Search Results

Search found 16473 results on 659 pages for 'game logic'.

Page 637/659 | < Previous Page | 633 634 635 636 637 638 639 640 641 642 643 644  | Next Page >

• TDD - beginner problems and stumbling blocks

  - by Noufal Ibrahim

  While I've written unit tests for most of the code I've done, I only recently got my hands on a copy of TDD by example by Kent Beck. I have always regretted certain design decisions I made since they prevented the application from being 'testable'. I read through the book and while some of it looks alien, I felt that I could manage it and decided to try it out on my current project which is basically a client/server system where the two pieces communicate via. USB. One on the gadget and the other on the host. The application is in Python. I started off and very soon got entangled in a mess of rewrites and tiny tests which I later figured didn't really test anything. I threw away most of them and and now have a working application for which the tests have all coagulated into just 2. Based on my experiences, I have a few questions which I'd like to ask. I gained some information from http://stackoverflow.com/questions/1146218/new-to-tdd-are-there-sample-applications-with-tests-to-show-how-to-do-tdd but have some specific questions which I'd like answers to/discussion on. Kent Beck uses a list which he adds to and strikes out from to guide the development process. How do you make such a list? I initially had a few items like "server should start up", "server should abort if channel is not available" etc. but they got mixed and finally now, it's just something like "client should be able to connect to server" (which subsumed server startup etc.). How do you handle rewrites? I initially selected a half duplex system based on named pipes so that I could develop the application logic on my own machine and then later add the USB communication part. It them moved to become a socket based thing and then moved from using raw sockets to using the Python SocketServer module. Each time things changed, I found that I had to rewrite considerable parts of the tests which was annoying. I'd figured that the tests would be a somewhat invariable guide during my development. They just felt like more code to handle. I needed a client and a server to communicate through the channel to test either side. I could mock one of the sides to test the other but then the whole channel wouldn't be tested and I worry that I'd miss that. This detracted from the whole red/green/refactor rhythm. Is this just lack of experience or am I doing something wrong? The "Fake it till you make it" left me with a lot of messy code that I later spent a lot of time to refactor and clean up. Is this the way things work? At the end of the session, I now have my client and server running with around 3 or 4 unit tests. It took me around a week to do it. I think I could have done it in a day if I were using the unit tests after code way. I fail to see the gain. I'm looking for comments and advice from people who have implemented large non trivial projects completely (or almost completely) using this methodology. It makes sense to me to follow the way after I have something already running and want to add a new feature but doing it from scratch seems to tiresome and not worth the effort. P.S. : Please let me know if this should be community wiki and I'll mark it like that. Update 0 : All the answers were equally helpful. I picked the one I did because it resonated with my experiences the most. Update 1: Practice Practice Practice!

  Read the article

• How to handle recurring dates (dates only) in .NET?

  - by Wayne M

  I am trying to figure out a good way to handle recurring events in .NET, specifically for an ASP.NET MVC application. The idea is that a user can create an event and specify that the event can occur repeatedly after a specific interval (e.g. "every two weeks", "once a month" and so on). What would be the best way to tackle this? My brainstorming right now is to have two tables: Job and RecurringJob. Job is the "master" record and has the description of the job as well a key to what customer it's for, while RecurringJob links back to Job and has additional info on what the occurrence frequency is (e.g. 1 for "once a month") as well as the timespan (e.g. "Weekly", "Monthly"). The issue is how to determine and set the next occurrence of the job since this will have to be something that's done regularly. I've seen two trains of thought with this: This logic should either be stored in a database column and periodically updated, or calculated on the fly in the code. Any thoughts or suggestions on tackling this? Edit: this is for a subscription based web app I'm creating to let service businesses schedule their common recurring jobs easily and track their customers. So a typical use might be to create a "Cut lawn" job for Mr Smith that occurs every month The exact date isn't important - it's the ability for the customer to see that Mr Smith gets his lawn cut every month and followup with him about it. Let me rephrase the above to better convey my idea. A sample use case for the application might be as follows: User pulls up the customer record for John Smith and clicks the Add Job link. The user fills out the form to create a job with a name of "Cut lawn", a start date of 11/15/2009, and selects a checkbox indicating that this job continually occurs. The user is presented with a secondary screen asking for the job frequency. The user indicates (haven't decided how at this point - let's assume select lists) that the job occurs once a month. User clicks save. Now, when the user views the record for John Smith, they can see that he has a job, "Cut lawn", that occurs every month starting from 11/15/2009. On the main dashboard when it's one week prior to the assumed start date, the user sees the job displayed with an indicator such as "12/15/2009 - Cut lawn (John Smith)". A week before the due date someone from the company calls him up to schedule and he says he's going to be out of town until 1/1/2010, so he wants his appointment rescheduled for that date. Our user can change the date for the job to be 1/1/2010, and now the recurrence will start one month from that date (e.g. next time will be 2/1/2010). The idea behind this is that the app is targeting businesses like lawn care, plumbers, carpet cleaners and the like where the exact date isn't as important (because it can and will change as people are busy), the key thing is to give the business an indicator that Mr. Smith's monthly service is coming up, and someone should give him a call to determine when exactly it can be scheduled for. In effect give these businesses a way to track repeat business and know when it's time to followup with a customer.

  Read the article

• iPhone app works hundreds of times, then crashes from memory error on startup, then never works unti

  - by peter

  I have a Cocos2d/openGL iPhone game. It's a universal app and I'm dealing with an occasional but nasty error on the iPad. We are loading a lot of textures up front (3 2048x2048 textures). I'm working on reducing this up front load, but what worries me is I really don't understand the root cause of this crash that permanently breaks the app. This is the deal: 1. App works fine for hundreds of plays on the iPad 2. Eventually (I'm guessing due to other programs using up some memory and not letting go or whatever) the app starts crashing on startup. It just closes again in the middle of loading. 3. The App will now never work again on that iPad, closing immediately every time, until the iPad is restarted. Obviously my app is demanding too much memory up front to work reliably every time, I get that. What I don't get is why when it fails once, it has failed forever until the iPad is restarted. Can anyone explain what is going on here? EDIT: forgot to add organizer crash lags just say low memory, like this every time (I changed my app name to MyAppName below). Again, I know it's low memory, but why does it stay low memory until restart?: Incident Identifier: E7A2507C-3FB1-4E3B-B315-09F094236541 CrashReporter Key: 0fda9d667f2c6073f20a76809aa25438b6854d15 OS Version: iPhone OS 3.2 (7B367) Date: 2010-04-30 16:59:44 -0400 Free pages: 437 Wired pages: 17228 Purgeable pages: 0 Largest process: MyAppName Processes Name UUID Count resident pages MyAppName <6307ce41802850944baa78d29224fa7f> 22385 (jettisoned) (active) mediaserverd <ea8bac28b06fe3980fdd44b5caceb563> 242 DTMobileIS <a0f651e43881e66f50f8a95abea72921> 5826 notification_pro <4c9a7ee0a5bbe160465991228f2d2f2e> 67 syslog_relay <4ceaed776d2df957fa130712f4ef21d0> 66 notification_pro <4c9a7ee0a5bbe160465991228f2d2f2e> 67 notification_pro <4c9a7ee0a5bbe160465991228f2d2f2e> 67 afcd <4f3c9566e33b4463f05603d990584e5d> 72 ptpd <83de0f774bd6553d513ae9e19b0f9b56> 181 syslogd <66247e305d5c0bf6f1ce1cc950653263> 81 lsd <a4d852c1c8da2b3d231bdc90887b52ba> 130 iapd <a8534cbde4b90ad5915dd26ab03ff3e3> 204 notifyd <5e9d5bee7c3eae1c8b494c79eb11406e> 71 BTServer <64e4a6ea6b1240db2331e05a29caa862> 108 CommCenter <97bf297944ac4bde19bcee96dd23bd5f> 181 SpringBoard <c7a5904c12db7b14334a4edaa4cabaa9> 5339 (active) configd <aca9fa3380322669164fd6b1a3864300> 373 fairplayd.K48 <2d997ffca1a568f9c5400ac32d8f0782> 84 locationd <dd1ea88105c62173908ce767db5c4d37> 599 mDNSResponder <820560222d47a1f2a0dce98a7f8a9721> 108 lockdownd <497fd54c79a680bf29f5d9320f514613> 303 MobileStorageMou <c277b79c2157c4dc5cfc5c3ca35bd5f2> 69 launchd <66972eee4d865c4383b33d985d22994b> 98 **End**

