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  • PHP running as a FastCGI application (php-cgi) - how to issue concurrent requests?

    - by Sbm007
    Some background information: I'm writing my own webserver in Java and a couple of days ago I asked on SO how exactly Apache interfaces with PHP, so I can implement PHP support. I learnt that FastCGI is the best approach (since mod_php is not an option). So I have looked at the FastCGI protocol specification and have managed to write a working FastCGI wrapper for my server. I have tested phpinfo() and it works, in fact all PHP functions seem to work just fine (posting data, sessions, date/time, etc etc). My webserver is able to serve requests concurrently (ie user1 can retrieve file1.html at the same time as user2 requesting some_large_binary_file.zip), it does this by spawning a new Java thread for each user request (terminating when completed or user connection with client is cancelled). However, it cannot deal with 2 (or more) FastCGI requests at the same time. What it does is, it queues them up, so when request 1 is completed immediately thereafter it starts processing request 2. I tested this with 2 PHP pages, one contains sleep(10) and the other phpinfo(). How would I go about dealing with multiple requests as I know it can be done (PHP under IIS runs as FastCGI and it can deal with multiple requests just fine). Some more info: I am coding under windows and my batch file used to execute php-cgi.exe contains: set PHP_FCGI_CHILDREN=8 set PHP_FCGI_MAX_REQUESTS=500 php-cgi.exe -b 9000 But it does not spawn 8 children, the service simply terminates after 500 requests. I have done research and from Wikipedia: Processing of multiple requests simultaneously is achieved either by using a single connection with internal multiplexing (ie. multiple requests over a single connection) and/or by using multiple connections Now clearly the multiple connections isn't working for me, as everytime a client requests something that involves FastCGI it creates a new socket to the FastCGI application, but it does not work concurrently (it queues them up instead). I know that internal multiplexing of FastCGI requests under the same connection is accomplished by issuing each unique FastCGI request with a different request ID. (also see the last 3 paragraphs of 'The Communication Protocol' heading in this article). I have not tested this, but how would I go about implementing that? I take it I need some kind of FastCGI Java thread which contains a Map of some sort and a static function which I can use to add requests to. Then in the Thread's run() function it would have a while loop and for every cycle it would check whether the Map contains new requests, if so it would assign them a request ID and write them to the FastCGI stream. And then wait for input etc etc, As you can see this becomes too complicated. Does anyone know the correct way of doing this? Or any thoughts at all? Thanks very much. Note, if required I can supply the code for my FastCGI wrapper.

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  • ANSI C as core of a C# project? Is this possible?

    - by Nektarios
    I'm writing a NON-GUI app which I want to be cross platform between OS X and Windows. I'm looking at the following architecture, but I don't know if it will work on the windows side: (Platform specific entry point) - ANSI C main loop = ANSI C model code doing data processing / logic = (Platform specific helpers) So the core stuff I'm planning to write in regular ANSI C, because A) it should be platform independent, B) I'm extremely comfortable with C, C) It can do the job and do it well (Platform specific entry point) can be written in whatever necessary to get the job done, this is a small amount of code, doesn't matter to me. (Platform specific helpers) is the sticky thing. This is stuff like parsing XML, accessing databases, graphics toolkit stuff, whatever. Things that aren't easy in C. Things that modern languages/frameworks will give for free. On OS X this code will be written in Objective-C interfacing with Cocoa. On Windows I'm thinking my best bet is to use C# So on Windows my architecture (simplified) looks like (C# or C?) - ANSI C - C# Is this possible? Some thoughts/suggestions so far.. 1) Compile my C core as a .dll -- this is fine, but seems there's no way to call my C# helpers unless I can somehow get function pointers and pass them to my core, but that seems unlikely 2) Compile a C .exe and a C# .exe and have them talk via shared memory or some kind of IPC. I'm not entirely opposed to this but it obviously introduces a lot of complexity so it doesn't seem ideal 3) Instead of C# use C++, it gets me some nice data management stuff and nice helper code. And I can mix it pretty easily. And the work I do could probably easily port to Linux. But I really don't like C++, and I don't want this to turn in to a 3rd-party-library-fest. Not that it's a huge deal, but it's 2010.. anything for basic data management should be built in. And targetting Linux is really not a priority. Note that no "total" alternatives are OK as suggested in other similar questions on SO I've seen; java, RealBasic, mono.. this is an extremely performance intensive application doing soft realtime for game/simulation purposes, I need C & friends here to do it right (maybe you don't, but I do)

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  • Refactoring Singleton Overuse

    - by drharris
    Today I had an epiphany, and it was that I was doing everything wrong. Some history: I inherited a C# application, which was really just a collection of static methods, a completely procedural mess of C# code. I refactored this the best I knew at the time, bringing in lots of post-college OOP knowledge. To make a long story short, many of the entities in code have turned out to be Singletons. Today I realized I needed 3 new classes, which would each follow the same Singleton pattern to match the rest of the software. If I keep tumbling down this slippery slope, eventually every class in my application will be Singleton, which will really be no logically different from the original group of static methods. I need help on rethinking this. I know about Dependency Injection, and that would generally be the strategy to use in breaking the Singleton curse. However, I have a few specific questions related to this refactoring, and all about best practices for doing so. How acceptable is the use of static variables to encapsulate configuration information? I have a brain block on using static, and I think it is due to an early OO class in college where the professor said static was bad. But, should I have to reconfigure the class every time I access it? When accessing hardware, is it ok to leave a static pointer to the addresses and variables needed, or should I continually perform Open() and Close() operations? Right now I have a single method acting as the controller. Specifically, I continually poll several external instruments (via hardware drivers) for data. Should this type of controller be the way to go, or should I spawn separate threads for each instrument at the program's startup? If the latter, how do I make this object oriented? Should I create classes called InstrumentAListener and InstrumentBListener? Or is there some standard way to approach this? Is there a better way to do global configuration? Right now I simply have Configuration.Instance.Foo sprinkled liberally throughout the code. Almost every class uses it, so perhaps keeping it as a Singleton makes sense. Any thoughts? A lot of my classes are things like SerialPortWriter or DataFileWriter, which must sit around waiting for this data to stream in. Since they are active the entire time, how should I arrange these in order to listen for the events generated when data comes in? Any other resources, books, or comments about how to get away from Singletons and other pattern overuse would be helpful.

