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• Taking wrong database configuration array

  - by user309076

  Hi, I have one application in which i have used 2 database connections. In my database config file i have given two arrays as below. $active_group = ‘default’; $active_record = TRUE; FIRST ARRAY $db[‘default’][‘hostname’] = ‘hostname’; .............. .......... SECOND ARRAY $db[‘another_db’][‘hostname’] = ‘hostname’; .............. .......... this is working fine. Now, I copied the entire CI folder to develop another application in which only one database connection needed. So, now, in the database config file, i deleted the second configuration array. But, the db class is taking first application’s second array i.e. “another_db” and it is giving the below error. “You have specified an invalid database connection group.” When i change the default (only one) array name to “another_db” in configuration file. It is working fine. Can’t understand from where it is taking the group name as “another_db”. My application autoloads database library. I have debugged the ci_auto_loader in Loader.php class where it calls $this-database() function with no parameters. But in function database($params, $, $) {}, if I echo $params it shows “another_db”.

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• Determining Best Table Structure for MySQL Performance

  - by Joe Majewski

  I'm working on a browser-based RPG for one of my websites, and right now I'm trying to determine the best way to organize my SQL tables for performance and maintenance. Here's my question: Does the number of columns in an SQL table affect the speed in which it can be queried? I am not a newbie when it comes to PHP or MySQL. I used to develop things with the common goal of getting them to work, but I've recently advanced to the stage where a functional program is not good enough unless it's fast and reliable. Anyways, right now I have a members table that has around 15 columns. It contains information such as the player's username, password, email, logins, page views, etcetera. It doesn't contain any information on the player's progress in the game, however. If I added columns for things such as army size, gold, turns, and whatnot, then it could easily rise to around 40 or 50 total columns. Oh, and my database structure IS normalized. Will a table with 50 columns that gets constantly queried be a bad idea? Should I split it into two tables; one for the user's general information and one for the user's game statistics? I know I could check the query time myself, but I haven't actually created the tables yet and I think I'd be better off with some professional advice on this important decision for my game. Thank you for your time! :)

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• Is there a way to create subdatabases as a kind of subfolders in sql server?

  - by user193655

  I am creating an application where there is main DB and where other data is stored in secondary databases. The secondary databases follow a "plugin" approach. I use SQL Server. A simple installation of the application will just have the mainDB, while as an option one can activate more "plug-ins" and for every plug-in there will be a new database. Now why I made this choice is because I have to work with an exisiting legacy system and this is the smartest thing I could figure to implement the plugin system. MainDB and Plugins DB have exactly the same schema (basically Plugins DB have some "special content", some important data that one can use as a kind of template - think to a letter template for example - in the application). Plugin DBs are so used in readonly mode, they are "repository of content". The "smart" thing is that the main application can also be used by "plugin writers", they just write a DB inserting content, and by making a backup of the database they creaetd a potential plugin (this is why all DBs has the same schema). Those plugins DB are downloaded from internet as there is a content upgrade available, every time the full PlugIn DB is destroyed and a new one with the same name is creaetd. This is for simplicity and even because the size of this DBs is generally small. Now this works, anyway I would prefer to organize the DBs in a kind of Tree structure, so that I can force the PlugIn DBs to be "sub-DBs" of the main application DB. As a workaround I am thinking of using naming rules, like: ApplicationDB (for the main application DB) ApplicationDB_PlugIn_N (for the N-th plugin DB) When I search for plugin 1 I try to connect to ApplicationDB_PlugIn_1, if I don't find the DB i raise an error. This situation can happen for example if som DBA renamed ApplicationDB_Plugin_1. So since those Plugin DBs are really dependant on ApplicationDB only I was trying to "do the subfolder trick". Can anyone suggest a way to do this? Can you comment on this self-made plugin approach I decribed above?

