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• Help Me With This Access Query

  - by yae

  I have 2 tables: "products" and "pieces" PRODUCTS idProd product price PIECES id idProdMain idProdChild quant idProdMain and idProdChild are related with the table: "products". Other considerations is that 1 product can have some pieces and 1 product can be a piece. Price product equal a sum of quantity * price of all their pieces. "Products" table contains all products (p EXAMPLE: TABLE PRODUCTS (idProd - product - price) 1 - Computer - 300€ 2 - Hard Disk - 100€ 3 - Memory - 50€ 4 - Main Board - 100€ 5 - Software - 50€ 6 - CDroms 100 un. - 30€ TABLE PIECES (id - idProdMain - idProdChild - Quant.) 1 - 1 - 2 - 1 2 - 1 - 3 - 2 3 - 1 - 4 - 1 WHAT I NEED? I need update the price of the main product when the price of the product child (piece) is changed. Following the previous example, if I change the price of this product "memory" (is a piece too) to 60€, then product "Computer" will must change his price to 320€ How I can do it using queries? Already I have tried this to obatin the price of the main product, but not runs. This query not returns any value: SELECT Sum(products.price*pieces.quant) AS Expr1 FROM products LEFT JOIN pieces ON (products.idProd = pieces.idProdChild) AND (products.idProd = pieces.idProdChild) AND (products.idProd = pieces.idProdMain) WHERE (((pieces.idProdMain)=5)); MORE INFO The table "products" contains all the products to sell that it is in the shop. The table "pieces" is to take a control of the compound products. To know those who are the products children. For example of compound product: computers. This product is composed by other products (motherboard, hard disk, memory, cpu, etc.)

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• Creating a smart text generator

  - by royrules22

  I'm doing this for fun (or as 4chan says "for teh lolz") and if I learn something on the way all the better. I took an AI course almost 2 years ago now and I really enjoyed it but I managed to forget everything so this is a way to refresh that. Anyway I want to be able to generate text given a set of inputs. Basically this will read forum inputs (or maybe Twitter tweets) and then generate a comment based on the learning. Now the simplest way would be to use a Markov Chain Text Generator but I want something a little bit more complex than that as the MKC basically only learns by word order (which word is more likely to appear after word x given the input text). I'm trying to see if there's something I can do to make it a little bit more smarter. For example I want it to do something like this: Learn from a large selection of posts in a message board but don't weight it too much For each post: Learn from the other comments in that post and weigh these inputs higher Generate comment and post See what other users' reaction to your post was. If good weigh it positively so you make more posts that are similar to the one made, and vice versa if negative. It's the weighing and learning from mistakes part that I'm not sure how to implement. I thought about Artificial Neural Networks (mainly because I remember enjoying that chapter) but as far as I can tell that's mainly used to classify things (i.e. given a finite set of choices [x1...xn] which x is this given input) not really generate anything. I'm not even sure if this is possible or if it is what should I go about learning/figuring out. What algorithm is best suited for this? To those worried that I will use this as a bot to spam or provide bad answers to SO, I promise that I will not use this to provide (bad) advice or to spam for profit. I definitely will not post it's nonsensical thoughts on SO. I plan to use it for my own amusement. Thanks!

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• backbone.js removing template from DOM upon success

  - by timpone

  I'm writing a simple message board app to learn backbone. It's going ok (a lot of the use of this isn't making sense) but am a little stuck in terms of how I would remove a form / html from the dom. I have included most of the code but you can see about 4 lines up from the bottom, the part that isn't working. How would I remove this from the DOM? thx in advance var MbForm=Backbone.View.extend({ events: { 'click button.add-new-post': 'savePost' }, el: $('#detail'), template:_.template($('#post-add-edit-tmpl').html()), render: function(){ var compiled_template = this.template(); this.$el.html(compiled_template); return this; }, savePost: function(e){ //var self=this; //console.log("I want you to say Hello!"); data={ header: $('#post_header').val(), detail: $('#post_detail').val(), forum_id: $('#forum_id').val(), post_id: $('#post_id').val(), parent_id: $('#parent_id').val() }; this.model.save(data, { success: function(){ alert('this saved'); //$(this.el).html('this is what i want'); this.$el.remove();// <- this is the part that isn't working /* none of these worked - error Uncaught TypeError: Cannot call method 'unbind' of undefined this.$el.unbind(); this.$el.empty(); this.el.unbind(); this.el.empty(); */ //this.unbind(); //self.append('this is appended'); } });