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  • MATLAB arbitrary code execution

    - by aristotle2600
    I am writing an automatic grader program under linux. There are several graders written in MATLAB, so I want to tie them all together and let students run a program to do an assignment, and have them choose the assignment. I am using a C++ main program, which then has mcc-compiled MATLAB libraries linked to it. Specifically, my program reads a config file for the names of the various matlab programs, and other information. It then uses that information to present choices to the student. So, If an assignment changes, is added or removed, then all you have to do is change the config file. The idea is that next, the program invokes the correct matlab library that has been compiled with mcc. But, that means that the libraries have to be recompiled if a grader gets changed. Worse, the whole program must be recompiled if a grader is added or removed. So, I would like one, simple, unchanging matlab library function to call the grader m-files directly. I currently have such a library, that uses eval on a string passed to it from the main program. The problem is that when I do this, apparently, mcc absorbs the grader m-code into itself; changing the grader m code after compilation has no effect. I would like for this not to happen. It was brought to my attention that Mathworks may not want me to be able to do this, since it could bypass matlab entirely. That is not my intention, and I would be happy with a solution that requires a full matlab install. My possible solutions are to use a mex file for the main program, or have the main program call a mcc library, which then calls a mex file, which then calls the proper grader. The reason I am hesitant about the first solution is that I'm not sure how many changes I would have to make to my code to make it work; my code is C++, not C, which I think makes things more complicated. The 2nd solution, though, may just be more complicated and ultimately have the same problem. So, any thoughts on this situation? How should I do this?

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  • NSFetchedResultsChangeUpdate crashes when called on a searched tableview

    - by Zachary Fisher
    So I nearly have this thing figured out, but I am stumbling over the NSFetchedResultsChangeUpdate when I update my managedObjectContext from a detail view that was entered after searching the table. I have a tableview generated from a core data set. I can enter a detail view from this table and make changes without any issue. I can also search the table and make changes MOST of the time without any issues. However, on certain objects, I get an "Exception was caught during Core Data change processing". I tracked this down to the NSFetchedResultsChangeUpdate. I'm using the following code: case NSFetchedResultsChangeUpdate: if (searchTermForSegue) { NSLog(@"index info:%@.....",theIndexPath); NSLog(@"crashing at the next line"); [self fetchedResultsController:self.searchFetchedResultsController configureCell:[tableView cellForRowAtIndexPath:theIndexPath] atIndexPath:theIndexPath]; break; } else { [self fetchedResultsController:controller configureCell:[tableView cellForRowAtIndexPath:theIndexPath] atIndexPath:theIndexPath]; } break; When the table is not being searched, it runs the else method and that works 100% of the time. When the table is being searched, it runs the if (searchTermForSegue) and that works most of the time, but not always. I logged theIndexPath and discovered the following: When it works, theIndexPath is correctly reporting the objects indexPat, when it fails, the wrong theIndexPath has been called. For example, if I do a search that narrows the tableView to 3 sections, 2 items in first, 1 in second, 1 in third, I get the following nslog: On first object: index info:<NSIndexPath 0xb0634d0> 2 indexes [0, 0]..... on second object: index info:<NSIndexPath 0xb063e70> 2 indexes [0, 1]..... on third object: index info:<NSIndexPath 0xb042880> 2 indexes [1, 0]..... but on the last object: index info:<NSIndexPath 0x9665790> 2 indexes [2, 17]..... it should be calling [2, 0] Note that I am simply updating these objects, not deleting them or adding new ones. Any thoughts would be appreciated!

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  • Should I create a unique clustered index, or non-unique clustered index on this SQL 2005 table?

    - by Bremer
    I have a table storing millions of rows. It looks something like this: Table_Docs ID, Bigint (Identity col) OutputFileID, int Sequence, int …(many other fields) We find ourselves in a situation where the developer who designed it made the OutputFileID the clustered index. It is not unique. There can be thousands of records with this ID. It has no benefit to any processes using this table, so we plan to remove it. The question, is what to change it to… I have two candidates, the ID identity column is a natural choice. However, we have a process which does a lot of update commands on this table, and it uses the Sequence to do so. The Sequence is non-unique. Most records only contain one, but about 20% can have two or more records with the same Sequence. The INSERT app is a VB6 piece of crud throwing thousands insert commands at the table. The Inserted values are never in any particular order. So the Sequence of one insert may be 12345, and the next could be 12245. I know that this could cause SQL to move a lot of data to keep the clustered index in order. However, the Sequence of the inserts are generally close to being in order. All inserts would take place at the end of the clustered table. Eg: I have 5 million records with Sequence spanning 1 to 5 million. The INSERT app will be inserting sequence’s at the end of that range at any given time. Reordering of the data should be minimal (tens of thousands of records at most). Now, the UPDATE app is our .NET star. It does all UPDATES on the Sequence column. “Update Table_Docs Set Feild1=This, Field2=That…WHERE Sequence =12345” – hundreds of thousands of these a day. The UPDATES are completely and totally, random, touching all points of the table. All other processes are simply doing SELECT’s on this (Web pages). Regular indexes cover those. So my question is, what’s better….a unique clustered index on the ID column, benefiting the INSERT app, or a non-unique clustered index on the Sequence, benefiting the UPDATE app?

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  • Basic drawing with Quartz 2D on iPhone

    - by wwrob
    My goal is to make a program that will draw points whenever the screen is touched. This is what I have so far: The header file: #import <UIKit/UIKit.h> @interface ElSimView : UIView { CGPoint firstTouch; CGPoint lastTouch; UIColor *pointColor; CGRect *points; int npoints; } @property CGPoint firstTouch; @property CGPoint lastTouch; @property (nonatomic, retain) UIColor *pointColor; @property CGRect *points; @property int npoints; @end The implementation file: //@synths etc. - (id)initWithFrame:(CGRect)frame { return self; } - (id)initWithCoder:(NSCoder *)coder { if(self = [super initWithCoder:coder]) { self.npoints = 0; } return self; } - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *touch = [touches anyObject]; firstTouch = [touch locationInView:self]; lastTouch = [touch locationInView:self]; } - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *touch = [touches anyObject]; lastTouch = [touch locationInView:self]; points = (CGRect *)malloc(sizeof(CGRect) * ++npoints); points[npoints-1] = CGRectMake(lastTouch.x-15, lastTouch.y-15,30,30); [self setNeedsDisplay]; } - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *touch = [touches anyObject]; lastTouch = [touch locationInView:self]; [self setNeedsDisplay]; } - (void)drawRect:(CGRect)rect { CGContextRef context = UIGraphicsGetCurrentContext(); CGContextSetLineWidth(context, 2.0); CGContextSetStrokeColorWithColor(context, [UIColor blackColor].CGColor); CGContextSetFillColorWithColor(context, pointColor.CGColor); for(int i=0; i<npoints; i++) CGContextAddEllipseInRect(context, points[i]); CGContextDrawPath(context, kCGPathFillStroke); } - (void)dealloc { free(points); [super dealloc]; } @end When I load this and click some points, it draws the first points normally, then then next points are drawn along with random ellipses (not even circles). Also I have another question: When is exactly drawRect executed?