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• my web service works locally but, not when it is deployed

  - by rogdawg

  When I deploy my web service, I get the following error: There is no build provider registered for the extension '.svc'. You can register one in the section in machine.config or web.config. Make sure is has a BuildProviderAppliesToAttribute attribute which includes the value 'Web' or 'All'. I found one thread (http://forums.asp.net/t/1228638.aspx) that suggested a solution but, I can not get it to work. If I make the changes to my web config file as suggested in the thread, I then get a configuration error. One odd thing is that, if I check the machine.config file on my machine, located at C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\CONFIG\machine.config, I don't see any of the config settings described in the thread. As a matter of fact, there is no mention of "compilation" or "buildProviders" at all. The on-line documents I have found regarding BuildProviderAppliesToAttribute have not been of any help. Thanks in advance for any advice you can give. Here is my entire config file listing: <?xml version="1.0"?>

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• Creating a join based on data from other tables...

  - by Workshop Alex

  I'm dealing with a database structure that can be defined as "illogical". It has about 100 different schema's with all different table structures per schema. Only one common factor is a "Version" table in each schema containing about 4 fields. (Thus, there are about 100 Version tables in the database.) There's also another table (view, actually) containing a list of all the schema's in the database that have a version table. I need a stored procedure that walks through all the schema's and selects all data from the Version table, adding the schema name as a fifth field to the result. Basically, this stored procedure is to return a list of all version records per schema. My idea: first walk through the schema list to create one new SQL statements that will JOIN all the schema.version tables into one SQL statement. Then I return the result of that query. How to do this? Or does anyone have a better suggestion? (No, redesigning the structure is NOT an option.)

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• Faster or more memory-efficient solution in Python for this Codejam problem.

  - by jeroen.vangoey

  I tried my hand at this Google Codejam Africa problem (the contest is already finished, I just did it to improve my programming skills). The Problem: You are hosting a party with G guests and notice that there is an odd number of guests! When planning the party you deliberately invited only couples and gave each couple a unique number C on their invitation. You would like to single out whoever came alone by asking all of the guests for their invitation numbers. The Input: The first line of input gives the number of cases, N. N test cases follow. For each test case there will be: One line containing the value G the number of guests. One line containing a space-separated list of G integers. Each integer C indicates the invitation code of a guest. Output For each test case, output one line containing "Case #x: " followed by the number C of the guest who is alone. The Limits: 1 = N = 50 0 < C = 2147483647 Small dataset 3 = G < 100 Large dataset 3 = G < 1000 Sample Input: 3 3 1 2147483647 2147483647 5 3 4 7 4 3 5 2 10 2 10 5 Sample Output: Case #1: 1 Case #2: 7 Case #3: 5 This is the solution that I came up with: with open('A-large-practice.in') as f: lines = f.readlines() with open('A-large-practice.out', 'w') as output: N = int(lines[0]) for testcase, i in enumerate(range(1,2*N,2)): G = int(lines[i]) for guest in range(G): codes = map(int, lines[i+1].split(' ')) alone = (c for c in codes if codes.count(c)==1) output.write("Case #%d: %d\n" % (testcase+1, alone.next())) It runs in 12 seconds on my machine with the large input. Now, my question is, can this solution be improved in Python to run in a shorter time or use less memory? The analysis of the problem gives some pointers on how to do this in Java and C++ but I can't translate those solutions back to Python.

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• How do you use a view with arguments as the site front page in Drupal?

  - by Justin

  I have a Drupal site and I have setup a view to power the front page. My goal is to be able to pass 0-2 arguments to the home page, that get passed into the view. However, I still need the normal Drupal pages to work. The list of arguments is known. For example: mysite.com/berlin/birds would pass in "berlin" as the first argument and "birds" as the second argument to the view that powers the front page. mysite.com/berlin would just pass in one argument, "berlin" mysite.com/admin would load the normal admin pages in Drupal I'm not clear on how to achieve this. Is there a hook I can use? I can't find one or think of one. Is there a way to specify this in the argument for the view itself? Perhaps I can write a hook that interjects when the URL is being loaded, and rewrite in the background? The solution I currently have is to add these paths (since my arguments are known) to the menu system. This works, except that when I the pages they aren't the front page, so the pages don't use the node themes I want (they use the node details theme).

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• .NET security mechanism to restrict access between two Types in the same project?

