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  • Django extending user model and displaying form

    - by MichalKlich
    Hello, I am writing website and i`d like to implement profile managment. Basic thing would be to edit some of user details by themself, like first and last name etc. Now, i had to extend User model to add my own stuff, and email address. I am having troubles with displaying form. Example will describe better what i would like achieve. This is mine extended user model. class UserExtended(models.Model): user = models.ForeignKey(User, unique=True) kod_pocztowy = models.CharField(max_length=6,blank=True) email = models.EmailField() This is how my form looks like. class UserCreationFormExtended(UserCreationForm): def __init__(self, *args, **kwargs): super(UserCreationFormExtended, self).__init__(*args, **kwargs) self.fields['email'].required = True self.fields['first_name'].required = False self.fields['last_name'].required = False class Meta: model = User fields = ('username', 'first_name', 'last_name', 'email') It works fine when registering, as i need allow users to put username and email but when it goes to editing profile it displays too many fields. I would not like them to be able to edit username and email. How could i disable fields in form? Thanks for help.

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  • Tool to migrate a repo with only read access?

    - by Corazu
    I have a subversion repository located on our school servers from a project my friends and I worked on the past semester. We want to take the project and polish it and make it more of a portfolio item and I'm not quite sure that the repo will stay intact on the school servers (they usually wipe it after a few semesters). I don't have access to dump the repo, although I've sent an email to see if I can get one - which would be the best solution. I tried svnsync but the school server doesn't support the replay command (probably turned off), so that won't work for me. Now, theoretically, wouldn't it be possible to (manually or programmatically) checkout each revision of the repository and check it in to a new repository on our own server? I think it would work - there's only 3 of us, and there's no working copy conflicts that we'd have to worry about, just want a copy of all the history in the repo in case we need to go back and look at it. That being said, before I go and reinvent a wheel by writing a script to do it - does something like this already exist? I have to figure there's already a tool to do it, or that someone has wrote a script to do it.

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  • Queries within queries: Is there a better way?

    - by mririgo
    As I build bigger, more advanced web applications, I'm finding myself writing extremely long and complex queries. I tend to write queries within queries a lot because I feel making one call to the database from PHP is better than making several and correlating the data. However, anyone who knows anything about SQL knows about JOINs. Personally, I've used a JOIN or two before, but quickly stopped when I discovered using subqueries because it felt easier and quicker for me to write and maintain. Commonly, I'll do subqueries that may contain one or more subqueries from relative tables. Consider this example: SELECT (SELECT username FROM users WHERE records.user_id = user_id) AS username, (SELECT last_name||', '||first_name FROM users WHERE records.user_id = user_id) AS name, in_timestamp, out_timestamp FROM records ORDER BY in_timestamp Rarely, I'll do subqueries after the WHERE clause. Consider this example: SELECT user_id, (SELECT name FROM organizations WHERE (SELECT organization FROM locations WHERE records.location = location_id) = organization_id) AS organization_name FROM records ORDER BY in_timestamp In these two cases, would I see any sort of improvement if I decided to rewrite the queries using a JOIN? As more of a blanket question, what are the advantages/disadvantages of using subqueries or a JOIN? Is one way more correct or accepted than the other?

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  • Prove correctness of unit test

    - by Timo Willemsen
    I'm creating a graph framework for learning purposes. I'm using a TDD approach, so I'm writing a lot of unit tests. However, I'm still figuring out how to prove the correctness of my unit tests For example, I have this class (not including the implementation, and I have simplified it) public class SimpleGraph(){ //Returns true on success public boolean addEdge(Vertex v1, Vertex v2) { ... } //Returns true on sucess public boolean addVertex(Vertex v1) { ... } } I also have created this unit tests @Test public void SimpleGraph_addVertex_noSelfLoopsAllowed(){ SimpleGraph g = new SimpleGraph(); Vertex v1 = new Vertex('Vertex 1'); actual = g.addVertex(v1); boolean expected = false; boolean actual = g.addEdge(v1,v1); Assert.assertEquals(expected,actual); } Okay, awesome it works. There is only one crux here, I have proved that the functions work for this case only. However, in my graph theory courses, all I'm doing is proving theorems mathematically (induction, contradiction etc. etc.). So I was wondering is there a way I can prove my unit tests mathematically for correctness? So is there a good practice for this. So we're testing the unit for correctness, instead of testing it for one certain outcome.