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  • Commitment to Zend Framework - any arguments against?

    - by Pekka
    I am refurbishing a big CMS that I have been working on for quite a number of years now. The product itself is great, but some components, the Database and translation classes for example, need urgent replacing - partly self-made as far back as 2002, grown into a bit of a chaos over time, and might have trouble surviving a security audit. So, I've been looking closely at a number of frameworks (or, more exactly, component Libraries, as I do not intend to change the basic structure of the CMS) and ended up with liking Zend Framework the best. They offer a solid MVC model but don't force you into it, and they offer a lot of professional components that have obviously received a lot of attention (Did you know there are multiple plurals in Russian, and you can't translate them using a simple ($number == 0) or ($number > 1) switch? I didn't, but Zend_Translate can handle it. Just to illustrate the level of thorougness the library seems to have been built with.) I am now literally at the point of no return, starting to replace key components of the system by the Zend-made ones. I'm not really having second thoughts - and I am surely not looking to incite a flame war - but before going onward, I would like to step back for a moment and look whether there is anything speaking against tying a big system closely to Zend Framework. What I like about Zend: As far as I can see, very high quality code Extremely well documented, at least regarding introductions to how things work (Haven't had to use detailed API documentation yet) Backed by a company that has an interest in seeing the framework prosper Well received in the community, has a considerable user base Employs coding standards I like Comes with a full set of unit tests Feels to me like the right choice to make - or at least, one of the right choices - in terms of modern, professional PHP development. I have been thinking about encapsulating and abstracting ZF's functionality into own classes to be able to switch frameworks more easily, but have come to the conclusion that this would not be a good idea because: it would be an unnecessary level of abstraction it could cost performance the big advantage of using a framework - the existence of a developer base that is familiar with its components - would partly be cancelled out therefore, the commitment to ZF would be a deep one. Thus my question: Is there anything substantial speaking against committing to the Zend Framework? Do you have insider knowledge of plans of Zend Inc.'s to go evil in 2011, and make it a closed source library? Is Zend Inc. run by vampires? Are there conceptual flaws in the code base you start to notice when you've transitioned all your projects to it? Is the appearance of quality code an illusion? Does the code look good, but run terribly slow on anything below my quad-core workstation?

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  • The 80 column limit, still useful?

    - by Tim Post
    Related: While coding, how many columns do you format for? Is there a valid reason for enforcing a maximum width of 80 characters in a code file, this day and age? I mostly use C, however this question is language agnostic. Its also subjective, so I'll tag it as such. Many individual projects set their own various coding standards, a guide to adjust your coding style. Many enforce an 80 column limit on code, i.e. don't force a dumb 80 x 25 terminal to wrap your lines in someone else's editor of choice if they are stuck with such a display, don't force them to turn off wrapping. Both private and open source projects usually have some style guidelines. My question is, in this day and age, is that requirement more of a pest than a helper? Does anyone still login via the local console with no framebuffer and actually edit code? If so, how often and why cant you use SSH? I help to manage a few open source projects, I was considering extending this limit to 110 columns, but I wanted to get feedback first. So, any feedback is appreciated. I can see the need to make certain OUTPUT of programs (i.e. a --help /h display) 80 columns or less, but I really don't see the need to force people to break up code under 110 columns long into 2 lines, when its easier to read on one line. I can also see the case for adhering to an 80 column limit if you're writing code that will be used on micro controllers that have to be serviced in the field with a god-knows-what terminal emulator. Beyond that, what are your thoughts? Edit: This is not an exact duplicate. I am asking very specific questions, such as how many people are actually still using such a display. I am also not asking "what is a good column limit", I'm proposing one and hoping to gather feedback. Beyond that, I'm also citing cases where the 80 column limit is still a good idea. I don't want a guide to my own "c-style", I'm hoping to adjust standards for several projects. If the duplicate in question had answered all of my questions, I would not have posted this one :) That will teach me to mention it next time. Edit 2 question |= COMMUNITY_WIKI

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  • Illegal Instruction When Programming C++ on Linux

    - by remagen
    Heyo, My program, which does exactly the same thing every time it runs (moves a point sprite into the distance) will randomly fail with the text on the terminal 'Illegal Instruction'. My googling has found people encountering this when writing assembly which makes sense because assembly throws those kinds of errors. But why would g++ be generating an illegal instruction like this? It's not like I'm compiling for Windows then running on Linux (which even then, as long as both are on x86 shouldn't AFAIK cause an Illegal Instruction). I'll post the main file below. I can't reliably reproduce the error. Although, if I make random changes (add a space here, change a constant there) that force a recompile I can get a binary which will fail with Illegal Instruction every time it is run, until I try setting a break point, which makes the illegal instruction 'dissapear'. :( #include <stdio.h> #include <stdlib.h> #include <GL/gl.h> #include <GL/glu.h> #include <SDL/SDL.h> #include "Screen.h" //Simple SDL wrapper #include "Textures.h" //Simple OpenGL texture wrapper #include "PointSprites.h" //Simple point sprites wrapper double counter = 0; /* Here goes our drawing code */ int drawGLScene() { /* These are to calculate our fps */ static GLint T0 = 0; static GLint Frames = 0; /* Move Left 1.5 Units And Into The Screen 6.0 */ glLoadIdentity(); glTranslatef(0.0f, 0.0f, -6); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT); glEnable(GL_POINT_SPRITE_ARB); glTexEnvi(GL_POINT_SPRITE, GL_COORD_REPLACE, GL_TRUE); glBegin( GL_POINTS ); /* Drawing Using Triangles */ glVertex3d(0.0,0.0, 0); glVertex3d(1.0,0.0, 0); glVertex3d(1.0,1.0, counter); glVertex3d(0.0,1.0, 0); glEnd( ); /* Finished Drawing The Triangle */ /* Move Right 3 Units */ /* Draw it to the screen */ SDL_GL_SwapBuffers( ); /* Gather our frames per second */ Frames++; { GLint t = SDL_GetTicks(); if (t - T0 >= 50) { GLfloat seconds = (t - T0) / 1000.0; GLfloat fps = Frames / seconds; printf("%d frames in %g seconds = %g FPS\n", Frames, seconds, fps); T0 = t; Frames = 0; counter -= .1; } } return 1; } GLuint objectID; int main( int argc, char **argv ) { Screen screen; screen.init(); screen.resize(800,600); LoadBMP("./dist/Debug/GNU-Linux-x86/particle.bmp"); InitPointSprites(); while(true){drawGLScene();} }