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• How to have current page selection using inludes navigation

  - by Anders Kitson

  I am using php includes to limit redundancy on my pages, how can I have my navigation have the current page selected with say a certain color for the HOME button when my navigation is called from a header.php file. If i were to say to add a "active" class to the home.php item and add a style so it looked different, that would happen across the board for all my pages, which is why I am using includes in the first place, how can I have one header.php file with my navigation, that also allows each page the ability to show the current page you are on reflected in the navigation? This is the nav portion of the header.php file <ul> <li><a href="index.php">About Us</a></li> <li><a href="portfolio.php">Portfolio</a></li> <li><a href="news.php">News</a></li> <li><a href="contact.php">Contact</a></li> </ul> This is the index.php file that the header.php file is included in <?php include("includes/header.php"); ?> <div class="span-8" id="welcome"> <p>Lorem ipsum</p> </div> <div class="span-16 last" id="slideshow"> <img src="images/introImage1.png" alt="fountain"> <img src="images/introImage2.png" alt="bench"> <img src="images/introImage3.png" alt="bridge"> </div> <?php include("includes/footer.php"); ?>

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• Idea for a small project, should I use Python?

  - by Robb

  I have a project idea, but unsure if using Python would be a good idea. Firstly, I'm a C++ and C# developer with some SQL experience. My day job is C++. I have a project idea i'd like to create and was considering developing it in a language I don't know. Python seems to be popular and has piqued my interests. I definitely use OOP in programming and I understand Python would work fine with that style. I could be way off on this, I've only read small bits and pieces about the language. The project won't be public or anything, just purely something of my own creation do dabble in at home. So the project would essentially represent a simple game idea I have. The game would consist roughly these things: Data structures to hold specific information (would be strongly typed). A way to output the gamestate for the players. This is completely up in the air, it can be graphical or text based, I don't really care at this point. A way to save off game data for the players in something like a database or file system. A relatively easy way for me to input information and a 'GO' button which processes the changes and obviously creates a new gamestate. The game would function similar to a board game. Really nothing out of the ordinary when I look back at that list. Would this be a fun way to learn Python or should I select another language?

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• Dynamically adding controls from an Event after Page_Init

  - by GenericTypeTea

  Might seem like a daft title as you shouldn't add dynamic controls after Page_Init if you want to maintain ViewState, but I couldn't think of a better way of explaining the problem. I have a class similar to the following: public class WebCustomForm : WebControl, IScriptControl { internal CustomRender Content { get { object content = this.Page.Session[this.SESSION_CONTENT_TRACKER]; return content as CustomRender; } private set { this.Page.Session[this.SESSION_CONTENT_TRACKER] = value; } } } CustomRender is an abstract class that implements ITemplate that I use to self-contain a CustomForms module I'm in the middle of writing. On the Page_Init of the page that holds the WebCustomForm, I Initialise the control by passing the relevant Ids to it. Then on the overridden OnInit method of the WebCustomForm I call the Instantiate the CustomRender control that's currently active: if (this.Content != null) { this.Content.InstantiateIn(this); } The problem is that my CustomRender controls need the ability to change the CustomRender control of the WebCustomForm. But when the events that fire on the CustomRender fire, the Page_Init event has obviously already gone off. So, my question is, how can I change the content of the WebCustomForm from a dynamically added control within it? The way I see it, I have two options: I separate the CustomRender controls out into their own stand alone control and basically have an aspx page per control and handle the events myself on the page (although I was hoping to just make a control I drop on the page and forget about) I don't use events and just keep requesting the current page, but with different Request Parameters Or I go back to the drawing board with any better suggetions anyone can give me.

