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  • Cant display button on specific rows of UITableView properly for iPhone

    - by varunwg
    Hi, I am trying to have a button for selected rows of my table. Here is the example code I am using: - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *ControlRowIdentifier = @"ControlRowIdentifier"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:ControlRowIdentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:ControlRowIdentifier] autorelease]; } if ([indexPath row] > 5) { UIImage *buttonUpImage = [UIImage imageNamed:@"button_up.png"]; UIImage *buttonDownImage = [UIImage imageNamed:@"button_down.png"]; UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom]; button.frame = CGRectMake(0.0, 0.0, buttonUpImage.size.width, buttonUpImage.size.height); [button setBackgroundImage:buttonUpImage forState:UIControlStateNormal]; [button setBackgroundImage:buttonDownImage forState:UIControlStateHighlighted]; [button setTitle:@"Tap" forState:UIControlStateNormal]; [button addTarget:self action:@selector(buttonTapped:) forControlEvents:UIControlEventTouchUpInside]; cell.accessoryView = button; } NSUInteger row = [indexPath row]; NSString *rowTitle = [list objectAtIndex:row]; cell.textLabel.text = rowTitle; return cell; } This code works absolutely fine when loaded for 1st time. So, as per the logic it shows 'Tap' button for all rows greater than 5. Problem occurs when I scroll up and down. Once I do that it just starts putting that button at any random row. I dont understand why it does that and it'll be really helpful if someone can give some tips on this. Thanks.

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  • How to get the size of a binary tree ?

    - by Andrei Ciobanu
    I have a very simple binary tree structure, something like: struct nmbintree_s { unsigned int size; int (*cmp)(const void *e1, const void *e2); void (*destructor)(void *data); nmbintree_node *root; }; struct nmbintree_node_s { void *data; struct nmbintree_node_s *right; struct nmbintree_node_s *left; }; Sometimes i need to extract a 'tree' from another and i need to get the size to the 'extracted tree' in order to update the size of the initial 'tree' . I was thinking on two approaches: 1) Using a recursive function, something like: unsigned int nmbintree_size(struct nmbintree_node* node) { if (node==NULL) { return(0); } return( nmbintree_size(node->left) + nmbintree_size(node->right) + 1 ); } 2) A preorder / inorder / postorder traversal done in an iterative way (using stack / queue) + counting the nodes. What approach do you think is more 'memory failure proof' / performant ? Any other suggestions / tips ? NOTE: I am probably going to use this implementation in the future for small projects of mine. So I don't want to unexpectedly fail :).

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  • Update successful notice with pure css and a close button

    - by Crays
    Hi guys, i've seen websites that allow you to say update your profile and when the stuff is done, they'll stay in the same page or redirect you to another and with a fancy notice that says "Update successful. click here to close" with a lowered opacity black background and a box in the middle with the text within. I've got most of the stuff, the lowred opacity black background, the middle box with the text and even the click here to close function. But how i did the "Click here to close" function is by using a link. Let's say after updating the profile, my script redirect me to index.php?update=successful then i use $update = $_GET['update']; if ($update == "successful") { echo '<div id="BlackScreen"><p id="MiddleBox">You\'ve successfully update your status!<br><span class="close"><a class="menu" href="index.php">Click to close. </a></span></div></div>'; } so that the lowered opacity background div will be gone, but is there another way to do this? Any tips please?