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  • Codeigniter: Retrieving data on button click with Ajax

    - by OllyTenerife
    I have a simple webpage which generates a random quote from my database upon refreshing the page. I wish to implement some AJAX and JQuery in order to generate quotes via the button rather than having to refresh the page. I have done some research but I am not sure how to implement this in Codeigniter. My current code is below... Page controller: public function index() { $this->load->model('quote_model', '', TRUE); $data['quotes'] = $this->quote_model->getRandom(); $this->load->view('home', $data); } The view: <?php include ('layout/header.php'); ?> <div class="container-fluid"> <div class="row"> <div class="col-md-4 quote-holder"> <img src="application/assets/alan1.jpg" alt="..." class="img-circle img-responsive"> <br> <blockquote class="text-center"> <p><?php echo $quotes[0]['quote']; ?></p> <footer class="text-center"><?php echo $quotes[0]['character_name']; ?> in <cite title="Source Title"><?php echo $quotes[0]['series_name']; ?></cite></footer> </blockquote> <button type="button" class="btn btn-default center-block">Generate quote</button> </div> </div> <?php include ('layout/footer.php'); ?> Here is the function in the model I am retrieving the data from: function getRandom() { $query = $this->db->query(" SELECT * FROM quotes, characters, series WHERE quotes.series_id = series.series_id AND quotes.character_id = characters.character_id ORDER BY rand() LIMIT 1 "); return $query->result_array(); } Should I simply be using something like this? $("button").click(function(){ $.get( "Page/index", function( data ) { //output data to page element... } });

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  • Patterns for dynamic CMS components (event driven?)

    - by CitrusTree
    Sorry my title is not great, this is my first real punt at moving 100% to OO as I've been procedural for more years than I can remember. I'm finding it hard to understand if what I'm trying to do is possible. Depending on people's thoughts on the 2 following points, I'll go down that route. The CMS I'm putting together is quote small, however focuses very much on different types of content. I could easily use Drupal which I'm very comfortable with, but I want to give myself a really good reasons to move myself into design patterns / OO-PHP 1) I have created a base 'content' class which I wish to be able to extend to handle different types of content. The base class, for example, handles HTML content, and extensions might handle XML or PDF output instead. On the other hand, at some point I may wish to extend the base class for a given project completely. I.e. if class 'content-v2' extended class 'content' for that site, any calls to that class should actually call 'content-v2' instead. Is that possible? If the code instantiates an object of type 'content' - I actually want it to instantiate one of type 'content-v2'... I can see how to do it using inheritance, but that appears to involve referring to the class explicitly, I can't see how to link the class I want it to use instead dynamically. 2) Secondly, the way I'm building this at the moment is horrible, I'm not happy with it. It feels very linear indeed - i.e. get session details get content build navigation theme page publish. To do this all the objects are called 1-by-1 which is all very static. I'd like it to be more dynamic so that I can add to it at a later date (very closely related to first question). Is there a way that instead of my orchestrator class calling all the other classes 1-by-1, then building the whole thing up at the end, that instead each of the other classes can 'listen' for specific events, then at the applicable point jump in and do their but? That way the orchestrator class would not need to know what other classes were required, and call them 1-by-1. Sorry if I've got this all twisted in my head. I'm trying to build this so it's really flexible.

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  • Using hidden values with jQuery (and ASP.NET MVC) -- not working?

    - by SlackerCoder
    Im using a couple of JSON calls to render data, etc etc. In order to keep the proper key value, I am storing it in a tag. I have this in several places in my code, none of which cause an issue like this one is. Here is the jQuery: The call that "sets" the value: $("a[id^='planSetupAddNewPlan']").live('click', function() { var x = $(this).attr('id'); x = x.substring(19); $("#hidPlanSetupCurrentGroupKey").val(x); $.getJSON("/GroupSetup/PlanSetupAddNewList", { GroupKey: x }, function(data) { $("#planSetupAddNew").html('' + data.TableResult + ''); alert('First Inside 2 ' + x); $.blockUI({ message: $("#planSetupAddNew") }); }); }); The call that "gets" the value: $("#ddlPlanSetupAddNewProduct").live('change', function() { var a = $("#hidPlanSetupCurrentGroupKey").val(); var prod = $(this).val(); alert(a); $.getJSON("/GroupSetup/PlanSetupChangePlanList", { GroupKey: a, Product: prod }, function(data) { if (data.Message == "Success") { $("#planSetupAddNewPlan").html('' + data.TableResult + ''); } else if (data.Message == "Error") { //Do something } }); }); Here is the html in question: <div id="planSetupAddNew" style="display:none; cursor: default;"> <input type="hidden" id="hidPlanSetupCurrentGroupKey" /> <div id="planSetupAddNewData"> </div> </div> In the first section, the alert ('First Inside 2 ' + x) returns what I expect (where x = the key value), and if I add a line to display the contents of the hidden field, that works as well: ie. var key = $("#hidPlanSetupCurrentGroupKey").val(); alert(key); In the "alert(a);" call, I am getting "undefined". I have looked at the other code in the same view and it is the same and it works. I must be missing something, or have some sort of mistype that I havent caught. Just an overview of the controller events: The first call (/GroupSetup/PlanSetupAddNewList) will return an html string building a "form" for users to enter information into. The second call (/GroupSetup/PlanSetupChangePlanList) just changes a second dropdown based on the first dropdown selection (overwriting the html in the div). If you need more info, let me know! Any thoughts/tips/pointers/suggestions?!?! Thanks for all your help :)

