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  • How does this Switch statement know which case to execute? (PHP/MySQL)

    - by ggfan
    Here is a code form a PHP+MySQL book I am reading and I am having trouble understanding this code. This code is about checking a file uploaded into a database. (Please excuse any spelling errors if any, I was typing it in) Q1: How does it know which case to echo? In the whole code, there is no mention of each case. Q2: Why do they skip case 5?! Or does it not matter which numbers you use(so I can have case 1, case 18, case 2?) if($_FILES['userfile']['error']>0) { echo 'Problem: '; switch($_FILES['userfile']['error']) { case 1: echo 'File exceeded upload_max_filesize'; break; case 2: echo 'File exceeded max_file_size'; break; case 3: echo 'File only partially uploaded'; break; case 4: echo 'No file uploaded'; break; case 6: echo 'Cannot upload file: no temp directory specified'; break; case 7: echo 'Upload failed: Cannot write to disk'; break; } exit; }

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  • CharField values disappearing after save (readonly field)

    - by jamida
    I'm implementing simple "grade book" application where the teacher would be able to update the grades w/o being allowed to change the students' names (at least not on the update grade page). To do this I'm using one of the read-only tricks, the simplest one. The problem is that after the SUBMIT the view is re-displayed with 'blank' values for the students. I'd like the students' names to re-appear. Below is the simplest example that exhibits this problem. (This is poor DB design, I know, I've extracted just the relevant parts of the code to showcase the problem. In the real example, student is in its own table but the problem still exists there.) models.py class Grade1(models.Model): student = models.CharField(max_length=50, unique=True) finalGrade = models.CharField(max_length=3) class Grade1OForm(ModelForm): student = forms.CharField(max_length=50, required=False) def __init__(self, *args, **kwargs): super(Grade1OForm,self).__init__(*args, **kwargs) instance = getattr(self, 'instance', None) if instance and instance.id: self.fields['student'].widget.attrs['readonly'] = True self.fields['student'].widget.attrs['disabled'] = 'disabled' def clean_student(self): instance = getattr(self,'instance',None) if instance: return instance.student else: return self.cleaned_data.get('student',None) class Meta: model=Grade1 views.py from django.forms.models import modelformset_factory def modifyAllGrades1(request): gradeFormSetFactory = modelformset_factory(Grade1, form=Grade1OForm, extra=0) studentQueryset = Grade1.objects.all() if request.method=='POST': myGradeFormSet = gradeFormSetFactory(request.POST, queryset=studentQueryset) if myGradeFormSet.is_valid(): myGradeFormSet.save() info = "successfully modified" else: myGradeFormSet = gradeFormSetFactory(queryset=studentQueryset) return render_to_response('grades/modifyAllGrades.html',locals()) template <p>{{ info }}</p> <form method="POST" action=""> <table> {{ myGradeFormSet.management_form }} {% for myform in myGradeFormSet.forms %} {# myform.as_table #} <tr> {% for field in myform %} <td> {{ field }} {{ field.errors }} </td> {% endfor %} </tr> {% endfor %} </table> <input type="submit" value="Submit"> </form>

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  • Bash and regex problem : check for tokens entered into a Coke vending machine

    - by Michael Mao
    Hi all: Here is a "challenge question" I've got from Linux system programming lecture. Any of the following strings will give you a Coke if you kick: L = { aaaa, aab, aba, baa, bb, aaaa"a", aaaa"b", aab"a", … ab"b"a, ba"b"a, ab"bbbbbb"a, ... } The letters shown in wrapped double quotes indicate coins that would have fallen through (but those strings are still part of the language in this example). Exercise (a bit hard) show this is the language of a regular expression And this is what I've got so far : #!/usr/bin/bash echo "A bottle of Coke costs you 40 cents" echo -e "Please enter tokens (a = 10 cents, b = 20 cents) in a sequence like 'abba' :\c" read tokens #if [ $tokens = aaaa ]||[ $tokens = aab ]||[ $tokens = bb ] #then # echo "Good! now a coke is yours!" #else echo "Thanks for your money, byebye!" if [[ $token =~ 'aaaa|aab|bb' ]] then echo "Good! now a coke is yours!" else echo "Thanks for your money, byebye!" fi Sadly it doesn't work... always outputs "Thanks for your money, byebye!" I believe something is wrong with syntax... We didn't provided with any good reference book and the only instruction from the professor was to consult "anything you find useful online" and "research the problem yourself" :( I know how could I do it in any programming language such as Java, but get it done with bash script + regex seems not "a bit hard" but in fact "too hard" for anyone with little knowledge on something advanced as "lookahead"(is this the terminology ?) I don't know if there is a way to express the following concept in the language of regex: Valid entry would consist of exactly one of the three components : aaaa, aab and bb, regardless of order, followed by an arbitrary sequence of a or b's So this is what is should be like : (a{4}Ua{2}bUb{2})(aUb)* where the content in first braces is order irrelevant. Thanks a lot in advance for any hints and/or tips :)

