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  • Reading Source Code Aloud

    - by Jon Purdy
    After seeing this question, I got to thinking about the various challenges that blind programmers face, and how some of them are applicable even to sighted programmers. Particularly, the problem of reading source code aloud gives me pause. I have been programming for most of my life, and I frequently tutor fellow students in programming, most often in C++ or Java. It is uniquely aggravating to try to verbally convey the essential syntax of a C++ expression. The speaker must give either an idiomatic translation into English, or a full specification of the code in verbal longhand, using explicit yet slow terms such as "opening parenthesis", "bitwise and", et cetera. Neither of these solutions is optimal. On the one hand, an idiomatic translation is only useful to a programmer who can de-translate back into the relevant programming code—which is not usually the case when tutoring a student. In turn, education (or simply getting someone up to speed on a project) is the most common situation in which source is read aloud, and there is a very small margin for error. On the other hand, a literal specification is aggravatingly slow. It takes far far longer to say "pound, include, left angle bracket, iostream, right angle bracket, newline" than it does to simply type #include <iostream>. Indeed, most experienced C++ programmers would read this merely as "include iostream", but again, inexperienced programmers abound and literal specifications are sometimes necessary. So I've had an idea for a potential solution to this problem. In C++, there is a finite set of keywords—63—and operators—54, discounting named operators and treating compound assignment operators and prefix versus postfix auto-increment and decrement as distinct. There are just a few types of literal, a similar number of grouping symbols, and the semicolon. Unless I'm utterly mistaken, that's about it. So would it not then be feasible to simply ascribe a concise, unique pronunciation to each of these distinct concepts (including one for whitespace, where it is required) and go from there? Programming languages are far more regular than natural languages, so the pronunciation could be standardised. Speakers of any language would be able to verbally convey C++ code, and due to the regularity and fixity of the language, speech-to-text software could be optimised to accept C++ speech with a high degree of accuracy. So my question is twofold: first, is my solution feasible; and second, does anyone else have other potential solutions? I intend to take suggestions from here and use them to produce a formal paper with an example implementation of my solution.

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  • Queue ExternalInterface calls to Flash Object in UpdatePanel - Needs Improvement?

    - by Laramie
    A Flash (actually Flex) object is created on an ASP.Net page within an Update Panel using a modified version of the embedCallAC_FL_RunContent.js script so it can be written in dynamically. It is re-created with this script with each partial postback to that panel. There are also other Update Panels on the page. With some postbacks (partial and full), External Interface calls such as $get('FlashObj').ExternalInterfaceFunc('arg1', 0, true); are prepared server-side and added to the page using ScriptManager.RegisterStartupScript. They're embedded in a function and stuffed into Sys.Application's load event, for example Sys.Application.add_load(funcContainingExternalInterfaceCalls). The problem is that because the Flash object's state state may change with each partial postback, the Flash (Flex) object and/or External Interface may not be ready or even exist yet in the DOM when the JavaScript - Flash External Interface call is made. It results in an "Object doesn't support this property or method" exception. I have a working strategy to make the ExternalInterface calls immediately if Flash is ready or else queue them until such time that Flash announces its readiness. //Called when the Flash object is initialized and can accept ExternalInterfaceCalls var flashReady = false; //Called by Flash when object is fully initialized function setFlashReady() { flashReady = true; //Make any queued ExternalInterface calls, then dequeue while (extIntQueue.length > 0) (extIntQueue.shift())(); } var extIntQueue = []; function callExternalInterface(flashObjName, funcName, args) { //reference to the wrapped ExternalInterface Call var wrapped = extWrap(flashObjName, funcName, args); //only procede with ExternalInterface call if the global flashReady variable has been set if (flashReady) { wrapped(); } else { //queue the function so when flashReady() is called next, the function is called and the aruments are passed. extIntQueue.push(wrapped); } } //bundle ExtInt call and hold variables in a closure function extWrap(flashObjName, funcName, args) { //put vars in closure return function() { var funcCall = '$get("' + flashObjName + '").' + funcName; eval(funcCall).apply(this, args); } } I set the flashReady var to dirty whenever I update the Update Panel that contains the Flash (Flex) object. ScriptManager.RegisterClientScriptBlock(parentContainer, parentContainer.GetType(), "flashReady", "flashReady = false;", true); I'm pleased that I got it to work, but it feels like a hack. I am still on the learning curve with respect to concepts like closures why "eval()" is apparently evil, so I'm wondering if I'm violating some best practice or if this code should be improved, if so how? Thanks.

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  • How to merge an improperly created "branch" that isn't really a branch (wasn't created by an svn cop

    - by MatrixFrog
    I'm working on a team with lots of people who are pretty unfamiliar with the concepts of version control systems, and are just kind of doing whatever seems to work, by trial and error. Someone created a "branch" from the trunk that is not ancestrally related to the trunk. My guess is it went something like this: They created a folder in branches. They checked out all the code from the trunk to somewhere on their desktop. They added all that code to the newly created folder as though it was a bunch of brand new files. So the repository isn't aware that all that code is actually just a copy of the trunk. When I look at the history of that branch in TortoiseSVN, and uncheck the "Stop on copy/rename" box, there is no revision that has the trunk (or any other path) under the "Copy from path" column. Then they made lots of changes on their "branch". Meanwhile, others were making lots of changes on the trunk. We tried to do a merge and of course it doesn't work. Because, the trunk and the fake branch are not ancestrally related. I can see only two ways to resolve this: Go through the logs on the "branch", look at every change that was made, and manually apply each change to the trunk. Go through the logs on the trunk, look at every change that was made between revision 540 (when the "branch" was created) and HEAD, and manually apply each change to the "branch". This involves 7 revisions one way or 11 revisions the other way, so neither one is really that terrible. But is there any way to cause the repository to "realize" that the branch really IS ancestrally related even though it was created incorrectly, so that we can take advantage of the built-in merging functionality in Eclipse/TortoiseSVN? (You may be wondering: Why did your company hire these people and allow them to access the SVN repository without making sure they knew how to use it properly first?! We didn't -- this is a school assignment, which is a collaboration between two different classes -- the ones in the lower class were given a very quick hand-wavey "overview" of SVN which didn't really teach them anything. I've asked everyone in the group to please PLEASE read the svn book, and I'll make sure we (the slightly more experienced half of the team) keep a close eye on the repository to ensure this doesn't happen again.)