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  • Sql Compact and __sysobjects

    - by Scott Wisniewski
    I have some SQL Compact queries that create tables inside of transaction. This is mainly because I need to simulate temporary tables, which SQL Compact does not support. I do this by creating a real table, and then dropping it at the end of the transaction. This mostly works. Sometimes, however, when creating the tables Sql Compact will try to acquire PAGE level locks on the __sysobjects table. If there are several concurrent queries running that create "temp" tables, the attempt to acquire a page lock can result in a dead lock followed by a SqlLockTimeout exception. For normal tables I could fix this using a "with (rowlock)" hint. However, because I'm not writing the query to insert into __sysobjets (SQL server does that in response to "create table") I can't do this. Does anyone know of a way I could get around this? I've thought about pulling the table creation out of the transaction, but that opens up the possibility of phantom temporary tables that I'd then need to clean up regularly. Ideally I'd like to avoid that if possible.

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  • Parse large XML file w/ script or use BioPython API ?

    - by jeremy04
    Hey guys this is my first question on here. I'm trying to make a local copy of the UniprotKB in SQL. The UniprotKB is 2.1GB, and it comes in XML and a special text format used by SwissProt Here are my options: 1) Use a SAX parser (XML) - I chose Ruby, and Nokogiri. I started writing the parser, but my initial reaction: how would I map the XML schema to the SAX parser? 2) BioPython - I already have BioSQL/Biopython installed, which literally created my SQL schema for me, and I was able to successfully insert one SwissProt/Uniprot txt file into the database. I'm running it right now (crosses fingers) on the entire 2.1gb. Here is the code I'm running: from Bio import SeqIO from BioSQL import BioSeqDatabase from Bio import SwissProt server = BioSeqDatabase.open_database(driver = "MySQLdb", user = "root", passwd = "", host="localhost", db = "bioseqdb") db = server["uniprot"] iterator = SeqIO.parse(open("/path/to/uniprot_sprot.dat", "r"), "swiss") db.load(iterator) server.commit() Edit: it's now crashing because the transactions are getting locked (since the tables are Innodb) Error Number: 1205 Lock wait timeout exceeded; try restarting transaction. I'm using MySQL version: 5.1.43 Should I switch my database to Postgrelsql ?

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  • Programming Environment for a Motorola 68000 in Linux

    - by Nick Presta
    Greetings all, I am taking a Structure and Application of Microcomputers course this semester and we're programming with the Motorola 68000 series CPU/board. The course syllabus suggests running something like Easy68K or Teesside Motorola 68000 Assembler/Emulator at home to test our programs. I told my prof I run x64 Linux and asked what sort of environment I would need to complete my coursework. He said that the easiest environment to use is a Windows XP 32bit VM with one of the two suggested applications installed, however, he doesn't really care what I use as long as I can test what I write at home. So I'm asking if there exists some sort of emulator or environment for Linux so I can test my code, and what sort of caveats I will run into by writing and testing my code in Linux. Also, I plan to do my editing in Vim, which probably isn't a problem, but I would like any insight into editors for 68000 assembly, if you have any. Thanks! EDIT: Just to clarify - I don't want to install Linux on the board at all - I want to program on my home machine, test the code locally, and then bring it onto the board for grading/running.

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  • Focus-dependent text change for TextBoxes in WPF

    - by Simon
    Hey there. I'm writing an application in WPF using the MVVM-pattern and will really often use TextBoxes. I don't want to use labels for the user to know user what the text box is for, i.e. I don't want something like this: <TextBlock> Name: </TextBlock> <TextBox /> Instead, I would like the TextBox to contain its own label. Statically, you would express it like this: <TextBox>Name</TextBox> If the cursor is displayed in the textbox, i.e. the TextBox gains focus, I want the description text to disappear. If the TextBox is left empty and it loses the focus, the description text should be shown again. It's similar to the search textbox of StackOverflow or the one of Firefox. (please tell me if your not sure what I mean). One TextBox's label may change at runtime, dependending on e.g. a ComboBox's selected element or a value in my ViewModel. (It's like in Firefox's search TextBox, if you select google from the search engins' menu, the TextBox's label changes to "Google", if you select "Yahoo" its set to "Yahoo"). Thus I want to be able to bind the label's content. Consider that I may already have a Binding on the Text-Property of the TextBox. How can implement such a behaviour and make it reusable for any of my TextBox's? Code is welcome but not needed; a description of what to do is enough. Thank you in advance.