  - by jdk

  Question: Is there a mechanism in the .NET Framework to hide one custom Type from another without using separate projects/assemblies? I'm using C# with ASP.NET in a Website project. Note: I'm not talking about access modifiers to hide members of a Type from another type - I mean to hide the Type itself. Background: I'm working in an ASP.NET Website project and the team has decided not to use separate project assemblies for different software layers. Therefore I'm looking for a way to have, for example, a DataAccess/ folder of which I disallow its classes to access other Types in the same ASP.NET Website project. In other words I want to fake the layers and have some kind of security mechanism around each layer to prevent it from accessing another. Obviously there's not a way to enforce this restriction using language-specific OO keywords so I am looking for something else, for example: maybe a permission framework or code access mechanism, maybe something that uses meta data like Attributes. Even something that restricts one namespace from accessing another. I'm unsure the final form it might take. If this were C++ I'd likely be using friend to make as solution, which doesn't translate to C# internal in this case although they're often compared. I don't really care whether the solution actually hides Types from each other or just makes them inaccessible; however I don't want to lock down one Type from all others, another reason access modifiers are not a solution. A runtime or design time answer will suffice. Looking for something easy to implement otherwise it's not worth the effort ...

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• Creating multiple instances of a generic database

  - by sagekilla

  Hi all, currently I'm trying to have a setup where a generic database is distributed to students. They would develop an application using this database (Say a shopping cart application), submit their project onto our server, and then it would be graded automatically. These databases are being run in Microsoft SQL Server 2005. We're using user instances to instantiate each database, and multiple requests could be serviced at once. But, the problem is when more than one student submitted a project to be graded, the first database to be instantiated would be the only one and would overwrite all other copies that were currently open. So if stu1 modified his database and stu2 and stu3 had their projects being graded concurrently, at the end of the grading stu1, stu2, and stu3 would have identical DB's at the end. Is there any way I can have multiple independent copies of a generic database, each of which I can load concurrently and modify without having any changes made to any one affecting the others? I did a little reading, and thought it might be possible to do something along the lines of: Student submits project Attach the database with unique db name (specified by student) Do all necessary operations Detach the database I'm unsure if this would fix our problem or be possible, so any help would be much appreciated!

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• Are reads and (transactional) writes faster for entities of the same group than otherwise?

  - by indiehacker

  What advantage is there to designing child-parent relationships, which allow us to do writes in transactions, when there is never a real concern for consistency and contention and those sort of more complex issues? Does it make writes and reads faster? Consider my situation where there are many .png images that are referenced to one mosaic layer, and these .png images are written just once by a single user. The user can design many mosaic layers and her mosaic layers and referenced image entities are never changed/updated, they are just deleted some time in the future. Other users can come to the web project site and interactively view the mosaic layer as different layouts/configurations of the images as they play (query) with different criteria. So reads should be very fast. So there is no real worry of contention, or users conflicting with one another with writing new image entities. And because of that I am assuming there is no "requirement" for the .png image entities to be grouped by their same mosaic layer in child-parent relationship. However, perhaps, since the documentation says they are stored close to one another, if the many image entities were grouped as children to a single mosaic layer parent than this has the advantage that the writing (in transaction) and reading will happen much faster?

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• How can this Ambient Context become null?

  - by Mark Seemann

  Can anyone help me explain how TimeProvider.Current can become null in the following class? public abstract class TimeProvider { private static TimeProvider current = DefaultTimeProvider.Instance; public static TimeProvider Current { get { return TimeProvider.current; } set { if (value == null) { throw new ArgumentNullException("value"); } TimeProvider.current = value; } } public abstract DateTime UtcNow { get; } public static void ResetToDefault() { TimeProvider.current = DefaultTimeProvider.Instance; } } Observations All unit tests that directly reference TimeProvider also invokes ResetToDefault() in their Fixture Teardown. There is no multithreaded code involved. Once in a while, one of the unit tests fail because TimeProvider.Current is null (NullReferenceException is thrown). This only happens when I run the entire suite, but not when I just run a single unit test, suggesting to me that there is some subtle test interdependence going on. It happens approximately once every five or six test runs. When a failure occurs, it seems to be occuring in the first executed tests that involves TimeProvider.Current. More than one test can fail, but only one fails in a given test run. FWIW, here's the DefaultTimeProvider class as well: public class DefaultTimeProvider : TimeProvider { private readonly static DefaultTimeProvider instance = new DefaultTimeProvider(); private DefaultTimeProvider() { } public override DateTime UtcNow { get { return DateTime.UtcNow; } } public static DefaultTimeProvider Instance { get { return DefaultTimeProvider.instance; } } } I suspect that there's some subtle interplay going on with static initialization where the runtime is actually allowed to access TimeProvider.Current before all static initialization has finished, but I can't quite put my finger on it. Any help is appreciated.