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• non static method cannot be referenced from a static context.

  - by David

  First some code: import java.util.*; ... class TicTacToe { ... public static void main (String[]arg) { Random Random = new Random() ; toerunner () ; // this leads to a path of methods that eventualy gets us to the rest of the code } ... public void CompTurn (int type, boolean debug) { ... boolean done = true ; int a = 0 ; while (!done) { a = Random.nextInt(10) ; if (debug) { int i = 0 ; while (i<20) { System.out.print (a+", ") ; i++; }} if (possibles[a]==1) done = true ; } this.board[a] = 2 ; } ... } //to close the class Here is the error message: TicTacToe.java:85: non-static method nextInt(int) cannot be referenced from a static context a = Random.nextInt(10) ; ^ What exactly went wrong? What does that error message "non static method cannot be referenced from a static context" mean?

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• What is your favorite API developer community site? And why? [closed]

  - by whatupwilly

  There are a lot of great sites out there that offer good documentation, tools, tips, best-practices, sample code, etc. for the API's they are publishing. A sample: http://apiwiki.twitter.com http://developer.netflix.com/ http://developers.facebook.com/ https://affiliate-program.amazon.com/gp/advertising/api/detail/main.html http://code.google.com/ http://remix.bestbuy.com/ http://www.flickr.com/services/api/misc.overview.html http://products.wolframalpha.com/api/webserviceapi.html There are some no-brainers that I think a good developer site should have: Hi level introduction Quick start guide API specific details - showing example request and responses Links to sample code and/or 3rd party libraries Developer registration (e.g. get an API key) Blog But what about some other things: Online-Forum or Msg Board vs. Google Group (or similar) Galleries/ShowCases - spotlighting great apps built on the API - who has done nice galleries? Community Wiki - How do people feel about letting the community have edit rights on API documentation pages Online testing tools (like Facebook has a lot of nice interactive tools to simulate request/responses) What are some packages that you would recommend to put this all together: pbwiki Google Group pages MediaWiki API vendor package such as Sonoa Systems that offers a customizable developer portal So, to summarize: What are some other great API developer portals out there What are some nice features you like on them Any recommendations on what to use to build these features out Thanks, Will Zappos.com Public API (soon to launch) Product Manager

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• Created files on Archos 5 invisible on Windows Xp

  - by user352042

  I am fairly new to Android and this is my first post so I apologise in advance if I am breaking protocol or posting to the wrong board. Please feel free to move this post to somewhere more appropriate if required. I am developing for the 160 Gb Archos 5 Internet tablet. Not ideal as a development platform I know, but customer requirements mean we have no choice. It is running Android 1.6. I have updated the device firmware to the most recent available. Updating the version of Android is not an option at this point. Part of my app's requirement is to write information out to .txt files on the external storage directory so that these can be copied over the USB connection to a Windows XP PC using the Mobile media device (MTP) mode. I have followed all instructions I have come across carefully, eg I check that the storage is available using the technique described at http://developer.android.com/guide/topics/data/data-storage.html#filesExternal. However, althoug the files are created succesfully on the device (I can browse them and open them using the device's File Explorer - they are fine), when I connect the device to a Windows XP computer none of the directories or files I created appear and the size of their parent files suggest they do not exist. I have tried running over the ADB, checked logcat, tried a (signed) release version and even written a second test application which just creates a folder (this behaves the same, ie it creates the folder but this is not visible in Windows Explorer) - nothing anywhere gives me any suggestion as to what the problem might be. If anyone has heard of this before or has any ideas as to what else | could try to fix it please get in touch! We do not have any other devices to test on at the moment, although I hope to remedy this soon, customer permitting.

