some good answers, but I think I need to rethink my method, so I'll describe the problem. I have a player who has a big blue box in front of him. This box shows which KActors will be pushed when he pulls the trigger: Currently, the blue box spawns a descendant of Actor which checks collision to see which KActors are touching it: foreach Owner.TouchingActors(class'DynamicSMActor', DynamicActorItt) { // do stuff } The problem is, if you check for touching between Actors and KActors, it looks like it does a plain axis-aligned bounding-box collision. The power will push the box on the lower right, when it's clear it's not touching the blue box. How should I do this properly? I just need a way to find out which KActors are touching that area, on a poly-by-poly level. These collisions are only done with rectangular boxes and simple sphere collision; we are aware of the potential for performance issues with complex objects and poly-collision. I've tried making the collision checker a KActor, but it doesn't report any TouchingActors. This issue is causing us trouble in a lot of other places as well. So solving this problem is a core issue in our game.

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  • How often do you review fundamentals?

    - by mlnyc
    So I've been out of school for a year and a half now. In school, of course we covered all the fundamentals: OS, databases, programming languages (i.e. syntax, binding rules, exception handling, recursion, etc), and fundamental algorithms. the rest were more in-depth topics on things like NLP, data mining, etc. Now, a year ago if you would have told me to write a quicksort, or reverse a singly-linked list, analyze the time complexity of this 'naive' algorithm vs it's dynamic programming counterpart, etc I would have been able to give you a decent and hopefully satisfying answer. But if you would have asked me more real world questions I might have been stumped (things like how would handle logging for an application, or security difference between GET and POST, differences between SQL Server and Oracle SQL, anything I list on my resume as currently working with [jQuery questions, ColdFusion questions, ...] etc) Now, I feel things are the opposite. I haven't wrote my own sort since graduating, and I don't really have to worry much about theoretical things that do not naturally fall into problems I am trying to solve. For example, I might give you some great SQL solutions using an analytical function that I would have otherwise been stumped on or write a cool web application using angular or something but ask me to write an algo for insertAfter(Element* elem) and I might not be able to do it in a reasonable time frame. I guess my question here to the experienced programmers is how do you balance the need to both learn and experiment with new technologies (fun!), working on personal projects (also fun!) working and solving real world problems in a timeboxed environment (so I might reach out to a library that does what I want rather than re-invent the wheel so that I can focus on the problem I am trying to solve) (work, basically), and refreshing on old theoretical material which is still valid for interviews and such (can be a drag)? Do you review older material (such as famous algorithms, dynamic programming, Big-O analysis, locking implementations) regularly or just when you need it? How much time do you dedicate to both in your 'deliberate practice' and do you have a certain to-do list of topics that you want to work on?

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  • Scale an image with unscalable parts

    - by Uko
    Brief description of problem: imagine having some vector picture(s) and text annotations on the sides outside of the picture(s). Now the task is to scale the whole composition while preserving the aspect ratio in order to fit some view-port. The tricky part is that the text is not scalable only the picture(s). The distance between text and the image is still relative to the whole image, but the text size is always a constant. Example: let's assume that our total composition is two times larger than a view-port. Then we can just scale it by 1/2. But because the text parts are a fixed font size, they will become larger than we expect and won't fit in the view-port. One option I can think of is an iterative process where we repeatedly scale our composition until the delta between it and the view-port satisfies some precision. But this algorithm is quite costly as it involves working with the graphics and the image may be composed of a lot of components which will lead to a lot of matrix computations. What's more, this solution seems to be hard to debug, extend, etc. Are there any other approaches to solving this scaling problem?

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  • How to create distinct set from other sets?

    - by shyam_baidya
    While solving the problems on Techgig.com, I got struck with one one of the problem. The problem is like this: A company organizes two trips for their employees in a year. They want to know whether all the employees can be sent on the trip or not. The condition is like, no employee can go on both the trips. Also to determine which employee can go together the constraint is that the employees who have worked together in past won't be in the same group. Examples of the problems: Suppose the work history is given as follows: {(1,2),(2,3),(3,4)}; then it is possible to accommodate all the four employees in two trips (one trip consisting of employees 1& 3 and other having employees 2 & 4). Neither of the two employees in the same trip have worked together in past. Suppose the work history is given as {(1,2),(1,3),(2,3)} then there is no way possible to have two trips satisfying the company rule and accommodating all the employees. Can anyone tell me how to proceed on this problem?