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  • Types issue in F#

    - by Andry
    Hello! In my ongoing adventure deep diving into f# I am understanding a lot of this powerful language but there are things that I still do not understand so clearly. One of the most important issues I need to master is types. Well the book I am reading is very straight forward and introduces entities and main functionalities with a direct approach. The first thing I could get start with is types. It introduces the main types as list, option, tuples, and so on... It is clearly underlined that all these types are IMMUTABLE for many reasons regarding functional programming and data consistance in functional programing. Well, no problems until now... But now I am getting started with Concrete Types... Well... I have problems in managing with types like list, option, tuples, types created through new operator and concrete types created using type keyword (for abbreviations, concrete types...). So my question is: how can I efficently catalogue/distinguish all types of data in f#???? I can create a perfect separation among types in C#, VB.NET... FOr example in VB.NET there are value and reference types while in C# there are only references and also int, double are treated as objects (they are objects while in VB.NET a value type is not a object and there is a split in types for this reason). Well in F# I cannot create such differences among types in the language. Can you help me? I hope I was clear.

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  • how to push different local git branches to heroku/master

    - by lsiden
    Heroku has a policy of ignoring all branches but 'master'. While I'm sure Heroku's designers have excellent reasons for for this policy (I'm guessing for storage and performance optimization), the consequence to me as a developer is that whatever local topic branch I may be working on, I would like an easy way to switch Heroku's master to that local topic branch and do a "git push heroku -f" to over-write master on Heroku. What I got from reading the "Pushing Refspecs" section of http://progit.org/book/ch9-5.html is git push -f heroku local-topic-branch:refs/heads/master What I'd really like is a way to set this up in the config file so that "git push heroku" always does the above, replacing local-topic-branch with the name of whatever my current branch happens to be. If anyone knows how to accomplish that, please let me know! The caveat for this, of course, is that this is only sensible if I am the only one who can push to that Heroku app/repository. A test or QA team might manage such a repository to try out different candidate branches, but they would have to coordinate so that they all agree on what branch they are pushing to it on any given day. Needless to say, it would also be a very good idea to have a separate remote repository (like Github) without this restriction for backing everything up to. I'd call that one "origin" and use "heroku" for Heroku so that "git push" always backs up everything to origin, and "git push heroku" pushes whatever branch I'm currently on to Heroku's master branch, overwriting it if necessary. Can anybody tell me if this would work? [remote "heroku"] url = [email protected]:my-app.git push = +refs/heads/*:refs/heads/master I'd like to hear from someone more experienced before I begin to experiment, although I suppose I could create a dummy app on Heroku and experiment with that. As for fetching, I don't really care if the Heroku repository is write-only. I still have a separate repository, like Github, for backup and cloning of all my work. Footnote: This question is similar to, but not quite the same as http://stackoverflow.com/questions/1489393/good-git-deployment-using-branches-strategy-with-heroku

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  • making arrays from tab-delimited text file column

