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• IIS URL Rewriting: How can I reliably keep relative paths when serving multiple files?

  - by NVRAM

  My WebApp is part CMS, and when I serve up an HTML page to the user it typically contains relative paths in a.href and img.src attributes. I currently have them accessed by urls like: ~/get-data.aspx/instance/user/page.html -- where instance indicates the particular instance for the report and "user/page.html" is a path created by an external application that generates the content. This works pretty reliably with code in the application's BeginRequest method that translates the text after ".aspx" into a query string, then uses Context.RewritePath(). So far so good, but I've just tripped over something that took me by surprise: it appears that if any of the query string ("instance/user/page.html") happens to contain a plus sign ("+") the BeginRequest method is never called, and a 404 is immediately returned to the user. So my question is two-fold: Am I correct in my belief that a "+" would cause the 404, and if so are there other things that could cause similar problems? Is there a way around that problem (perhaps a different method than BeginRequest)? Is there a better way to preserve relative URL paths for generated content than what I'm using? I'd rather not require site admins to install a 3rd party rewrite tool if I can help it.

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• PHP check http referer for form submitted by AJAX, secure?

  - by Michael Mao

  Hi all: This is the first time I am working for a front-end project that requires server-side authentication for AJAX requests. I've encountered problems like I cannot make a call of session_start as the beginning line of the "destination page", cuz that would get me a PHP Warning : Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at C:\xampp\htdocs\comic\app\ajaxInsert Book.php:1) in C:\xampp\htdocs\comic\app\common.php on line 10 I reckon this means I have to figure out a way other than checking PHP session variables to authenticate the "caller" of this PHP script, and this is my approach : I have a "protected" PHP page, which must be used as the "container" of my javascript that posts the form through jQuery $.ajax(); method In my "receiver" PHP script, what I've got is: <?php define(BOOKS_TABLE, "books"); define(APPROOT, "/comic/"); define(CORRECT_REFERER, "/protected/staff/addBook.php"); function isRefererCorrect() { // the following line evaluates the relative path for the referer uri, // Say, $_SERVER['HTTP_REFERER'] returns "http://localhost/comic/protected/staff/addBook.php" // Then the part we concern is just this "/protected/staff/addBook.php" $referer = substr($_SERVER['HTTP_REFERER'], 6 + strrpos($_SERVER['HTTP_REFERER'], APPROOT)); return (strnatcmp(CORRECT_REFERER, $referer) == 0) ? true : false; } //http://stackoverflow.com/questions/267546/correct-http-header-for-json-file header('Content-type: application/json charset=UTF-8'); header('Cache-Control: no-cache, must-revalidate'); echo json_encode(array ( "feedback"=>"ok", "info"=>isRefererCorrect() )); ?> My code works, but I wonder is there any security risks in this approach? Can someone manipulate the post request so that he can pretend that the caller javascript is from the "protected" page? Many thanks to any hints or suggestions.

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• [Delphi] How would you refactor this code?

  - by Al C

  This hypothetical example illustrates several problems I can't seem to get past, even though I keep trying!! ... Suppose the original code is a long event handler, coded in the UI, triggered when a user clicks a cell in a grid. Expressed as pseudocode it's: if Condition1=true then begin //loop through every cell in row, //if aCell/headerCellValue>1 then //color aCell red end else if Condition2=true then begin //do some other calculation adding cell and headerCell values, and //if some other product>2 then //color the whole row green end else show an error message I look at this and say "Ah, refactor to the strategy pattern! The code will be easier to understand, easier to debug, and easier to later extend!" I get that. And I can easily break the code into multiple procedures. The problem is ultimately scope related. Assume the pseudocode makes extensive use of grid properties, values displayed in cells, maybe even built-in grid methods. How do you move all that to another unit, without referencing the grid component in the UI--which would break all the "rules" about loose coupling that make OOP valuable? ... I'm really looking forward to responses. Thanks, as always -- Al C.