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  • Web-Frameworks for Education Management Systems?

    - by Indebi
    So, I'm working on an idea and I'll go into a brief overview of that but my question is, What are some good web frameworks for this situation? I have some experience in the following languages: C# Python I have considerably more experience in C# than Python, however I am expecting to learn new things. My idea is this, a completely web-based community-oriented Education Management System that focuses on making students and teachers day-to-day lives easier. For students it will provide a centralized place for them to do homework, study for tests, and reinforce concepts learned previously in class. For teachers it will give them a centralized place to handle assignments, attendance, homework, tests, and all other major parts of classroom management. All of that, but in a community-oriented fashion. Everything a teacher does is shared and open to constructive criticism, allowing other teachers to use their assignments/tests and for students or other teachers to comment, rate and criticize their assignments. This encourages an environment of openness that will allow teacher's to focus on teaching and student's to focus on learning. And that community wouldn't be limited to one school or school-district, this system would be completely school-independent. Please note that I have no problem with hearing constructive criticism on this idea, however I would prefer if this post was more focused on my question. I have somewhat explored about the following options: Django ASP.NET Ruby on Rails Silverlight (1) I have Django installed and I played with it for a little bit, I really like how easy setting up databases are and how it handles the database completely for you. I don't really know how to use it very well and I don't quite understand the Model-View-Controller paradigm(?) for it yet but I haven't thought about it much. I also like the fact that it uses Python. (2) I don't really like Visual Studio for developing in ASP.NET, I hate the way the web-designer works and it just feels clunky and old. I like the server-side development part though. I don't like how expensive ASP.NET and overall Visual Studio is, even if I do get it for free for now using DreamSpark (3) I haven't been able to explore much with this, I could not get Rails (or maybe Ruby) properly installed. I first installed it within RadRails and that didn't work so I uninstalled RadRails and then installed the latest version of Ruby off the official Windows Installer and then installed Ruby on Rails through gem and even after all that it still didn't work, so I installed Netbeans and attempted to use it there but it still did not work (4) I like Silverlight in some extents, I've played with this one the most, it's very similar to WPF (which I've used the most) in a lot of ways but I don't like how database connectivity works, at least in comparison to Django. I also dislike how expensive everything with Microsoft is, even if I get it for free for now with DreamSpark. I would like to hear some suggestions from experienced web-developers as to what I should use and why, or at least what some good options are for my scenario Your help would be very appreciated

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  • Nice, clean, simple way of getting a dataset from ASP.NET to plain HTML jQuery or JavaScript library

    - by David S
    I know this is a probable open ended question, and I have tried looking around so much over the last year or two... maybe I am looking for a perfect place that doesn't exist! of course it's all about perception no less.. Anyway, just to clarify what I am trying to do and why: I want to be able to use (primarily for the moment) ASP.NET or services thereof to get a dataset - whatever the source data, I can obviously get a dataset of rows/Columns. I want to be able to, as simply as possible, get that data over to the client via xml/json/whatever, to then use in a "variety" of ways. "Variety" of ways meaning I would like to "easily" bind that data to say a grid, or a combo dropdown or just simply render to a textbox - BUT by referencing the dataset as I would say on the serverside. Now I know this all sounds simplistic, and I know there are lots of complications.. so I have tried the following so far over the last year or so: ExtJS - very good, nice solid framework, but just found it a bit too much to use in everyday basic apps - great if I was building a whole application with it Yahoo YUI - not looked recently, but I guess some of the concepts with ExtJS were similar? JQuery - of course to get data etc, it was ok, and I guess there are so many 3rd party plugins, that a mix and match might work? Adobe SPRY - ironically this was as close to getting a dataset style structure to Javascript/client, although it seemed to drop off/go quiet..? I maybe wrong.. I did have a very cursory play with Tibco GI and another one I cannot remember the name of! but again, it felt like it was great to build a whole app perhaps? Anyway, I am very amazed by all of the technologies coming out, and really not biased one way or the other, I really just want a very simple way of getting data from the server, and having a basic/very flexible way of working with that data in the client without using server technologies.. I need to keep the server flexible as I may need to use PHP, or java technologies not just .NET So again, sorry for the rambles, but if anyone out there has had a simple experience, or would like to share some ideas, it would be very welcomed!! David.

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  • Basic Ruby On Rails Linking Help

    - by dweebsonduty
    So I am beginning to work with Rails and I get some of the concepts but am stuck on an important one. Let's say I have customers which has many jobs and jobs which belongs to customers. How would I go about creating a new job for a customer? I can create a link that goes to customers/1/jobs/new and I can grab the customer ID but how do I tell it that I am creating a job for customer 1? I know this is the most basic of things but I just need a push in the right direction. This is my form so far: How do I get :customer_id to populate with the customer_id param? <h1>New job</h1> <% form_for(@job) do |f| %> <%= f.error_messages %> <p> <%= f.label :customer_id %><br /> <%= f.text_field :customer_id %> </p> <p> <%= f.label :manufacturer %><br /> <%= f.text_field :manufacturer %> </p> <p> <%= f.label :serial_number %><br /> <%= f.text_field :serial_number %> </p> <p> <%= f.label :problem %><br /> <%= f.text_area :problem %> </p> <p> <%= f.label :notes %><br /> <%= f.text_area :notes %> </p> <p> <%= f.label :status %><br /> <%= f.text_field :status %> </p> <p> <%= f.label :tech_id %><br /> <%= f.text_field :tech_id %> </p> <p> <%= f.submit 'Create' %> </p> <% end %> <%= link_to 'Back', jobs_path %>