  Read the article

• Mysql - help me optimize this query (improved question)

  - by sandeepan-nath

  About the system: - There are tutors who create classes and packs - A tags based search approach is being followed.Tag relations are created when new tutors register and when tutors create packs (this makes tutors and packs searcheable). For details please check the section How tags work in this system? below. Following is the concerned query SELECT SUM(DISTINCT( t.tag LIKE "%Dictatorship%" )) AS key_1_total_matches, SUM(DISTINCT( t.tag LIKE "%democracy%" )) AS key_2_total_matches, COUNT(DISTINCT( od.id_od )) AS tutor_popularity, CASE WHEN ( IF(( wc.id_wc > 0 ), ( wc.wc_api_status = 1 AND wc.wc_type = 0 AND wc.class_date > '2010-06-01 22:00:56' AND wccp.status = 1 AND ( wccp.country_code = 'IE' OR wccp.country_code IN ( 'INT' ) ) ), 0) ) THEN 1 ELSE 0 END AS 'classes_published', CASE WHEN ( IF(( lp.id_lp > 0 ), ( lp.id_status = 1 AND lp.published = 1 AND lpcp.status = 1 AND ( lpcp.country_code = 'IE' OR lpcp.country_code IN ( 'INT' ) ) ), 0) ) THEN 1 ELSE 0 END AS 'packs_published', td . *, u . * FROM tutor_details AS td JOIN users AS u ON u.id_user = td.id_user LEFT JOIN learning_packs_tag_relations AS lptagrels ON td.id_tutor = lptagrels.id_tutor LEFT JOIN learning_packs AS lp ON lptagrels.id_lp = lp.id_lp LEFT JOIN learning_packs_categories AS lpc ON lpc.id_lp_cat = lp.id_lp_cat LEFT JOIN learning_packs_categories AS lpcp ON lpcp.id_lp_cat = lpc.id_parent LEFT JOIN learning_pack_content AS lpct ON ( lp.id_lp = lpct.id_lp ) LEFT JOIN webclasses_tag_relations AS wtagrels ON td.id_tutor = wtagrels.id_tutor LEFT JOIN webclasses AS wc ON wtagrels.id_wc = wc.id_wc LEFT JOIN learning_packs_categories AS wcc ON wcc.id_lp_cat = wc.id_wp_cat LEFT JOIN learning_packs_categories AS wccp ON wccp.id_lp_cat = wcc.id_parent LEFT JOIN order_details AS od ON td.id_tutor = od.id_author LEFT JOIN orders AS o ON od.id_order = o.id_order LEFT JOIN tutors_tag_relations AS ttagrels ON td.id_tutor = ttagrels.id_tutor JOIN tags AS t ON ( t.id_tag = ttagrels.id_tag ) OR ( t.id_tag = lptagrels.id_tag ) OR ( t.id_tag = wtagrels.id_tag ) WHERE ( u.country = 'IE' OR u.country IN ( 'INT' ) ) AND CASE WHEN ( ( t.id_tag = lptagrels.id_tag ) AND ( lp.id_lp 0 ) ) THEN lp.id_status = 1 AND lp.published = 1 AND lpcp.status = 1 AND ( lpcp.country_code = 'IE' OR lpcp.country_code IN ( 'INT' ) ) ELSE 1 END AND CASE WHEN ( ( t.id_tag = wtagrels.id_tag ) AND ( wc.id_wc 0 ) ) THEN wc.wc_api_status = 1 AND wc.wc_type = 0 AND wc.class_date '2010-06-01 22:00:56' AND wccp.status = 1 AND ( wccp.country_code = 'IE' OR wccp.country_code IN ( 'INT' ) ) ELSE 1 END AND CASE WHEN ( od.id_od 0 ) THEN od.id_author = td.id_tutor AND o.order_status = 'paid' AND CASE WHEN ( od.id_wc 0 ) THEN od.can_attend_class = 1 ELSE 1 END ELSE 1 END GROUP BY td.id_tutor HAVING key_1_total_matches = 1 AND key_2_total_matches = 1 ORDER BY tutor_popularity DESC, u.surname ASC, u.name ASC LIMIT 0, 20 The problem The results returned by the above query are correct (AND logic working as per expectation), but the time taken by the query rises alarmingly for heavier data and for the current data I have it is like 25 seconds as against normal query timings of the order of 0.005 - 0.0002 seconds, which makes it totally unusable. It is possible that some of the delay is being caused because all the possible fields have not yet been indexed. The tag field of tags table is indexed. Is there something faulty with the query? What can be the reason behind 20+ seconds of execution time? How tags work in this system? When a tutor registers, tags are entered and tag relations are created with respect to tutor's details like name, surname etc. When a Tutors create packs, again tags are entered and tag relations are created with respect to pack's details like pack name, description etc. tag relations for tutors stored in tutors_tag_relations and those for packs stored in learning_packs_tag_relations. All individual tags are stored in tags table. The explain query output:- Please see this screenshot - http://www.test.examvillage.com/Explain_query.jpg

  Read the article

• How perform USort() on an Array of Objects class definition as a method?

  - by user558724

  class Contact{ public $name; public $bgcolor; public $lgcolor; public $email; public $element; public function __construct($name, $bgcolor, $lgcolor, $email, $element) { $this->name = $name; $this->bgcolor = $bgcolor; $this->lgcolor = $lgcolor; $this->email = $email; $this->element = $element; } public static function sortByName(Contact $p1, Contact $p2) { return strcmp($p1->name, $p2->name); } } class ContactList implements Iterator, ArrayAccess { protected $_label; protected $_contacts = array(); public function __construct($label) { $this->_label = $label; } public function getLabel() { return $this->_label; } public function addContact(Contact $contact) { $this->_contacts[] = $contact; } public function current() { return current($this->_contacts); } public function key() { return key($this->_contacts); } public function next() { return next($this->_contacts); } public function rewind() { return reset($this->_contacts); } public function valid() { return current($this->_contacts); } public function offsetGet($offset) { return $this->_contacts[$offset]; } public function offsetSet($offset, $data) { if (!$data instanceof Contact) throw new InvalidArgumentException('Only Contact objects allowed in a ContactList'); if ($offset == '') { $this->_contacts[] = $data; } else { $this->_contacts[$offset] = $data; } } public function offsetUnset($offset) { unset($this->_contacts[$offset]); } public function offsetExists($offset) { return isset($this->_contacts[$offset]); } public function sort($attribute = 'name') { $sortFct = 'sortBy' . ucfirst(strtolower($attribute)); if (!in_array($sortFct, get_class_methods('Contact'))) { throw new Exception('contact->sort(): Can\'t sort by ' . $attribute); } usort($this->contact, 'ContactList::' . $sortFct); } } public function Sort($property, $asc=true) { // this is where sorting logic takes place $_pd = $this->_contact->getProperty($property); if ($_pd == null) { user_error('Property '.$property.' does not exist in class '.$this->_contact->getName(), E_WARNING); return; } // set sortDescriptor ContactList::$sortProperty = $_pd; // and apply sorting usort($this->_array, array('ContactList', ($asc?'USortAsc':'USortDesc'))); } function getItems(){ return $this->_array; } class SortableItem extends ContactList { static public $sortProperty; static function USortAsc($a, $b) { /*@var $_pd ReflectionProperty*/ /* $_pd = self::$sortProperty; if ($_pd !== null) { if ($_pd->getValue($a) === $_pd->getValue($b)) return 0; else return (($_pd->getValue($a) < $_pd->getValue($b))?-1:1); } return 0; } static function USortDesc($a, $b) { return -(self::USortAsc($a,$b)); } } This approach keeps giving me PHP Warnings: usort() [function.usort]: of all kinds which I can provide later as needed to comment out those methods and definitions in order to test and fix some minor bugs of our program. **$billy parameters are already defined. $all -> addContact($billy); // --> ended up adding each contact manually above $all->Sort('name',true); $items = $all->getItems(); foreach($items as $contact) { echo $contact->__toString(); } $all->sort(); The reason for using usort is to re-arrange the order alphabetically by name but somehow is either stating that the function comparison needs to be an array or another errors which obviously I have seemed to pass. Any help would be greatly appreciated, thanks in advance.