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• Form submit capture into database not working

  - by kielie

  Hi guys, I have a form that has two buttons on it, one yes, one no, and at the moment I capture the clicked button into a database, but for some reason, it doesn't always capture the clicked button, I have gone through all my code and everything seems fine, here is the form <div id="mid_prompt"> <form action="refer.php" method="post" onsubmit="return submit_form()" > <div class="prompt_container" style="float: left;"> <span class="prompt_item"><input type="image" src="images/yes.jpg" alt="submit" name="refer" value="yes" /></span> </div> </form> <form action="thank_you.php" method="post" onsubmit="return submit_form()" > <div class="prompt_container" style="float: right;"> <span class="prompt_item"><input type="image" src="images/no.jpg" alt="submit" name="refer" value="no" /></span> </div> </form> </div> I am using sessions to carry the variables all the way to the end of the forms where I then write all the data to a database, I have checked my sessions and they seem to be working fine, the only one that is giving problems is the yes/no. So basically I need it to capture that yes/no everytime. Thanx in advance!

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• VB6 Game Development

  - by CVS-2600Hertz-wordpress-com

  Hi All, I am developing a game in VB6 (plz don't ask me why :) ). The storyboard is ready and a rough implementation is underway. I am following a "pure-software-rendering" approach. (i.e. no DirectX, no openGL etc.) Amongst many others, the following "serious" problems exist: 2D alpha transparency reqd. to implement overlays. Parallax implementation to give depth-of-field illusion. Capturing mouse-scroll events globally (as in FPS-es; mapping them to changing weapon). Async sound play with absolute "near-zero-lag". Any ideas anyone. Please suggest any well documented library/ocx or sample-code. Plz do suggest solutions with good performance and as little overhead as possible. Also, anyone who has developed any games, and would be open to sharing her/his code would be highly appreciated. (any well-acknowledged VB games whose source-code i can study??) UPDATE: Here is a screen shot of GearHead Garage. This picture ought to describe what i was attempting in words above... :) Thank You

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• Opening my application when a usb device is inserted on Windows using WMI

  - by rsteckly

  Hi, I'm trying to launch an event when someone plugs in a usb device. For now, I'm content to simply print something to the console (in the finished product, it will launch an application). This code is very loosely adapted from: http://serverfault.com/questions/115496/use-wmi-to-detect-a-usb-drive-was-connected-regardless-of-whether-it-was-mounted There's two problems: 1) I need to pass the argument to Management scope dynamically because this will be installed on computers I don't use or whose name I don't know. 2) I'm getting an invalid namespace exception when I call w.Start(); Any ideas what I'm doing wrong? static ManagementEventWatcher w=null; static void Main(string[] args) { AddInstUSBHandler(); for(;;); } public static void USBRemoved(object sneder, EventArgs e) { Console.WriteLine("A USB device inserted"); } static void AddInstUSBHandler() { WqlEventQuery q; ManagementScope scope = new ManagementScope("HQ\\DEV1"); scope.Options.EnablePrivileges=true; q=new WqlEventQuery(); q.EventClassName+="_InstanceCreationEvent"; q.WithinInterval=new TimeSpan(0,0,3); q.Condition=@"TargetInstance ISA 'Win32_USBControllerdevice'"; w=new ManagementEventWatcher(scope,q); w.EventArrived+=new EventArrivedEventHandler(USBRemoved); w.Start(); }

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• Multi-threaded library calls in ASP.NET page request.