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  • Given the Following List (UL), how can it be serialized and sent to the Database

    - by nobosh
    I have the follow structure which is created with a nested sortable: <UL id="container"> <LI id="main1"> <input type="checkbox" /> Lorem ipsum dolor sit amet, consectetur <UL> <LI id="child2"> <input type="checkbox" /> In hac habitasse platea dictumst. <UL></UL> </LI> </UL> </LI> <LI id="main3"> <input type="checkbox" /> In hac habitasse platea dictumst. <UL></UL> </LI> <LI id="main4"> <input type="checkbox" /> In hac habitasse platea dictumst. <UL></UL> </LI> <LI id="main5"> <input type="checkbox" /> In hac habitasse platea dictumst. <UL></UL> </LI> </UL> Where I'm stuck is how to send this back to the database. I"m guessing that it needs to be serialized, does that sound right to? so that is looks something like: item[]=main1&item[]=221&item_221[]=21&item_221[]=2&item_221[]=211&item[]=22 I'm a little lost at this point and appreciate any tips to move me in the right direction. Thanks, B

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  • Convincing why testing is good

    - by FireAphis
    Hello, In my team of real-time-embedded C/C++ developers, most people don't have any culture of testing their code beyond the casual manual sanity checks. I personally strongly believe in advantages of autonomous automatic tests, but when I try to convince I get some reappearing arguments like: We will spend more time on writing the tests than writing the code. It takes a lot of effort to maintain the tests. Our code is spaghetti; no way we can unit-test it. Our requirement are not sealed – we’ll have to rewrite all the tests every time the requirements are changed. Now, I'd gladly hear any convincing tips and advises, but what I am really looking for are references to researches, articles, books or serious surveys that show (preferably in numbers) how testing is worth the effort. Something like "We in IBM/Microsoft/Google, surveying 3475 active projects, found out that putting 50% more development time into testing decreased by 75% the time spent on fixing bugs" or "after half a year, the time needed to write code with test was only marginally longer than what used to take without tests". Any ideas? P.S.: I'm adding C++ tag too in case someone has a specific experience with convincing this, usually elitist, type of developers :-)

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  • git commit best practices

    - by Ivan Z. Siu
    I am using git to manage a C++ project. When I am working on the projects, I find it hard to organize the changes into commits when changing things that are related to many places. For example, I may change a class interface in a .h file, which will affect the corresponding .cpp file, and also other files using it. I am not sure whether it is reasonable to put all the stuff into one big commit. Intuitively, I think the commits should be modular, each one of them corresponds to a functional update/change, so that the collaborators could pick things accordingly. But seems that sometimes it is inevitable to include lots of files and changes to make a functional change actually work. Searching did not yield me any good suggestion or tips. Hence I wonder if anyone could give me some best practices when doing commits. Thanks! PS. I've been using git for a while and I know how to interactively add/rebase/split/amend/... What I am asking is the PHILOSOPHY part.

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  • How do I access Dictionary items?

    - by salvationishere
    I am developing a C# VS2008 / SQL Server website app and am new to the Dictionary class. Can you please advise on best method of accomplishing this? Here is a code snippet: SqlConnection conn2 = new SqlConnection(connString); SqlCommand cmd = conn2.CreateCommand(); cmd.CommandText = "dbo.AppendDataCT"; cmd.CommandType = CommandType.StoredProcedure; cmd.Connection = conn2; SqlParameter p1, p2, p3; foreach (string s in dt.Rows[1].ItemArray) { DataRow dr = dt.Rows[1]; // second row p1 = cmd.Parameters.AddWithValue((string)dic[0], (string)dr[0]); p1.SqlDbType = SqlDbType.VarChar; p2 = cmd.Parameters.AddWithValue((string)dic[1], (string)dr[1]); p2.SqlDbType = SqlDbType.VarChar; p3 = cmd.Parameters.AddWithValue((string)dic[2], (string)dr[2]); p3.SqlDbType = SqlDbType.VarChar; } but this is giving me compiler error: The best overloaded method match for 'System.Collections.Generic.Dictionary<string,string>.this[string]' has some invalid arguments I just want to access each value from "dic" and load into these SQL parameters. How do I do this? Do I have to enter the key? The keys are named "col1", "col2", etc., so not the most user-friendly. Any other tips? Thanks!