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• Why ntp settle time toe long?

  - by fercis

  I simply try to set-up NTP to my system. Both server and clients will run on my computer which are linked together with local link. One of them will have the reference clock. Both the server and Client are linux Ubuntu. I install ntp daemon to both sides. In clients, I enter the ip address of the server to /etc/ntp.conf. Everything works fine. However, the setting of the time to correct time in client side takes too long time (around 17 minutes). Is it possible to gather correct time just at startup. I write some code that regularly calls "ntpdate " by system call and the problem is solved but there has to be something that allows me to decrease the poll time of the client to 1-2 minutes. There are some settings as maxpoll - minpoll in ntp.conf, but I couldn't manage to understand their function, because with the best configuration (minpoll 4? 16 seconds?) I also cannot see that client side corrects its time before 10 minutes. In addition, in some cases my client is an embedded system (ARM - IGEP board) and it always opens with an irrelevant date (2-3 years ago). So the time that takes to correct the time should not depend on the time difference also.

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• Java - How to declare table[i][j] elements as instance variables?

  - by JDelage

  All, I am trying to code a Connect4 game. For this, I have created a P4Game class and a P4Board class which represents the i X j dimensions of the Connect4 board. In P4Game, I have the following: public class P4Game{ //INSTANCE VARIABLES private int nbLines; private int nbColumns; private P4Board [][] position; //CONSTRUCTOR public P4Game(int nbLines, int nbColumns){ this.nbColumns = nbColumns; this.nbLines = nbLines; P4Board [][] position = new P4Board [nbLines][nbColumns]; //Creates the table to receive the instances of the P4Board object.*/ for (int i=0; i<nbLines; i++){ for (int j=0; j<nbColumns; j++){ this.position[i][j] = new P4Board(i,j); //Meant to create each object at (line=i, column=j) } } } This causes a NullPointerException in the nested loops where I mention this.position[i][j]. I reference those objects in other methods of this class so I need them to be instance variables. I suppose the exception is due to the fact that I have not listed the table element position[i][j] as an instance variable at the beginning of the class. my question to people here is (1) is my assumption correct, and if so (2) what would be the syntax to declare instance variables of this form? Thank you all for your help with what I realize is a very basic question. Hopefully it will also benefit other newbies. Cheers, JDelage

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• MouseMotion Sensor Method Call

  - by user321894

  I have a soon-to-be due assignment due in computer science. I have encountered a problem, for which no matter how long I study the API's of the class and superclasses, I can not figure out. Suppose I wish to design a sort of "Breakout game" where the mouse motion controls the motion of a block that is used to bounce a ball, which then destroys multi colored bricks. How do you specifically make the block "listen" to the mouse? The below code is what I have attempted to achieve the desired results. /** Breakout Program*/ public class Breakout extends GraphicsProgram implements MouseMotionListener { ... /** The Paddle Itself */ private GRect paddle = new GRect(0, HEIGHT-PADDLEBOTTOM_OFFSET, PADDLEWIDTH, PADDLEHEIGHT); ... /** Run the Breakout program. */ public void run() { paddle.setFillColor(Color.BLACK); paddle.setFilled(true); add(paddle); paddle.addMouseListener(this); ... } /** Move the horizontal middle of the paddle to the x-coordinate of the mouse position - * -but keep the paddle completely on the board. */ public void mouseMoved(MouseEvent e) { GPoint p= new GPoint(e.getPoint()); double x = p.getX(); paddle.setLocation(x, HEIGHT-PADDLEBOTTOM_OFFSET); } } Any clarification on why/what I am doing incorrectly would be helpful, thanks.

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• Easiest way to programmatically create email accounts for use by web app?