  - by ProfK

  I have an ASP.NET app, very basic, but right now too much code to post if we're lucky and I don't have to. We have a class called ReportGenerator. On a button click, method GenerateReports is called. It makes an async call to InternalGenerateReports using ThreadPool.QueueUserWorkItem and returns, ending the ASP.NET response. It doesn't provide any completion callback or anything. InternalGenerateReports creates and maintains five threads in the threadpool, one report per thread, also using QueueUserWorkItem, by 'creating' five threads, also with and waiting until calls on all of them complete, in a loop. Each thread uses an ASP.NET ReportViewer control to render a report to HTML. That is, for 200 reports, InternalGenerateReports should create 5 threads 40 times. As threads complete, report data is queued, and when all five have completed, report data is flushed to disk. My biggest problems are that after running for just one report, the aspnet process is 'hung', and also that at around 200 reports, the app just hangs. I just simplified this code to run in a single thread, and this works fine. Before we get into details like my code, is there anything obvious in the above scendario that might be wrong?

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• Locating SSL certificate, key and CA on server

  - by jovan

  Disclaimer: you don't need to know Node to answer this question but it would help. I have a Node server and I need to make it work with HTTPS. As I researched around the internet, I found that I have to do something like this: var fs = require('fs'); var credentials = { key: fs.readFileSync('path/to/ssl/private-key'), cert: fs.readFileSync('path/to/ssl/cert'), ca: fs.readFileSync('path/to/something/called/CA') }; var app = require('https').createServer(credentials, handler); I have several problems with this. First off, all the examples I found use completely different approaches. Some link to .pem files for both the certificate and key. I don't know what pem files are but I know my certificate is .crt and my key is .key. Some start off at the root folder and some seem to just have these .pem files in the application directory. I don't. Some use the ca thing too and some don't. This CA is supposed to be my domain's CA bundle according to some articles - but none explain where to find this file. In the ssl directory on my server I have one .crt file in the certs directory and one .key file in the keys directory, in addition to an empty csrs directory and an ssl.db file. So, where do I find these 3 files (key, cert, ca) and how do I link to them correctly?

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• SQLAlchemy: who is in charge of the "session"? ( and how to unit-test with sessions )

  - by Nick Perkins

  I need some guidance on how to use session objects with SQLAlchemy, and how to organize Unit Tests of my mapped objects. What I would like to able to do is something like this: thing = BigThing() # mapped object child = thing.new_child() # create and return a related object thing.save() # will also save the child object In order to achieve this, I was thinking of having the BigThing actually add itself ( and it's children ) to the database -- but maybe this not a good idea? One reason to add objects as soon as possible is Automatic id values that are assigned by the database -- the sooner they are available, the fewer problems there are ( right? ) What is the best way to manage session objects? Who is in charge of the session? Should it be created only when required? or saved for a long time? What about Unit Tests for my mapped objects?...how should the session be handled? Is it ever OK to have mapped objects just automatically add themselves to a database? or is that going to lead to trouble?

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• Dangers when deploying Flash/Flex UI test automation hooks to production?

  - by Merlyn Morgan-Graham

  I am interested in doing automated testing against a Flex based UI. I have found out that my best options for UI automation (due to being C# controllable, good licensing conditions, etc) all seem to require that I compile test hooks into my application. Because of this, I am thinking of recommending that these hooks be compiled into our build. I have found a few places on the net that recommend not deploying bits with this instrumentation enabled, and I'd like to know why. Is it a performance drain, or a security risk? If it is a security risk, can you explain how the attack surface is increased? I am not a Flash or Flex developer, though I have some experience with threat modeling. For reference, here's the tools I'm specifically considering: QTP Selenium-Flex API I am having problems finding all the warnings/suggestions I found last night, but here's an example that I can find: http://www.riatest.com/products/getting-started.html Warning! Automation enabled applications expose all properties of all GUI components. This makes them vulnerable to malicious use. Never make automation enabled application publicly available. Always restrict access to such applications and to RIATest Loader to trusted users only. Related question (how to do conditional compilation to insert/remove those hooks): Conditionally including Flex libraries (SWCs) in mxmlc/compc ant tasks

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• nginx 0.7.65 rewrite url with querystring problem?