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  • Plotting a graph with GD

    - by Nayena
    Here it goes. I have been thinking about this for a long time, and havent really been able to put up a proper way to do it yet. I havent implemented anything yet, as im still designing the thing. The idea is that i crawl a website for internal links, i got this settled, its easy, but after the crawling, i end up with an array with lots of links, and how many times those particular link appears on the site that i crawled (and how they're connected). With this huge array, i want to draw a graph somehow. Assuming i can handle the data correctly, the real question here is how i can draw this in a image by the use of the GD library. I figured if theres less than 12 elements, i can align them up on a unit circle spacing them up as a circle and then connecting them accordingly, so anything up to 12 elements shouldn't be a problem, but if theres more than 12, it could be awesome getting them lined up like this Or well, thats just a rough drawing, but i guess its just to prove a point. So i'm here looking for guidance or tips towards getting the math down to getting the stuff lined up in a good way. I have previously made bar-graphs, so i have little experience doing math with GD. If possible, id prefer not using some plotter-library - in the end, it gives me a better understanding on how things are supposed to be.

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  • Best way to implement game loop without freezing UI thread

    - by Matt H
    I'm trying to make a simple 2D game in Java. So far I have a JFrame, with a menubar, and a class which extends JPanel and overrides it's paint method. Now, I need to get a game loop going, where I will update the position of images and so on. However, I'm stuck at how best to achieve this. Should I use multi-threading, because surely, if you put an infinite loop on the main thread, the UI (and thus my menu bar) will freeze up? Here's my code so far: import java.awt.Color; import java.awt.Graphics; import javax.swing.JPanel; @SuppressWarnings("serial") public class GameCanvas extends JPanel { public void paint(Graphics g) { while (true) { g.setColor(Color.DARK_GRAY); try { Thread.sleep(100); } catch (InterruptedException e) { e.printStackTrace(); } } } } import javax.swing.JFrame; import javax.swing.JMenu; import javax.swing.JMenuBar; import javax.swing.JMenuItem; @SuppressWarnings("serial") public class Main extends JFrame { GameCanvas canvas = new GameCanvas(); final int FRAME_HEIGHT = 400; final int FRAME_WIDTH = 400; public static void main(String args[]) { new Main(); } public Main() { super("Game"); JMenuBar menuBar = new JMenuBar(); JMenu fileMenu = new JMenu("File"); JMenuItem startMenuItem = new JMenuItem("Pause"); menuBar.add(fileMenu); fileMenu.add(startMenuItem); super.add(canvas); super.setVisible(true); super.setSize(FRAME_WIDTH, FRAME_WIDTH); super.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); super.setJMenuBar(menuBar); } } Any pointers/tips? Also, where should I put my loop? In my main class, or my GameCanvas class? Any help is appreciated, thanks.

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  • Black Corners On Grouped UITableViewCells Only After Navigation Pops

    - by coneybeare
    I am not graphics expert but I somehow managed to make some good looking custom grouped UITableViewCells by setting the background view to a backgroundView with some CG code. In all SDK's up to 3.1.3 (maybe 3.2... I haven't tested on the iPad) this was working great, but I think a more recent SDK has introduced a change in the way graphics are cached offscreen. Upon first render, everything is great: The drawing is fine and the corners are transparent. If I push a couple of view controllers on the navigation stack and come back, there are now black corners that appear in the views: BEFORE && AFTER I have tons of code, most of which is written up here. I have tried tweaking to the best of my ability, looking at the docs for applicable changes, but after at least 8 hours in I still cannot find what might cause this. I have tried setting every view I can think of to be backgroundColor=clearColor and opaque=NO What else am I missing? Any debugging tips? UPDATE: I have some debug code in viewDidAppear that prints the backgroundColor and class description of all the subviews. - (void)debugView:(UIView *)view { DebugLog(@"%@ - %@", view.backgroundColor, [[view class] description]); for (UIView* child in view.subviews) { [self debugView:child]; } } - (void)viewDidAppear:(BOOL)animated { [super viewDidAppear:animated]; [DownloadController.networkQueue setSuspended:NO]; for (TTTableViewCell *cell in [self.tableView visibleCells]) { [cell debugView:cell]; } } With this code, I inspect the backgroundColor settings of the cell views on first load, when it is fine, and then again after coming back. There are some differences, but all the colors are still set to be clear. This leads me to believe the issue is underneath the UITableViewCell. UPDATE 2: I have created a simple sample application to highlight the problem here