  - by cadwag

  I have a web app that create groups. Each group gets their own discussion board. I would like to add the feature of allowing users to send emails to their "group" within the web app to start a new discussion or reply to an email from the "group" to make a new post in an already ongoing discussion. For example, to start a new discussion a user would send: From: [email protected] To: [email protected] Subject: Hey guys! Meet up on Tuesday? Body: Yes? No? All members of the group would receive an email: From: [email protected] Subject: Hey guys! Meet up on Tuesday? Body: Yes? No? Reply-To: group1@ example.com And, the app would start a new discussion with: Author: Bill Fake Subject: Hey guys! Meet up on Tuesday? Body: Yes? No? This is a pretty standard feature for Google Groups and other big sites. So how do us mere mortals go about implementing this? Is there an easy way? Or do I: 1. Install postfix 2. Write scripts to create new accounts for each new group 3. Access the server periodically via pop3 (or imap?) to retrieve the email messages sent to each account? 4. Parse the message for content If it's the latter, did I miss a step?

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• Adding <tr> from repeater's ItemDataBound Event

  - by nemiss

  My repeater's templates generate a table, where each item is a table row. When a very very specific condition is met (itemdata), I want to add an additional row to the table from this event. How can I do that? protected void rptData_ItemDataBound(object sender, RepeaterItemEventArgs e) { if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem) { bool tmp = bool.Parse(DataBinder.Eval(e.Item.DataItem, "somedata").ToString()); if (!tmp && e.Item.ItemIndex != 0) { //Add row after this item } } } I can use e.Item.Controls.Add() and add TableRow but for that I need to locate a table right? How can I solve that? UPDATE I will explain now why I need this: I am creating a sort of message board, where data entries are displayed in a tabled style. The first items in the table are "important" items after those items, i want to add this row. I could solved it using 2 repeaters, where the first repeater will be bounded to pinned items, and the second repeater will be bounded to refular items. But I don't want to have to repeaters nor I want to complex the business logic for separating the fetched data to pinned and not-pinned collection. I think the best opton is to do it "onfly", using one repeater and one datasource.

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• LINQ to Entities question about orderby and null collections.

  - by Chevex

  I am currently developing a forum. I am new to LINQ and EF. In my forum I have a display that shows a list of topics with the most recent topics first. The problem is that "most recent" is relative to the topic's replies. So I don't want to order the list by the topic's posted date, rather I want to order the list by the topic's last reply's posted date. So that topics with newer replies pop back to the top of the list. This is rather simple if I knew that every topic had at least one reply; I would just do this: var topicsQuery = from x in board.Topics orderby x.Replies.Last().PostedDate descending select x; However, in many cases the topic has no replies. In which case I would like to use the topic's posted date instead. Is there a way within my linq query to order by x.PostedDate in the event that the topic has no replies? I'm getting confused by this and any help would be appreciated. With the above query, it breaks on topics with no replies because of the x.Replies.Last() which assumes there are replies. LastOrDefault() doesn't work because I need to access the PostedDate property which also assumes a reply exists. Thanks in advance for any insight.

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• How to find an embedded platform?

  - by gmagana

  I am new to the locating hardware side of embedded programming and so after being completely overwhelmed with all the choices out there (pc104, custom boards, a zillion option for each board, volume discounts, devel kits, ahhh!!) I am asking here for some direction. Basically, I must find a new motherboard and (most likely) re-implement the program logic. Rewriting this in C/C++/Java/C#/Pascal/BASIC is not a problem for me. so my real problem is finding the hardware. This motherboard will have several other devices attached to it. Here is a summary of what I need to do: Required: 2 RS232 serial ports (one used all the time for primary UI, the second one not continuous) 1 modem (9600+ baud ok) [Modem will be in simultaneous use with only one of the serial port devices, so interrupt sharing with one serial port is OK, but not both] Minimum permanent/long term storage: Whatever O/S requires + 1 MB (executable) + 512 KB (Data files) RAM: Minimal, whatever the O/S requires plus maybe 1MB for executable. Nice to have: USB port(s) Ethernet network port Wireless network Implementation languages (any O/S I will adapt to): First choice Java/C# (Mono ok) Second choice is C/Pascal Third is BASIC Ok, given all this, I am having a lot of trouble finding hardware that will support this that is low in cost. Every manufacturer site I visit has a lot of options, and it's difficult to see if their offering will even satisfy my must-have requirements (for example they sometimes list 3 "serial ports", but it appears that only one of the three is RS232, for example, and don't mention what the other two are). The #1 constraint is cost, #2 is size. Can anyone help me with this? This little task has left me thinking I should have gone for EE and not CS :-). EDIT: A bit of background: This is a system currently in production, but the original programmer passed away, and the current hardware manufacturer cannot find hardware to run the (currently) DOS system, so I need to reimplement this in a modern platform. I can only change the programming and the motherboard hardware.