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  • Need help with joins in sqlalchemy

    - by Steve
    I'm new to Python, as well as SQL Alchemy, but not the underlying development and database concepts. I know what I want to do and how I'd do it manually, but I'm trying to learn how an ORM works. I have two tables, Images and Keywords. The Images table contains an id column that is its primary key, as well as some other metadata. The Keywords table contains only an id column (foreign key to Images) and a keyword column. I'm trying to properly declare this relationship using the declarative syntax, which I think I've done correctly. Base = declarative_base() class Keyword(Base): __tablename__ = 'Keywords' __table_args__ = {'mysql_engine' : 'InnoDB'} id = Column(Integer, ForeignKey('Images.id', ondelete='CASCADE'), primary_key=True) keyword = Column(String(32), primary_key=True) class Image(Base): __tablename__ = 'Images' __table_args__ = {'mysql_engine' : 'InnoDB'} id = Column(Integer, primary_key=True, autoincrement=True) name = Column(String(256), nullable=False) keywords = relationship(Keyword, backref='image') This represents a many-to-many relationship. One image can have many keywords, and one keyword can relate back to many images. I want to do a keyword search of my images. I've tried the following with no luck. Conceptually this would've been nice, but I understand why it doesn't work. image = session.query(Image).filter(Image.keywords.contains('boy')) I keep getting errors about no foreign key relationship, which seems clearly defined to me. I saw something about making sure I get the right 'join', and I'm using 'from sqlalchemy.orm import join', but still no luck. image = session.query(Image).select_from(join(Image, Keyword)).\ filter(Keyword.keyword == 'boy') I added the specific join clause to the query to help it along, though as I understand it, I shouldn't have to do this. image = session.query(Image).select_from(join(Image, Keyword, Image.id==Keyword.id)).filter(Keyword.keyword == 'boy') So finally I switched tactics and tried querying the keywords and then using the backreference. However, when I try to use the '.images' iterating over the result, I get an error that the 'image' property doesn't exist, even though I did declare it as a backref. result = session.query(Keyword).filter(Keyword.keyword == 'boy').all() I want to be able to query a unique set of image matches on a set of keywords. I just can't guess my way to the syntax, and I've spent days reading the SQL Alchemy documentation trying to piece this out myself. I would very much appreciate anyone who can point out what I'm missing.

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  • How do we, as a community, help encourage programming in public schools? (Or state Schools for the U

    - by NoMoreZealots
    PRIMARY MOTIVATION My office gets involved with the "First Robotics" competitions and one thing that lingers year to year is the students typically have no preparation for doing even simple programming as part of the public schools system. While the science classes provide some basic grasp of mechanical and electrical concepts, by in large computer programming gets no coverage from the curriculum. (This my be different in other areas of the country/world.) What makes it worse is there is only a short period of time you have to prepare the student's and help them design the robot. Talking to some professors from local colleges, it's a problem because you can't assume even the most basic understanding for freshman CS majors. Languages like Python, Lua and BASIC are simple enough for at least high school level students, if not younger. SCOPE So how do you get public schools to support a programming, at least to the level of "Try it in BASIC" examples that used to be at the end of a chapter in my Algebra book? At least enough to prepare them for event's such as the FIRST Robotic competitions. Which the primary objectives are to teach problem solving and team work, and to possible foster an interest in Math, Science and Engineering in general. (Not force feed to them, as some people her seem to be implying.) Edit: Why teach kids: (Since 2000 CS enrollment in US colleges has decreased by 70% while college enrollment has increased, this is a PROBLEM.) Saying there is no value in teaching someone programming in Jr./High school because they might think "they know programming." Is like saying there's no value in teaching High school science and physics, because they might decide they "know physics." Leading to abuse like: "I passed a high school physics class, I'm going to develop a Unified Quantum Gravitational Theory." Better Prepared students are better students. Instead it would allows college programs to raise the bar on the entry level courses, allowing students to be weeded out based on their understanding of more advanced material. Plus people who did poorly in that in topic in High school aren't as likely to say "I think there's money in computer's so I'll computer science." Plus if people take it in high school and decide THEN that it's not for them, it's better than them wasting their money to PAY a college to figure that out. The result is that people who take the degree are more likely to succeed and be there for the RIGHT reasons. (i.e. It's what they REALLY want to do. And that's REALLY the key to being good at anything.) Programming is like anything else, the more practice and genuine interest you have the better you get. If you start them later, they get less practice. The earlier give them the opportunity to start, the more practice they will get. All other things equal, the more practice the better the programmer.

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  • feeling insufficient while looking for a programming job ...