  Read the article

• color objects in C or C ++ [closed]

  - by jazz

  Possible Duplicate: Colors in C language i copied a game from a book which name is paratrooper i ask this question again i also provide the code of the objects which i create there i want to change the color of these objects but i didn't understand how to do that so can any one plz help me how to do that.Listen guys they are not the standard functions but i use the graphics library for these functions and i can't find the function in the library file of graphics. i hope u understand know.this code will not run properly so plz tell me something about the function which color it i can't put the image other wize i show u the image it will make alot easieer #include "graphics.h" #include "stdio.h" #include "conio.h" #include "process.h" #include "alloc.h" #include "stdlib.h" #include "math.h" #include "dos.h" main() { int gm=CGAHI, gd=CGA, key=0, area; initgraph(&gd, &gm, "C:\\tc\\bgi"); helidraw(246,50,-1); getch(); return 0; } helidraw ( int x, int y, int d ) { int direction, i, j ; if ( d ) direction = -1 ; else direction = 1 ; i = 3 ; j = 8 ; line ( x - j - 8, y - i - 2, x + j + 8, y - i - 2 ) ; line ( x - j + 5, y - i - 1, x + j - 5, y - i - 1 ) ; line ( x - j, y - i, x + j, y - i ) ; for ( ; i > 0 ; i--, j += 2 ) { putpixel ( x - ( direction * j ), y - i, 1 ) ; line ( x + ( direction * j ), y - i, x + ( direction * ( j - 8 ) ), y - i ) ; } i = 0 ; j -= 2 ; line ( x - ( direction * j ), y - i, x - ( direction * ( j + 17 ) ), y - i ) ; line ( x - ( direction * j ), y - i + 1, x - ( direction * ( j + 7 ) ), y - i + 1 ) ; putpixel ( x - ( direction * ( j + 19 ) ), y - i - 1, 1 ) ; for ( ; i < 3 ; i++, j -= 2 ) { putpixel ( x - j, y + i, 1 ) ; putpixel ( x + j, y + i, 1 ) ; } line ( x - j, y + i, x + j, y + i ) ; putpixel ( x - j + 3, y + i + 1, 1 ) ; putpixel ( x + j - 3, y + i + 1, 1 ) ; line ( x - j - 10, y + i + 2, x + j + 10, y + i + 2 ) ; putpixel ( x + ( direction * ( j + 12 ) ), y + i + 1, 1 ) ; }

  Read the article

• GLKit Memory Leak copywithZone

  - by TommyT39

  Running the instruments utility against the game I'm writing shows a bunch of memory leaks related to copy with Zone when I cycle through an array and draw some simple cube objects. Im not sure the best way to track this down as I'm new to OpenGL programming. My program is using ARC and is set to build for IOS 5. I am initializing GLKit to use OPenGl 2.0 and using the BafeEffect so I don't have to write my own shaders etc.. This shouldn't be rocket science. Im guessing that I must be not releasing something within the draw function. Below is the code to my draw function. Could you guys take a look and see if anything stands out as the problem? One other thing to note is that I'm using 15 different textures, the cubes can be 1 of 15 different ones. I have a property set on the cube class for the texture and I set it as I create the cube in there array. But I do load all 15 when my programs view did load starts.They are small .jps files that are less than 75k each and each cube uses the same texture all the way around so shouldn't be too big of an issue. Here is the code to my draw function: - (void)draw { GLKMatrix4 xRotationMatrix = GLKMatrix4MakeXRotation(rotation.x); GLKMatrix4 yRotationMatrix = GLKMatrix4MakeYRotation(rotation.y); GLKMatrix4 zRotationMatrix = GLKMatrix4MakeZRotation(rotation.z); GLKMatrix4 scaleMatrix = GLKMatrix4MakeScale(scale.x, scale.y, scale.z); GLKMatrix4 translateMatrix = GLKMatrix4MakeTranslation(position.x, position.y, position.z); GLKMatrix4 modelMatrix = GLKMatrix4Multiply(translateMatrix,GLKMatrix4Multiply(scaleMatrix,GLKMatrix4Multiply(zRotationMatrix, GLKMatrix4Multiply(yRotationMatrix, xRotationMatrix)))); GLKMatrix4 viewMatrix = GLKMatrix4MakeLookAt(0, 0, 1, 0, 0, -5, 0, 1, 0); effect.transform.modelviewMatrix = GLKMatrix4Multiply(viewMatrix, modelMatrix); effect.transform.projectionMatrix = GLKMatrix4MakePerspective(0.125*M_TAU, 1.0, 2, 0); effect.texture2d0.name = wallTexture.name; [effect prepareToDraw]; glEnable(GL_DEPTH_TEST); glEnable(GL_CULL_FACE); glEnableVertexAttribArray(GLKVertexAttribPosition); glVertexAttribPointer(GLKVertexAttribPosition, 3, GL_FLOAT, GL_FALSE, 0, triangleVertices); glEnableVertexAttribArray(GLKVertexAttribTexCoord0); glVertexAttribPointer(GLKVertexAttribTexCoord0, 2, GL_FLOAT, GL_FALSE, 0, textureCoordinates); glDrawArrays(GL_TRIANGLES, 0, 18); glDisableVertexAttribArray(GLKVertexAttribPosition); glDisableVertexAttribArray(GLKVertexAttribTexCoord0); }

  Read the article

• Sprite not moving when using a function from another class SFML c++

  - by user2892932

  I have a Game.cpp, and I am calling a update function in my Player class. In my player update Function I have it to check for keyboard input, and it seems to work, but whenever I try to call the .move() function, it seems to not work. I get no errors either. I am new to sfml, and decent with c++. Help is appreciated! #include "Player.h" Player::Player(void): vel(0), maxvel(100) { Load("Assets/sss.png",true); } void Player::Update(sf::Sprite& p) { if (sf::Keyboard::isKeyPressed(sf::Keyboard::A)) { moveObject(-3,0, p); } if(sf::Keyboard::isKeyPressed(sf::Keyboard::D)) { moveObject(-3,0, p); } } Player::~Player(void) { } This is the GameObject cpp #include "GameObject.h" #include <iostream> GameObject::GameObject(void) { isLoaded = false; } void GameObject::Load(std::string flname, bool isPlayer) { if(!tex.loadFromFile(flname)) { EXIT_FAILURE; } else { if(isPlayer) { if(!tex.loadFromFile(flname, sf::IntRect(0,0,33,33))) { EXIT_FAILURE; } else { std::cout << "Loading image" << "\n"; filename = flname; spr.setTexture(tex); isLoaded = true; } } else { std::cout << "Loading image" << "\n"; filename = flname; spr.setTexture(tex); isLoaded = true; } } } void GameObject::Draw(sf::RenderWindow & window) { if(isLoaded) { window.draw(spr); window.display(); std::cout << "Sprite drew" << "\n"; } } void GameObject::setPos(float x, float y) { if(isLoaded) { spr.setPosition(x,y); } } sf::Vector2f GameObject::GetObjPos() { return spr.getPosition(); } sf::Sprite& GameObject::getSprite() { return spr; } void GameObject::moveObject(float x, float y, sf::Sprite& sp) { sp.move(x, y); } GameObject::~GameObject(void) { }

  Read the article

• Running out of memory.. How?