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• Bitwise operators and converting an int to 2 bytes and back again.

  - by aKiwi

  first time user, Hi guys! So hopefully someone can help.. My background is php so entering the word of lowend stuff like, char is bytes, which are bits.. which is binary values.. etc is taking some time to get the hang of ;) What im trying to do here is sent some values from an Ardunio board to openFrameWorks (both are c++). What this script currently does (and works well for one sensor i might add) when asked for the data to be sent is.. int value_01 = analogRead(0); // which outputs between 0-1024 unsigned char val1; unsigned char val2; //some Complicated bitshift operation val1 = value_01 &0xFF; val2 = (value_01 >> 8) &0xFF; //send both bytes Serial.print(val1, BYTE); Serial.print(val2, BYTE); Apparently this is the most reliable way of getting the data across.. So now that it is send via serial port, the bytes are added to a char string and converted back by.. int num = ( (unsigned char)bytesReadString[1] << 8 | (unsigned char)bytesReadString[0] ); So to recap, im trying to get 4 sensors worth of data (which im assuming will be 8 of those serialprints?) and to have int num_01 - num_04... at the end of it all. Im assuming this (as with most things) might be quite easy for someone with experience in these concepts.. Any help would be greatly appreciated. Thanks

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• Memeory Leak in Windows Page file when calling a shell command

  - by Arno

  I have an issue on our Windows 2003 x64 Build Server when invoking shell commands from a script. Each call causes a "memory leak" in the page file so it grows quite rapidly until it reaches the maximum and the machine stops working. I can reproduce the problem very nicely by running a perl script like for ($count=1; $count<5000; $count++) { system "echo huhu"; } It is independent of he scripting language as the same happens with lua: for i=1,5000 do os.execute("echo huhu") end I found somebody describing the same issue with php at http://www.issociate.de/board/post/454835/Memory_leak_occurs_when_exec%28%29_function_is_used_on_Windows_platform.html His solution: Firewall/Virus Scanner does not apply, neither are running on the machine. We can also reproduce the issue on other Developer Machines running XP 64, but not on XP 32 Bit. I also found an article describing a leak situation in page file at http://www.programfragment.com/ The guilty guy for the allocation is C:\WINDOWS\System32\svchost.exe -k netsvcs which runs all the basic Windows services. Does anybody know the issue and how to resolve it ?

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• UITableView UITableViewCell dynamic UILabel Height storyboard

  - by Mikel Nelson

  This isn'an a question, just a results log on an issue I had with XCode 4.5 storyboards and dynamic height UITableCell with a UILabel. The issue was; the initial display of a cell would only show part of the resized UILabel contents, and that the visual UILabel was not resized. It would only display correctly after scrolling off the top of the Table and back down. I did the calculations in hieghtForRowAtIndexPath and sizeToFit the UILabel in rowAtIndexPath. The sizes where coming up ok in debug, but the device was not updating the display with the correct size and UILable.text value. I had created the dynamic UITableCell in a storyboard. However, I had set the width and height to a nominal value (290x44). It turns out, this was causing my issues. I set the width and height to zero (0) in the story board, and everything started working correctly. (i.e. the UILabels displayed at the correct size with full content). I was unable to find anything online on this issue, except for some references to creating the custom table cell with a frame of zero. Turns out, that was really the answer (for me).