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  • Tokenizing numbers for a parser

    - by René Nyffenegger
    I am writing my first parser and have a few questions conerning the tokenizer. Basically, my tokenizer exposes a nextToken() function that is supposed to return the next token. These tokens are distinguished by a token-type. I think it would make sense to have the following token-types: SYMBOL (such as <, :=, ( and the like REMARK (or a comment) NUMBER IDENT (such as the name of a function or a variable) STRING (Something enclosed between "....") Now, do you think this makes sense? Also, I am struggling with the NUMBER token-type. Do you think it makes more sense to further split it up into a NUMBER and a FLOAT token-type? Without a FLOAT token-type, I'd receive NUMBER (eg 402), a SYMBOL (.) followed by another NUMBER (eg 203) if I were about to parse a float. Finally, what do you think makes more sense for the tokenizer to return when it encounters a -909? Should it return the SYMBOL - first, followed by the NUMBER 909 or should it return a NUMBER -909 right away?

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  • Evaluating expressions using Visual Studio 2005 SDK rather than automation's Debugger::GetExpression

    - by brone
    I'm looking into writing an addin (or package, if necessary) for Visual Studio 2005 that needs watch window type functionality -- evaluation of expressions and examination of the types. The automation facilities provide Debugger::GetExpression, which is useful enough, but the information provided is a bit crude. From looking through the docs, it sounds like an IDebugExpressionContext2 would be more useful. With one of these it looks as if I can get more information from an expression -- detailed information about the type and any members and so on and so forth, without having everything come through as strings. I can't find any way of actually getting a IDebugExpressionContext2, though! IDebugProgramProvider2 sort of looks relevant, in that I could start with IDebugProgramProvider2::GetProviderProcessData and then slowly drill down until reaching something that can supply my expression context -- but I'll need to supply a port to this, and it's not clear how to retrieve the port corresponding to the current debug session. (Even if I tried every port, it's not obvious how to tell which port is the right one...) I'm becoming suspicious that this simply isn't a supported use case, but with any luck I've simply missed something crashingly obvious. Can anybody help?

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  • MySQL developer here -- Nesting with select * finicky in Oracle 10g?

    - by John Sullivan
    I'm writing a simple diagnostic query then attempting to execute it in the Oracle 10g SQL Scratchpad. EDIT: It will not be used in code. I'm nesting a simple "Select *" and it's giving me errors. In the SQL Scratchpad for Oracle 10g Enterprise Manager Console, this statement runs fine. SELECT * FROM v$session sess, v$sql sql WHERE sql.sql_id(+) = sess.sql_id and sql.sql_text <> ' ' If I try to wrap that up in Select * from () tb2 I get an error, "ORA-00918: Column Ambiguously Defined". I didn't think that could ever happen with this kind of statement so I am a bit confused. select * from (SELECT * FROM v$session sess, v$sql sql WHERE sql.sql_id(+) = sess.sql_id and sql.sql_text <> ' ') tb2 You should always be able to select * from the result set of another select * statement using this structure as far as I'm aware... right? Is Oracle/10g/the scratchpad trying to force me to accept a certain syntactic structure to prevent excessive nesting? Is this a bug in scratchpad or something about how oracle works?

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  • Are there any downsides in using C++ for network daemons?