    - by absolutenewbie
    I was wondering if anyone could help a desperate newbie with perl with the following question. I've been trying all day but with my perl book at work, I can't seem to anything relevant in google...or maybe am genuinely stupid with this. I have a file that looks something like the following: Bob April Bob April Bob March Mary August Robin December Robin April The output file I'm after is: Bob April April March Mary August Robin December April So that it lists each month in the order that it appears for each person. I tried making it into a hash but of course it wouldn't let me have duplicates so I thought I would like to have arrays for each name (in this example, Bob, Mary and Robin). I'm afraid to upload the code I've been trying to tweak because I know it'll be horribly wrong. I think I need to define(?) the array. Would this be correct? Any help would be greatly appreciated and I promise I will be studying more about perl in the meantime. Thank you for your time, patience and help. #!/usr/bin/perl -w while (<>) { chomp; if (defined $old_name) { $name=$1; $month=$2; if ($name eq $old_name) { $array{$month}++; } else { print "$old_name"; foreach (@array) { push (@array, $month); print "\t@array"; } print "\n"; @array=(); $array{$month}++; } } else { $name=$1; $month=$2; $array{month}++; } $old_name=$name; } print "$old_name"; foreach (@array) { push (@array, $month); print "\t@array"; } print "\n";

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  • Intelligent web features, algorithms (people you may follow, similar to you ...)

    - by hilal
    I have 3 main questions about the algorithms in intelligent web (web 2.0) Here the book I'm reading http://www.amazon.com/Algorithms-Intelligent-Web-Haralambos-Marmanis/dp/1933988665 and I want to learn the algorithms in deeper 1. People You may follow (Twitter) How can one determine the nearest result to my requests ? Data mining? which algorithms? 2. How you’re connected feature (Linkedin) Simply algorithm works like that. It draws the path between two nodes let say between Me and the other person is C. Me - A, B - A connections - C . It is not any brute force algorithms or any other like graph algorithms :) 3. Similar to you (Twitter, Facebook) This algorithms is similar to 1. Does it simply work the max(count) friend in common (facebook) or the max(count) follower in Twitter? or any other algorithms they implement? I think the second part is true because running the loop dict{count, person} for person in contacts: dict.add(count(common(person))) return dict(max) is a silly act in every refreshing page. 4. Did you mean (Google) I know that they may implement it with phonetic algorithm http://en.wikipedia.org/wiki/Phonetic_algorithm simply soundex http://en.wikipedia.org/wiki/Soundex and here is the Google VP of Engineering and CIO Douglas Merrill speak http://www.youtube.com/watch?v=syKY8CrHkck#t=22m03s What about first 3 questions? Any ideas are welcome ! Thanks

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  • What computer science topic am I trying to describe?

    - by ItzWarty
    I've been programming for around... 6-8 years, and I've begun to realize that I don't really know what really happens at the low-ish level when I do something like int i = j%348 The thing is, I know what j%348 does, it divides j by 348 and finds the remainder. What I don't know is HOW the computer does this. Similarly, I know that try { blah(); }catch(Exception e){ blah2(); } will invoke blah and if blah throws, it will invoke blah2... however, I have no idea how the computer does this instead of err... crashing or ending execution. And I figure that in order for me to get "better" at programming, I should probably know what my code is really doing. [This would probably also help me optimize and... err... not do stupid things] I figure that what I'm asking for is probably something huge taught in universities or something, but to be honest, if I could learn a little, I would be happy. The point of the question is: What topic/computer-science-course am I asking about? Because in all honesty, I don't know. Since I don't know what the topic is called, I'm unable to actually find a book or online resource to learn about the topic, so I'm sort of stuck. I'd be eternally thankful if someone helped me =/

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  • How to change the margin of code's frame of showexpl.sty when numbers=none?