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  • [C++] std::string manipulation: whitespace, "newline escapes '\'" and comments #

    - by rubenvb
    Kind of looking for affirmation here. I have some hand-written code, which I'm not shy to say I'm proud of, which reads a file, removes leading whitespace, processes newline escapes '\' and removes comments starting with #. It also removes all empty lines (also whitespace-only ones). Any thoughts/recommendations? I could probably replace some std::cout's with std::runtime_errors... but that's not a priority here :) const int RecipeReader::readRecipe() { ifstream is_recipe(s_buffer.c_str()); if (!is_recipe) cout << "unable to open file" << endl; while (getline(is_recipe, s_buffer)) { // whitespace+comment removeLeadingWhitespace(s_buffer); processComment(s_buffer); // newline escapes + append all subsequent lines with '\' processNewlineEscapes(s_buffer, is_recipe); // store the real text line if (!s_buffer.empty()) v_s_recipe.push_back(s_buffer); s_buffer.clear(); } is_recipe.close(); return 0; } void RecipeReader::processNewlineEscapes(string &s_string, ifstream &is_stream) { string s_temp; size_t sz_index = s_string.find_first_of("\\"); while (sz_index <= s_string.length()) { if (getline(is_stream,s_temp)) { removeLeadingWhitespace(s_temp); processComment(s_temp); s_string = s_string.substr(0,sz_index-1) + " " + s_temp; } else cout << "Error: newline escape '\' found at EOF" << endl; sz_index = s_string.find_first_of("\\"); } } void RecipeReader::processComment(string &s_string) { size_t sz_index = s_string.find_first_of("#"); s_string = s_string.substr(0,sz_index); } void RecipeReader::removeLeadingWhitespace(string &s_string) { const size_t sz_length = s_string.size(); size_t sz_index = s_string.find_first_not_of(" \t"); if (sz_index <= sz_length) s_string = s_string.substr(sz_index); else if ((sz_index > sz_length) && (sz_length != 0)) // "empty" lines with only whitespace s_string.clear(); } Some extra info: the first s_buffer passed to the ifstream contains the filename, std::string s_buffer is a class data member, so is std::vector v_s_recipe. Any comment is welcome :)

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  • StringIndexOutOfBoundsException: String index out of range 0

    - by Evan F
    I'm trying to write a program to take the first letter of the user input to generate a username. I'm trying to write it so that if the user leaves the input blank, then the letter that would otherwise be taken to generate the username defaults to the letter 'z'. Here is my full code: import java.util.Scanner; /** UsernameGenerator.java Generates a username based on the users inputs. @author: Evan Fravert */ public class UsernameGenerator { /** * Generates a username based on the users inputs. *@param args command line argument */ public static void main(String[] args) { // abcde String first; String middle; String last; String password1; String password2; int randomNum; randomNum = (int) (Math.random() * 1000) + 100; Scanner userInput = new Scanner(System.in); System.out.println("Please enter your first name:"); first = userInput.nextLine(); String firstLower = first.toLowerCase(); System.out.println("Please enter your middle name:"); middle = userInput.nextLine(); String middleLower = middle.toLowerCase(); System.out.println("Please enter your last name:"); last = userInput.nextLine(); int lastEnd = last.length()-1; String lastLower = last.toLowerCase(); System.out.println("Please enter your password:"); password1 = userInput.nextLine(); System.out.println("Please enter your password again:"); password2 = userInput.nextLine(); char firstLetter = firstLower.charAt(0); char middleLetter = middleLower.charAt(0); char lastLetter = lastLower.charAt(0); char lastLast = lastLower.charAt(lastEnd); if first.length() == 0) { firstLetter = 'z'; } else { firstLetter = firstLower.charAt(0); } System.out.println("Your username is " + firstLetter + "" + middleLetter + "" + lastLetter + "" + "" + lastLast + "" + randomNum); System.out.println("Your password is " + password1); System.out.println("Welcome " + first + " " + middle + " " + last + "!"); } }

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  • SQL Server 2005: Update rows in a specified order (like ORDER BY)?

    - by JMTyler
    I want to update rows of a table in a specific order, like one would expect if including an ORDER BY clause, but SQL Server does not support the ORDER BY clause in UPDATE queries. I have checked out this question which supplied a nice solution, but my query is a bit more complicated than the one specified there. UPDATE TableA AS Parent SET Parent.ColA = Parent.ColA + (SELECT TOP 1 Child.ColA FROM TableA AS Child WHERE Child.ParentColB = Parent.ColB ORDER BY Child.Priority) ORDER BY Parent.Depth DESC; So, what I'm hoping that you'll notice is that a single table (TableA) contains a hierarchy of rows, wherein one row can be the parent or child of any other row. The rows need to be updated in order from the deepest child up to the root parent. This is because TableA.ColA must contain an up-to-date concatenation of its own current value with the values of its children (I realize this query only concats with one child, but that is for the sake of simplicity - the purpose of the example in this question does not necessitate any more verbosity), therefore the query must update from the bottom up. The solution suggested in the question I noted above is as follows: UPDATE messages SET status=10 WHERE ID in (SELECT TOP (10) Id FROM Table WHERE status=0 ORDER BY priority DESC ); The reason that I don't think I can use this solution is because I am referencing column values from the parent table inside my subquery (see WHERE Child.ParentColB = Parent.ColB), and I don't think two sibling subqueries would have access to each others' data. So far I have only determined one way to merge that suggested solution with my current problem, and I don't think it works. UPDATE TableA AS Parent SET Parent.ColA = Parent.ColA + (SELECT TOP 1 Child.ColA FROM TableA AS Child WHERE Child.ParentColB = Parent.ColB ORDER BY Child.Priority) WHERE Parent.Id IN (SELECT Id FROM TableA ORDER BY Parent.Depth DESC); The WHERE..IN subquery will not actually return a subset of the rows, it will just return the full list of IDs in the order that I want. However (I don't know for sure - please tell me if I'm wrong) I think that the WHERE..IN clause will not care about the order of IDs within the parentheses - it will just check the ID of the row it currently wants to update to see if it's in that list (which, they all are) in whatever order it is already trying to update... Which would just be a total waste of cycles, because it wouldn't change anything. So, in conclusion, I have looked around and can't seem to figure out a way to update in a specified order (and included the reason I need to update in that order, because I am sure I would otherwise get the ever-so-useful "why?" answers) and I am now hitting up Stack Overflow to see if any of you gurus out there who know more about SQL than I do (which isn't saying much) know of an efficient way to do this. It's particularly important that I only use a single query to complete this action. A long question, but I wanted to cover my bases and give you guys as much info to feed off of as possible. :) Any thoughts?