    - by badcat
    Hey guys! I've been writing a number of network daemons in different languages over the past years, and now I'm about to start a new project which requires a new custom implementation of a properitary network protocol. The said protocol is pretty simple - some basic JSON formatted messages which are transmitted in some basic frame wrapping to have clients know that a message arrived completely and is ready to be parsed. The daemon will need to handle a number of connections (about 200 at the same time) and do some management of them and pass messages along, like in a chat room. In the past I've been using mostly C++ to write my daemons. Often with the Qt4 framework (the network parts, not the GUI parts!), because that's what I also used for the rest of the projects and it was simple to do and very portable. This usually worked just fine, and I didn't have much trouble. Being a Linux administrator for a good while now, I noticed that most of the network daemons in the wild are written in plain C (of course some are written in other languages, too, but I get the feeling that 80% of the daemons are written in plain C). Now I wonder why that is. Is this due to a pure historic UNIX background (like KISS) or for plain portability or reduction of bloat? What are the reasons to not use C++ or any "higher level" languages for things like daemons? Thanks in advance! Update 1: For me using C++ usually is more convenient because of the fact that I have objects which have getter and setter methods and such. Plain C's "context" objects can be a real pain at some point - especially when you are used to object oriented programming. Yes, I'm aware that C++ is a superset of C, and that C code is basically C++. But that's not the point. ;)

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  • Initialize listitem with blanks?

    - by VBartilucci
    Say I have a list made up of a listitem which contains three strings. I add a new listitem, and try to assign the values of said strings from an outside source. If one of those items is unassigned, the value in the listitem remains as null (unassigned). As a result I get an error if I try to assign that value to a field on my page. I can do a check on isNullOrEmpty for each field on the page, but that seems inefficient. I'd rather initialize the values to "" (Empty string) in the codebehind and send valid data. I can do it manually: ClaimPwk emptyNode = new ClaimPwk(); emptyNode.cdeAttachmentControl = ""; emptyNode.cdeRptTransmission = ""; emptyNode.cdeRptType = ""; headerKeys.Add(emptyNode); But I have some BIG list items, and writing that for those will get tedious. So is there a command, or just plain an easier way to initialize a listitem to empty string as opposed to null? Or has anyone got a better idea?

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  • stop android emulator call

    - by Shahzad Younis
    I am working on an Android application, having functionality like voicemail. I am using BroadcastReceiver to get dialing events. I have to get the event "WHEN CALL IS UNANSWERED (not picked after few rings) FROM RECEIVER". I will do some actions on caller end against this event. I am using AVD emulator, and I do call from one instance to another instance and it calls perfectly, but the problem is: It continuously calls until I reject or accept the call. This way I cannot detect that "CALL IS UNANSWERED AFTER A NUMBER OF RINGS". So I want the Caller emulator to drop the call after a number of rings (if unanswered) like a normal phone. I can do it (drop the call after some time) by writing some code, but I need the natural functionality of phone in the emulator. Can anyone please guide me? Is there any settings in the emulator? Or something else? The code is shown below in case it helps: public class MyPhoneReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { Bundle extras = intent.getExtras(); if (extras != null) { String state = "my call state = " + extras.getString(TelephonyManager.EXTRA_STATE); Log.w("DEBUG", state); } }

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  • JavaScript window object element properties

    - by Timothy
    A coworker showed me the following code and asked me why it worked. <span id="myspan">Do you like my hat?</span> <script type="text/javascript"> var spanElement = document.getElementById("myspan"); alert("Here I am! " + spanElement.innerHTML + "\n" + myspan.innerHTML); </script> I explained that a property is attached to the window object with the name of the element's id when the browser parses the document which then contains a reference to the appropriate dom node. It's sort of as if window.myspan = document.getElementById("myspan") is called behind the scenes as the page is being rendered. The ensuing discussion we had raised a few of questions: The window object and most of the DOM are not part of the official JavaScript/ECMA standards, but is the above behavior documented in any other official literature, perhaps browser-related? The above works in a browser (at least the main contenders) because there is a window object, but fails in something like rhino. Is writing code that relys on this considered bad practice because it makes too many assumptions about the execution environment? Are there any browsers in which the above would fail, or is this considered standard behavior across the board? Does anyone here know the answers to those questions and would be willing to enlighten me? I tried a quick internet search, but I admit I'm not sure how to even properly phrase the query. Pointers to references and documentation are welcome.

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  • Use properties or methods to expose business rules in C#?