    - by suugaku
    Hi all, I want to align the code's frame with the formated text's frame. If the numbers=left,the mission is accomplished by configuring xleftmargin, xrightmargin, framesep, and numbersep. However, when I set numbers=none, I cannot accomplish my mission by configuring those properties. Regardless of the values set to those properties, the code's frame remains unchanged and expands beyond the \textwidth. Please see my code snippet below. Thank you in advance. \documentclass[a4paper,11pt,twoside,final,dvips]{book} \usepackage{xcolor} \usepackage{showexpl} \lstset{% breaklines=true, breakindent=0pt, basicstyle=\color{magenta}\ttfamily\tiny, keywordstyle=\color{blue}\sffamily\bfseries, identifierstyle=\color{black}, commentstyle=\color{cyan}\itshape, stringstyle=\rmfamily, showstringspaces=false, tabsize=2, %========== FRAME ========== frame=single, framerule=0.4pt, rulecolor=\color{red}, framesep=3pt, %========== MARGIN ========== xleftmargin=3.4pt, xrightmargin=3.4pt, %========== NUMBER ========== numbers=left, numberstyle=\color{red}\tiny, numbersep=6.4pt, explpreset={language={[LaTeX]TeX},pos=b}% } \usepackage{lipsum} \usepackage{printlen} %------------------------- MARKER ------------------------ \newlength{\halftextwidth} \setlength{\halftextwidth}{\textwidth*\real{0.5}} \newcommand*{\MARKER}% {% \uselengthunit{cm} \par\noindent\strut\vrule% \hrulefill~% {\color{red}\scriptsize half text area: \printlength{\halftextwidth}}% ~\hrulefill\vrule% \hrulefill~% {\color{red}\scriptsize half text area: \printlength{\halftextwidth}}% ~\hrulefill\vrule% \marginpar% {% \strut\vrule\hrulefill~% {\color{red}\scriptsize margin area: \rndprintlength{\marginparwidth}}% ~\hrulefill\vrule% }% \par% }% \begin{document} \chapter{I love \LaTeXe, but $\cdots$} \section{With numbers=left} \vfill \MARKER \begin{LTXexample} \lipsum[1-1] \end{LTXexample} \MARKER \vfill \pagebreak \section{With numbers=none} \vfill \MARKER % Any values that are assigned to xleftmargin or xrightmargin % have no effect on the margin of the code's frame. \begin{LTXexample}[numbers=none,xleftmargin=10.4pt,xrightmargin=10.4pt] \lipsum[1-1] \end{LTXexample} \MARKER \vfill \end{document}

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  • Good Learning Method for Objective-C?

    - by Josh Kahane
    Hi I know this must be asked a millions times and can't be easy to answer as there is o definitive method, but any help would be appreciated, thanks. I have been playing around with all sorts of things in Xcode and with Objective-C, however I can't seem to find a good way of learning things in an efficient way. I have bought the book 'Programming in Objective-C 2.0' and its great but just lays down the basics it seems. I want to learn in the 2D game development direction, then of course 3D after nailing that, if thats the right thing to do? I am 17 currently in year 13, last year of school/A Levels and am almost definitely taking a gap year. Any good, well known reputable courses online or offline (real world)? This is my first programming language, and I am absolutely serious about learning this. One last question, is when learning things online, I have in the past started building a feature and learning a certain aspect in programming only to find out after adding more its slows down the app or its to inefficient. Is the key to use a certain method in a certain situation (being os many ways to do the same thing) or use any of those methods and refine it in your app to make it run smoothly? Sorry, its hard for me to know when I have little experience, thus far. Sorry for rambling on! I would appreciate any help, thank you!

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  • How to avoid loading a LINQ to SQL object twice when editting it on a website.

    - by emzero
    Hi guys I know you are all tired of this Linq-to-Sql questions, but I'm barely starting to use it (never used an ORM before) and I've already find some "ugly" things. I'm pretty used to ASP.NET Webforms old school developing, but I want to leave that behind and learn the new stuff (I've just started to read a ASP.NET MVC book and a .NET 3.5/4.0 one). So here's is one thing I didn't like and I couldn't find a good alternative to it. In most examples of editing a LINQ object I've seen the object is loaded (hitting the db) at first to fill the current values on the form page. Then, the user modify some fields and when the "Save" button is clicked, the object is loaded for second time and then updated. Here's a simplified example of ScottGu NerdDinner site. // // GET: /Dinners/Edit/5 [Authorize] public ActionResult Edit(int id) { Dinner dinner = dinnerRepository.GetDinner(id); return View(new DinnerFormViewModel(dinner)); } // // POST: /Dinners/Edit/5 [AcceptVerbs(HttpVerbs.Post), Authorize] public ActionResult Edit(int id, FormCollection collection) { Dinner dinner = dinnerRepository.GetDinner(id); UpdateModel(dinner); dinnerRepository.Save(); return RedirectToAction("Details", new { id=dinner.DinnerID }); } As you can see the dinner object is loaded two times for every modification. Unless I'm missing something about LINQ to SQL caching the last queried objects or something like that I don't like getting it twice when it should be retrieved only one time, modified and then comitted back to the database. So again, am I really missing something? Or is it really hitting the database twice (in the example above it won't harm, but there could be cases that getting an object or set of objects could be heavy stuff). If so, what alternative do you think is the best to avoid double-loading the object? Thank you so much, Greetings!