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  • Architectural Design for a Data-Driven Silverlight WP7 app

    - by Rosarch
    I have a Silverlight Windows Phone 7 app that pulls data from a public API. I find myself doing much of the same thing over and over again: In the UI, set a loading message or loading progress bar in place of where the content is Get the content, which may be already in memory, cached in isolated file storage, or require an HTTP request If the content can not be acquired (no network connection, etc), display an error message If the content is acquired, display it in the UI Keep the content in main memory for subsequent queries The content that is displayed to the user can be taken directly from a data source, such as an ObservableCollection, or it may be a query on a data source. I would like to factor out this repetitive process into a framework where ideally only the following needs to be specified: Where to display the content in the UI The UI elements to show while loading, on failure, and on success The URI of the HTTP request How to parse the HTTP response into the data structure that will kept in memory The location of the file in isolated storage, if it exists How to parse the file contents into the data structure that will be kept in memory It may sound like a lot, but two strings, three FrameworkElements, and two methods is less than the overhead that I currently have. Also, this needs to work for however the data is maintained in memory, and needs to work for direct collections and queries on those collections. My questions are: Has something like this already been implemented? Are my thoughts about the topic above fundamentally wrong in some way? Here is a design I'm thinking of: There are two components, a View and a Model. The View is given the FrameworkElements for loading, failure, and success. It is also given a reference to the corresponding Model. The View is a UserControl that is placed somewhere in the UI. The Model a class that is given the URI for the data, a method of how to parse the data, and optionally a filename and how to parse the file. It is responsible for retrieving the data and notifying the View whenever the current status (loading/fail/success) changes. If the data downloaded from the network is different from the cache, the network data takes precedence. When the app closes or is tombstoned, the model writes the data to the cache. How does that sound?

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  • New to MVC. Actionscript 3.0 Appreciate your help.

    - by Combustion007
    Hello Everyone, I am new to design patterns and am trying to learn the MVC implementation. I have written four classes: DataModel DataView DataController Main Main serves as the application facade. The main FLA is called HelloWorld. I have a symbol called "Box" in HelloWorld. I just would like to add an instance of the "Box" on the stage. Eventually I would like to place a button and when the button is clicked, the Box instance color will be changed. I would appreciate any help, please help me figure out what am I doing wrong. Here are my Classes: DATAMODEL CLASS: package { import flash.events.*; public class DataModel extends EventDispatcher { public static const UPDATE:String = "modelUpdate"; private var _color:Number = (Math.round(Math.random()* 0xffffff)); public function DataModel() { trace("DATA MODEL INIT"); } public function get color():Number { return _color; } public function set color(p:Number):void { _color = p; notifyObserver(); } public function notifyObserver():void { dispatchEvent(new Event(DataModel.UPDATE)); } } } //DATACONTROLLER CLASS: package { import flash.events.; import flash.display.; import flash.errors.*; public class DataController { private var _model:DataModel; public function DataController(m:DataModel) { trace("DATACONTROLLER INIT"); _model = m; } } } DATAVIEW CLASS: package { import flash.events.; import flash.display.; import flash.errors.*; public class DataView extends Sprite { private var _model:DataModel; private var _controller:DataController; private var b:Box; public function DataView(m:DataModel, c:DataController) { _model = m; _controller = c; b = new Box(); b.x = b.y = 100; addChild(b); } } } And Finally THE FACADE: package { import flash.display.; import flash.events.; import flash.text.; import flash.errors.; public class Main extends Sprite { private var _model:DataModel; private var _controller:DataController; private var _view:DataView; public function Main(m:DataModel, c:DataController, v:DataView) { _model = m; _controller = c; _view = v; addChild(v); } } } When I test the movie: I get this error: ArgumentError: Error #1063: Argument count mismatch on Main(). Expected 3, got 0. Thanks alot.

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  • 'Timeout Expired' error against local SQL Express on only 2 LINQ Methods...

    - by Refracted Paladin
    I am going to sum up my problem first and then offer massive details and what I have already tried. Summary: I have an internal winform app that uses Linq 2 Sql to connect to a local SQL Express database. Each user has there own DB and the DB stay in sync through Merge Replication with a Central DB. All DB's are SQL 2005(sp2or3). We have been using this app for over 5 months now but recently our users are getting a Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. Detailed: The strange part is they get that in two differnt locations(2 differnt LINQ Methods) and only the first time they fire in a given time period(~5mins). One LINQ method is pulling all records that match a FK ID and then Manipulating them to form a Heirarchy View for a TreeView. The second is pulling all records that match a FK ID and dumping them into a DataGridView. The only things I can find in common with the 2 are that the first IS an IEnumerable and the second converts itself from IQueryable - IEnumerable - DataTable... I looked at the query's in Profiler and they 'seemed' normal. They are not very complicated querys. They are only pulling back 10 - 90 records, from one table. Any thoughts, suggestions, hints whatever would be greatly appreciated. I am at my wit's end on this.... public IList<CaseNoteTreeItem> GetTreeViewDataAsList(int personID) { var myContext = MatrixDataContext.Create(); var caseNotesTree = from cn in myContext.tblCaseNotes where cn.PersonID == personID orderby cn.ContactDate descending, cn.InsertDate descending select new CaseNoteTreeItem { CaseNoteID = cn.CaseNoteID, NoteContactDate = Convert.ToDateTime(cn.ContactDate). ToShortDateString(), ParentNoteID = cn.ParentNote, InsertUser = cn.InsertUser, ContactDetailsPreview = cn.ContactDetails.Substring(0, 75) }; return caseNotesTree.ToList<CaseNoteTreeItem>(); } AND THIS ONE public static DataTable GetAllCNotes(int personID) { using (var context = MatrixDataContext.Create()) { var caseNotes = from cn in context.tblCaseNotes where cn.PersonID == personID orderby cn.ContactDate select new { cn.ContactDate, cn.ContactDetails, cn.TimeSpentUnits, cn.IsCaseLog, cn.IsPreEnrollment, cn.PresentAtContact, cn.InsertDate, cn.InsertUser, cn.CaseNoteID, cn.ParentNote }; return caseNotes.ToList().CopyLinqToDataTable(); } }

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  • ActionScript 2: Event doesn't fire?