  - by maxdj

  I'm attempting to write a solver for a particular puzzle. It tries to find a solution by trying every possible move one at a time until it finds a solution. The first version tried to solve it depth-first by continually trying moves until it failed, then backtracking, but this turned out to be too slow. I have rewritten it to be breadth-first using a queue structure, but I'm having problems with memory management. Here are the relevant parts: int main(int argc, char *argv[]) { ... int solved = 0; do { solved = solver(queue); } while (!solved && !pblListIsEmpty(queue)); ... } int solver(PblList *queue) { state_t *state = (state_t *) pblListPoll(queue); if (is_solution(state->pucks)) { print_solution(state); return 1; } state_t *state_cp; puck new_location; for (int p = 0; p < puck_count; p++) { for (dir i = NORTH; i <= WEST; i++) { if (!rules(state->pucks, p, i)) continue; new_location = in_dir(state->pucks, p, i); if (new_location.x != -1) { state_cp = (state_t *) malloc(sizeof(state_t)); state_cp->move.from = state->pucks[p]; state_cp->move.direction = i; state_cp->prev = state; state_cp->pucks = (puck *) malloc (puck_count * sizeof(puck)); memcpy(state_cp->pucks, state->pucks, puck_count * sizeof(puck)); /*CRASH*/ state_cp->pucks[p] = new_location; pblListPush(queue, state_cp); } } } return 0; } When I run it I get the error: ice(90175) malloc: *** mmap(size=2097152) failed (error code=12) *** error: can't allocate region *** set a breakpoint in malloc_error_break to debug Bus error The error happens around iteration 93,000. From what I can tell, the error message is from malloc failing, and the bus error is from the memcpy after it. I have a hard time believing that I'm running out of memory, since each game state is only ~400 bytes. Yet that does seem to be what's happening, seeing as the activity monitor reports that it is using 3.99GB before it crashes. I'm using http://www.mission-base.com/peter/source/ for the queue structure (it's a linked list). Clearly I'm doing something dumb. Any suggestions?

  Read the article

• Specializating a template function that takes a universal reference parameter

  - by David Stone

  How do I specialize a template function that takes a universal reference parameter? foo.hpp: template<typename T> void foo(T && t) // universal reference parameter foo.cpp template<> void foo<Class>(Class && class) { // do something complicated } Here, Class is no longer a deduced type and thus is Class exactly; it cannot possibly be Class &, so reference collapsing rules will not help me here. I could perhaps create another specialization that takes a Class & parameter (I'm not sure), but that implies duplicating all of the code contained within foo for every possible combination of rvalue / lvalue references for all parameters, which is what universal references are supposed to avoid. Is there some way to accomplish this? To be more specific about my problem in case there is a better way to solve it: I have a program that can connect to multiple game servers, and each server, for the most part, calls everything by the same name. However, they have slightly different versions for a few things. There are a few different categories that these things can be: a move, an item, etc. I have written a generic sort of "move string to move enum" set of functions for internal code to call, and my server interface code has similar functions. However, some servers have their own internal ID that they communicate with, some use strings, and some use both in different situations. Now what I want to do is make this a little more generic. I want to be able to call something like ServerNamespace::server_cast<Destination>(source). This would allow me to cast from a Move to a std::string or ServerMoveID. Internally, I may need to make a copy (or move from) because some servers require that I keep a history of messages sent. Universal references seem to be the obvious solution to this problem. The header file I'm thinking of right now would expose simply this: namespace ServerNamespace { template<typename Destination, typename Source> Destination server_cast(Source && source); } And the implementation file would define all legal conversions as template specializations.

  Read the article

• How do I code a loop for my echo statements?

  - by ggg

  <?php defined('_JEXEC') or die('Restricted access'); $db =& JFactory::getDBO(); $query0 = "SELECT * FROM `#__chesspositions` WHERE . . . . ."; //echo $query0; $db->setQuery($query0); $ginfo = $db->loadObjectList(); //echo $ginfo[0]; echo $db->getErrorMsg(); if(empty($ginfo)){ echo "<center><h2 style='color:navy'>No game found, we apologize</h2></center>"; }else{ $query1= "SELECT * FROM `#__chessmoves` WHERE Id='".$ginfo[0]->MoveDataId."'"; $db->setQuery($query1); echo $db->getErrorMsg(); $gmove = $db->loadObjectList(); } //define array; //how do I code a foreach loop (or any other type of loop) here? //I'm having trouble properly defining the array and structuring the syntax. echo "[Event \"".$ginfo[0]->Event."\"]\n"; echo "[Site \"".$ginfo[0]->Site."\"]\n"; echo "[Date \"".$ginfo[0]->Date."\"]\n"; echo "[Round \"".$ginfo[0]->Round."\"]\n"; echo "[White \"".$ginfo[0]->White."\"]\n"; echo "[Black \"".$ginfo[0]->Black."\"]\n"; echo "[Result \"".$ginfo[0]->Result."\"]\n"; echo "[ECO \"".$ginfo[0]->ECO."\"]\n"; echo "[WhiteElo \"".$ginfo[0]->WhiteElo."\"]\n"; echo "[BlackElo \"".$ginfo[0]->BlackElo."\"]\n"; echo "[Annotator \"".$ginfo[0]->Annotator."\"]\n"; echo "[SetUp \"".$ginfo[0]->SetUp."\"]\n"; echo $gmove[0]->MoveData; ?>

  Read the article

• How to design a data model that deals with (real) contracts?

  - by Geoffrey

  I was looking for some advice on designing a data model for contract administration. The general life cycle of a contract is thus: Contract is created and in a "draft" state. It is viewable internally and changes may be made. Contract goes out to vendor, status is set to "pending" Contract is rejected by vendor. At this state, nothing can be done to the contract. No statuses may be added to the collection. Contract is accepted by vendor. At this state, nothing can be done to the contract. No statuses may be added to the collection. I obviously want to avoid a situation where the contract is accepted and, say, the amount is changed. Here are my classes: [EnforceNoChangesAfterDraftState] public class VendorContract { public virtual Vendor Vendor { get; set; } public virtual decimal Amount { get; set; } public virtual VendorContact VendorContact { get; set; } public virtual string CreatedBy { get; set; } public virtual DateTime CreatedOn { get; set; } public virtual FileStore Contract { get; set; } public virtual IList<VendorContractStatus> ContractStatus { get; set; } } [EnforceCorrectWorkflow] public class VendorContractStatus { public virtual VendorContract VendorContract { get; set; } public virtual FileStore ExecutedDocument { get; set; } public virtual string Status { get; set; } public virtual string Reason { get; set; } public virtual string CreatedBy { get; set; } public virtual DateTime CreatedOn { get; set; } } I've omitted the filestore class, which is basically a key/value lookup to find the document based on its guid. The VendorContractStatus is mapped as a many-to-one in Nhibernate. I then use a custom validator as described here. If anything but draft is returned in the VendorContractStatus collection, no changes are allowed. Furthermore the VendorContractStatus must follow the correct workflow (you can add a rejected after a pending, but you can't add anything else to the collection if a reject or accepted exists, etc.). All sounds alright? Well a colleague has argued that we should simply add an "IsDraft" bool property to VendorContract and not accept updates if IsDraft is false. Then we should setup a method inside of VendorContractStatus for updating the status, if something gets added after a draft, it sets the IsDraft property of VendorContract to false. I do not like this as it feels like I'm dirtying up the POCOs and adding logic that should persist in the validation area, that no rules should really exist in these classes and they shouldn't be aware of their states. Any thoughts on this and what is the better practice from a DDD perspective? From my view, if in the future we want more complex rules, my way will be more maintainable over the long run. Say we have contracts over a certain amount to be approved by a manager. I would think it would be better to have a one-to-one mapping with a VendorContractApproval class, rather than adding IsApproved properties, but that's just speculation. This might be splitting hairs, but this is the first real gritty enterprise software project we've done. Any advice would be appreciated!