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  • what is standard approach to create a responsive website using javascript,php ajax and perhaps zend framework [closed]

    - by shawndreck
    I am working on a web system currently and plans to heavily use javascript with ajax to make the user interface more friendlier, not fancy as such. The javascript will be used for client side form validation, data loading from server and creating proper content with the result, also to for floating windows during add/edit or external references. Here is a scenerio that could clearify my question. A user wants to update card but instead of jumping to another page to verify the available colors,size and prizes of product, those information are shown in a floating window and changes in the floating window can affect the underlying one. My question is : 1. What are some of the approaches to encounter this situation? 2. Are there any helpful tips, tricks and links on this subject? I am comfortable with js,php and zend. I would appreciate any advice,tip and tricks, problem solving approach to handle a situation like this! Thanks in advance. Hope this make sense.

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  • IPhone track title

    - by woodbase
    If you have an IPhone, you probably know that the name in the playlist comes from the “Title”-attribute instead of the filename. Usually that is not a problem. But when I plug my IPhone to the car stereo the tracks are sorted alphabetically by the “title”-attribute. That becomes a problem when You have an e-book where each chapter starts with “Track 01”. You can manually update this in the file properties (from the context menu in Windows Explorer), but doing so for +200 tracks – no thank you :) The FileInfo-class does not contain a property for this special audio file attribute. However the problem is easily solved using TagLib. The method below, not optimized in any way - just solving the problem at hand, will set the “title”-attribute to the file name. private static void UpdateTitleAttr(string dirPath, string fileFilter)         {             var files = System.IO.Directory.GetFiles(dirPath, fileFilter);                         foreach (var file in files)             {                 var f = TagLib.File.Create(file);                 var newTitle = f.Name.Substring(f.Name.LastIndexOf(@"\") + 1);                 f.Tag.Title = newTitle;                 f.Save();                }         } So now I can hear e-books while driving :P

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  • C programming multiple storage backends

    - by ahjmorton
    I am starting a side project in C which requires multiple storage backends to be driven by a particular piece of logic. These storage backends would each be linked with the decision of which one to use specified at runtime. So for example if I invoke my program with one set of parameters it will perform the operations in memory but if I change the program configuration it would write to disk. The underlying idea is that each storage backend should implement the same protocol. In other words the logic for performing operations should need to know which backend it is operating on. Currently the way I have thought to provide this indirection is to have a struct of function pointers with the logic calling these function pointers. Essentially the struct would contain all the operations needed to implement the higher level logic E.g. struct Context { void (* doPartOfDoOp)(void) int (* getResult)(void); } //logic.h void doOp(Context * context) { //bunch of stuff context->doPartOfDoOp(); } int getResult(Context * context) { //bunch of stuff return context->getResult(); } My questions is if this way of solving the problem is one a C programmer would understand? I am a Java developer by trade but enjoy using C/++. Essentially the Context struct provides an interface like level of indirection. However I would like to know if there is a more idiomatic way of achieving this.

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  • Win 8: Adding a boot volume to an MBR dynamic disk [NOT about changing to basic disks]