    - by user325661
    Hello everybody It's really dream to be programmer for me.So i always wanted to be .I had so small knowledges from commodore basic which i couldn't figure out anything in it .Then i tried to learn Visual basic 6 by myself and result wasn't good as i expected because i even didn't understand classes.Then i left to learning programming and to dream to be programmer. But challenge hadn't finished yet . After all of these i started to learn c# and i did chess engine which i hadn't believe that i can create one.I sometimes feel that i understand many thing about programming like knowing classes ,inheritance,abstract class and methods why exist , interfaces ,extension methods ,static classes ,threads. but i am not expert all in it . i just know that as i need . i don't know still i will learn many thing about these.i have also learned html, css2 , php and database concepts a little sql ,tables relations between primary keys etc but i haven't used them in praticaly . i just did some samples so i feel i am lack of knowledges. As a result still i can't evaluate my skills and can't decide what is my level.I just feel myself one step ahead of junior sometimes :) . Still can't decide that it is time to job seeking. While searching job on web i have never seen a junior advertisement. All looking for a good experiencing one.Nobody care about juniors. When found job advertisement which i feel sufficient myself a little then i start to feel that i think i can't do what they want from me and loosing job after have it in short time would leave many crap feelings into my low self-confidence. Please advise me something ... Also i want to ask some of concentrate questions. 1) If i enter a job which i can't provide their expectations should be in employers responsibility to test me while apply the job ? 2) If i answer "yes , i can " questions which is abstract(for example: can u do something like this) would be my responsibility ? Because such abstract questions is not clear and can't know before start it what i really can or not . 3) i have no professional experiences in this job so i even don't know how teams working on projects but a friend of me said that programmers only write method bodies while seniors create all project.So it looks what i can do really easy but i feel that small companies doesn't work like this so it is better work in a big company for starting who has seniors? 4)last applied job was looking for c# . net developer but then i learn that they need .net web developer.Does it take long time to learn specific sides of web programming while knowing c# desktop programming ? Thanks for all answers since now.

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  • Are there programs that iteratively write new programs?

    - by chris
    For about a year I have been thinking about writing a program that writes programs. This would primarily be a playful exercise that might teach me some new concepts. My inspiration came from negentropy and the ability for order to emerge from chaos and new chaos to arise out of order in infinite succession. To be more specific, the program would start by writing a short random string. If the string compiles the programs will log it for later comparison. If the string does not compile the program will try to rewrite it until it does compile. As more strings (mini 'useless' programs) are logged they can be parsed for similarities and used to generate a grammar. This grammar can then be drawn on to write more strings that have a higher probability of compilation than purely random strings. This is obviously more than a little silly, but I thought it would be fun to try and grow a program like this. And as a byproduct I get a bunch of unique programs that I can visualize and call art. I'll probably write this in Ruby due to its simple syntax and dynamic compilation and then I will visualize in processing using ruby-processing. What I would like to know is: Is there a name for this type of programming? What currently exists in this field? Who are the primary contributors? BONUS! - In what ways can I procedurally assign value to output programs beyond compiles(y/n)? I may want to extend the functionality of this program to generate a program based on parameters, but I want the program to define those parameters through running the programs that compile and assigning meaning to the programs output. This question is probably more involved than reasonable for a bonus, but if you can think of a simple way to get something like this done in less than 23 lines or one hyperlink, please toss it into your response. I know that this is not quite meta-programming and from the little I know of AI and generative algorithms they are usually more goal oriented than what I am thinking. What would be optimal is a program that continually rewrites and improves itself so I don't have to ^_^

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  • Collision point of 2 curves in a 3d-room

    - by Frank
    Hello, i am programming a small game for quite some time. We started coding a small FPS-Shooter inside of a project at school to get a bit experience using directX. I dont know why, but i couldnt stop the project and started programming at home aswell. At the moment i am trying to create some small AI. Of cause thats definatlly not easy, but thats my personal goal anyways. The topic could prolly fill multiple books hehe. I've got the walking part of my bots done so far. They walk along a scriped path. I am not working on the "aiming" of the bots. While programming that i hit on some math problem i couldnt solve yet. I hope of your input on this to help me get further. Concepts, ideas and everything else are highly appreciated. Problem: Calculate the position (D3DXVECTOR3) where the curve of the projectile (depends on gravity, speed), hit the curved of the enemys walking path (depends on speed). We assume that the enemy walks in a constant line. Known variables: float projectilSpeed = 2000 m/s //speed of the projectile per second float gravitation = 9.81 m/s^2 //of cause the gravity lol D3DXVECTOR3 targetPosition //position of the target stored in a vector (x,y,z) D3DXVECTOR3 projectilePosition //position of the projectile D3DXVECTOR3 targetSpeed //stores the change of the targets position in the last second Variabledefinition ProjectilePosition at time of collision = ProjectilePos_t TargetPosition at time of collision = TargetPos_t ProjectilePosition at time 0, now = ProjectilePos_0 TargetPosition at time 0, now = TargetPos_0 Time to impact = t Aim-angle = theta My try: Found a formular to calculate "drop" (Drop of the projectile based on the gravity) on Wikipedia: float drop = 0.5f * gravity * t * t The speed of the projectile has a horizontal and a vertical part.. Found a formular for that on wikipedia aswell: ProjectilVelocity.x = projectilSpeed * cos(theta) ProjectilVelocity.y = projectilSpeed * sin(theta) So i would assume this is true for the projectile curve: ProjectilePos_t.x = ProjectilePos_0.x + ProjectileSpeed * t ProjectilePos_t.y = ProjectilePos_0.y + ProjectileSpeed * t + 0.5f * gravity * t * t ProjectilePos_t.z = ProjectilePos_0.z + ProjectileSpeed * t The target walk with a constant speed, so we can determine his curve by this: TargetPos_t = TargetPos_0 + TargetSpeed * D3DXVECTOR3(t, t, t) Now i dont know how to continue. I have to solve it somehow to get a hold on the time to impact somehow. As a basic formular i could use: float time = distanz / projectileSpeed But that wouldnt be truly correct as it would assume a linear "Trajectory". We just find this behaivor when using a rocket. I hope i was able to explain the problem as much as possible. If there are questions left, feel free to ask me! Greets from germany, Frank

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  • Entity Framework 4 CTP 5 POCO - Many-to-many configuration, insertion, and update?