    - by Pascal Schuster
    So I have a soundHandler class that's supposed to play sounds and then point back to a function on the timeline when the sound has completed playing. But somehow, only one of the sounds plays when I try it out. EDIT: After that sound plays, nothing happens, even though I have EventHandlers set up that are supposed to do something. Here's the code: import mx.events.EventDispatcher; class soundHandler { private var dispatchEvent:Function; public var addEventListener:Function; public var removeEventListener:Function; var soundToPlay; var soundpath:String; var soundtype:String; var prefix:String; var mcname:String; public function soundHandler(soundpath:String, prefix:String, soundtype:String, mcname:String) { EventDispatcher.initialize(this); _root.createEmptyMovieClip(mcname, 1); this.soundpath = soundpath; this.soundtype = soundtype; this.prefix = prefix; this.mcname = mcname; } function playSound(file, callbackfunc) { _root.soundToPlay = new Sound(_root.mcname); _global.soundCallbackfunc = callbackfunc; _root.soundToPlay.onLoad = function(success:Boolean) { if (success) { _root.soundToPlay.start(); } }; _root.soundToPlay.onSoundComplete = function():Void { trace("Sound Complete: "+this.soundtype+this.prefix+this.file+".mp3"); trace(arguments.caller); dispatchEvent({type:_global.soundCallbackfunc}); trace(this.toString()); trace(this.callbackfunction); }; _root.soundToPlay.loadSound("../sound/"+soundpath+"/"+soundtype+prefix+file+".mp3", true); _root.soundToPlay.stop(); } } Here's the code from the .fla file: var playSounds:soundHandler = new soundHandler("signup", "su", "s", "mcs1"); var file = "000"; playSounds.addEventListener("sixtyseconds", this); playSounds.addEventListener("transition", this); function sixtyseconds() { trace("I am being called! Sixtyseconds"); var phase = 1; var file = random(6); if (file == 0) { file = 1; } if (file<10) { file = "0"+file; } file = phase+file; playSounds.playSound(file, "transition"); } function transition() { trace("this works"); } playSounds.playSound(file, "sixtyseconds"); I'm at a total loss for this one. Have been wasting hours to figure it out already. Any help will be deeply appreciated.

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  • Drupal incorrectly espaces tags in javascript

    - by sergdev
    I installed drupal-6.16. I applied the patch from the post http://drupal.org/node/222926#comment-930745. It works correctly in simple cases. But for following code for counter is handled incorrectly: <br><br> Text <br><br> <!-- counter.1Gb.ua --> <script language="javascript" type="text/javascript"> cgb_js="1.0"; cgb_r=""+Math.random()+"&r="+ escape(document.referrer)+"&pg="+ escape(window.location.href); document.cookie="rqbct=1; path=/"; cgb_r+="&c="+ (document.cookie?"Y":"N"); </script><script language="javascript1.1" type="text/javascript"> cgb_js="1.1";cgb_r+="&j="+ (navigator.javaEnabled()?"Y":"N")</script> <script language="javascript1.2" type="text/javascript"> cgb_js="1.2"; cgb_r+="&wh="+screen.width+ 'x'+screen.height+"&px="+ (((navigator.appName.substring(0,3)=="Mic"))? screen.colorDepth:screen.pixelDepth)</script> <script language="javascript1.3" type="text/javascript"> cgb_js="1.3"</script> <script language="javascript" type="text/javascript">cgb_r+="&js="+cgb_js; document.write("<a href='http://www.1Gb.ua?cnt=1416'>"+ "<img src='http://counter.1Gb.ua/cnt.aspx?"+ "u=1416&"+cgb_r+ "&' border=0 width=88 height=31 "+ "alt='1Gb.ua counter'><\/a>")</script> <noscript><a href='http://www.1Gb.ua?cnt=1416'> <img src="http://counter.1Gb.ua/cnt.aspx?u=1416" border=0 width="88" height="31" alt="1Gb.ua counter"></a> </noscript> <!-- /counter.1Gb.ua --> It modifies the string "alt='1Gb.ua counter' /><\/a>")</a></script> to "alt='1Gb.ua counter' />&lt;\/a>")</a></script> Does anybody have this code working? If so how this can be fixed? Thanks a lot in advance!

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  • GTK+ widgets/windows being (randomly) corrupted, with what seems to be timers.

    - by nubela
    Hi, I have recently implemented a scrolling text across an area of limited screen estate using a timers repeating every 100ms, and some simple string appending. However, after this very implementation, I have come to realise that my GUI is getting randomly bugged/corrupted after a certain while. That is to say that some widgets/windows become completely white, and eventually the entire GUI turns white and unclickable. What is weird is that there is no error debug output at all. Having said that, I am using Mono with GTK-Sharp for the application. Does anyone have an idea or a possible clue how and why this is happening? If not, how can I further debug this properly? Thanks, really appreciate it. PS: Sometimes, it takes up to 1.5 hours for the thing to start corrupting, it has random timeframes for it to start happening. This is my the code implemented that caused this issue: void ScrollSyncTo(object sender, System.Timers.ElapsedEventArgs e) { //initial check if it fits nicely alr if (sync_to_full_txt.Length <= sync_to_max_char) { sync_to_timer.Stop(); return; } //check for pause if (sync_to_pause >= 0) { sync_to_pause--; return; } //check direction int temp_psn; string temp_str; if (sync_to_direction) { temp_psn = sync_to_posn + 1; if (sync_to_full_txt.Substring(temp_psn).Length < sync_to_max_char) { sync_to_pause = sync_to_break_steps; sync_to_direction = false; sync_to_posn = sync_to_full_txt.Length - 1; System.GC.Collect(); return; } else { temp_str = sync_to_full_txt.Substring(temp_psn, sync_to_max_char); } } else { temp_psn = sync_to_posn - 1; if (temp_psn + 1 < sync_to_max_char) { sync_to_pause = sync_to_break_steps; sync_to_direction = true; sync_to_posn = 0; System.GC.Collect(); return; } else { temp_str = sync_to_full_txt.Substring(temp_psn - sync_to_max_char + 1, sync_to_max_char); } } //lets move it sync_to.Text = temp_str; sync_to_posn = temp_psn; }