  Read the article

• Looking for best practise for writing a serial device communication app in C#

  - by cdotlister

  I am pretty new to serial comms, but would like advise on how to best achieve a robust application which speak to and listens to a serial device. I have managed to make use of System.IO.serialport, and successfully connected to, sent data to and recieved from my device. The way things work is this. My application connects to the Com Port and opens the port.... I then connect my device to the com port, and it detects a connectio to the PC, so sends a bit of text. it's really just copyright info, as well as the version of the firmware. I don't do anything with that, except display it in my 'activity' window. The device then waits. I can then query information, but sending a command such as 'QUERY PARAMETER1'. It then replies with something like: 'QUERY PARAMETER1\r\n\r\n76767\r\n\r\n' I then process that. I can then update it by sending 'SET PARAMETER1 12345', and it will reply with 'QUERY PARAMETER1\r\n\r\n12345\r\n\r\n'. All pretty basic. So, what I have done is created a Communication Class. this call is called in it's own thread, and sends data back to the main form... and also allows me to send messages to it. Sending data is easy. Recieving is a bit more tricky. I have employed the use of the datarecieved event, and when ever data comes in, I echo that to my screen. My problem is this: When I send a command, I feel I am being very dodgy in my handling. What I am doing is, lets say I am sending 'QUERY PARAMETER1'. I send the command to the device, I then put 'PARAMETER1' into a global variable, and I do a Thread.Sleep(100). On the data recieved, I then have a bit of logic that checks the incoming data, and sees if the string CONTAINS the value in the gloabl variable. As the reply may be 'QUERY PARAMETER1\r\n\r\n76767\r\n\r\n', it sees that it contains my parameter, parses the string, and returns the value I am looking for, but placing it into another global variable. My sending method was sleeping for 100ms. It then wakes, and checks the returned global variable. If it has data... then I'm happy, and I process the data. Problem is... if the sleep is too short.. it will fail. And I feel it's flakey.. putting stuff into variables.. then waiting... The other option is to use ReadLine instead, but that's very blocking. So I remove the datarecieved method, and instead... just send the data... then call ReadLine(). That may give me better results. There's no time, except when we connect initially, that data comes from the device, without me requesting it. So, maybe readline will be simpler and safer? Is this known as 'Blocking' reads? Also, can I set a timeout? Hopefully someone can guide me.

  Read the article

• extensible database design: automatic ALTER TABLE or serialize() field BLOB ?

  - by mario

  I want an adaptable database scheme. But still use a simple table data gateway in my application, where I just pass an $data[] array for storing. The basic columns are settled in the initial table scheme. There will however arise a couple of meta fields later (ca 10-20). I want some flexibility there and not adapt the database manually each time, or -worse- change the application logic just because of new fields. So now there are two options which seem workable yet not overkill. But I'm not sure about the scalability or database drawbacks. (1) Automatic ALTER TABLE. Whenever the $data array is to be saved, the keys are compared against the current database columns. New columns get defined before the $data is INSERTed into the table. Actually seems simple enough in test code: function save($data, $table="forum") { // columns if ($new_fields = array_diff(array_keys($data), known_fields($table))) { extend_schema($table, $new_fields, $data); } // save $columns = implode("`, `", array_keys($data)); $qm = str_repeat(",?", count(array_keys($data)) - 1); echo ("INSERT INTO `$table` (`$columns`) VALUES (?$qm);"); function known_fields($table) { return unserialize(@file_get_contents("db:$table")) ?: array("id"); function extend_schema($table, $new_fields, $data) { foreach ($new_fields as $field) { echo("ALTER TABLE `$table` ADD COLUMN `$field` VARCHAR;"); Since it is mostly meta information fields, adding them just as VARCHAR seems sufficient. Nobody will query by them anyway. So the database is really just used as storage here. However, while I might want to add a lot of new $data fields on the go, they will not always be populated. (2) serialize() fields into BLOB. Any new/extraneous meta fields could be opaque to the database. Simply sorting out the virtual fields from the real database columns is simple. And the meta fields can just be serialize()d into a blob/text field then: function ext_save($data, $table="forum") { $db_fields = array("id", "content", "flags", "ext"); // disjoin foreach (array_diff(array_keys($data),$db_fields) as $key) { $data["ext"][$key] = $data[$key]; unset($data[$key]); } $data["ext"] = serialize($data["ext"]); Unserializing and unpacking this 'ext' column on read queries is a minor overhead. The advantage is that there won't be any sparsely filled columns in the database, so I guess it's compacter and faster than the AUTO ALTER TABLE approach. Of course, this method prevents ever using one of the new fields in a WHERE or GROUP BY clause. But I think none of the possible meta fields (user_agent, author_ip, author_img, votes, hits, last_modified, ..) would/should ever be used there anyway. So I currently prefer the 'ext' blob approach, even if it's a one-way ticket. How are such columns called usually? (looking for examples/doc) Would you use XML serialization for (very theoretical) in-database queries? The adapting table scheme seems a "cleaner" interface, even if most columns might remain empty then. How does that impact speed? How many such sparse VARCHAR fields can MySQL/innodb stomach? But most importantly: Is there any standard implementation for this? A pseudo ORM with automatic ALTER TABLE tricks? Storing a simple column list seems workable, but something like pdo::getColumnMeta would be more robust.

  Read the article

• Java: Preventing array going out of bounds.

  - by Troy

  I'm working on a game of checkers, if you want to read more about you can view it here; http://minnie.tuhs.org/I2P/Assessment/assig2.html When I am doing my test to see if the player is able to get to a certain square on the grid (i.e. +1 +1, +1 -1 .etc) from it's current location, I get an java.lang.ArrayIndexOutOfBoundsException error. This is the code I am using to make the move; public static String makeMove(String move, int playerNumber) { // variables to contain the starting and destination coordinates, subtracting 1 to match array size int colStart = move.charAt(1) - FIRSTCOLREF - 1; int rowStart = move.charAt(0) - FIRSTROWREF - 1; int colEnd = move.charAt(4) - FIRSTCOLREF - 1; int rowEnd = move.charAt(3) - FIRSTROWREF - 1; // variable to contain which player is which char player, enemy; if (playerNumber==1) { player= WHITEPIECE; enemy= BLACKPIECE; } else { player= BLACKPIECE; enemy= WHITEPIECE; } // check that the starting square contains a player piece if (grid [ colStart ] [ rowStart ] == player) { // check that the player is making a diagonal move if (grid [ colEnd ] [ rowEnd ] == grid [ (colStart++) ] [ (rowEnd++) ] && grid [ colEnd ] [ rowEnd ] == grid [ (colStart--) ] [ (rowEnd++) ] && grid [ colEnd ] [ rowEnd ] == grid [ (colStart++) ] [ (rowEnd--) ] && grid [ colEnd ] [ rowEnd ] == grid [ (colStart--) ] [ (rowEnd--) ]) { // check that the destination square is free if (grid [ colEnd ] [ rowEnd ] == BLANK) { grid [ colStart ] [ rowStart ] = BLANK; grid [ colEnd ] [ rowEnd ] = player; } } // check if player is jumping over a piece else if (grid [ colEnd ] [ rowEnd ] == grid [ (colStart+2) ] [ (rowEnd+2) ] && grid [ colEnd ] [ rowEnd ] == grid [ (colStart-2) ] [ (rowEnd+2) ] && grid [ colEnd ] [ rowEnd ] == grid [ (colStart+2) ] [ (rowEnd-2) ] && grid [ colEnd ] [ rowEnd ] == grid [ (colStart-2) ] [ (rowEnd-2) ]) { // check that the piece in between contains an enemy if ((grid [ (colStart++) ] [ (rowEnd++) ] == enemy ) && (grid [ (colStart--) ] [ (rowEnd++) ] == enemy ) && (grid [ (colStart++) ] [ (rowEnd--) ] == enemy ) && (grid [ (colStart--) ] [ (rowEnd--) ] == enemy )) { // check that the destination is free if (grid [ colEnd ] [ rowEnd ] == BLANK) { grid [ colStart ] [ rowStart ] = BLANK; grid [ colEnd ] [ rowEnd ] = player; } } } } I'm not sure how I can prevent the error from happening, what do you recommend?

  Read the article

• Primary language - C++/Qt, C#, Java?