    - by Stilez
    (This is NOT aiming to convert to basic disk. In this question, the disk stays dynamic but becomes bootable) There doesn't seem to be a clear, well stated answer I can find, for the question "What are the criteria for Windows 8 to successfully boot from an MBR dynamic disk", or "how do I fix a dynamic MBR partition that's failing boot"? I've tried to educate myself but can't find crucial information to clear it all up. My existing HDD/SSD setup: DISK 0 ~ 60GB SSD/MBR/basic: (350MB recovery)(60GB windows 8 bootable) DISK 1 ~ 512GB SSD/MBR/dynamic: (350MB recovery)(60GB unallocated)(410GB mirrored data) DISK 2 ~ 512GB SSD/MBR/dynamic: (350MB recovery)(60GB unallocated)(410GB mirrored data) DISKS 3, 4, 5: (ignored for simplicity: 2xHDD RAID1 + caching SSD) I'm heavy duty on data crunching and virtualisation, just maxxed out 32GB RAM @ 2133 and moved to 4960X + 64GB. Disk 0 is a pure system disk of little value, and virtualisations runs off mirrored SSDs (Samsung 840 Pro 512 x 2) for double speed reading and so they snapshot in reasonable time. I'm using 4 SATA3 ports and the board only has two decent Intel ports (onboard Marvell are poorer quality). I'm wary of choosing between LSI, HighPoint and other 3rd party controllers as I'm unfamiliar with the maze of decent RAID cards (that's a whole other issue!). I want to cut down my SSD needs by moving the boot volume and caching volume to the 840 pros, giving a setup with 2 fewer SSDs: DISK 0 ~ 512GB SSD/MBR/dynamic: (350MB recovery)(60GB boot)(410GB mirrored data) DISK 1 ~ 512GB SSD/MBR/dynamic: (350MB recovery)(30GB cache for the ICH10R mirror)(30GB temp)(410GB mirrored data) DISKS 2, 3: (2xHDD RAID1) Intel's RST allows this, Win 8 allows booting off a MBR/dynamic disk, and the two 60GB SSDs are hardly the fastest SSDs anyway, they'll get repurposed. Moving the caching volume is easy. Moving the boot volume has me stumped. The difficulty is, I'm hitting a wall of knowledge here. I have a UEFI Asus motherboard with an previous traditional MBR/basic boot disk, and I want it to boot from a disk and volume that's MBR/dynamic. The disk copy is physically ok (Partition Wizard Server will copy to dynamic volumes) but then hits a light blue 0xc000000e boot error. No real surprise, I expected to have some boot fixing, but had expected Windows to boot-fix it (all drivers exist), or the usual manual fixes to work. Specifically, I don't know enough, to know what's got to be manually checked and perhaps corrected for the disk to boot (legacy/uefi/bios, odd partitions, boot tables, disk IDs, hidden boot files, oh my!), or if I need to change any of this secure boot/UEFI/legacy stuff in the bios, convert a 512 SSD to basic and then back to dynamic when working, or if the issue is pure OS config using "diskpart", "bootsect" and "bootrec" from the Win8 DVD. The old system disk still boots but I don't know enough to figure what to fix, to make the system boot as I want. The answers probably aren't hard but the real issue is my confusion and missing information. Thanks for helping!

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  • URL Rewrite – Multiple domains under one site. Part II