    - by Saxman
    I really need someone to help me to fully understand how to do many-to-many relationship with Entity Framework 4 CTP 5, POCO. I need to understand 3 concepts: How to config my model to indicates some tables are many-to-many. How to properly do insert. How to properly do update. Here are my current models: public class MusicSheet { [Key] public int ID { get; set; } public string Title { get; set; } public string Key { get; set; } public virtual ICollection<Author> Authors { get; set; } public virtual ICollection<Tag> Tags { get; set; } } public class Author { [Key] public int ID { get; set; } public string Name { get; set; } public string Bio { get; set; } public virtual ICollection<MusicSheet> MusicSheets { get; set; } } public class Tag { [Key] public int ID { get; set; } public string TagName { get; set; } public virtual ICollection<MusicSheet> MusicSheets { get; set; } } As you can see, the MusicSheet can have many Authors or Tags, and an Author or Tag can have multiple MusicSheets. Again, my questions are: What to do on the EntityTypeConfiguration to set the relationship between them as well as mapping to an table/object that associates with the many-to-many relationship. How to insert a new music sheets (where it might have multiple authors or multiple tags). How to update a music sheet. For example, I might set TagA, TagB to MusicSheet1, but later I need to change the tags to TagA and TagC. It seems like I need to first check to see if the tags already exists, if not, insert the new tag and then associate it with the music sheet (so that I doesn't re-insert TagA?). Or this is something already handled by the framework? Thank you very much. I really hope to fully understand it rather than just doing it without fully understand what's going on. Especially on #3.

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  • How do I do high quality scaling of a image?

    - by pbhogan
    I'm writing some code to scale a 32 bit RGBA image in C/C++. I have written a few attempts that have been somewhat successful, but they're slow and most importantly the quality of the sized image is not acceptable. I compared the same image scaled by OpenGL (i.e. my video card) and my routine and it's miles apart in quality. I've Google Code Searched, scoured source trees of anything I thought would shed some light (SDL, Allegro, wxWidgets, CxImage, GD, ImageMagick, etc.) but usually their code is either convoluted and scattered all over the place or riddled with assembler and little or no comments. I've also read multiple articles on Wikipedia and elsewhere, and I'm just not finding a clear explanation of what I need. I understand the basic concepts of interpolation and sampling, but I'm struggling to get the algorithm right. I do NOT want to rely on an external library for one routine and have to convert to their image format and back. Besides, I'd like to know how to do it myself anyway. :) I have seen a similar question asked on stack overflow before, but it wasn't really answered in this way, but I'm hoping there's someone out there who can help nudge me in the right direction. Maybe point me to some articles or pseudo code... anything to help me learn and do. Here's what I'm looking for: 1. No assembler (I'm writing very portable code for multiple processor types). 2. No dependencies on external libraries. 3. I am primarily concerned with scaling DOWN, but will also need to write a scale up routine later. 4. Quality of the result and clarity of the algorithm is most important (I can optimize it later). My routine essentially takes the following form: DrawScaled( uint32 *src, uint32 *dst, src_x, src_y, src_w, src_h, dst_x, dst_y, dst_w, dst_h ); Thanks! UPDATE: To clarify, I need something more advanced than a box resample for downscaling which blurs the image too much. I suspect what I want is some kind of bicubic (or other) filter that is somewhat the reverse to a bicubic upscaling algorithm (i.e. each destination pixel is computed from all contributing source pixels combined with a weighting algorithm that keeps things sharp. EXAMPLE: Here's an example of what I'm getting from the wxWidgets BoxResample algorithm vs. what I want on a 256x256 bitmap scaled to 55x55. And finally: the original 256x256 image

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  • Java app makes screen display unresponsive after 10 minutes of user idle time

    - by Ross
    I've written a Java app that allows users to script mouse/keyboard input (JMacro, link not important, only for the curious). I personally use the application to automate character actions in an online game overnight while I sleep. Unfortunately, I keep coming back to the computer in the morning to find it unresponsive. Upon further testing, I'm finding that my application causes the computer to become unresponsive after about 10 minutes of user idle time (even if the application itself it simulating user activity). I can't seem to pin-point the issue, so I'm hoping somebody else might have a suggestion of where to look or what might be causing the issue. The relevant symptoms and characteristics: Unresponsiveness occurs after user is idle for 10 minutes User can still move the mouse pointer around the screen Everything but the mouse appears frozen... mouse clicks have no effect and no applications update their displays, including the Windows 7 desktop I left the task manager up along the with the app overnight so I could see the last task manager image before the screen freezes... the Java app is at normal CPU/Memory usage and total CPU usage is only ~1% After moving the mouse (in other words, the user comes back from being idle), the screen image starts updating again within 30 minutes (this is very hit and miss... sometimes 10 minutes, sometimes no results after two hours) User can CTRL-ALT-DEL to get to Windows 7's CTRL-ALT-DEL screen (after a 30 second pause). User is still able to move mouse pointer, but clicking any of the button options causes the screen to appear to freeze again On some very rare occasions, the system never freezes, and I come back to it in the morning with full responsiveness The Java app automatically stops input scripting in the middle of the night, so Windows 7 detects "real" idleness and turns the monitors into Standby mode... which they successfully come out of upon manually moving the mouse in the morning when I wake up, even though the desktop display still appears frozen Given the symptoms and characteristics of the issue, it's as if the Java app is causing the desktop display of the logged in user to stop updating, including any running applications. Programming concepts and Java packages used: Multi-threading Standard out and err are rerouted to a javax.swing.JTextArea The application uses a Swing GUI awt.Robot (very heavily used) awt.PointerInfo awt.MouseInfo System Specs: Windows 7 Professional Java 1.6.0 u17 In conclusion, I should stress that I'm not looking for any specific solutions, as I'm not asking a very specific question. I'm just wondering if anybody has run into a similar problem when using the Java libraries that I'm using. I would also gladly appreciate any suggestions for things to try to attempt to further pinpoint what is causing my problem. Thanks! Ross PS, I'll post an update/answer if I manage to stumble across anything else while I continue to debug this.