  - by Airjoe

  I'm looking for some input, but let me start with a bit of background (for tl;dr skip to end). I'm an IT major with a concentration in networking. While I'm not a CS major nor do I want to program as a vocation, I do consider myself a programmer and do pretty well with the concepts involved. I've been programming since about 6th grade, started out with a proprietary game creation language that made my transition into C++ at college pretty easy. I like to make programs for myself and friends, and have been paid to program for local businesses. A bit about that- I wrote some programs for a couple local businesses in my senior year in high school. I wrote management systems for local shops (inventory, phone/pos orders, timeclock, customer info, and more stuff I can't remember). It definitely turned out to be over my head, as I had never had any formal programming education. It was a great learning experience, but damn was it crappy code. Oh yeah, by the way, it was all vb6. So, I've used vb6 pretty extensively, I've used c++ in my classes (intro to programming up to algorithms), used Java a little bit in another class (had to write a ping client program, pretty easy) and used Java for some simple Project Euler problems to help learn syntax and such when writing the program for the class. I've also used C# a bit for my own simple personal projects (simple programs, one which would just generate an HTTP request on a list of websites and notify if one responded unexpectedly or not at all, and another which just held a list of things to do and periodically reminded me to do them), things I would've written in vb6 a year or two ago. I've just started using Qt C++ for some undergrad research I'm working on. Now I've had some formal education, I [think I] understand organization in programming a lot better (I didn't even use classes in my vb6 programs where I really should have), how it's important to structure code, split into functions where appropriate, document properly, efficiency both in memory and speed, dynamic and modular programming etc. I was looking for some input on which language to pick up as my "primary". As I'm not a "real programmer", it will be mostly hobby projects, but will include some 'real' projects I'm sure. From my perspective: QtC++ and Java are cross platform, which is cool. Java and C# run in a virtual machine, but I'm not sure if that's a big deal (something extra to distribute, possibly a bit slower? I think Qt would require additional distributables too, right?). I don't really know too much more than this, so I appreciate any help, thanks! TL;DR Am an avocational programmer looking for a language, want quick and straight forward development, liked vb6, will be working with database driven GUI apps- should I go with QtC++, Java, C#, or perhaps something else?

  Read the article

• AIDL based two way communication

  - by sshasan

  I have two apps between which I want some data exchanged. As they are running in different processes, so, I am using AIDL to communicate between them. Now, everything is happening really great in one direction (say my apps are A and B) i.e. data is being sent from A to B but, now I need to send some data from B to A. I noticed that we need to include the app with the AIDL in the build path of app where the AIDL method will be called. So in my case A includes B in its build path. For B to be able to send something to A, by that logic, B would need A in its build path. This would create a cycle. I am stuck at this point. And I cannot think of a work around this loop. Any help would be greatly appreciated :) . Thanks! ----EDIT---- So, I following the advice mentioned in one of the comments below, I have the following code In the IPCAIDL project the AIDL file resides, its contents are package ipc.android.aidl; interface Iaidl{ boolean pushBoolean(boolean flag); } This project is being used as a library in both the IPCServer and the IPC Client. The IPCServer Project has the service which defines what happens with the AIDL method. The file is booleanService.java package ipc.android.server; import ipc.android.aidl.Iaidl; import android.app.Service; import android.content.Intent; import android.os.IBinder; import android.os.RemoteException; import android.util.Log; public class booleanService extends Service { @Override public IBinder onBind(Intent intent) { return new Iaidl.Stub() { @Override public boolean pushBoolean(boolean arg0) throws RemoteException { Log.i("SERVER(IPC AIDL)", "Truth Value:"+arg0); return arg0; } }; } } The IPCClient file which calls this method is package ipc.android.client2; import ipc.android.aidl.Iaidl; import android.app.Activity; import android.content.ComponentName; import android.content.Context; import android.content.Intent; import android.content.ServiceConnection; import android.os.Bundle; import android.os.IBinder; import android.os.RemoteException; import android.view.View; import android.widget.Button; public class IPCClient2Activity extends Activity { Button b1; Iaidl iAIDL; boolean k = false; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); bindService(new Intent("ipc.android.server.booleanService"), conn, Context.BIND_AUTO_CREATE); startService(new Intent("ipc.android.server.booleanService")); b1 = (Button) findViewById(R.id.button1); b1.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if(k){ k = false; } else{ k = true; } try { iAIDL.pushBoolean(k); } catch (RemoteException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }); } private ServiceConnection conn = new ServiceConnection() { @Override public void onServiceDisconnected(ComponentName name) { // TODO Auto-generated method stub } @Override public void onServiceConnected(ComponentName name, IBinder service) { iAIDL = Iaidl.Stub.asInterface(service); } }; } The manifest file for IPCServer includes the declaration of the service.

  Read the article

• The best JSF coding pattern for editing JPA entities using @RequestScoped only

  - by AlanObject

  I am in a project where I will write a lot of pages like this, so I want to use the most efficient (to write) coding pattern. Background: In the past I have used CODI's @ViewAccessScoped to preserve state between requests, and more recently I have started using flash scoped objects to save state. I can't use JSF @ViewScoped because I use CDI and they don't play well together. So I want to see if I can do this with only @RequestScoped backing beans. The page is designed like this (the p namespace is Primefaces): <f:metadata> <f:viewParam name="ID" value="#{backing.id}" /> </f:metadata> .... <h1>Edit Object Page</h1> <h:form id="formObj" rendered="#{backing.accessOK}"> <p:panelGrid columns="2"> <h:outputLabel value="Field #1:"/> <p:inputText value="#{backing.record.field1}" /> (more input fields) <h:outputLabel value="Action:" /> <h:panelGroup> <p:commandButton value="Save" action="#{backing.save}" /> <p:commandButton value="Cancel" action="backing.cancel" /> </h:panelGroup> </p:panelGrid> <p:messages showDetail="true" showSummary="true" /> </h:form> If the page is requested, the method accessOK() has the ability to keep the h:form from being rendered. Instead, the p:messages is shown with whatever FacesMessage(s) the accessOK() method cares to set. The pattern for the bean backing looks like this: @Named @RequestScoped public class Backing { private long id; private SomeJPAEntity record; private Boolean accessOK; public long getId() { return id; } public void setId(long value) { id = value; } public boolean accessOK() { if (accessOK != null) return accessOK; if (getRecord() == null) { // add a FacesMessage that explains the record // does not exist return accessOK = false; // note single = } // do any other access checks, such as write permissions return accessOK = true; } public SomeJPAEntity getRecord() { if (record != null) return record; if (getId() > 0) record = // get the record from DB else record = new SomeJPAEntity(); return record; } public String execute() { if (!accessOK()) return null; // bad edit // do other integrity checks here. If fail, set FacesMessages // and return null; if (getId() > 0) // merge the record back into the data base else // persist the record } } Here is what goes wrong with this model. When the Save button is clicked, a new instance of Backing is built, and then there are a lot of calls to the getRecord() getter before the setID() setter is called. So the logic in getRecord() breaks because it cannot rely on the id property being valid when it is called. When this was a @ViewAccessScoped (or ViewScoped) backing bean, then both the id and record properties are already set when the form is processed with the commandButton. Alternatively you can save those properties in flash storage but that has its own problems I want to avoid. So is there a way to make this programming model work within the specification?

  Read the article

• Applying Unity in dynamic menu

  - by Rajarshi

  I was going through Unity 2.0 to check if it has an effective use in our new application. My application is a Windows Forms application and uses a traditional bar menu (at the top), currently. My UIs (Windows Forms) more or less support Dependency Injection pattern since they all work with a class (Presentation Model Class) supplied to them via the constructor. The form then binds to the properties of the supplied P Model class and calls methods on the P Model class to perform its duties. Pretty simple and straightforward. How P Model reacts to the UI actions and responds to them by co-ordinating with the Domain Class (Business Logic/Model) is irrelevant here and thus not mentioned. The object creation sequence to show up one UI from menu then goes like this - Create Business Model instance Create Presentation Model instance with Business Model instance passed to P Model constructor. Create UI instance with Presentation Model instance passed to UI constructor. My present solution: To show an UI in the method above from my menu I would have to refer all assemblies (Business, PModel, UI) from my Menu class. Considering I have split the modules into a number of physical assemblies, that would be a dificult task to add references to about 60 different assemblies. Also the approach is not very scalable since I would certainly need to release more modules and with this approach I would have to change the source code every time I release a new module. So primarily to avoid the reference of so many assemblies from my Menu class (assembly) I did as below - Stored all the dependency described above in a database table (SQL Server), e.g. ModuleShortCode | BModelAssembly | BModelFullTypeName | PModelAssembly | PModelFullTypeName | UIAssembly | UIFullTypeName Now used a static class named "Launcher" with a method "Launch" as below - Launcher.Launch("Discount") Launcher.Launch("Customers") The Launcher internally uses data from the dependency table and uses Activator.CreateInstance() to create each of the objects and uses the instance as constructor parameter to the next object being created, till the UI is built. The UI is then shown as a modal dialog. The code inside Launcher is somewhat like - Form frm = ResolveForm("Discount"); frm.ShowDialog(); The ResolveForm does the trick of building the chain of objects. Can Unity help me here? Now when I did that I did not have enough information on Unity and now that I have studied Unity I think I have been doing more or less the same thing. So I tried to replace my code with Unity. However, as soon as I started I hit a block. If I try to resolve UI forms in my Menu as Form customers = myUnityContainer.Resolve(); or Form customers = myUnityContainer.Resolve(typeof(Customers)); Then either way, I need to refer to my UI assembly from my Menu assembly since the target Type "Customers" need to be known for Unity to resolve it. So I am back to same place since I would have to refer all UI assemblies from the Menu assembly. I understand that with Unity I would have to refer fewer assemblies (only UI assemblies) but those references are needed which defeats my objectives below - Create the chain of objects dynamically without any assembly reference from Menu assembly. This is to avoid Menu source code changing every time I release a new module. My Menu also is built dynamically from a table. Be able to supply new modules just by supplying the new assemblies and inserting the new Dependency row in the table by a database patch. At this stage, I have a feeling that I have to do it the way I was doing, i.e. Activator.CreateInstance() to fulfil all my objectives. I need to verify whether the community thinks the same way as me or have a better suggestion to solve the problem. The post is really long and I sincerely thank you if you come til this point. Waiting for your valuable suggestions. Rajarshi