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  • Need some help/advice on WCF Per-Call Service and NServiceBus interop.

    - by Alexey
    I have WCF Per-Call service wich provides data for clients and at the same time is integrated with NServiceBus. All statefull objects are stored in UnityContainer wich is integrated into custom service host. NServiceBus is configured in service host and uses same container as service instances. Every client has its own instance context(described by Juval Lowy in his book in chapter about Durable Services). If i need to send request over bus I just use some kind of dispatcher and wait response using Thread.Sleep().Since services are per-call this is ok afaik. But I am confused a bit about messages from bus, that service must handle and provide them to clients. For some data like stock quotes I just update some kind of statefull object and and then, when clients invoke GetQuotesData() just provide data from this object. But there are numerous service messages like new quote added and etc. At this moment I have an idea to implement something like "Postman daemon" =)) and store this type of messages in instance context. Then client will invoke "GetMail()",recieve those messages and parse them. Problem is that NServiceBus messages are "Interface based" and I cant pass them over WCF, so I need to convert them to types derieved from some abstract class. Dunno what is best way to handle this situation. Will be very gratefull for any advice on this. Thanks in advance.

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  • DDD: Persisting aggregates

    - by Mosh
    Hello, Let's consider the typical Order and OrderItem example. Assuming that OrderItem is part of the Order Aggregate, it an only be added via Order. So, to add a new OrderItem to an Order, we have to load the entire Aggregate via Repository, add a new item to the Order object and persist the entire Aggregate again. This seems to have a lot of overhead. What if our Order has 10 OrderItems? This way, just to add a new OrderItem, not only do we have to read 10 OrderItems, but we should also re-insert all these 10 OrderItems again. (This is the approach that Jimmy Nillson has taken in his DDD book. Everytime he wants to persists an Aggregate, he clears all the child objects, and then re-inserts them again. This can cause other issues as the ID of the children are changed everytime because of the IDENTITY column in database.) I know some people may suggest to apply Unit of Work pattern at the Aggregate Root so it keeps track of what has been changed and only commit those changes. But this violates Persistence Ignorance (PI) principle because persistence logic is leaking into the Domain Model. Has anyone thought about this before? Mosh

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  • Creating ListView with check boxes...Android

    - by deewangan
    Hello, I am trying to create a listview that has check box beside each item. (i am following a code from the book android), but i can't get it to work, every time i run it, it crashes. since i am very new to this android staff, i have no clue what to do to get it to work, any help is appreciated.the code is below. *i have created two layout files in names of list and list_item. the code for the main activity: public class ListDemoActivity extends ListActivity { /** Called when the activity is first created. */ String[] listItems = {"exploring", "android","list", "activities"}; private SimpleCursorAdapter adapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.lists); //setListAdapter(new ArrayAdapter(this,android.R.layout.simple_list_item_1, listItems)); //setContentView(R.layout.lists); Cursor c = getContentResolver().query(People.CONTENT_URI, null, null, null, null); startManagingCursor(c); String[] cols = new String[]{People.NAME}; int[] names = new int[]{R.id.row_tv}; adapter = new SimpleCursorAdapter(this,R.layout.list_item,c,cols,names); this.setListAdapter(adapter); } } the lists file content: <?xml version="1.0" encoding="utf-8"?> and the list_item file content: <?xml version="1.0" encoding="utf-8"?>

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  • What's the best way to transition to MVC coding?

    - by ggfan
    It's been around 5 months since I picked up a PHP book and started coding in PHP. At first, I created all my sites without any organizational plan or MVC. I soon found out that was a pain.. Then I started to read on stackoverflow on how to separate php and html and that's what I have been doing ever since. Ex: profile.php <--this file is HTML,css. I just echo the functions here. profile_functions.php <--this file is mostly PHP. has the functions. This is how I have been separating all my coding so far and now I feel I should move on and start MVC. But the problem is, I never used classes before and suck with them. And since MVC (such as cakephp and codeigniter) is all classes, that can't be good. My question: Is there any good books/sites/articles that teaches you how to code in MVC? I am looking for beginner beginner books :) I just started reading the codeigniter manuel and I think I am going to use that. When I looked at the example MVC, they use different PHP coding. When I start coding in MVC, would I have to learn a "new" way to code? Because right now I am coding in pure basic PHP.