    - by Val
    I'm writing a class to encapsulate some business rules, each of which is represented by a boolean value. The class will be used in processing an InfoPath form, so the rules get the current program state by looking up values in a global XML data structure using XPath operations. What's the best (most idiomatic) way to expose these rules to callers -- properties or public methods? Call using properties Rules rules = new Rules(); if ( rules.ProjectRequiresApproval ) { // get approval } else { // skip approval } Call using methods Rules rules = new Rules(); if ( rules.ProjectRequiresApproval() ) { // get approval } else { // skip approval } Rules class exposing rules as properties public class Rules() { private int _amount; private int threshold = 100; public Rules() { _amount = someExpensiveXpathOperation; } // rule property public bool ProjectRequiresApproval { get { return _amount < threshold } } } Rules class exposing rules as methods public class Rules() { private int _amount; private int threshold = 100; public Rules() { _amount = someExpensiveXpathOperation; } // rule method public bool ProjectRequiresApproval() { return _amount < threshold; } } What are the pros and cons of one over the other?

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  • How do you clear your mind after 8-10 hours per day of coding?

    - by Bryan
    Related Question- Ways to prepare your mind before coding?. I'm having a hard time taking my mind off of work projects in my personal time. It's not that I have a stressful job or tight deadlines; I love my job. I find that after spending the whole day writing code & trying to solve problems, I have an extremely hard time getting it out of my mind. I'm constantly thinking about the current project/problem/task all the time. It's keeping me from relaxing, and in the long run it just builds stress. Personal projects help to some extent, but mostly just to distract me. I still have source code bouncing around my head 16 hours a day. I'm still relatively new to the workforce. Have you struggled with this, perhaps as a young developer? How did you overcome it? Can anyone offer general advice on winding down after a long programming session?

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  • Hash Code for a group of three fields

    - by Gauranga
    I have three fields namely Number1 Number2 Time I am trying to write a function in java that returns a unique hash value (long needs to be the return type of hash) for the above fields. This hash would then be used to store database rows corresponding to the above mentioned fields in a HashSet. I am new to writing a hash code function, can someone please review what I have. Any help would be appreciated. public class HashCode { private long Number1; private long Number2; String Time; public HashCode(long Number1, long Number2, String Time){ this.Number1 = Number1; this.Number2 = Number2; this.Time = Time; } public long getHashCode() { long hash = 3; hash = 47 * hash + (long) (this.Number1 ^ (this.Number1 >>> 32)); hash = 47 * hash + (long) (this.Number2 ^ (this.Number2 >>> 32)); hash = 47 * hash + (this.Time != null ? this.Time.hashCode() : 0); return hash; } }

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  • PHP static objects giving a fatal error

    - by Webbo
    I have the following PHP code; <?php component_customer_init(); component_customer_go(); function component_customer_init() { $customer = Customer::getInstance(); $customer->set(1); } function component_customer_go() { $customer = Customer::getInstance(); $customer->get(); } class Customer { public $id; static $class = false; static function getInstance() { if(self::$class == false) { self::$class = new Customer; } else { return self::$class; } } public function set($id) { $this->id = $id; } public function get() { print $this->id; } } ?> I get the following error; Fatal error: Call to a member function set() on a non-object in ....../classes/customer.php on line 9 Can anyone tell me why I get this error? I know this code might look strange, but it's based on a component system that I'm writing for a CMS. The aim is to be able to replace HTML tags in the template e.g.; <!-- component:customer-login --> with; <?php component_customer_login(); ?> I also need to call pre-render methods of the "Customer" class to validate forms before output is made etc. If anyone can think of a better way, please let me know but in the first instance, I'd like to know why I get the "Fatal error" mentioned above. Cheers

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  • Calling a jQuery method at declaration time, and then onEvent