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• Prevent hash navigation url

  - by Koningh

  I have the following problem: I'm using a slider (coda) to let people navigate trough some 'pages'. The slider uses hash links to navigate to the next page/slide. If a user is at page one (#page1), there is a link which will lead the user to page 2 (#page2) and so on. At the top of the slider the numbers of the pages appear as a link, but only when the page is visited. So if there are six pages and the user navigates from the first to the second and then the third one, there are only three links at the top of the slider (to page one, two and three). The problem is that a user can navigate to page five (or any page actually) without first visiting the pages previous to page five by just using the hash URL and typing the whole link in their address bar. For example if I would type www.mydomain.com/slider/index.php#page5 the slider automatically navigates to the fifth slide/page of the slider and thereby skipping the first four. I want to allow users to navigate to #page5 only if they have visited the first four (So by clicking trough the slides). This means that if they would go to #page5 directly by typing the URL in the address bar, I would like them to be send to the first page (#page1). Does anyone have any idea on solving this?

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• how to Add-in load again n again for every instance of an application?

  - by Ashwin Upadhyay

  I have one qus. i created one shared add-in in c#.net. This add-in is working fine. now i want this add-in is load again n again when any office application is opened. For e.g. when i open any MS word document then add-in is load for that and if after that i opened another MS word document without closing previously opened document then add-in is again load for newly opend MS word document. But when i opened MS word at first time the add-in is load and if i opened MS word again but add-in is already loaded. my requirement is like that-my add-in is worked backgroundly that is its work only to record the opening,closing time of the word document and how much time spend onto that word document and also the name of this document. But when i opened one word document then add-in is loaded for that and if againg opened new word document then becaz of previously opened document add-in is not load for that document remember that priviously opened document is not closed. but if i closed previously opened document then for new document add-in is load.

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• How do I access a <form> that is not the master page <form>?

  - by VBCSharp

  Winforms developer converting to web developer. I know the part about the Master Page having the tag, what is not clear is if I can or can not have another in one of my content pages. I have been seeing both answers doing searches. I see yes you can if only one has runat=server. The thing is I have a that contains several radio buttons on a web page that has a master page. I have a .js file that has a function if I send the name into it, it will loop thru the controls in the form to see which one is selected and return the desired date horizon(MTD, QTD, YTD, etc.). When I run this on a non master page web page it works fine. However, when I run on a web page that has a master page I can't seem to get to the element. I tried getElementByID, I tried looping through the page elements, etc. Maybe I am going about this incorrectly and I hope someone can straighten me out. Here is the code from my .js file that may help explain what I am trying to do a little better. var frmDateRanges = document.getElementById(formFieldName); var chosen; var len = frmDateRanges.DateRanges.length; for(i=0;i<len;i++) { if(frmDateRanges.DateRanges[i].checked) { chosen = frmDateRanges.DateRanges[i].value; } } where formFieldName is an arguement that is passed into the function and DateRanges is the name value given to the radio buttons. In the button I call this function I have: onclick ="FunctionCall('frmDateRanges')" FunctionCall is just for description purposes, 'frmDateRanges' is the name and id given to the form action="" Thanks for the help as I am stumped at this point. If there is a better way to do this please let me know that as well.