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  • What is the best way to handle autorotation with multiple subview?

    - by thangnguyen
    I am learning and programing an application. I do this project based on what I learned from the book Beginning iphone 3 development. I have two main questions here: I would like to create a multi utility application so I need multiple-view. I have a main view controller which will control switching between views. In this example I have two views A and B. I have 2 view controller A and B which will handles all of events on these 2 views. I have 2 nib files viewA.xib and viewB.xib. One of the uitility is reading PDF. So I create another class which handle the PDF file which can load a PDF page call PDFview. From Interface Builder, I selected class identity for view of the viewB.xib as PDFView class. The result is I can switching between View A and view B. View B will display the content of the PDF page. I am not sure if my solution is right or wrong but now I don't know how to handle the autorotation. The rotation will active the view controller B. But the PDFView handle how to display the PDF on the View. Could you please tell me how I should handle this in a right way? Second question: Should I create the subview automatically? In case I need to do the swipe page animation, how can I do that? I think that I need to load another subview so I can do the animation when swap view. But I think this solution will waste the resource. I can just load another page of the PDF, but in this case I don't know how to use animation? Please tell me how I should solve this? I highly appreciate your time reading and answering my question. Thang Nguyen

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  • Why is it assumed that send may return with less than requested data transmitted on a blocking socke

    - by Ernelli
    The standard method to send data on a stream socket has always been to call send with a chunk of data to write, check the return value to see if all data was sent and then keep calling send again until the whole message has been accepted. For example this is a simple example of a common scheme: int send_all(int sock, unsigned char *buffer, int len) { int nsent; while(len 0) { nsent = send(sock, buffer, len, 0); if(nsent == -1) // error return -1; buffer += nsent; len -= nsent; } return 0; // ok, all data sent } Even the BSD manpage mentions that ...If no messages space is available at the socket to hold the message to be transmitted, then send() normally blocks... Which indicates that we should assume that send may return without sending all data. Now I find this rather broken but even W. Richard Stevens assumes this in his standard reference book about network programming, not in the beginning chapters, but the more advanced examples uses his own writen (write all data) function instead of calling write. Now I consider this still to be more or less broken, since if send is not able to transmit all data or accept the data in the underlying buffer and the socket is blocking, then send should block and return when the whole send request has been accepted. I mean, in the code example above, what will happen if send returns with less data sent is that it will be called right again with a new request. What has changed since last call? At max a few hundred CPU cycles have passed so the buffer is still full. If send now accepts the data why could'nt it accept it before? Otherwise we will end upp with an inefficient loop where we are trying to send data on a socket that cannot accept data and keep trying, or else? So it seems like the workaround, if needed, results in heavily inefficient code and in those circumstances blocking sockets should be avoided at all an non blocking sockets together with select should be used instead.

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  • Great examples of self-paced labs and exercises

    - by Mayo
    It is probably a safe bet that many of us are what they call Tactile / Kinesthetic Learners meaning that we learn best when we are physically doing something as opposed to listening to an online tutorial or reading a book. My goal with this question is to derive a list of books or online resources that serve as superb examples of self-paced programming labs and exercises. For example, I was extremely impressed with the SportsStore exercise in Steven Sanderson's Pro ASP.NET MVC Framework. The exercise spanned multiple chapters and gradually introduced new topics. I was also impressed with the materials associated with the Windows Azure Boot Camp. The demos and lab materials, accessible through the website, allow us to practice and reinforce what we can read about in articles and books. Please list any examples you might have, one per submission, below. The question is language/platform agnostic. Suggestions can be generic or specific to a given technology (PHP, SQL Server, Azure, Flash, Objective C, etc.). I only ask that the answers pertain to labs and exercises that relate to programming. My hope is that the best answers will float to the top allowing developers to review the top answers and find another programming topic that can be learned through example.