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  • jQuery ajax returns

    - by Tom
    I think this will be some obvious problem, but I cannot figure it out. I hope someone can help me. So I have a slider with 3 slides - Intro, Question, Submit Now I want to make sure that if the question is answered wrong people cannot slide to Submit. The function to move slide is like this: function changeSlide(slide){ // In case current slide is question check the answer if (jQuery('.modalSteps li.current',base).hasClass('questionStep')){ checkAnswer(jQuery('input[name="question_id"]',base).val(), jQuery('input[name="answer"]:checked',base).val()); } jQuery('.modalSteps li.current',base).fadeOut('fast',function(){ jQuery(this).removeClass('current'); jQuery(slide).fadeIn('fast',function(){ jQuery(slide).addClass('current'); }); }); // In case the new slide is question, load the question if (jQuery(slide).hasClass('questionStep')){ var country = jQuery('input[name="country"]:checked',base).val(); loadQuestion(country); } } Now as you can see on first lines, I am calling function checkAnswer, which takes id of question and id of answer and pass it to the AJAX call. function checkAnswer(question, answer){ jQuery.ajax({ url: window.base_url+'ajax/check_answer/'+question+'/'+answer+'/', success: function(data){ if (!data.success){ jQuery('.question',base).html(data.message); } } }); } The problem i am having is that I cannot say if(checkAnswer(...)){} Because of Ajax it always returns false or undefined. What I need is something like this: function changeSlide(slide){ // In case current slide is question check the answer if (jQuery('.modalSteps li.current',base).hasClass('questionStep')){ if (!checkAnswer(jQuery('input[name="question_id"]',base).val(), jQuery('input[name="answer"]:checked',base).val())){ return false; } } ... So it will prevent the slide from moving on. Now when Im thinking about it, I will probably have slide like "Wrong answer" so I could just move the slide there, but I would like to see the first solution anyway. Thank you for tips

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  • jQuery re-checking check boxes

    - by Jacob
    Hi, I having problems with re-checking some checkboxes after and ajax call updates a table. I have a table of what the project calls 'shares'. I want to: 1) check for and save any checked shares to an array 2) Do my ajax call to update the table of shares 3) Re-check any there we checked before the ajax update. My code is not working and I can't see why? Any tips, help or advise much appreciated. // Array to hold our checked share ids var savedShareIDs = new Array(); // Add checked share ids into array $("input:checkbox[name=share_ids]:checked").each(function() { savedShareIDs.push($(this).val()); }); // Do ajax update Dajaxice.pagination_shares('Dajax.process',{'id':1, 'page':1}) // Re-check any that were checked before ajax update $("input:checkbox[name=share_ids]").each(function() { if ( $.inArray( $(this).val(), savedShareIDs) > -1 ) { $(this).attr('checked',true) } }); The problem is the checkboxes are not checking. I'm pretty sure the loop is working and the inArray check works. Just not checking the checkboxes. Can anyone see where I'm going wrong? Thanks.

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  • UML diagrams that are actually pretty?

    - by Borek
    I'm looking for a diagramming software that would produce good looking output. It doesn't need to support everything (or even much) from UML, is doesn't need to have code engineering functions or anything, it just needs to produce visually interesting output. Here is a couple of samples of products that I consider ugly / not good enough: Visio with default UML stencils (didn't find better looking ones), Enterprise Architect, Dia, ArgoUML and many other "professional" UML tools. A couple of visually compelling tools that I considered (but found issues with): Visual Studio class diagrams - just for .NET classes but the output is miles better than what UML tools typically produce NClass - similar to VS's class diagrams but I could not find the "pretty", blue skin anywhere yuml.me - very nice but lacking some advanced layout options. I have to say that I find their style almost ideal for high-level diagrams - they look sketchy which is good. Balsamiq - I think Joel used this for hginit.com and I liked it. However, it's not suited for creating software diagrams so I can imagine it would be quite a lot of work MS Word has actually quite a good graphics engine but I'd rather leave this as a choice of the last resort I'd be grateful for any good tips.