    - by cesarsalazar
    I've been writing JS (mainly jQuery) for quite a few months now, but today I decided to make my first abstraction as a jQuery method. I already have working code but I feel/know that I'm not doing it the right way, so I come here for some enlightenment. Note: Please do not reply that there's already something out there that does the trick as I already know that. My interest in this matter is rather educational. What my code is intended to do (and does): Limit the characters of a textfield and change the color of the counter when the user is approaching the end. And here's what I have: $(function(){ $('#bio textarea').keyup(function(){ $(this).char_length_validation({ maxlength: 500, warning: 50, validationSelector: '#bio .note' }) }) $('#bio textarea').trigger('keyup'); }) jQuery.fn.char_length_validation = function(opts){ chars_left = opts.maxlength - this.val().length; if(chars_left >= 0){ $(opts.validationSelector + ' .value').text(chars_left); if(chars_left < opts.warning){ $(opts.validationSelector).addClass('invalid'); } else{ $(opts.validationSelector).removeClass('invalid'); } } else{ this.value = this.value.substring(0, opts.maxlength); } } In the HTML: <div id="bio"> <textarea>Some text</textarea> <p class="note> <span class="value">XX</span> <span> characters left</span> </p> </div> Particularly I feel really uncomfortable binding the event each on each keyup instead of binding once and calling a method later. Also, (and hence the title) I need to call the method initially (when the page renders) and then every time the user inputs a character. Thanks in advance for your time :)

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  • Problems applying texture to a triangle strip using glTexCoordPointer

    - by Alexey
    Hi, I'm writing a pretty simple piece of code which should draw a plane. The plane must have two different textures on its sides, like if it was a book page. I'm trying to achieve this by doing this: glFrontFace(GL_CCW); glBindTexture(GL_TEXTURE_2D, textures[kActiveSideLeft]); glVertexPointer(3, GL_FLOAT, 0, vertexCoordinates); glTexCoordPointer(2, GL_FLOAT, 0, textureCoordinates); glDrawArrays(GL_TRIANGLE_STRIP, 0, (2 * kHorizontalSegmentsCount + 4) * kVerticalSegmentsCount); glFrontFace(GL_CW); glBindTexture(GL_TEXTURE_2D, textures[kActiveSideRight]); glVertexPointer(3, GL_FLOAT, 0, vertexCoordinates); glTexCoordPointer(2, GL_FLOAT, 0, textureCoordinates); glDrawArrays(GL_TRIANGLE_STRIP, 0, (2 * kHorizontalSegmentsCount + 4) * kVerticalSegmentsCount); textures[] array contains 2 GLuint textures which specify appropriate textures. vertexCoordinates and textureCoordinates contain vertexes and texture coordinates respectively ((2 * kHorizontalSegmentsCount + 4) * kVerticalSegmentsCount) equals 15 and that's exactly how many elements I have in the arrays I set up opengl like this: glEnable(GL_DEPTH_TEST); glClearDepthf(1.0f); glDepthFunc(GL_LEQUAL); glClearColor(0.0, 1.0, 1.0, 1.0); glEnable(GL_TEXTURE_2D); glEnable(GL_CULL_FACE); glCullFace(GL_BACK); glEnableClientState(GL_VERTEX_ARRAY); glEnableClientState(GL_TEXTURE_COORD_ARRAY); glDisableClientState(GL_NORMAL_ARRAY); glDisableClientState(GL_COLOR_ARRAY); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); What happens is when I run it front side of the plane looks Ok, but it appears like if texture coordinates weren't applied to the back side. It appears like texture on the back side is just tiled and not connected to vertexes by any means. Any idea what am I doing wrong? Or any idea about what can I do to debug this problem? Thanks.

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  • PHP question about global variables and form requests

    - by user220201
    Hi, This is probably a stupid question but will ask anyway sine I have no idea. I have written basic php code which serve forms. Say I have a login page and I serve it using the login.php page and it will be called in the login.html page like this - <form action="login.php" method="post"> By this it is also implied that every POST needs its own php file, doesn't it? This kind of feels weird. Is there a way to have a single file, say code.php, and just have each of the forms as functions instead? EDIT: Specifically, say I have 5 forms that are used one after the other in my application. Say after login the user does A, B, C and D tasks each of which are sent to the server as a POST request. So instead of having A.php, B.php, C.php and D.php I would like to have a single code.php and have A(), B(), C() and D() as functions. Is there a way to do this? Also on the same note, how do I deal with say a global array (e.g. an array of currently logged in users) across multiple forms? I want to do this without writing to a DB. I know its probably better to write to a DB and query but is it even possible to do it with a global array? The reason I was thinking about having all the form functions in one file is to use a global array. Thanks, - Pav

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  • python os.mkfifo() for Windows