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  • VB.NET handling data between different forms

    - by niuchu
    Hi, I'm writing a simple application - address book. User enters new addresses and they are added as an entry to a list visible on the main form (frmStart). I use one form to add and edit (AddContForm). Add button on the frmStart works fine, however I experience some problems with the edit button as when I press it and enter new data they are added as new entry however the previous entry is still there. Logic is handled by Contact.vb class. Please let me know how to fix this problem. Here is the code: Contact.vb Public Class Contact Public Contact As String Public Title As String Public Fname As String Public Surname As String Public Address As String Private myCont As String Public Property Cont() Get Return myCont End Get Set(ByVal value) myCont = Value End Set End Property Public Overrides Function ToString() As String Return Me.Cont End Function Public Sub Display() Dim C As New Contact C.Cont = frmAddCont.txtTitle.Text C.Fname = frmAddCont.txtFName.Text C.Surname = frmAddCont.txtSName.Text C.Address = frmAddCont.txtAddress.Text frmStart.lstContact.Items.Add(C) End Sub End Class Here is frmStart.vb Public Class frmStart Public Button As String Private Sub btnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click Button = "" Button = "Add" frmAddCont.ShowDialog() End Sub Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDel.Click Button = "" Button = "Del" Dim DelCont As Contact DelCont = Me.lstContact.SelectedItem() lstContact.Items.Remove(DelCont) End Sub Private Sub lstContact_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lstContact.SelectedIndexChanged End Sub Private Sub btnEdit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnEdit.Click Button = "" Button = "Edit" Dim C As Contact If lstContact.SelectedItem IsNot Nothing Then C = DirectCast(lstContact.SelectedItem, Contact) frmAddCont.ShowDialog() End If End Sub End Class Here is AddContFrm.vb Public Class frmAddCont Public Class ControlObject Dim Title As String Dim FName As String Dim SName As String Dim Address As String Dim TelephoneNumber As Integer Dim emailAddress As String Dim Website As String Dim Photograph As String End Class Private Sub btnConfirmAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnConfirmAdd.Click Dim B As String B = frmStart.Button Dim C As New Contact C.Display() Me.Hide() If B = "Edit" Then C = DirectCast(frmStart.lstContact.SelectedItem, Contact) frmStart.lstContact.SelectedItems.Remove(C) End If End Sub Private Sub frmAddCont_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load End Sub End Class

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  • Which language should I pick up: VB.Net or C#

    - by magius
    I'm looking to pick up either C# or VB.Net. I'd done a fair bit of VB6 programming in the past. I'm looking at getting the book, Visual Basic .NET or C#, Which to Choose? but I'm hoping that someone has read it, or used both languages and can offer advice. Should I just RTFB? Edit: Anders Sandvig raised a valid question. I'm intending to develop ActiveX applications that will be served through IE. Edit: Given that the functionality is pretty close and my favored approach to learning is to "just build it" and solve problems by looking it up on the internet, I've decided that the choice of language will be based on how easy it is to learn it. I looked around and found sites like C# Corner that supports my approach. Personal note: I wish I could also select Seb Nilsson's response as an accepted answer as well. Thanks guys for your input! Alright, then! I admit, theoretically, this topic is subjective; but a quick tally of answers seems to skew votes heavily in C#'s favor. Anyway, I'm really after experiences like what Keith's alluding to. I'm hoping he'll return to this topic and drop us a few more gems.

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  • What do these C operators mean?

    - by Melkhiah66
    I'm reading the book "Programming Challenges: The Programming Contest Training Manual" and are implementing a problem where I do not understand the use of operators c1 and the comparison if (n&1), someone could help me to know they mean? this is the example code #include <stdio.h> #define MAX_N 300 #define MAX_D 150 long cache[MAX_N/2][2]; void make_cache(int n,int d,int mode) { long tmp[MAX_D]; int i,count; for(i=0;i<MAX_D;i++) tmp[i]=0; tmp[0]=1;count=0; while(count<=n) { count++; for(i=(count&1);i<=d;i+=2) { if(i) tmp[i] = tmp[i-1] + tmp[i+1]; else if(!mode) tmp[0]=tmp[1]; else tmp[0]=0; } if((count&1)==(d&1)) cache[count>>1][mode]=tmp[d]; } } int main() { int n,d,i; long sum; while(1) { scanf("%d %d",&n,&d); if(n&1) sum=0; else if(d==1) sum=1; else if(n<(d<<1)) sum=0; else if(n==(d<<1)) sum=1; else { make_cache(n,d,0); make_cache(n,d,1); sum=0; for(i=0;i<=(n>>1);i++) sum+=cache[i][0]*cache[(n>>1)-i][1]; } printf("%ld\n",sum); } return 0; }

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  • How to have a policy class implement a virtual function?