  Read the article

• How should I handle the case in which a username is already in use?

  - by idealmachine

  I'm a JavaScript programmer and new to PHP and MySQL (want to get into server-side coding). Because I'm trying to learn PHP by building a simple online game (more specifically, correspondence chess), I'm starting by implementing a simple user accounts system. Of course, user registration comes first. What are the best practices for: How I should handle the (likely) possibility that when a user tries to register, the username he has chosen is already in use, particularly when it comes to function return values?($result === true is rather ugly, and I'm not sure whether checking the MySQL error code is the best way to do it either) How to cleanly handle varying page titles?($gPageTitle = '...'; require_once 'bgsheader.php'; is also rather ugly) Anything else I'm doing wrong? In some ways, PHP is rather different from JavaScript... Here is a (rather large) excerpt of the code I have written so far. Note that this is a work in progress and is missing security checks that I will add as my next step. function addUser( $username, $password ) { global $gDB, $gPasswordSalt; $stmt = $gDB->prepare( 'INSERT INTO user(user_name, user_password, user_registration) VALUES(?, ?, NOW())' ); $stmt || trigger_error( 'Failed to prepare statement: ' . htmlspecialchars( $gDB->error ) ); $hashedPassword = hash_hmac( 'sha256', $password, $gPasswordSalt, true ); $stmt->bind_param( 'ss', $username, $hashedPassword ); if( $stmt->execute() ) { return true; } elseif( $stmt->errno == 1062) { return 'exists'; } else { trigger_error( 'Failed to execute statement: ' . htmlspecialchars( $stmt->error ) ); } } $username = $_REQUEST['username']; $password = $_REQUEST['password']; $result = addUser( $username, $password ); if( $result === true ) { $gPageTitle = 'Registration successful'; require_once 'bgsheader.php'; echo '<p>You have successfully registered as ' . htmlspecialchars( $username ) . ' on this site.</p>'; } elseif( $result == 'exists' ) { $gPageTitle = 'Username already taken'; require_once 'bgsheader.php'; echo '<p>Someone is already using the username you have chosen. Please try using another one instead.'; } else { trigger_error('This should never happen'); } require_once 'bgsfooter.php';

  Read the article

• Android Google Analytics

  - by ibenot

  I'm trying to use Google Analytics in my Android application with Google Configuration Add .jar in my project Insert this in AndroidManifest Add this in my java file public class MainActivity extends Activity { GoogleAnalyticsTracker tracker; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); tracker = GoogleAnalyticsTracker.getInstance(); tracker.startNewSession("My-UA–XXXXXXXX", this); setContentView(R.layout.main); Button createEventButton = (Button)findViewById(R.id.NewEventButton); createEventButton.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { tracker.trackEvent( "Clicks", // Category "Button", // Action "clicked", // Label 77); // Value } }); setContentView(R.layout.main); Button createPageButton = (Button)findViewById(R.id.NewPageButton); createPageButton.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // Add a Custom Variable to this pageview, with name of "Medium" and value "MobileApp" and // scope of session-level. tracker.setCustomVar(1, "Navigation Type", "Button click", 2); // Track a page view. This is probably the best way to track which parts of your application // are being used. // E.g. // tracker.trackPageView("/help"); to track someone looking at the help screen. // tracker.trackPageView("/level2"); to track someone reaching level 2 in a game. // tracker.trackPageView("/uploadScreen"); to track someone using an upload screen. tracker.trackPageView("/testApplicationHomeScreen"); } }); Button quitButton = (Button)findViewById(R.id.QuitButton); quitButton.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { finish(); } }); Button dispatchButton = (Button)findViewById(R.id.DispatchButton); dispatchButton.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // Manually start a dispatch, not needed if the tracker was started with a dispatch // interval. tracker.dispatch(); } }); } @Override protected void onDestroy() { super.onDestroy(); // Stop the tracker when it is no longer needed. tracker.stopSession(); } } == And it's ok, no error, compiling and executing but i have created my ua account yesterday (more 24h) and i have nothing in my google analytics panel. My Question : is there an error in my code or i want to wait again ? Live trafic works for Android application (like tradicional website) ??? I have no information about Live trafic (when i play my app, i would like to show the number of person using my application) and Saved trafic (with viewed pages, time) Thank you for your replies and excuse my poor english :) bye

  Read the article

• What are the principles of developing web-applications with action-based java frameworks?

  - by Roman

  Background I'm going to develop a new web-application with java. It's not very big or very complex and I have enough time until it'll "officially" start. I have some JSF/Facelets development background (about half a year). And I also have some expirience with JSP+JSTL. In self-educational purpose (and also in order to find the best solution) I want to prototype the new project with one of action-based frameworks. Actually, I will choose between Spring MVC and Stripes. Problem In order to get correct impression about action-based frameworks (in comparison with JSF) I want to be sure that I use them correctly (in bigger or lesser extent). So, here I list some most-frequent tasks (at least for me) and describe how I solve them with JSF. I want to know how they should be solved with action-based framework (or separately with Spring MVC and Stripes if there is any difference for concrete task). Rendering content: I can apply ready-to-use component from standard jsf libraries (core and html) or from 3rd-party libs (like RichFaces). I can combine simple components and I can easily create my own components which are based on standard components. Rendering data (primitive or reference types) in the correct format: Each component allow to specify a converter for transforming data in both ways (to render and to send to the server). Converter is, as usual, a simple class with 2 small methods. Site navigation: I specify a set of navigation-cases in faces-config.xml. Then I specify action-attribute of a link (or a button) which should match one or more of navigation cases. The best match is choosen by JSF. Implementing flow (multiform wizards for example): I'm using JSF 1.2 so I use Apache Orchestra for the flow (conversation) scope. Form processing: I have a pretty standard java-bean (backing bean in JSF terms) with some scope. I 'map' form fields on this bean properties. If everything goes well (no exceptions and validation is passed) then all these properties are set with values from the form fields. Then I can call one method (specified in button's action attribute) to execute some logic and return string which should much one of my navigation cases to go to the next screen. Forms validation: I can create custom validator (or choose from existing) and add it to almost each component. 3rd-party libraries have sets of custom ajax-validators. Standard validators work only after page is submitted. Actually, I don't like how validation in JSF works. Too much magic there. Many standard components (or maybe all of them) have predefined validation and it's impossible to disable it (Maybe not always, but I met many problems with it). Ajax support: many 3rd-party libraries (MyFaces, IceFaces, OpenFaces, AnotherPrefixFaces...) have strong ajax support and it works pretty well. Until you meet a problem. Too much magic there as well. It's very difficult to make it work if it doesn't work but you've done right as it's described in the manual. User-friendly URLs: people say that there are some libraries for that exist. And it can be done with filters as well. But I've never tried. It seems too complex for the first look. Thanks in advance for explaning how these items (or some of them) can be done with action-based framework.