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  • How to decide between using PLINQ and LINQ at runtime?

    - by Hamish Grubijan
    Or decide between a parallel and a sequential operation in general. It is hard to know without testing whether parallel or sequential implementation is best due to overhead. Obviously it will take some time to train "the decider" which method to use. I would say that this method cannot be perfect, so it is probabilistic in nature. The x,y,z do influence "the decider". I think a very naive implementation would be to give both 1/2 chance at the beginning and then start favoring them according to past performance. This disregards x,y,z, however. I suspect that this question would be better answered by academics than practitioners. Anyhow, please share your heuristic, your experience if any, your tips on this. Sample code: public interface IComputer { decimal Compute(decimal x, decimal y, decimal z); } public class SequentialComputer : IComputer { public decimal Compute( ... // sequential implementation } public class ParallelComputer : IComputer { public decimal Compute( ... // parallel implementation } public class HybridComputer : IComputer { private SequentialComputer sc; private ParallelComputer pc; private TheDecider td; // Helps to decide between the two. public HybridComputer() { sc = new SequentialComputer(); pc = new ParallelComputer(); td = TheDecider(); } public decimal Compute(decimal x, decimal y, decimal z) { decimal result; decimal time; if (td.PickOneOfTwo() == 0) { // Time this and save result into time. result = sc.Compute(...); } else { // Time this and save result into time. result = pc.Compute(); } td.Train(time); return result; } }

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  • Output problem in mysql query in MFC program

    - by D.Gaughan
    Im currently working on a small MFC program that outputs data from a mysql database. I can get output when im using an sql statement that does not contain any variable eg. select album from Artists; but when i try to use a variable the program compiles but i get no output eg. mysql_perform_query(conn,select album from Artists where artists = '"+m_search_edit"'") Here is the function for mysql_perform_query: MYSQL_RES* mysql_perform_query(MYSQL *conn, const char* query) { // send the query to the database if (mysql_query(conn, query)) { // printf("MySQL query error : %s\n", mysql_error(conn)); // exit(1); } return mysql_use_result(conn); } And here is the code block for outputting the data: struct connection_details mysqlD; mysqlD.server = "www.freesqldatabase.com"; // where the mysql database is mysqlD.user = "**********"; // the root user of mysql mysqlD.password = "***********"; // the password of the root user in mysql mysqlD.database = "***************"; // the databse to pick // connect to the mysql database conn = mysql_connection_setup(mysqlD); CStringA query; query.Format("select album from Artists where artist = '%s'", CT2CA(m_search_edit)); res = mysql_perform_query(conn, query); //res = mysql_perform_query (conn, "select distinct artist from Artists"); while((row = mysql_fetch_row(res)) != NULL){ CString str; UpdateData(); str = ("%s\n", row[0]); UpdateData(FALSE); m_list_control.AddString(str); } The m_search_edit variable is the variable for an edit box. I am using Visual Studio 2008 with one copy of this program unicode and one nonunicode, I also have a version built with VC++ 6. Any tips on how I can get output from the databse using the m_search_edit variable??