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• Jquery :not()selector

  - by kim

  <html lang="en"> <head> <style> #thisdiv {padding:10px; margin:-15px 0 0 40px; background-color:#333; position:absolute; display:none;} div.block {margin-top:10px; width:200px;} div#thisdiv a {color:#fff;} </style> </head> <body> <div id ="one" class="block"><a href="">one</a></div> <div id="thisdiv">hello</div> <div id ="two"class="block">two</div> <div id ="three"class="block">three/div> <script src="http://code.jquery.com/jquery-latest.js"></script> <script> $(document).ready(function() { $('#one').hover(function() { $('#thisdiv').fadeIn(400); }); $('div:not(#thisdiv)').mouseleave(function() { $('#thisdiv').fadeOut(400) }); }); </script> </body> </html> #thisdiv doesn't fadeOut. I could have used the following, but it only fades out if the cursor mouse outs of #thisdiv. Is there any way i can solve this so when the cursor navigates away from anyway, the div still fade out. $('#thisdiv').mouseleave(function() { $('#thisdiv').fadeOut(400) }); I couldn't figure out what's why jquery's :not selector is not doing what I wanted to. Am i using it wrongly?

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• when is a v-table created in C++?

  - by saminny

  When exactly does the compiler create a virtual function table? 1) when the class contains at least one virtual function. OR 2) when the immediate base class contains at least one virtual function. OR 3) when any parent class at any level of the hierarchy contains at least one virtual function. A related question to this: Is it possible to give up dynamic dispatch in a C++ hierarchy? e.g. consider the following example. #include <iostream> using namespace std; class A { public: virtual void f(); }; class B: public A { public: void f(); }; class C: public B { public: void f(); }; Which classes will contain a V-Table? Since B does not declare f() as virtual, does class C get dynamic polymorphism?

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• Reading and writing to files simultaneously?

  - by vipersnake005

  Moved the question here. Suppose, I want to store 1,000,000,000 integers and cannot use my memory. I would use a file(which can easily handle so much data ). How can I let it read and write and the same time. Using fstream file("file.txt', ios::out | ios::in ); doesn't create a file, in the first place. But supposing the file exists, I am unable to use to do reading and writing simultaneously. WHat I mean is this : Let the contents of the file be 111111 Then if I run : - #include <fstream> #include <iostream> using namespace std; int main() { fstream file("file.txt",ios:in|ios::out); char x; while( file>>x) { file<<'0'; } return 0; } Shouldn't the file's contents now be 101010 ? Read one character and then overwrite the next one with 0 ? Or incase the entire contents were read at once into some buffer, should there not be atleast one 0 in the file ? 1111110 ? But the contents remain unaltered. Please explain. Thank you.

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• VS2010 + IE8 Debugging woes - Element not found

  - by Chin

  I am having great difficulty trying to debug with vs2010 and IE8, though I think the problem is more IE8 specific. When starting a debug session 9 times out of 10 I will have the following problem. IE tab says connecting.. - then after a 5 second wait I will get an error in VS saying element not found. Even when I click ok to dismiss the error, the IE window still shows connecting... I will then have to kill the IE process to be able to close IE to try again. Sometimes however I am lucky and it starts. But the whole thing is so random I have no clue where to start. One thing I have noticed is that I always have 2 IE processes started even though there is only one window open. One has a small footprint of 100k, I presume it is some kind of helper. I am using a static port with the built in WebDev server. If anyone has had similar problems please let me know how you resolved it. Its driving me nuts! thanks

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• Response Redirect - Open Link in New Window

  - by bacis09

  First, I've taken the time to review this question which seems to be the most similar, however, the solution that seems to have been selected will not work in my scenario.Not to mention I worry about some of the comments claiming it to be brittle or an inadequate solution. http://stackoverflow.com/questions/104601/asp-net-response-redirect-to-new-window -We have an XML document which basically contains all of the information for a Side menu. -We have numerous URLS which are stored in a constants class. -One of the elements in a string of XML (well call it label) is used to determine if the menu item is created as a LinkButton or a Label. -Links use a custom user control that is used standard for all links across the application (why suggestion on similar thread doesn't work - I don't want all links to open in a new window - just one) -One of the elements in a string of XML (well call it function) is used in a Switch statement to generate our links using Response Redirect. It may look something like this. switch (function) { case goto 1: string url; if (user_group == 1) { url = Constants.CONSTANT1 } else { url = Constants.CONSTANT2 } Response.Redirect(url) case goto 2: ...... default: ...... break; } Given this scenario, I'm trying to find the best way to quickly open a New Window, when a specific case in this switch statement is met. Can it be done with Response Redirect (this seems to be arguable - people say no it can't, yet other people say they have made it work)? If not, what alternative can work here?