    - by dehmann
    I'm trying to design a policy-based class, where a certain interface is implemented by the policy itself, so the class derives from the policy, which itself is a template (I got this kind of thinking from Alexandrescu's book): #include <iostream> #include <vector> class TestInterface { public: virtual void test() = 0; }; class TestImpl1 { public: void test() {std::cerr << "Impl1" << std::endl;} }; template<class TestPolicy> class Foo : public TestInterface, TestPolicy { }; Then, in the main() function, I call test() on (potentially) various different objects that all implement the same interface: int main() { std::vector<TestInterface*> foos; foos.push_back(new Foo<TestImpl1>()); foos[0]->test(); delete foos[0]; return 0; } It doesn't compile, though, because the following virtual functions are pure within ‘Foo<TestImpl1>’: virtual void TestInterface::test() I thought TestInterface::test() is implemented because we derive from TestImpl1?

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  • Mathematics for Computer Science Students

    - by Ender
    To cut a long story short, I am a CS student that has received no formal Post-16 Maths education for years. Right now even my Algebra is extremely rusty and I have a couple of months to shape up my skills. I've got a couple of video lectures in my bookmarks, consisting of: Pre-Calculus Algebra Calculus Probability Introduction to Statistics Differential Equations Linear Algebra My aim as of today is to be able to read the CLRS book Introduction to Algorithms and be able to follow the Mathematical notation in that, as well as being able to confidently read and back-up any arguments written in Mathematical notation. Aside from these video lectures, can anyone recommend any good books to help teach someone wishing to go from a low-foundation level to a more advanced level of Mathematics? Just as a note, I've taken a first-year module in Analytical Modelling, so I understand some of the basic concepts of Discrete Mathematics. EDIT: Just a note to those that are looking to learn Linear Algebra using the Video Lectures I have posted up. Peteris Krumins' Blog contains a run-through of these lecture notes as well as his own commentary and lecture notes, an invaluable resource for those looking to follow the lectures too.

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  • How reliable is Verify() in Moq?

    - by matthewayinde
    I'm only new to Unit Testing and ASP.NET MVC. I've been trying to get my head into both using Steve Sanderson's "Pro ASP.NET MVC Framework". In the book there is this piece of code: public class AdminController : Controller { ... [AcceptVerbs(HttpVerbs.Post)] public ActionResult Edit(Product product, HttpPostedFileBase image) { ... productsRepository.SaveProduct(product); TempData["message"] = product.Name + " has been saved."; return RedirectToAction("Index"); } } That he tests like so: [Test] public void Edit_Action_Saves_Product_To_Repository_And_Redirects_To_Index() { // Arrange AdminController controller = new AdminController(mockRepos.Object); Product newProduct = new Product(); // Act var result = (RedirectToRouteResult)controller.Edit(newProduct, null); // Assert: Saved product to repository and redirected mockRepos.Verify(x => x.SaveProduct(newProduct)); Assert.AreEqual("Index", result.RouteValues["action"]); } THE TEST PASSES. So I intensionally corrupt the code by adding "productsRepository.DeleteProduct(product);" after the "SaveProduct(product);" as in: ... productsRepository.SaveProduct(product); productsRepository.DeleteProduct(product); ... THE TEST PASSES.(i.e Condones a calamitous [hypnosis + intellisense]-induced typo :) ) Could this test be written better? Or is there something I should know? Thanks a lot.

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  • Convert MFC Doc/View to?

    - by Harvey
    My question will be hard to form, but to start: I have an MFC SDI app that I have worked on for an embarrassingly long time, that never seemed to fit the Doc/View architecture. I.e. there isn't anything useful in the Doc. It is multi-threaded and I need to do more with threading, etc. I dream about also porting it to Linux X Windows, but I know nothing about that programming environment as yet. Maybe Mac also. My question is where to go from here? I think I would like to convert from MFC Doc/View to straight Win API stuff with message loops and window procedures, etc. But the task seems to be huge. Does the Linux X Windows environment use a similar kind of message loop, window procedure architecture? Can I go part way? Like convert a little at a time without rendering my program unusable for long periods of work? What is the best book to read to help me to move in that direction.

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