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  • wrap from last screen to first screen in android Launcher2

    - by poboy975
    hi, I'm learning java and android. and I've been looking at trying to wrap the last screen to the first screen in the android Launcher2. I've tried googleing, and searching here, but there really isnt much information about the launcher2 source...I've been modifying the workspace.java file, but there has been minimal effect. no wrap around so far...I have not been able to find a .xml file that also might control the hard stop when you reach the end of the screens. I'll give a small example of the code that i have been modifying. original code: public void scrollRight() { clearVacantCache(); if (mNextScreen == INVALID_SCREEN && mCurrentScreen < getChildCount() -1 && mScroller.isFinished()) { snapToScreen(mCurrentScreen + 1); } modified code: public void scrollRight() { clearVacantCache(); if (mNextScreen == INVALID_SCREEN && mCurrentScreen < getChildCount() -1 && mScroller.isFinished()) { snapToScreen(mCurrentScreen + 1); }if (mCurrentScreen == getChildCount() -1 && mScroller.isFinished()) { snapToScreen(0); I would appreciate any tips or pointers if anyone has an idea where i'm going wrong, or someplace i can search to get the answers. the code looks to me like it should work, but I'm probably missing something obvious.

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  • Enterprise integration of disparate systems

    - by Chris Latta
    We're about to embark on a fairly large integration effort to kill off a bunch of Access and Sql Server databases and get everything into one coherent enterprise system. There are also a number of other systems (accounting, CRM, payroll, MS Exchange) that hold critical data that we need to integrate (use for data validation in other systems), report on and otherwise expose. It is likely that some of these systems will change in the next few years, so we need to isolate our systems to be ready for change. Ideally we would be able to expose our forms in a consistent manner across as many of our our systems as possible without having to re-develop them for each system. We are currently targeting SharePoint (2007 and soon 2010), Office (2007 and soon 2010 - Word, Excel, PowerPoint and Outlook), Reporting Services, .Net console applications, .Net Windows applications, shell extensions, and with the possibility of exposing some functionality on mobile devices (BlackBerries currently, maybe iPhones later) and via our website. We're moving development to Visual Studio 2010 (from 2005) ahead of migrating to SharePoint 2010 and Office 2010. Given that most of our development is presently targeted to the .Net framework (mostly in C#) it seems logical to stick with this unless there is some compelling reason to switch frameworks/platform for some aspects. We're thinking of your standard Database-Data Integration layer-Business Objects Layer-Web Services (or REST) layer-Client Application plus doing our own client application with WPF (or something else?) forms that can also be exposed in the MS systems (SharePoint, Office, Windows). So, we don't want much, just everything :) Basically we need to isolate ourselves from database and systems changes, create an API that can be used throughout our systems and then make this functionality available in our client applications. I'm very keen to get pointers from anyone who has tips on how to pull this off. Should we look at the Enterprise Library as a place to start? Is REST with ASP.Net MVC2 a better solution than Web Services for a system like this? Will WPF deliver forms re-use or is there something better?

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  • Validating parameters according to a fixed reference

    - by James P.
    The following method is for setting the transfer type of an FTP connection. Basically, I'd like to validate the character input (see comments). Is this going overboard? Is there a more elegant approach? How do you approach parameter validation in general? Any comments are welcome. public void setTransferType(Character typeCharacter, Character optionalSecondCharacter) throws NumberFormatException, IOException { // http://www.nsftools.com/tips/RawFTP.htm#TYPE // Syntax: TYPE type-character [second-type-character] // // Sets the type of file to be transferred. type-character can be any // of: // // * A - ASCII text // * E - EBCDIC text // * I - image (binary data) // * L - local format // // For A and E, the second-type-character specifies how the text should // be interpreted. It can be: // // * N - Non-print (not destined for printing). This is the default if // second-type-character is omitted. // * T - Telnet format control (<CR>, <FF>, etc.) // * C - ASA Carriage Control // // For L, the second-type-character specifies the number of bits per // byte on the local system, and may not be omitted. final Set<Character> acceptedTypeCharacters = new HashSet<Character>(Arrays.asList( new Character[] {'A','E','I','L'} )); final Set<Character> acceptedOptionalSecondCharacters = new HashSet<Character>(Arrays.asList( new Character[] {'N','T','C'} )); if( acceptedTypeCharacters.contains(typeCharacter) ) { if( new Character('A').equals( typeCharacter ) || new Character('E').equals( typeCharacter ) ){ if( acceptedOptionalSecondCharacters.contains(optionalSecondCharacter) ) { executeCommand("TYPE " + typeCharacter + " " + optionalSecondCharacter ); } } else { executeCommand("TYPE " + typeCharacter ); } } }