  - by WisdomFusion

  Hi, all Recently, I altered my web server lighty to nginx. And now, Struggling with some problems. First, I have a site in nginx which only rewrites urls and redircts them to a new domain, and this site has exactly no file in its root directory. I put some rewrite rules (just string rules, no querystring) in my nginx.conf list 1 rewrite ^/index_([0-9]+)(.*)$ /forum-$1-1.html last; rewrite ^/dispbbs_([0-9]+)_([0-9]+)\.html$ /thread-$2-1-1.html last; Those rules work perfect till now. However, some rules that used to rewrite url with querystring do not work as hoped. list 2 location /index.asp { if ($arg_boardid ~ "^([0-9]+)") { rewrite ^ /forum-$arg_boardid-1.html break; } rewrite ^ /index.php break; } location /dispbbs.asp { rewrite ^ /thread-$arg_id-1-1.html break; } And, these rules are converted from rules under httpd server, list 3 ^/dispbbs\.asp\?boardID=([0-9]+)&ID=([0-9]+).*$ /thread-$2-1-1.html; ^/dispbbs\.asp\?(.*)&id=([0-9]+)(.*)$ /thread-$2-1-1.html; ^/index\.asp\?boardid=([0-9]+)(.*)$ /forum-$1-1.html; ^/index\.asp\?boardid=([0-9]+)$ /forum-$1-1.html; ^/index\.asp$ /index.php; So, what's the matter with rules listed in the list 2? and how could I make it woking. V/R, gavin

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• Few Basic Questions in Overriding

  - by Dahlia

  I have few problems with my basic and would be thankful if someone can clear this. What does it mean when I say base *b = new derived; Why would one go for this? We very well separately can create objects for class base and class derived and then call the functions accordingly. I know that this base *b = new derived; is called as Object Slicing but why and when would one go for this? I know why it is not advisable to convert the base class object to derived class object (because base class is not aware of the derived class members and methods). I even read in other StackOverflow threads that if this is gonna be the case then we have to change/re-visit our design. I understand all that, however, I am just curious, Is there any way to do this? class base { public: void f(){cout << "In Base";} }; class derived:public base { public: void f(){cout << "In Derived";} }; int _tmain(int argc, _TCHAR* argv[]) { base b1, b2; derived d1, d2; b2 = d1; d2 = reinterpret_cast<derived*>(b1); //gives error C2440 b1.f(); // Prints In Base d1.f(); // Prints In Derived b2.f(); // Prints In Base d1.base::f(); //Prints In Base d2.f(); getch(); return 0; } In case of my above example, is there any way I could call the base class f() using derived class object? I used d1.base()::f() I just want to know if there any way without using scope resolution operator? Thanks a lot for your time in helping me out!

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• How to .NET package JavaScript/bookmarklet as Interner Explorer 8/9 Plugin?

  - by Don

  How to .NET package JavaScript/bookmarklet as Interner Explorer 8/9 Plugin? I have recently finished writing JavaScript code for a browser addon, which basically (once the JS is included) runs on page-load, for given domains it then checks for certain elements in the DOM and adds new relevant elements(/information) to the page. Since the JavaScript only reads/affects the HTML DOM independently (and does not need any toolbar buttons or anything else) the JS purely needs adding to the browser's webpages. I have packaged the code to work with Firefox and Chrome and those are both working well, and I can run the code for IE in 'bookmarklet' form without problems, but I would like to learn how to package JavaScript as an actual .NET .MSI addon/plugin that will install for the current Internet Explorer 8/9. Does anyone know of a suitable guide or method I might refer to please? I have tried searching online for tutorials but most walkthroughs refer to writing the plugin body itself (which might involve unnecessary stages/includes) and are thus not regarding packing existing JS. I hope someone might have the solution please? Note: Someone packaged an old version for me as a MSI installer for Internet Explorer 7 a year ago, which installed into Program Files with a plugin.dll plugin.tlb and plugin.InstallState plus BandObjectLib.dll Interop.SHDocVw.dll and Microsoft.mshtml.dll if that is useful.