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• Java website protection solutions (especially XSS)

  - by Mark

  I'm developing a web application, and facing some security problems. In my app users can send messages and see other's (a bulletin board like app). I'm validating all the form fields that users can send to my app. There are some very easy fields, like "nick name", that can be 6-10 alpabetical characters, or message sending time, which is sended to the users as a string, and then (when users ask for messages, that are "younger" or "older" than a date) I parse this with SimpleDateFormat (I'm developing in java, but my question is not related to only java). The big problem is the message field. I can't restrict it to only alphabetical characters (upper or lowercase), because I have to deal with some often use characters like ",',/,{,} etc... (users would not be satisfied if the system didn't allow them to use these stuff) According to this http://ha.ckers.org/xss.html, there are a lot of ways people can "hack" my site. But I'm wondering, is there any way I can do to prevent that? Not all, because there is no 100% protection, but I'd like a solution that can protect my site. I'm using servlets on the server side, and jQuery, on the client side. My app is "full" AJAX, so users open 1 JSP, then all the data is downloaded and rendered by jQuery using JSON. (yeah, I know it's not "users-without-javascript" friendly, but it's 2010, right? :-) ) I know front end validation is not enough. I'd like to use 3 layer validation: - 1. front end, javascript validate the data, then send to the server - 2. server side, the same validation, if there is anything, that shouldn't be there (because of client side javascript), I BAN the user - 3. if there is anything that I wasn't able to catch earlier, the rendering process handle and render appropriately Is there any "out of the box" solution, especially for java? Or other solution that I can use?

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• Searching in graphs trees with Depth/Breadth first/A* algorithms

  - by devoured elysium

  I have a couple of questions about searching in graphs/trees: Let's assume I have an empty chess board and I want to move a pawn around from point A to B. A. When using depth first search or breadth first search must we use open and closed lists ? This is, a list that has all the elements to check, and other with all other elements that were already checked? Is it even possible to do it without having those lists? What about A*, does it need it? B. When using lists, after having found a solution, how can you get the sequence of states from A to B? I assume when you have items in the open and closed list, instead of just having the (x, y) states, you have an "extended state" formed with (x, y, parent_of_this_node) ? C. State A has 4 possible moves (right, left, up, down). If I do as first move left, should I let it in the next state come back to the original state? This, is, do the "right" move? If not, must I transverse the search tree every time to check which states I've been to? D. When I see a state in the tree where I've already been, should I just ignore it, as I know it's a dead end? I guess to do this I'd have to always keep the list of visited states, right? E. Is there any difference between search trees and graphs? Are they just different ways to look at the same thing?

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• Trouble decoding JSON string with PHP

  - by Anthony

  I'm trying to send an array of objects from JS to PHP using JSON. I have an array of players as follows: var player; var players = new Array(); //loop for number of players player = new Object(); player.id = theID; players[i] = player; Then my AJAX call looks like this: JSONplayers = JSON.stringify(players); $.ajax({ type: "POST", url: "php/ajax_send_players.php", data: { "players" : JSONplayers } On the PHP side the decode function looks like this $players = $_REQUEST['players']; echo var_dump($players); $players = json_decode($players); echo 'players: ' .$players. '--'. $players[0] . '--'. $players[0]->id; Debugging in chrome, the JSON players var looks like this before it is sent: JSONplayers: "[{"id":"Percipient"},{"id":"4"}]" And when I vardump in PHP it looks OK, giving this: string(40) "[{\"id\":\"Percipient\"},{\"id\":\"4\"}]" But I can't access the PHP array, and the echo statement about starting with players: outputs this: players: ---- Nothing across the board...maybe it has something to do with the \'s in the array, I am new to this and might be missing something very simple. Any help would be greatly appreciated. note I've also tried json_decode($players, true) to get it as an assoc array but get similar results.