    - by user302099
    Hello. Short version (if you can answer the short version it does the job for me, the rest is mainly for the benefit of other people with a similar task): In python in Windows, I want to create 2 file objects, attached to the same file (it doesn't have to be an actual file on the hard-drive), one for reading and one for writing, such that if the reading end tries to read it will never get EOF (it will just block until something is written). I think in linux os.mkfifo() would do the job, but in Windows it doesn't exist. What can be done? (I must use file-objects). Some extra details: I have a python module (not written by me) that plays a certain game through stdin and stdout (using raw_input() and print). I also have a Windows executable playing the same game, through stdin and stdout as well. I want to make them play one against the other, and log all their communication. Here's the code I can write (the get_fifo() function is not implemented, because that's what I don't know to do it Windows): class Pusher(Thread): def __init__(self, source, dest, p1, name): Thread.__init__(self) self.source = source self.dest = dest self.name = name self.p1 = p1 def run(self): while (self.p1.poll()==None) and\ (not self.source.closed) and (not self.source.closed): line = self.source.readline() logging.info('%s: %s' % (self.name, line[:-1])) self.dest.write(line) self.dest.flush() exe_to_pythonmodule_reader, exe_to_pythonmodule_writer =\ get_fifo() pythonmodule_to_exe_reader, pythonmodule_to_exe_writer =\ get_fifo() p1 = subprocess.Popen(exe, shell=False, stdin=subprocess.PIPE, stdout=subprocess.PIPE) old_stdin = sys.stdin old_stdout = sys.stdout sys.stdin = exe_to_pythonmodule_reader sys.stdout = pythonmodule_to_exe_writer push1 = Pusher(p1.stdout, exe_to_pythonmodule_writer, p1, '1') push2 = Pusher(pythonmodule_to_exe_reader, p1.stdin, p1, '2') push1.start() push2.start() ret = pythonmodule.play() sys.stdin = old_stdin sys.stdout = old_stdout

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  • Have you dealt with space hardening?

    - by Tim Post
    I am very eager to study best practices when it comes to space hardening. For instance, I've read (though I can't find the article any longer) that some core parts of the Mars rovers did not use dynamic memory allocation, in fact it was forbidden. I've also read that old fashioned core memory may be preferable in space. I was looking at some of the projects associated with the Google Lunar Challenge and wondering what it would feel like to get code on the moon, or even just into space. I know that space hardened boards offer some sanity in such a harsh environment, however I'm wondering (as a C programmer) how I would need to adjust my thinking and code if I was writing something that would run in space? I think the next few years might show more growth in private space companies, I'd really like to at least be somewhat knowledgeable regarding best practices. Can anyone recommend some books, offer links to papers on the topic or (gasp) even a simulator that shows you what happens to a program if radiation, cold or heat bombards a board that sustained damage to its insulation? I think the goal is keeping humans inside of a space craft (as far as fixing or swapping stuff) and avoiding missions to fix things. Furthermore, if the board maintains some critical system, early warnings seem paramount.

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  • Efficient way to maintain a sorted list of access counts in Python

    - by David
    Let's say I have a list of objects. (All together now: "I have a list of objects.") In the web application I'm writing, each time a request comes in, I pick out up to one of these objects according to unspecified criteria and use it to handle the request. Basically like this: def handle_request(req): for h in handlers: if h.handles(req): return h return None Assuming the order of the objects in the list is unimportant, I can cut down on unnecessary iterations by keeping the list sorted such that the most frequently used (or perhaps most recently used) objects are at the front. I know this isn't something to be concerned about - it'll make only a miniscule, undetectable difference in the app's execution time - but debugging the rest of the code is driving me crazy and I need a distraction :) so I'm asking out of curiosity: what is the most efficient way to maintain the list in sorted order, descending, by the number of times each handler is chosen? The obvious solution is to make handlers a list of (count, handler) pairs, and each time a handler is chosen, increment the count and resort the list. def handle_request(req): for h in handlers[:]: if h[1].handles(req): h[0] += 1 handlers.sort(reverse=True) return h[1] return None But since there's only ever going to be at most one element out of order, and I know which one it is, it seems like some sort of optimization should be possible. Is there something in the standard library, perhaps, that is especially well-suited to this task? Or some other data structure? (Even if it's not implemented in Python) Or should/could I be doing something completely different?

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