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  • installing a package with xml based configuration in python

    - by saminny
    Hi, I am planning to write a generic python module for installing a package. This script should retrieve the module from a remote machine or locally and install it on a given host and user. However, there needs to be changes made to the package files based on the host, user and given environment. My approach is to use XML to describe changes to be made to package files based on environment. It will first extract the package to the user directory and then using an xml configuration file, it should replace the file values in the package directory. The xml would look something like this: <package version="1.3.3"> <environment type="prod"> <file dir="d1/d2" name="f1"> <var id="RECV_HOST" value="santo"> <var id="RECV_PORT" value="RECV_PORT_SERVICE" type="service"> <var id="JEPL_SERVICE_NAME" value="val_omgact"> </file> <var dir="d4/d3/s2" name="f2"> <var id="PRECISION" value="true"> <var id="SEND_STATUS_CODE" value="323"> <var id="JEPL_SERVICE_NAME" value="val_omgact"> </file> </environment> <environment type="qa"> <file dir="d1/d2" name="f1"> <var id="RECV_HOST" value="test"> <var id="RECV_PORT" value="1444"> <var id="JEPL_SERVICE_NAME" value="val_tsdd"> </file> <file dir="d4/d3/s2" name="f2"> <var id="PRECISION" value="false"> <var id="SEND_STATUS_CODE" value="323"> <var id="JEPL_SERVICE_NAME" value="val_dsd"> </file> </environment> </package> What are your thoughts on this approach? Is there an existing python module, package or script that I could use for this purpose since this seems fairly generic and can be used for any installation. Thanks! Sam

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  • -[NSConcreteMutableData release]: message sent to deallocated instance

    - by kamibutt
    Dear members, I am facing a problem of -[NSConcreteMutableData release]: message sent to deallocated instance, i have attached my sample code as well. - (IBAction)uploadImage { NSString *urlString = @"http://192.168.1.108/iphoneimages/uploadfile.php?userid=1&charid=23&msgid=3"; //if(FALSE) for (int i=0; i<[imgArray count]; i++) { // setting up the request object now NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init]; [request setURL:[NSURL URLWithString:urlString]]; [request setHTTPMethod:@"POST"]; /* add some header info now we always need a boundary when we post a file also we need to set the content type You might want to generate a random boundary.. this is just the same as my output from wireshark on a valid html post */ NSString *boundary = [NSString stringWithString:@"---------------------------14737809831466499882746641449"]; NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@",boundary]; [request addValue:contentType forHTTPHeaderField: @"Content-Type"]; /* now lets create the body of the post */ NSMutableData *body = [[NSMutableData data] autorelease]; NSString *str = [NSString stringWithFormat:@"Content-Disposition: form-data; name=\"userfile\"; filename=\"ipodfile%d.jpg\"\r\n",i]; [body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]]; [body appendData:[[NSString stringWithString:str] dataUsingEncoding:NSUTF8StringEncoding]]; [body appendData:[[NSString stringWithString:@"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]]; NSData *imageData = UIImageJPEGRepresentation([imgArray objectAtIndex:i], 90); [body appendData:[NSData dataWithData:imageData]]; [body appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]]; // setting the body of the post to the reqeust [request setHTTPBody:body]; // now lets make the connection to the web [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil]; //NSString *returnString = [[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding]; //NSLog(@"%@",returnString); [imageData release]; [request release]; //[body release]; } } It successfully upload the images to the folder and there is no any error in the execution but when it complete it process and try to go back it give error -[NSConcreteMutableData release]: message sent to deallocated instance Please help me out. Thanks

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  • Calculating Growth-Rates by applying log-differences

    - by mropa
    I am trying to transform my data.frame by calculating the log-differences of each column and controlling for the rows id. So basically I like to calculate the growth rates for each id's variable. So here is a random df with an id column, a time period colum p and three variable columns: df <- data.frame (id = c("a","a","a","c","c","d","d","d","d","d"), p = c(1,2,3,1,2,1,2,3,4,5), var1 = rnorm(10, 5), var2 = rnorm(10, 5), var3 = rnorm(10, 5) ) df id p var1 var2 var3 1 a 1 5.375797 4.110324 5.773473 2 a 2 4.574700 6.541862 6.116153 3 a 3 3.029428 4.931924 5.631847 4 c 1 5.375855 4.181034 5.756510 5 c 2 5.067131 6.053009 6.746442 6 d 1 3.846438 4.515268 6.920389 7 d 2 4.910792 5.525340 4.625942 8 d 3 6.410238 5.138040 7.404533 9 d 4 4.637469 3.522542 3.661668 10 d 5 5.519138 4.599829 5.566892 Now I have written a function which does exactly what I want BUT I had to take a detour which is possibly unnecessary and can be removed. However, somehow I am not able to locate the shortcut. Here is the function and the output for the posted data frame: fct.logDiff <- function (df) { df.log <- dlply (df, "code", function(x) data.frame (p = x$p, log(x[, -c(1,2)]))) list.nalog <- llply (df.log, function(x) data.frame (p = x$p, rbind(NA, sapply(x[,-1], diff)))) ldply (list.nalog, data.frame) } fct.logDiff(df) id p var1 var2 var3 1 a 1 NA NA NA 2 a 2 -0.16136569 0.46472004 0.05765945 3 a 3 -0.41216720 -0.28249264 -0.08249587 4 c 1 NA NA NA 5 c 2 -0.05914281 0.36999681 0.15868378 6 d 1 NA NA NA 7 d 2 0.24428771 0.20188025 -0.40279188 8 d 3 0.26646102 -0.07267311 0.47041227 9 d 4 -0.32372771 -0.37748866 -0.70417351 10 d 5 0.17405309 0.26683625 0.41891802 The trouble is due to the added NA-rows. I don't want to collapse the frame and reduce it, which would be automatically done by the diff() function. So I had 10 rows in my original frame and am keeping the same amount of rows after the transformation. In order to keep the same length I had to add some NAs. I have taken a detour by transforming the data.frame into a list, add the NAs, and afterwards transform the list back into a data.frame. That looks tedious. Any ideas to avoid the data.frame-list-data.frame class transformation and optimize the function?

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