  Read the article

• many-to-many-to-many, incl alignment of data from diff sources

  - by JefeCoon

  Re-factoring dbase to support many:many:many. At the second and third levels we need to preserve end-user 'mapping' or aligning of data from different sources, e.g. Order 17 FirstpartyOrderID => aha LineItem_for_BigShinyThingy => AA-1 # maps to 77-a LineItem_for_BigShinyThingy => AA-2 # maps to 77-b, 77-c LineItem_for_LittleWidget => AA-x # maps to 77-zulu, 77-alpha, 99-foxtrot LineItem_for_LittleWidget => AA-y # maps to 77-zulu, 99-foxtrot LineItem_for_LittleWidget => AA-z # maps to 77-alpha ThirdpartyOrderID => foo LineItem_for_BigShinyThingy => 77-a LineItem_for_BigShinyThingy => 77-b LineItem_for_BigShinyThingy => 77-c LineItem_for_LittleWidget => 77-zulu LineItem_for_LittleWidget => 77-alpha ThirdpartyOrderID => bar LineItem_for_LittleWidget => 99-foxtrot Each LineItem has daily datapoints reported from its own source (Firstparty|Thirdparty). In our UI & app we provide tools to align these, then we'd like to save them into the cleanest possible schema for querying, enabling us to diff the reported daily datapoints, and perform other daily calculations (which we'll store in the dbase also, fortunately that should be cake once we've nailed this). We need to map related [firstparty|thirdparty]line_items which have their own respective datapoints. We'll be using the association to pull each line_items collection of datapoints for summary and discrepancy calculations. I'm considering two options, std has_many,through x2 --or-- possibly (scary) ubermasterjoin table OptionA: order<<-->> order_join_table[id,order_id,firstparty_order_id,thirdparty_order_id] <<-->>line_item order_join_table[firstparty_order_id]-->raw_order[id] order_join_table[thirdparty_order_id]-->raw_order[id] raw_order-->raw_line_items[raw_order_id] line_item<<-->> line_item_join[id,LI_join_id,firstparty_LI,thirdparty_LI <<-->>raw_line_items line_item_join[firstparty_LI]-->raw_line_item[id] line_item_join[thirdparty_LI]-->raw_line_item[id] raw_line_item<<-->>datapoints = we rely upon join to store all mappings of first|third orders & line_items = keys to raw_* enable lookup of these order & line_item details = concerns about circular references and/or lack of correct mapping logic, e.g order--line_item--raw_line_items vs. order--raw_order--raw_line_items OptionB: order<<-->> join_master[id,order_id,FP_order_id,TP_order_id,FP_line_item_id,TP_line_item_id] join_master[FP_order_id & TP_order_id]-->raw_order[id] join_master[FP_line_item_id & TP_line_item_id]-->raw_line_item[id] = every combo of FP_line_item + TP_line_item writes a record into the join_master table = "theoretically" queries easy/fast/flexible/sexy At long last, my questions: a) any learnings from painful firsthand experience about how best to implement/tune/optimize many-to-many-to-many relationships b) in rails? c) any painful gotchas (circular references, slow queries, spaghetti-monsters) to watch out for? d) any joy & goodness in Rails3 that makes this magically easy & joyful? e) anyone written the "how to do many-to-many-to-many schema in Rails and make it fast & sexy?" tutorial that I somehow haven't found? If not, I'll follow up with our learnings in the hope it's helpful.. Thanks in advance- --Jeff

  Read the article

• Need some help synch'ing outer loop counter with dialog.onconfirm()

  - by Chris Barnhill

  I am writing a game for Facebook. IN the following code, I have a problem. I have a for loop executing, and in that loop, I call a dialog and implement 'onconfirm' for the dialog. The problem is that I need to access th e loop counter inside of the onconfirm function. But because the onconfirm is called outside of the scope of the for loop, the counter value is no longer valid because it's been incremented. I need some way to pass the counter value to the dialog onconfirm as it was at the time the dialog was displayed, not after the loop has finished. Or maybe someone has a better solution. Any help would be appreciated. Thanks. function unloadCargo() { //debugger; var actionPrompt = document.getElementById('action-prompt'); actionPrompt.setTextValue('Unloading cargo...'); var ajax = new Ajax(); ajax.responseType = Ajax.JSON; ajax.ondone = function(data) { debugger; if(data.unloadableCargo.length == 0) { loadCargo(); } else { //console.log('unloadable cargo='+dump(data.unloadableCargo)); var i = 0; var j = 0; var ucCount = data.unloadableCargo.length; for(i = 0; i < ucCount; i++) { cargoDialog = new Dialog(); cargoDialog.showChoice('Unload Cargo', 'Unload ' + data.unloadableCargo[i].goods_name + ' at ' + data.unloadableCargo[i].city_name + ' for ' + data.unloadableCargo[i].payoff + 'M euros?'); cargoDialog.onconfirm = function() { //console.log('unloadable cargo onconfirm='+dump(data.unloadableCargo)); var ajax = new Ajax(); var param = {"city_id": data.unloadableCargo[i].city_id, "goods_id": data.unloadableCargo[i].goods_id, "payoff": data.unloadableCargo[i].payoff}; ajax.ondone = function(demandData) { var demands = document.getElementById('demands'); var innerXhtml = '<span>'; for(var j = 0; j < demandData.demands.length; j++) { innerXhtml = innerXhtml + ' <div class="demand-item"><div class="demand-city">' + demandData.demands[j].city + '</div><div class="demand-pay">' + demandData.demands[j].cost + '</div><div class="demand-goods">' + demandData.demands[j].goods + '</div></div>'; } innerXtml = innerXhtml + ' </span>'; demands.setInnerXHTML(innerXhtml); // update balance loadCargo(); } ajax.post(baseURL + "/turn/do-unload-cargo", param); } cargoDialog.oncancel = function() { loadCargo(); } } //loadCargo(); } } ajax.post(baseURL + '/turn/unload-cargo'); }

  Read the article

• NHibernate: How is identity Id updated when saving a transient instance?

  - by bretddog

  If I use session-per-transaction and call: session.SaveOrUpdate(entity) corrected: session.SaveOrUpdateCopy(entity) ..and entity is a transient instance with identity-Id=0. Shall the above line automatically update the Id of the entity, and make the instance persistent? Or should it do so on transaction.Commit? Or do I have to somehow code that explicitly? Obviously the Id of the database row (new, since transient) is autogenerated and saved as some number, but I'm talking about the actual parameter instance here. Which is the business logic instance. EDIT Mappings: public class StoreMap : ClassMap<Store> { public StoreMap() { Id(x => x.Id).GeneratedBy.Identity(); Map(x => x.Name); HasMany(x => x.Staff) // 1:m .Cascade.All(); HasManyToMany(x => x.Products) // m:m .Cascade.All() .Table("StoreProduct"); } } public class EmployeeMap : ClassMap<Employee> { public EmployeeMap() { Id(x => x.Id).GeneratedBy.Identity(); Map(x => x.FirstName); Map(x => x.LastName); References(x => x.Store); // m:1 } } public class ProductMap : ClassMap<Product> { public ProductMap() { Id(x => x.Id).GeneratedBy.Identity(); Map(x => x.Name).Length(20); Map(x => x.Price).CustomSqlType("decimal").Precision(9).Scale(2); HasManyToMany(x => x.StoresStockedIn) .Cascade.All() .Inverse() .Table("StoreProduct"); } } EDIT2 Class definitions: public class Store { public int Id { get; private set; } public string Name { get; set; } public IList<Product> Products { get; set; } public IList<Employee> Staff { get; set; } public Store() { Products = new List<Product>(); Staff = new List<Employee>(); } // AddProduct & AddEmployee is required. "NH needs you to set both sides before // it will save correctly" public void AddProduct(Product product) { product.StoresStockedIn.Add(this); Products.Add(product); } public void AddEmployee(Employee employee) { employee.Store = this; Staff.Add(employee); } } public class Employee { public int Id { get; private set; } public string FirstName { get; set; } public string LastName { get; set; } public Store Store { get; set; } } public class Product { public int Id { get; private set; } public string Name { get; set; } public decimal Price { get; set; } public IList<Store> StoresStockedIn { get; private set; } }

  Read the article

< Previous Page | 633 634 635 636 637 638 639 640 641 642 643 644  | Next Page >