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  • Myself throwing NullReferenceException... needs help

    - by Amit Ranjan
    I know it might be a weird question and its Title too, but i need your help. I am a .net dev , working on platform for the last 1.5 years. I am bit confused on the term usually we say " A Good Programmer ". I dont know ,what are the qualities of a good programmer ? Is the guy who writes a bug free code? or Can develop applications solely? or blah blah blah...lots of points. I dont know... But as far i am concerned , I know I am not a good programmer, still in learning phase an needs a lot to learn in coming days. So you guys are requested to please help me with this two problems of mine My first problem is regarding the proper Error Handling, which is a most debatable aspect of programming. We all know we use ` try { } catch { } finally { } ` in our code to manage exception. But even if I use try { } catch(exception ex) { throw ex } finally { } , different guys have different views. I still dont know the good way to handle errors. I can write code, use try-catch but still i feel I lacks something. When I saw the codes generated by .net fx tools even they uses throw ex or `throw new Exception("this is my exception")`.. I am just wondering what will be the best way to achieve the above. All means the same thing but why we avoid something. If it has some demerits then it must be made obselete.Anyways I still dont have one [how to handle errors efficiently?]. I generally follow the try-catch(execoption ex){throw ex}, and usually got stucked in debates with leads why you follow this why not that... 2.Converting your entire code blocks in modules using Design patterns of some OOPs concepts. How do you guys decide what architeture or pattern will be the best for my upcoming application based on its working, flow etc. I need to know what you guys can see that I can't. Since I know , I dont have that much experience but I can say, with my experience that experience doesnot comes either from degree/certificates or success you made instead it cames from failures you faced or got stucking situations. Pleas help me out.

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  • Learn C# now or finish up with Java and then learn C#?

    - by Sahat
    Ok here is my situation. I've studied Java in my college for 2 semesters. But you know they teach you jack in there, just the basics. We skipped half of our textbook and even then our professors don't teach from section to section of each chapter. I don't blame them. It's hard as it is for new students to understand even the basic concepts of programming. Now this is a community college we are talking about and not Stanford, MIT or Berkeley. So like I said I've done 2 semester of Java. I really like our textbook because it has some challenging projects to do at the end of each chapter. This textbook is pretty clear and i have no problem understanding it (although 2-D and 3-D Arrays have given me some trouble). I have tried reading a few C# books such as Pro C# 2008 and .NET 3.5 and C# 4.0 in a Nutshell. I found these books to be dry and overloaded with information that put me to sleep (No offense to the authors of those 2 wonderful, according to amazon ratings, books). Would you suggest I finish my Java textbook, brush up my knowledge of Arrays, Polymorphism, and etc that are universal to most programming languages. And then switch to C#, plus the syntax is very similar so it should be easy to switch. Or should I just start learning C# right now from the very beginning? If it's the latter then could you recommend some free online resources that will keep me engaged and at the same time teach me everything I need to know about C#. Someone has recommended me to learn .NET first, but I found it to be not the brightest idea. .NET is just a big monster full of libraries. How am I going to apply it if I don't even know the C# or VB!? Anyway back to my question: Master Java and switch to C# or just go with C#? DISCLAIMER: I don't want to start .NET vs J2EE or C# vs Java flame war. I am going with C#. I've decided that I want to work in a Microsoft shop in the future. .NET is what I want to learn. Thanks! Will be waiting for the answers.

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  • segmented reduction with scattered segments

    - by Christian Rau
    I got to solve a pretty standard problem on the GPU, but I'm quite new to practical GPGPU, so I'm looking for ideas to approach this problem. I have many points in 3-space which are assigned to a very small number of groups (each point belongs to one group), specifically 15 in this case (doesn't ever change). Now I want to compute the mean and covariance matrix of all the groups. So on the CPU it's roughly the same as: for each point p { mean[p.group] += p.pos; covariance[p.group] += p.pos * p.pos; ++count[p.group]; } for each group g { mean[g] /= count[g]; covariance[g] = covariance[g]/count[g] - mean[g]*mean[g]; } Since the number of groups is extremely small, the last step can be done on the CPU (I need those values on the CPU, anyway). The first step is actually just a segmented reduction, but with the segments scattered around. So the first idea I came up with, was to first sort the points by their groups. I thought about a simple bucket sort using atomic_inc to compute bucket sizes and per-point relocation indices (got a better idea for sorting?, atomics may not be the best idea). After that they're sorted by groups and I could possibly come up with an adaption of the segmented scan algorithms presented here. But in this special case, I got a very large amount of data per point (9-10 floats, maybe even doubles if the need arises), so the standard algorithms using a shared memory element per thread and a thread per point might make problems regarding per-multiprocessor resources as shared memory or registers (Ok, much more on compute capability 1.x than 2.x, but still). Due to the very small and constant number of groups I thought there might be better approaches. Maybe there are already existing ideas suited for these specific properties of such a standard problem. Or maybe my general approach isn't that bad and you got ideas for improving the individual steps, like a good sorting algorithm suited for a very small number of keys or some segmented reduction algorithm minimizing shared memory/register usage. I'm looking for general approaches and don't want to use external libraries. FWIW I'm using OpenCL, but it shouldn't really matter as the general concepts of GPU computing don't really differ over the major frameworks.

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  • polymorphism, inheritance in c# - base class calling overridden method?