    - by OWScott
    I believe I have it … I’ve been meaning to put together the ultimate outgoing rule for hosting multiple domains under one site.  I finally sat down this week and setup a few test cases, and created one rule to rule them all.  In Part I of this two part series, I covered the incoming rule necessary to host a site in a subfolder of a website, while making it appear as if it’s in the root of the site.  Part II won’t work without applying Part I first, so if you haven’t read it, I encourage you to read it now. However, the incoming rule by itself doesn’t address everything.  Here’s the problem … Let’s say that we host www.site2.com in a subfolder called site2, off of masterdomain.com.  This is the same example I used in Part I.   Using an incoming rewrite rule, we are able to make a request to www.site2.com even though the site is really in the /site2 folder.  The gotcha comes with any type of path that ASP.NET generates (I’m sure other scripting technologies could do the same too).  ASP.NET thinks that the path to the root of the site is /site2, but the URL is /.  See the issue?  If ASP.NET generates a path or a redirect for us, it will always add /site2 to the URL.  That results in a path that looks something like www.site2.com/site2.  In Part I, I mentioned that you should add a condition where “{PATH_INFO} ‘does not match’ /site2”.  That allows www.site2.com/site2 and www.site2.com to both function the same.  This allows the site to always work, but if you want to hide /site2 in the URL, you need to take it one step further. One way to address this is in your code.  Ultimately this is the best bet.  Ruslan Yakushev has a great article on a few considerations that you can address in code.  I recommend giving that serious consideration.  Additionally, if you have upgraded to ASP.NET 3.5 SP1 or greater, it takes care of some of the references automatically for you. However, what if you inherit an existing application?  Or you can’t easily go through your existing site and make the code changes?  If this applies to you, read on. That’s where URL Rewrite 2.0 comes in.  With URL Rewrite 2.0, you can create an outgoing rule that will remove the /site2 before the page is sent back to the user.  This means that you can take an existing application, host it in a subfolder of your site, and ensure that the URL never reveals that it’s in a subfolder. Performance Considerations Performance overhead is something to be mindful of.  These outbound rules aren’t simply changing the server variables.  The first rule I’ll cover below needs to parse the HTML body and pull out the path (i.e. /site2) on the way through.  This will add overhead, possibly significant if you have large pages and a busy site.  In other words, your mileage may vary and you may need to test to see the impact that these rules have.  Don’t worry too much though.  For many sites, the performance impact is negligible. So, how do we do it? Creating the Outgoing Rule There are really two things to keep in mind.  First, ASP.NET applications frequently generate a URL that adds the /site2 back into the URL.  In addition to URLs, they can be in form elements, img elements and the like.  The goal is to find all of those situations and rewrite it on the way out.  Let’s call this the ‘URL problem’. Second, and similarly, ASP.NET can send a LOCATION redirect that causes a redirect back to another page.  Again, ASP.NET isn’t aware of the different URL and it will add the /site2 to the redirect.  Form Authentication is a good example on when this occurs.  Try to password protect a site running from a subfolder using forms auth and you’ll quickly find that the URL becomes www.site2.com/site2 again.  Let’s term this the ‘redirect problem’. Solving the URL Problem – Outgoing Rule #1 Let’s create a rule that removes the /site2 from any URL.  We want to remove it from relative URLs like /site2/something, or absolute URLs like http://www.site2.com/site2/something.  Most URLs that ASP.NET creates will be relative URLs, but I figure that there may be some applications that piece together a full URL, so we might as well expect that situation. Let’s get started.  First, create a new outbound rule.  You can create the rule within the /site2 folder which will reduce the performance impact of the rule.  Just a reminder that incoming rules for this situation won’t work in a subfolder … but outgoing rules will. Give it a name that makes sense to you, for example “Outgoing – URL paths”. Precondition.  If you place the rule in the subfolder, it will only run for that site and folder, so there isn’t need for a precondition.  Run it for all requests.  If you place it in the root of the site, you may want to create a precondition for HTTP_HOST = ^(www\.)?site2\.com$. For the Match section, there are a few things to consider.  For performance reasons, it’s best to match the least amount of elements that you need to accomplish the task.  For my test cases, I just needed to rewrite the <a /> tag, but you may need to rewrite any number of HTML elements.  Note that as long as you have the exclude /site2 rule in your incoming rule as I described in Part I, some elements that don’t show their URL—like your images—will work without removing the /site2 from them.  