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  • i read that for RESTful websites. it is not good to use $_SESSION. Why is it not good? how then do i

    - by keisimone
    I read that it is not good to use $_SESSION. http://www.recessframework.org/page/towards-restful-php-5-basic-tips I am creating a WEBSITE, not web service in PHP. and i am trying to make it more RESTful. at least in spirit. right now i am rewriting all the action to use Form tags POST and add in a hidden value called _method which would be "delete" for deleting action and "put" for updating action. however, i am not sure why it is recommended NOT to use $_SESSION. i would like to know why and what can i do to improve. To allow easy authorization checking, what i did was to after logging in the user, the username is stored in the $_SESSION. Everytime the user navigates to a page, the page would check if the username is stored inside $_SESSION and then based on the $_SESSION retrieves all the info including privileges from the database and then evaluates the authorization to access the page based on the info retrieved. Is the way I am implementing bad? not RESTful? how do i improve performance and security? Thank you.

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  • Reduce durability in MySQL for performance

    - by Paul Prescod
    My site occasionally has fairly predictable bursts of traffic that increase the throughput by 100 times more than normal. For example, we are going to be featured on a television show, and I expect in the hour after the show, I'll get more than 100 times more traffic than normal. My understanding is that MySQL (InnoDB) generally keeps my data in a bunch of different places: RAM Buffers commitlog binary log actual tables All of the above places on my DB slave This is too much "durability" given that I'm on an EC2 node and most of the stuff goes across the same network pipe (file systems are network attached). Plus the drives are just slow. The data is not high value and I'd rather take a small chance of a few minutes of data loss rather than have a high probability of an outage when the crowd arrives. During these traffic bursts I would like to do all of that I/O only if I can afford it. I'd like to just keep as much in RAM as possible (I have a fair chunk of RAM compared to the data size that would be touched over an hour). If buffers get scarce, or the I/O channel is not too overloaded, then sure, I'd like things to go to the commitlog or binary log to be sent to the slave. If, and only if, the I/O channel is not overloaded, I'd like to write back to the actual tables. In other words, I'd like MySQL/InnoDB to use a "write back" cache algorithm rather than a "write through" cache algorithm. Can I convince it to do that? If this is not possible, I am interested in general MySQL write-performance optimization tips. Most of the docs are about optimizing read performance, but when I get a crowd of users, I am creating accounts for all of them, so that's a write-heavy workload.

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  • C# Homework - control structures (for, if)

    - by Freakingout
    I got a homework assignment today: "Create a program that calculates out how many ways you can add three numbers so that they equal 1000." I think this code should work, but it doesn't write out anything. using System; namespace ConsoleApp02 { class Program { public static void Main(string[] args) { for(int a = 0; a < 1000; a++) { for(int b = 0; b < 1000; b++) { for(int c = 0; c < 1000; c++) { for(int puls = a + b + c; puls < 1000; puls++) { if(puls == 1000) { Console.WriteLine("{0} + {1} + {2} = 1000", a, b, c); } } } } } Console.ReadKey(true); } } } What am I doing wrong? Any tips or solution?

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  • Rotating png images using css in IE

    - by Ernest Shulikovski
    Here is a mockup for something called "Diversity Disc": http://diversity.iest.pl/ It is just three disks that you can rotate and read "results". I am using there just four png images, and rotate using jQuery f.i: $.fn.rleft = function() { return this.animate({ rotate: '-=45deg' }); }; It works not so bad in most new browser. But in all versions of IE things go terribly wrong. There is problem with rotation, and with png: after rotation, there is happening something very ugly with alpha transparency of those images. So my question is, is this possible to make it work in IE 8 and 7 (and, more or less IE 6?). If no I will be forced to order it in Flash. But I would like first to try to do it using just css and javascript (svg?). So what I am doing wrong? Do you have any tips, for using different technology, or js library? Thank you in advance for any answers.