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• How to create a snowstorm on your Windows desktop?

  - by Vilx-

  Practical uses aside, how (if it is possible at all) could you create a "snowing" effect on your desktop PC running Windows? Preferably with nothing but raw C/C++ and WinAPI. The requirements for the snow are: Appears over everything else shown; Snowflakes are small, possibly simple dots or clusters of a few white pixels; Does not bother working with the computer (clicking a snowflake sends the click through to the underlying window); Plays nicely with users dragging windows; Multimonitor capable. Bonus points for any of the following features: Snow accumulates on the lower edge of the window or the taskbar (if it's at the bottom of the screen); Snow accumulates also on top-level windows. Or perhaps some snow accumulates, some continues down, accumulating on every window with a title bar; Snow accumulated on windows gets "shaken off" when windows are dragged; Snow accumulated on taskbar is aware of the extended "Start" button under Vista/7. Snowflakes have shadows/outlines, so they are visible on white backgrounds; Snowflakes have complex snowflike-alike shapes (they must still be tiny). Most of these effects are straightforward enough, except the part where snow is click-through and plays nicely with dragging of windows. In my early days I've made an implementation that draws on the HDC you get from GetDesktopWindow(), which was click-through, but had problems with users dragging windows (snowflakes rendered on them got "dragged along"). The solution may use Vista/7 Aero features, but, of course, a universal solution is preferred. Any ideas? :)

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• How to best launch C++ application from web page

  - by JB

  I guess there are two parts to this question, one technical and one best practice for security and doing things "right". I'm working on a little game using C++ / directx but I would like to be able to launch it from a web page by someone clicking on a link on that page. Ideally I would like the first time they clicked for it to launch an installer downloads and installs the game on their machine, and then the next time to launch an application which updates the game from a web site if it's old and then launches it. I have no problems with the expected security popups and questions the first time it runs. I want people to be certain what they are installing and understand what they are doing. But it would be nice if once it is installed they could run it with the minimum of fuss. My question then is what technologies I could use to do this? I'm thinking that it would need a browser plugin and an activex control so that first time you'd install that, and subsequently the control/plugin would be able to launch the game. I'm not sure that under newer browser secuity models that a plugin would have the permissions to be able to run an installer though or silently invoke applications on the client machine even if they are already installed. Is there a more sensible way to achive what I want to achieve? And I'm worried about the security aspects too. I want this to be convenient for users but I of course want to do it "right". I know this can be done as I've seen several mmorpg type games that launch in this way from the browser now but it's not entirely clear to me how they've done it.

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• Web Hosting: Any web host that supports files more than 50,000 in number?

  - by Devner

  Hi all, For my PHP & mySQL based application, I am trying to buy website hosting from a host who does not have a limit on the number of files I carry in my hosting account. Almost all the websites have a common limit of 50,000 files (some websites call it 50,000 nodes). The rest(to the extent of my search) are not even close. I have gone through the various websites, Googled lot of information, have spoken with the customer service of the hosting companies and they said that they have a limit of 50,000 files and that's why they call it the LIMIT. Now I have my application, which is a kind of social networking website, where people can upload various files of varying file size. So say if 50,000 users were to join the website and upload 1 file each, the limit of 50,000 will be reached very easily and my 50,001 customer will start facing file upload problems (& so will my account). So I would like to know if there's any website hosting services that do NOT levy such restrictions. In summary, I need the following options: No maximum file limit (more than 50,000 files in account). No maximum file upload limit in server setting (10MB, 12MB, 15MB, 20MB, etc.). Ability to upload files of various types (zip, flv, jg, png, etc.). Ability to stream Audio and Video (live audio & video not necessary). Access to .htaccess Access to php.ini, my.cnf or my.ini (this would be a plus) Supports SSL. Provides dedicated hosting(& IP) as well. Monthly payments without contracts are a plus. If you know of any such website hosting services, please post a reply ( a link to the same will be appreciated ). Thank you.