    - by Andrew Johns
    This code doesn't work, but hopefully you'll get what I'm trying to achieve here. I've got a Money class, which I've taken from http://www.noticeablydifferent.com/CodeSamples/Money.aspx, and extended it a little to include currency conversion. The implementation for the actual conversion rate could be different in each project, so I decided to move the actual method for retrieving a conversion rate (GetCurrencyConversionRate) into a derived class, but the ConvertTo method contains code that would work for any implementation assuming the derived class has overriden GetCurrencyConversionRate so it made sense to me to keep it in the parent class? So what I'm trying to do is get an instance of SubMoney, and be able to call the .ConvertTo() method, which would in turn use the overriden GetCurrencyConversionRate, and return a new instance of SubMoney. The problem is, I'm not really understanding some concepts of polymorphism and inheritance yet, so not quite sure what I'm trying to do is even possible in the way I think it is, as what is currently happening is that I end up with an Exception where it has used the base GetCurrencyConversionRate method instead of the derived one. Something tells me I need to move the ConvertTo method down to the derived class, but this seems like I'll be duplicating code in multiple implementations, so surely there's a better way? public class Money { public CurrencyConversionRate { get { return GetCurrencyConversionRate(_regionInfo.ISOCurrencySymbol); } } public static decimal GetCurrencyConversionRate(string isoCurrencySymbol) { throw new Exception("Must override this method if you wish to use it."); } public Money ConvertTo(string cultureName) { // convert to base USD first by dividing current amount by it's exchange rate. Money someMoney = this; decimal conversionRate = this.CurrencyConversionRate; decimal convertedUSDAmount = Money.Divide(someMoney, conversionRate).Amount; // now convert to new currency CultureInfo cultureInfo = new CultureInfo(cultureName); RegionInfo regionInfo = new RegionInfo(cultureInfo.LCID); conversionRate = GetCurrencyConversionRate(regionInfo.ISOCurrencySymbol); decimal convertedAmount = convertedUSDAmount * conversionRate; Money convertedMoney = new Money(convertedAmount, cultureName); return convertedMoney; } } public class SubMoney { public SubMoney(decimal amount, string cultureName) : base(amount, cultureName) {} public static new decimal GetCurrencyConversionRate(string isoCurrencySymbol) { // This would get the conversion rate from some web or database source decimal result = new Decimal(2); return result; } }

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  • Where should I initialize variables for an OO Recursive Descent Parse Tree?

    - by Vasto
    I'd like to preface this by stating that this is for a class, so please don't solve this for me. One of my labs for my cse class is creating an interpreter for a BNF that was provided. I understand most of the concepts, but I'm trying to build up my tree and I'm unsure where to initialize values. I've tried in both the constructor, and in the methods but Eclipse's debugger still only shows the left branch, even though it runs through completely. Here is my main procedure so you can get an idea of how I'm calling the methods. public class Parser { public static void main(String[] args) throws IOException { FileTokenizer instance = FileTokenizer.Instance(); FileTokenizer.main(args); Prog prog = new Prog(); prog.ParseProg(); prog.PrintProg(); prog.ExecProg(); } Now here is My Prog class: public class Prog { private DeclSeq ds; private StmtSeq ss; Prog() { ds = new DeclSeq(); ss = new StmtSeq(); } public void ParseProg() { FileTokenizer instance = FileTokenizer.Instance(); instance.skipToken(); //Skips program (1) // ds = new DeclSeq(); ds.ParseDS(); instance.skipToken(); //Skips begin (2) // ss = new StmtSeq(); ss.ParseSS(); instance.skipToken(); } I've tried having Prog() { ds = null; ss = null; } public void ParseProg() { FileTokenizer instance = FileTokenizer.Instance(); instance.skipToken(); //Skips program (1) ds = new DeclSeq(); ds.ParseDS(); ... But it gave me the same error. I need the parse tree built up so I can do a pretty print and an execute command, but like I said, I only get the left branch. Any help would be appreciated. Explanations why are even more so appreciated. Thank you, Vasto

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  • What makes great software?

    - by VirtuosiMedia
    From the perspective of an end user, what makes a software great rather than just good or functional? What are some fundamental principles that can shift the way a software is used and perceived? What are some of the little finishing touches that help put an application over the top? I'm in the later stages of developing a web app and I'm looking for ideas or concepts that I may have missed. If you have specific examples of software or apps that you absolutely love, please share the reasons or features that make it special. Keep in mind that I'm looking for examples that directly affect the end user, but not necessarily just UI suggestions. Here are some of the principles and little touches I'm trying to use: Keep the UI as simple as possible. Remove absolutely everything that isn't necessary. Use progressive disclosure when more information can be needed sometimes but isn't needed all the time. Provide inline help and useful error messages. Verbs on buttons wherever possible. Make anything that's clickable obvious. Fast, responsive UI. Accessibility (this is a work in progress). Reusable UI patterns. Once a user learns a skill, they will be able to use it in multiple places. Intelligent default settings. Auto-focusing forms when filling out the form is the primary action to be taken on the page. Clear metaphors (like tabs) and headings indicating location within the app. Automating repetitive tasks (with the ability to disable the automation). Use standardized or accepted metaphors for icons (like an "x" for delete). Larger text sizes for improved readability. High contrast so that each section is distinct. Making sure that it's obvious on every page what the user is supposed to do by establishing a clear information hierarchy and drawing the eye to the call to action. Most deletions can be undone. Discoverability - Make it easy to learn how to do new tasks. Group similar elements together.