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• Mercurial: Class library that will exist for both .NET 3.5 and 4.0?

  - by Lasse V. Karlsen

  I have a rather big class library written in .NET 3.5 that I'd like to upgrade to make available for .NET 4.0 as well. In that process, I will rip out a lot of old junk, and rewrite some code to better take advantage of the new classes and support in .NET 4.0 (like TPL.) The class libraries will thus diverge, but still be similar enough that some bug-fixes can be done to both in the same manner. How should I best organize this class library in Mercurial? I'm using Kiln (fogbugz) if that matters. I'm thinking: Named branches in one repository, can then transplant any bugfixes from one to the other Unnamed branches in one repository, can also transplant, but I think this will look messy Separate repositories, will have to reimplement the bugfixes (or use a non-mercurial-integraded compare tool to help me) What would you do? (any other alternatives that I haven't though of is welcome as well.) Note that the class libraries will diverge pretty heavily in areas, I have some remnants of old collection-type code that does something similar to Linq that I will remove, and some code that uses it that I will rewrite to use the Linq-methods instead. As such, just copying the project files and using #if NET40..#endif sections is not going to work out. Also, the 3.5 version of the class library will not be getting many new features, mostly just critical bug-fixes, so keeping both versions equally "alive" isn't really necessary. Thus, separate copies of all the files are good enough.

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• Android: Calculator on showing 0 immediately after the dot

  - by pearmak

  I am now working on a calculator, and everything works fine except for decimal places. The calculator contains 2 displays actually, one is called fakedisplay for actual operations, and one is called Display, for presenting the desired format, ie adding commas. When pressing 12345.678, Display will follow fakedisplay and present as 12,345.678, but if i press 12345.009, the fakedisplay will work normally as 12345.009, but the Display stuck as 12,345 until 9 is pressed, and at that time it will show 12,345.009 normally. However, it is strange that when the user presses 0, there is no response, and until pressing 9, 009 will then immediately append. I know this arise from the parsing code, but based on this, how could I amend the following code? I really cannot think of any solution... Many thanks for all your advice! one.setOnClickListener(new View.OnClickListener() { if (str.length()<15) {Fakedisplay.append("1");} DecimalFormat myFormatter1 = new DecimalFormat("###,###,###,###.#################"); String str1=Fakedisplay.getText().toString(); String stripped1 = Double.valueOf(str1).toString(); stripped1 = myFormatter1.format(Double.valueOf(stripped1)); if (stripped1.endsWith(".0")) stripped1 = stripped1.substring(0, stripped1.length() - 2); Display.setText(stripped1);

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• allowing bb code but not java script

  - by user1405062

  Hello im trying to get the hang of using bb codes onto my normal php site ( not forum or anything just a normal site ) I have seen a few posts like this one http://www.pixel2life.com/forums/index.php?/topic/10659-php-bbcode-parser/ which says i need a bb parser. I was just wondering can anyone show me how i would use one ? I have a status box were users can update there status but i would like to allow bb codes but not java script. So when im doing my inserting into the db i strip the status like so.. $status= mysql_real_escape_string($_POST['status']); $status2= strip_tags($status); And that stops the java script and tags from getting though but i need the bb code tags to come though but carry on blocking the java script code is there anyway to do this ? Also then i just echo it out echo $status2 ; But just plain text shows so was just wondering if anyone knows how to let though bb code and stop java script and could some one show me how to use the bb parasher ? also need to know how to echo out the bb coding...

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• How to check the correct radio button.