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• What are possible/good ways to prototype iPhone applications?

  - by Ted Johnson

  This is intentionally left broad. If you wanted to show users what iPhone/mobile applications could to for them. The more interactive the better, but it must be quick to build as you can't code up every idea. Let us assume real-time games are out of scope. Throw out ideas or state which approach would be best. Here are some of my ideas, what are yours? Hack a app that loads mostly web or image content, but has hyperlinks to get around in. This would mean static data. Build screens which look great but can only be navigated in a story board type fashion. Load the web version or equivalent on the iPhone and say: now image the buttons and navigation is better. A paper based prototype. Flash or video walk through running on the phone. String existing iPhone apps and web pages together with minimal glue just to convey the idea. Can anyone share prototyping methods for other mobile devices? Ex: The palm prototype was just a block of wood and note pad that was carried around.

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• Best solution for an StringToInt function in C#

  - by StefanE

  Hi, I were asked to do an StringToInt / Int.parse function on the white board in an job interview last week and did not perform very good but I came up with some sort of solution. Later when back home I made one in Visual Studion and I wonder if there are any better solution than mine below. Have not bothred with any more error handling except checking that the string only contains digits. private int StrToInt(string tmpString) { int tmpResult = 0; System.Text.Encoding ascii = System.Text.Encoding.ASCII; byte[] tmpByte = ascii.GetBytes(tmpString); for (int i = 0; i <= tmpString.Length-1; i++) { // Check whatever the Character is an valid digit if (tmpByte[i] > 47 && tmpByte[i] <= 58) // Here I'm using the lenght-1 of the string to set the power and multiply this to the value tmpResult += (tmpByte[i] - 48) * ((int)Math.Pow(10, (tmpString.Length-i)-1)); else throw new Exception("Non valid character in string"); } return tmpResult; }

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• Processing velocity-vectors during collision as neatly as possible

  - by DevEight

  Hello. I'm trying to create a good way to handle all possible collisions between two objects. Typically one will be moving and hitting the other, and should then "bounce" away. What I've done so far (I'm creating a typical game where you have a board and bounce a ball at bricks) is to check if the rectangles intersect and if they do, invert the Y-velocity. This is a really ugly and temporary solution that won't work in the long haul and since this is kind of processing is very common in games I'd really like to find a great way of doing this for future projects aswell. Any links or helpful info is appreciated. Below is what my collision-handling function looks like right now. protected void collision() { #region Boundaries if (bal.position.X + bal.velocity.X >= viewportRect.Width || bal.position.X + bal.velocity.X <= 0) { bal.velocity.X *= -1; } if (bal.position.Y + bal.velocity.Y <= 0) { bal.velocity.Y *= -1; } #endregion bal.rect = new Rectangle((int)bal.position.X+(int)bal.velocity.X-bal.sprite.Width/2, (int)bal.position.Y-bal.sprite.Height/2+(int)bal.velocity.Y, bal.sprite.Width, bal.sprite.Height); player.rect = new Rectangle((int)player.position.X-player.sprite.Width/2, (int)player.position.Y-player.sprite.Height/2, player.sprite.Width, player.sprite.Height); if (bal.rect.Intersects(player.rect)) { bal.position.Y = player.position.Y - player.sprite.Height / 2 - bal.sprite.Height / 2; if (player.position.X != player.prevPos.X) { bal.velocity.X -= (player.prevPos.X - player.position.X) / 2; } bal.velocity.Y *= -1; } foreach (Brick b in brickArray.list) { b.rect.X = Convert.ToInt32(b.position.X-b.sprite.Width/2); b.rect.Y = Convert.ToInt32(b.position.Y-b.sprite.Height/2); if (bal.rect.Intersects(b.rect)) { b.recieveHit(); bal.velocity.Y *= -1; } } brickArray.removeDead(); }

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