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  • Ruby shortest way to write rnd hex

    - by Whirlwin
    Hi. What I have is a method used to generate random hex values. E.g 666 or FF7 However, I don't think it looks simple/elegant at all.. What I want is to make it more simple which perhaps will make my code shorter as well, but I don't know how. That is why I need tips or hints Here is my code so far: def random_values random_values = Array.new letters = ['A','B','C','D','E','F'] for i in 1..15 if i <= 9 random_values << i else random_values << letters[i-10] end end return random_values.shuffle[0].to_s + random_values.shuffle[0].to_s + random_values.shuffle[0].to_s end As you probably see, I do not generate random numbers. I just shuffle the array containing the values I want, meaning all the numbers in the array are unique, which is not needed, but was the easiest solution for me when I wrote the code. I am most concerned about the return line.. If only it was possible to write like: return 3.times { random_values.shuffle[0] } or return random_values.shuffle[0].to_s *3 Thanks in advance!

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  • Cleaning up PHP Code

    - by Michael
    Hi, I've noticed I am a very sloppy coder and do things out of the ordinary. Can you take a look at my code and give me some tips on how to code more efficiently? What can I do to improve? session_start(); /check if the token is correct/ if ($_SESSION['token'] == $_GET['custom1']){ /*connect to db*/ mysql_connect('localhost','x','x') or die(mysql_error()); mysql_select_db('x'); /*get data*/ $orderid = mysql_real_escape_string($_GET['order_id']); $amount = mysql_real_escape_string($_GET['amount']); $product = mysql_real_escape_string($_GET['product1Name']); $cc = mysql_real_escape_string($_GET['Credit_Card_Number']); $length = strlen($cc); $last = 4; $start = $length - $last; $last4 = substr($cc, $start, $last); $ipaddress = mysql_real_escape_string($_GET['ipAddress']); $accountid = $_SESSION['user_id']; $credits = mysql_real_escape_string($_GET['custom3']); /*insert history into db*/ mysql_query("INSERT into billinghistory (orderid, price, description, credits, last4, orderip, accountid) VALUES ('$orderid', '$amount', '$product', '$credits', '$last4', '$ipaddress', '$accountid')"); /*add the credits to the users account*/ mysql_query("UPDATE accounts SET credits = credits + $credits WHERE user_id = '$accountid'"); /*redirect is successful*/ header("location: index.php?x=1"); }else{ /*something messed up*/ header("location: error.php"); }

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  • Windows 2008 VPS hosting experiences

    - by Luke Bennett
    Whilst similar questions exist, I couldn't find any which quite match my request. I'm looking for hosting for some personal .NET projects which for various reasons I do not want to host on our servers at work. I need to be able to host multiple sites and for that reason I'm thinking of a VPS with RDP access for the time being - don't fancy shared hosting as I feel that doesn't offer me the flexbility and control I'm looking for. What experiences do people have of Windows 2008 VPS providers? I've come across a few possibilities although it seems a lot of places are still on Windows 2003 with 2008 'coming soon'. Is VPS the best way to go? Eventually (depending on how the projects take off) I intend to get a dedicated box but at this stage it's not cost-effective. Also, what are people's experiences of running SQL Server Express on a VPS? What would you say the minimum requirements are for CPU/memory? I know it's not going to be anywhere near as performant as SQL Server 2005/8 running on a dedicated box but I'm hoping it will be an acceptable starting point. Any other tips/advice also welcome! Edit: Forgot to mention, I'm ideally looking for UK hosting although I'm open to alternatives.

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