  - by MrW

  I have a Table containing some information that I need. All these rows also contains a column with a radio button in it so that the user is suppose to be able to check one of the rows as default. When I'm bringing the data back from the DB and want to select the one that's currentlly the default one. <% foreach (var item in (IEnumerable<Locale>) ViewData["Locales"]) { %> <tr> <td> <%= Html.Encode(item.Language.Name) %> </td> <td> <input type="radio" id="defaultLocale" name="defaultLocele" value="on" checked="<%= item.Default == false ? "false" : "true" %>" /> </td> I've also tried to do this: <input type="radio" id="defaultLocale" name="defaultLocele" value="on" checked="<%=item.Default == false ? "" : "checked" %>" /> but nothing seems to do the right thing. I always end up with having the last row in checked, which it isn't for sure.

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• Coding the R-ight way - avoiding the for loop

  - by mropa

  I am going through one of my .R files and by cleaning it up a little bit I am trying to get more familiar with writing the code the r-ight way. As a beginner, one of my favorite starting points is to get rid of the for() loops and try to transform the expression into a functional programming form. So here is the scenario: I am assembling a bunch of data.frames into a list for later usage. dataList <- list (dataA, dataB, dataC, dataD, dataE ) Now I like to take a look at each data.frame's column names and substitute certain character strings. Eg I like to substitute each "foo" and "bar" with "baz". At the moment I am getting the job done with a for() loop which looks a bit awkward. colnames(dataList[[1]]) [1] "foo" "code" "lp15" "bar" "lh15" colnames(dataList[[2]]) [1] "a" "code" "lp50" "ls50" "foo" matchVec <- c("foo", "bar") for (i in seq(dataList)) { for (j in seq(matchVec)) { colnames (dataList[[i]])[grep(pattern=matchVec[j], x=colnames (dataList[[i]]))] <- c("baz") } } Since I am working here with a list I thought about the lapply function. My attempts handling the job with the lapply function all seem to look alright but only at first sight. If I write f <- function(i, xList) { gsub(pattern=c("foo"), replacement=c("baz"), x=colnames(xList[[i]])) } lapply(seq(dataList), f, xList=dataList) the last line prints out almost what I am looking for. However, if i take another look at the actual names of the data.frames in dataList: lapply (dataList, colnames) I see that no changes have been made to the initial character strings. So how can I rewrite the for() loop and transform it into a functional programming form? And how do I substitute both strings, "foo" and "bar", in an efficient way? Since the gsub() function takes as its pattern argument only a character vector of length one.

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• boost::asio::io_service throws exception

  - by Ace

  Okay, I seriously cannot figure this out. I have a DLL project in MSVC that is attempting to use Asio (from Boost 1.45.0), but whenever I create my io_service, an exception is thrown. Here is what I am doing for testing purposes: void run() { boost::this_thread::sleep(boost::posix_time::seconds(5)); try { boost::asio::io_service io_service; } catch (std::exception & e) { MessageBox(NULL, e.what(), "Exception", MB_OK); } } BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved) { if (fdwReason == DLL_PROCESS_ATTACH) { boost::thread thread(run); } return TRUE; } This is what the message box shows: winsock: WSAStartup cannot function at this time because the underlying system it uses to provide network services is currently unavailable Here is what MSDN says about it (error code 10091, WSASYSNOTREADY): Network subsystem is unavailable. This error is returned by WSAStartup if the Windows Sockets implementation cannot function at because the underlying system it uses to provide network services is currently unavailable. Users should check: That the appropriate Windows Sockets DLL file is in the current path. That they are not trying to use more than one Windows Sockets implementation simultaneously. If there is more than one Winsock DLL on your system, be sure the first one in the path is appropriate for the network subsystem currently loaded. The Windows Sockets implementation documentation to be sure all necessary components are currently installed and configured correctly. Yet none of this seems to apply to me (or so I think). Here is my command line: /O2 /GL /D "_WIN32_WINNT=0x0501" /D "_WINDLL" /FD /EHsc /MD /Gy /Fo"Release\" /Fd"Release\vc90.pdb" /W3 /WX /nologo /c /TP /errorReport:prompt If anyone knows what might be wrong, please help me out! Thanks.

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