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• Function pointers in Objective-C

  - by Stefan Klumpp

  I have the following scenario: Class_A - method_U - method_V - method_X - method_Y Class_B - method_M - method_N HttpClass - startRequest - didReceiveResponse // is a callback Now I want to realize these three flows (actually there are many more, but these are enough to demonstrate my question): Class_A :: method_X -> HttpClass :: startRequest:params -> ... wait, wait, wait ... -> HttpClass :: didReceiveResponse -> Class_A :: method_Y:result and: Class_A :: method_U -> HttpClass :: startRequest:params -> ... wait, wait, wait ... -> HttpClass :: didReceiveResponse -> Class_A :: method_V:result and the last one: Class_B :: method_M -> HttpClass :: startRequest:params -> ... wait, wait, wait ... -> HttpClass :: didReceiveResponse -> Class_B :: method_N:result Please note, that the methods in Class_A and Class_B have different names and functionality, they just make us of the same HttpClass. My solution now would be to pass a C function pointer to startRequest, store it in the HttpClass and when didReceiveResponse gets called I invoke the function pointer and pass the result (which will always be a JSON Dictionary). Now I'm wondering if there can be any problems using plain C or if there are better solutions doing it in a more Objective-C way. Any ideas?

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• How to close all tabs in Safari using AppleScript?

  - by Form

  I have made a very simple AppleScript to close all tabs in Safari. The problem is, it works, but not completely. Here's the code: tell application "Safari" repeat with aWindow in windows repeat with aTab in tabs of aWindow aTab close end repeat end repeat end tell I've also tried this script: tell application "Safari" repeat with i from 0 to the number of items in windows set aWindow to item i of windows repeat with j from 0 to the number of tabs in aWindow set aTab to item j of tabs of aWindow aTab close end repeat end repeat end tell ... but it does not work either. I tried that on my system (MacBook Pro jan 2008), as well as on a Mac Pro G5 under Tiger and the script fails on both, albeit with a much less descriptive error on Tiger. The problem is that only a couple of tabs are closed. Running the script a few times closes a few tab each time until none is left, but always fails with the same error after closing a few tabs. Under Leopard I get an out of bounds error. Since I am using fast enumeration (not using "repeat from 0 to number of items in windows") I don't see how I can get an out of bounds error with this... My goal is to use the Cocoa Scripting Bridge to close tabs in Safari from my Objective-C Cocoa application but the Scripting Bridge fails in the same manner. The non-deletable tabs show as NULL in the Xcode debugger, while the other tabs are valid objects from which I can get values back (such as their title). In fact I tried with the Scripting Bridge first then told myself why not try this directly in AppleScript and I was surprised to see the same results. I must have a glaring omission or something in there... (seems like a bug in Safari AppleScript support to me... :S) I've used repeat loops and Obj-C 2.0 fast enumeration to iterate through collections before with zero problems, so I really don't see what's wrong here. Anyone can help? Thanks in advance!

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• problem creating jpg thumb with php

  - by Ross

  Hi, I am having problems creating a thumbnail from an uploaded image, my problem is (i) the quality (ii) the crop http://welovethedesign.com.cluster.cwcs.co.uk/phpimages/large.jpg http://welovethedesign.com.cluster.cwcs.co.uk/phpimages/thumb.jpg If you look the quality is very poor and the crop is taken from the top and is not a resize of the original image although the dimesions mean it is in proportion. The original is 1600px wide by 1100px high. Any help would be appreciated. $thumb = $targetPath."Thumbs/".$fileName; $imgsize = getimagesize($targetFile); $image = imagecreatefromjpeg($targetFile); $width = 200; //New width of image $height = 138; //This maintains proportions $src_w = $imgsize[0]; $src_h = $imgsize[1]; $thumbWidth = 200; $thumbHeight = 138; // Intended dimension of thumb // Beyond this point is simply code. $sourceImage = imagecreatefromjpeg($targetFile); $sourceWidth = imagesx($sourceImage); $sourceHeight = imagesy($sourceImage); $targetImage = imagecreate($thumbWidth,$thumbHeight); imagecopyresized($targetImage,$sourceImage,0,0,0,0,$thumbWidth,$thumbWidth,imagesx($sourceImage),imagesy($sourceImage)); //imagejpeg($targetImage, "$thumbPath/$thumbName"); imagejpeg($targetImage, $thumb); chmod($thumb, 0755);