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  • Learning... anything really

    - by WebDevHobo
    I'm particularly interested in Windows PowerShell, but here's a somewhat more general complaint: When asking for help on learning something new, be it a small subject on PHP or understanding a class in Java, what usually happens is that people direct me towards the documentation pages. What I'm looking for is somewhat of a course. A deep explanation of why something works the way it does. I know my basic programming, like Java and C#. I've never seen C or C++, though I have seen a bit of assembler. I know what the Stack and Heap are, how boxing and unboxing works, why you have to deep-copy an array instead of copying the pointer and some other things. Windows PowerShell on the other hand, I know nothing about. And I notice that when reading the small document or some code, I usually forget what it does or why it works. What I am looking for is preferably, a nice tutorial that explains the beginnings, the concepts, and goes to more difficult things at a steady pace. The only thing documentation can do is explain what a function does. That's no good to me since I don't know what I want to do yet. I could read about a thousand functions, and forget about most of them, because I don't need to implement them right after it. Randomly wandering through the documentation doesn't do me any good. So conclude, what is a good tutorial on Windows Powershell? One which explains in clear language what is happening, one which builds on previous things learned. I don't think googling this is a good idea. Doing a Google search on this would turn up numerous tutorials. And experience tells me that you have to look long and hard to find the gem you're looking for. That's why I'm asking here. Because this is the place where you can find more experienced people. Many of the PowerShell guys among you will know the good ones already, and by asking you, I avoid wasting time that could be spent learning. So to summarize: I will not google this!

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  • 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?

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  • Spring MVC, REST, and HATEOAS

    - by SingleShot
    I'm struggling with the correct way to implement Spring MVC 3.x RESTful services with HATEOAS. Consider the following constraints: I don't want my domain entities polluted with web/rest constructs. I don't want my controllers polluted with view constructs. I want to support multiple views. Currently I have a nicely put together MVC app without HATEOAS. Domain entities are pure POJOs without any view or web/rest concepts embedded. For example: class User { public String getName() {...} public String setName(String name) {...} ... } My controllers are also simple. They provide routing and status, and delegate to Spring's view resolution framework. Note my application supports JSON, XML, and HTML, yet no domain entities or controllers have embedded view information: @Controller @RequestMapping("/users") class UserController { @RequestMapping public ModelAndView getAllUsers() { List<User> users = userRepository.findAll(); return new ModelAndView("users/index", "users", users); } @RequestMapping("/{id}") public ModelAndView getUser(@PathVariable Long id) { User user = userRepository.findById(id); return new ModelAndView("users/show", "user", user); } } So, now my issue - I'm not sure of a clean way to support HATEOAS. Here's an example. Let's say when the client asks for a User in JSON format, it comes out like this: { firstName: "John", lastName: "Smith" } Let's also say that when I support HATEOAS, I want the JSON to contain a simple "self" link that the client can then use to refresh the object, delete it, or something else. It might also have a "friends" link indicating how to get the user's list of friends: { firstName: "John", lastName: "Smith", links: [ { rel: "self", ref: "http://myserver/users/1" }, { rel: "friends", ref: "http://myserver/users/1/friends" } ] } Somehow I want to attach links to my object. I feel the right place to do this is in the controller layer as the controllers all know the correct URLs. Additionally, since I support multiple views, I feel like the right thing to do is somehow decorate my domain entities in the controller before they are converted to JSON/XML/whatever in Spring's view resolution framework. One way to do this might be to wrap the POJO in question with a generic Resource class that contains a list of links. Some view tweaking would be required to crunch it into the format I want, but its doable. Unfortunately nested resources could not be wrapped in this way. Other things that come to mind include adding links to the ModelAndView, and then customizing each of Spring's out-of-the-box view resolvers to stuff links into the generated JSON/XML/etc. What I don't want is to be constantly hand-crafting JSON/XML/etc. to accommodate various links as they come and go during the course of development. Thoughts?

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  • Primary language - QtC++, 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?

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  • NHibernate does not update entity when repository is passed by constructor

    - by Alex
    Hi everybody, I am developing with NHibernate for the first time in conjunction with ASP.NET MVC and StructureMap. The CodeCampServer serves as a great example for me. I really like the different concepts which were implemented there and I can learn a lot from it. In my controllers I use Constructur Dependency Injection to get an instance of the specific repository needed. My problem is: If I change an attribute of the customer the customer's data is not updated in the database, although Commit() is called on the transaction object (by a HttpModule). public class AccountsController : Controller { private readonly ICustomerRepository repository; public AccountsController(ICustomerRepository repository) { this.repository = repository; } public ActionResult Save(Customer customer) { Customer customerToUpdate = repository .GetById(customer.Id); customerToUpdate.GivenName = "test"; //<-- customer does not get updated in database return View(); } } On the other hand this is working: public class AccountsController : Controller { [LoadCurrentCustomer] public ActionResult Save(Customer customer) { customer.GivenName = "test"; //<-- Customer gets updated return View(); } } public class LoadCurrentCustomer : ActionFilterAttribute { public override void OnActionExecuting(ActionExecutingContext filterContext) { const string parameterName = "Customer"; if (filterContext.ActionParameters.ContainsKey(parameterName)) { if (filterContext.HttpContext.User.Identity.IsAuthenticated) { Customer CurrentCustomer = DependencyResolverFactory .GetDefault() .Resolve<IUserSession>() .GetCurrentUser(); filterContext.ActionParameters[parameterName] = CurrentCustomer; } } base.OnActionExecuting(filterContext); } } public class UserSession : IUserSession { private readonly ICustomerRepository repository; public UserSession(ICustomerRepository customerRepository) { repository = customerRepository; } public Customer GetCurrentUser() { var identity = HttpContext.Current.User.Identity; if (!identity.IsAuthenticated) { return null; } Customer customer = repository.GetByEmailAddress(identity.Name); return customer; } } I also tried to call update on the repository like the following code shows. But this leads to an NHibernateException which says "Illegal attempt to associate a collection with two open sessions". Actually there is only one. public ActionResult Save(Customer customer) { Customer customerToUpdate = repository .GetById(customer.Id); customer.GivenName = "test"; repository.Update(customerToUpdate); return View(); } Does somebody have an idea why the customer is not updated in the first example but is updated in the second example? Why does NHibernate say that there are two open sessions?

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