That reduces the processing needed for this rule. Leave the “matching scope” at “Response” and choose the elements that you want to change. Set the pattern to “^(?:site2|(.*//[_a-zA-Z0-9-\.]*)?/site2)(.*)”.  Make sure to replace ‘site2’ with your subfolder name in both places.  Yes, I realize this is a pretty messy looking rule, but it handles a few situations.  This rule will handle the following situations correctly: Original Rewritten using {R:1}{R:2} http://www.site2.com/site2/default.aspx http://www.site2.com/default.aspx http://www.site2.com/folder1/site2/default.aspx Won’t rewrite since it’s a sub-sub folder /site2/default.aspx /default.aspx site2/default.aspx /default.aspx /folder1/site2/default.aspx Won’t rewrite since it’s a sub-sub folder. For the conditions section, you can leave that be. Finally, for the rule, set the Action Type to “Rewrite” and set the Value to “{R:1}{R:2}”.  The {R:1} and {R:2} are back references to the sections within parentheses.  In other words, in http://domain.com/site2/something, {R:1} will be http://domain.com and {R:2} will be /something. If you view your rule from your web.config file (or applicationHost.config if it’s a global rule), it should look like this: <rule name="Outgoing - URL paths" enabled="true"> <match filterByTags="A" pattern="^(?:site2|(.*//[_a-zA-Z0-9-\.]*)?/site2)(.*)" /> <action type="Rewrite" value="{R:1}{R:2}" /> </rule> Solving the Redirect Problem Outgoing Rule #2 The second issue that we can run into is with a client-side redirect.  This is triggered by a LOCATION response header that is sent to the client.  Forms authentication is a common example.  To reproduce this, password protect your subfolder and watch how it redirects and adds the subfolder path back in. Notice in my test case the extra paths: http://site2.com/site2/login.aspx?ReturnUrl=%2fsite2%2fdefault.aspx I want to remove /site2 from both the URL and the ReturnUrl querystring value.  For semi-readability, let’s do this in 2 separate rules, one for the URL and one for the querystring. Create a second rule.  As with the previous rule, it can be created in the /site2 subfolder.  In the URL Rewrite wizard, select Outbound rules –> “Blank Rule”. Fill in the following information: Name response_location URL Precondition Don’t set Match: Matching Scope Server Variable Match: Variable Name RESPONSE_LOCATION Match: Pattern ^(?:site2|(.*//[_a-zA-Z0-9-\.]*)?/site2)(.*) Conditions Don’t set Action Type Rewrite Action Properties {R:1}{R:2} It should end up like so: <rule name="response_location URL"> <match serverVariable="RESPONSE_LOCATION" pattern="^(?:site2|(.*//[_a-zA-Z0-9-\.]*)?/site2)(.*)" /> <action type="Rewrite" value="{R:1}{R:2}" /> </rule> Outgoing Rule #3 Outgoing Rule #2 only takes care of the URL path, and not the querystring path.  Let’s create one final rule to take care of the path in the querystring to ensure that ReturnUrl=%2fsite2%2fdefault.aspx gets rewritten to ReturnUrl=%2fdefault.aspx. The %2f is the HTML encoding for forward slash (/). Create a rule like the previous one, but with the following settings: Name response_location querystring Precondition Don’t set Match: Matching Scope Server Variable Match: Variable Name RESPONSE_LOCATION Match: Pattern (.*)%2fsite2(.*) Conditions Don’t set Action Type Rewrite Action Properties {R:1}{R:2} The config should look like this: <rule name="response_location querystring"> <match serverVariable="RESPONSE_LOCATION" pattern="(.*)%2fsite2(.*)" /> <action type="Rewrite" value="{R:1}{R:2}" /> </rule> It’s possible to squeeze the last two rules into one, but it gets kind of confusing so I felt that it’s better to show it as two separate rules. Summary With the rules covered in these two parts, we’re able to have a site in a subfolder and make it appear as if it’s in the root of the site.  Not only that, we can overcome automatic redirecting that is caused by ASP.NET, other scripting technologies, and especially existing applications. Following is an example of the incoming and outgoing rules necessary for a site called www.site2.com hosted in a subfolder called /site2.  Remember that the outgoing rules can be placed in the /site2 folder instead of the in the root of the site. <rewrite> <rules> <rule name="site2.com in a subfolder" enabled="true" stopProcessing="true"> <match url=".*" /> <conditions logicalGrouping="MatchAll" trackAllCaptures="false"> <add input="{HTTP_HOST}" pattern="^(www\.)?site2\.com$" /> <add input="{PATH_INFO}" pattern="^/site2($|/)" negate="true" /> </conditions> <action type="Rewrite" url="/site2/{R:0}" /> </rule> </rules> <outboundRules> <rule name="Outgoing - URL paths" enabled="true"> <match filterByTags="A" pattern="^(?:site2|(.*//[_a-zA-Z0-9-\.]*)?/site2)(.*)" /> <action type="Rewrite" value="{R:1}{R:2}" /> </rule> <rule name="response_location URL"> <match serverVariable="RESPONSE_LOCATION" pattern="^(?:site2|(.*//[_a-zA-Z0-9-\.]*)?/site2)(.*)" /> <action type="Rewrite" value="{R:1}{R:2}" /> </rule> <rule name="response_location querystring"> <match serverVariable="RESPONSE_LOCATION" pattern="(.*)%2fsite2(.*)" /> <action type="Rewrite" value="{R:1}{R:2}" /> </rule> </outboundRules> </rewrite> If you run into any situations that aren’t caught by these rules, please let me know so I can update this to be as complete as possible. Happy URL Rewriting!

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