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• Where to master HTML, CSS ans Javascript?

  - by Shahensha

  I got interested in web-development lately. I am still a student. I learnt basics of HTML, CSS and JavaScript! Then I thought I should improve my server side scripting. So I am learning Struts2 and I am doing better there. Now I have decided I should finally put my skill to some use. So I and my friend have decided to come up with a fun website for our class. But now I am realizing that, though I know server-side scripting to a good extent (not great, just good considering I am a beginner), I am nowhere near good in the basic elements viz. HTML, CSS and JavaScript! I mean, I can't do cool stuff with it. I am aware of w3schools, but it would be great if you can point out a more intuitive place where I can learn to do all the cool stuff in a short time. Some of the problems I am facing are: 1) How should I design the basic layout of my website? 2) How can I use 3rd party APIs like that of Facebook graph? regards shahensha

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• Executing untrusted code

  - by MainMa

  Hi, I'm building a C# application which uses plug-ins. The application must guarantee to the user that plug-ins will not do whatever they want on the user machine, and will have less privileges that the application itself (for example, the application can access its own log files, whereas plug-ins cannot). I considered three alternatives. Using System.AddIn. I tried this alternative first, because it seamed much powerful, but I'm really disappointed by the need of modifying the same code seven times in seven different projects each time I want to modify something. Besides, there is a huge number of problems to solve even for a simple Hello World application. Using System.Activator.CreateInstance(assemblyName, typeName). This is what I used in the preceding version of the application. I can't use it nevermore, because it does not provide a way to restrict permissions. Using System.Activator.CreateInstance(AppDomain domain, [...]). That's what I'm trying to implement now, but it seems that the only way to do that is to pass through ObjectHandle, which requires serialization for every used class. Although plug-ins contain WPF UserControls, which are not serializable. So is there a way to create plug-ins containing UserControls or other non serializable objects and to execute those plug-ins with a custom PermissionSet ?

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• Event feed implementation - will it scale?

  - by SlappyTheFish

  Situation: I am currently designing a feed system for a social website whereby each user has a feed of their friends' activities. I have two possible methods how to generate the feeds and I would like to ask which is best in terms of ability to scale. Events from all users are collected in one central database table, event_log. Users are paired as friends in the table friends. The RDBMS we are using is MySQL. Standard method: When a user requests their feed page, the system generates the feed by inner joining event_log with friends. The result is then cached and set to timeout after 5 minutes. Scaling is achieved by varying this timeout. Hypothesised method: A task runs in the background and for each new, unprocessed item in event_log, it creates entries in the database table user_feed pairing that event with all of the users who are friends with the user who initiated the event. One table row pairs one event with one user. The problems with the standard method are well known – what if a lot of people's caches expire at the same time? The solution also does not scale well – the brief is for feeds to update as close to real-time as possible The hypothesised solution in my eyes seems much better; all processing is done offline so no user waits for a page to generate and there are no joins so database tables can be sharded across physical machines. However, if a user has 100,000 friends and creates 20 events in one session, then that results in inserting 2,000,000 rows into the database. Question: The question boils down to two points: Is this worst-case scenario mentioned above problematic, i.e. does table size have an impact on MySQL performance and are there any issues with this mass inserting of data for each event? Is there anything else I have missed?

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• vectorizing loops in Matlab - performance issues

  - by Gacek

  This question is related to these two: http://stackoverflow.com/questions/2867901/introduction-to-vectorizing-in-matlab-any-good-tutorials http://stackoverflow.com/questions/2561617/filter-that-uses-elements-from-two-arrays-at-the-same-time Basing on the tutorials I read, I was trying to vectorize some procedure that takes really a lot of time. I've rewritten this: function B = bfltGray(A,w,sigma_r) dim = size(A); B = zeros(dim); for i = 1:dim(1) for j = 1:dim(2) % Extract local region. iMin = max(i-w,1); iMax = min(i+w,dim(1)); jMin = max(j-w,1); jMax = min(j+w,dim(2)); I = A(iMin:iMax,jMin:jMax); % Compute Gaussian intensity weights. F = exp(-0.5*(abs(I-A(i,j))/sigma_r).^2); B(i,j) = sum(F(:).*I(:))/sum(F(:)); end end into this: function B = rngVect(A, w, sigma) W = 2*w+1; I = padarray(A, [w,w],'symmetric'); I = im2col(I, [W,W]); H = exp(-0.5*(abs(I-repmat(A(:)', size(I,1),1))/sigma).^2); B = reshape(sum(H.*I,1)./sum(H,1), size(A, 1), []); But this version seems to be as slow as the first one, but in addition it uses a lot of memory and sometimes causes memory problems. I suppose I've made something wrong. Probably some logic mistake regarding vectorizing. Well, in fact I'm not surprised - this method creates really big matrices and probably the computations are proportionally longer. I have also tried to write it using nlfilter (similar to the second solution given by Jonas) but it seems to be hard since I use Matlab 6.5 (R13) (there are no sophisticated function handles available). So once again, I'm asking not for ready solution, but for some ideas that would help me to solve this in reasonable time. Maybe you will point me what I did wrong.

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• SQL Server 2005 - Enabling both Named Pipes & TCP/IP protocols?

  - by Clinemi

  We have a SQL Server 2005 database, and currently all our users are connecting to the database via the TCP/IP protocol. The SQL Server Configuration Manager allows you to "enable" both Named Pipes, and TCP/IP connections at the same time. Is this a good idea? My question is not whether we should use named pipes instead of TCP/IP, but are there problems associated with enabling both? One of our client's IT guys, says that enabling database communication with both protocols will limit the bandwidth that either protocol can use - to like 50% of the total. I would think that the bandwidth that TCP/IP could use would be directly tied (inversely) to the amount of traffic that Named Pipes (or any of the other types of traffic) were occupying on the network at that moment. However, this IT person is indicating that the fact that we have enabled two protocols on the server, artificially limits the bandwidth that TCP/IP can use. Is this correct? I did Google searches but could not come up with an answer to this question. Any help would be appreciated.

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• jquery plugin caroufredsel hide next/prev buttons until mouseover carousel

  - by John Magnolia

  I am trying to make the buttons hide by default and they only become visible when the mouse is over. Although I am having problems where the carousel core code seems to be adding display block even if I set display none in the CSS. var $slides = $("#slides"); $slides.find('ul.banners').eq(0).carouFredSel({ height: 360, items: { visible: 1 }, scroll: { easing: "easeInOutSine", duration: 1200 }, auto: { delay: 1000 }, prev: { button: $slides.find('.prev'), items: 1 }, next:{ button: $slides.find('.next'), items: 1 }, pagination: { container: $slides.find(".pagination"), keys: true, anchorBuilder: function(nr) { return '<li><a href="#"><span>'+nr+'</span></a></li>'; } } }); $slideButtons = $slides.find(".next,.prev"); $slides.find('ul.banners').hover(function(){ $slideButtons.fadeIn(); },function(){ $slideButtons.fadeOut(); }); HTML <div id="slides"> <ul class="banners"> <li><img /></li> <li><img /></li> </ul> <ul class="pagination"></ul> <div class="next">Next</div> <div class="prev">Previous</div> </div>

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