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Please suggest other ways of communicating between server & client.

- by Geo

I'm writing a TCP chat server ( programming language does not mather ). It's a school project for my nephew, so it won't be released, and all questions I'm asking are just for my knowledge :). . Some of the things it will support: chatting between users ( doh ), it will be multithreaded sending each other files I know I could easily get away with all the stuff above if I go with serialization, and just send objects from client to server and back. But, if I do that, it will be limited to a specific programming language ( meaning clients written in other programming languages may not be able to deserialize the objects ). What would be the way to go so that other clients written in other languages could be supported? One way to go, off the top of my head, would be to go in this direction: the server & the client communicate by sending messages & chunks ( in lieu of other names ). Here's what I mean by this: every time the client/server wants to send something ( text message or file ) it will first send a simple text message ( newline terminated ) with the number of the chunks it will send. Example: command 4,20,30,40,50 Where command would be something like instant-message or file,4 would be the number of chunks to be sent, 20 would be the size in bytes of the first chunk, 30 of the 2nd, and so forth. after the message was sent, the client/server will start sending chunks ( of sizes mentioned in the sent message ). What do you think about implementing the client/server communication this way? What better options are there?

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C++ reference variable again!!!

- by kumar_m_kiran

Hi All, I think most would be surprised about the topic again, However I am referring to a book "C++ Common Knowledge: Essential Intermediate Programming" written by "Stephen C. Dewhurst". In the book, he quotes a particular sentence (in section under Item 5. References Are Aliases, Not Pointers), which is as below A reference is an alias for an object that already exists prior to the initialization of the reference. Once a reference is initialized to refer to a particular object, it cannot later be made to refer to a different object; a reference is bound to its initializer for its whole lifetime Can anyone please explain the context of "cannot later be made to refer to a different object" Below code works for me, #include <iostream> using namespace std; int main(int argc, char *argv[]) { int i = 100; int& ref = i; cout<<ref<<endl; int k = 2000; ref = k; cout<<ref<<endl; return 0; } Here I am referring the variable ref to both i and j variable. And the code works perfectly fine. Am I missing something? I have used SUSE10 64bit linux for testing my sample program. Thanks for your input in advance.

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Make joomla blog link to inner pages(or blog roll post actual)

- by somdow

So i was told to create a blog for client in Joomla and, i have minimal knowledge of Joomla inner workings. I made the blog as seen here http://www.assurancepower.com/about-us/blog.html But the problem is that, the headers/titles for each story in that blog roll cant be clicked. Im wondering is there a way i can make this happen? Essentially this page is a collection of the stories and i want to be able to click on a particular one (any of them) and be taken to its inner page/full version of the story. Not exactly sure what im supposed to do/search for. Im not sure if joomla has a wordpress like functions.php or for example, is there somewhere i can instert a....maybe something like how wordpress does it with permalinks like so: <?php permalink(); ?> //title link here to the actual story. or something like <?php bloginfo('url');?>// this relative link for WP. Etc, All i want is to be able to have these titles in this story be active links to their full counterpart. Not sure what to look for/how to go about fixing this. Thanks in advanced.

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jquery an div tags used in a ordered list

- by shan2on

hello everyone, i'm not sure where my errors are lying but here is my scenario... i have an un-ordered list in html that handles my main link bar... <ul id="navlist"> <li><a href="/" id="current">home</a></li> <li><a href="#" id="search">search</a></li> <li><a href="#" id="users">login</a></li> </ul> and what i want done is to call each id and have jQuery handle each and dislpay it where specified in my css file... for now, lets just ignore my "home" link... here is a snippet of my inline jquery $(document).ready(function() { $("a").click(function () { $("div#login").slideToggle("fast"); }); }) Now, whichever div i specify, it calls that ... however it will only call one div, using either from the un-orderd list, as mentioned above in the html. My Goal is to call a search bar when search is clicked, and to call a login box when login is clicked. to my knowledge (noob), i believe use an as a class, however that is what brings me here. i believe my error is in my jquery and not my css, as stated above, either instance will be displayed when the jquery function calls either tag. any help is greatly appreciated. thanks in advance shan2on

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How often should network traffic/collisions cause SNMP Sets to fail?

- by A. Levy

My team has a situation where an SNMP SET will fail once every two weeks or so. Since this set happens automatically, we don't necessarily notice it immediately when it fails, and this can result in an inconsistent configuration and associated wailing and gnashing of teeth. The plan is to fix this by having our software automatically retry the SET when it fails. The problem is, we aren't sure why the failure is happening. My (extremely limited) knowledge of SNMP isn't particularly helpful in diagnosing this problem, so I thought I'd ask StackOverflow for some advice. We think that every so often a spike in network traffic will cause the SET to fail. Since SNMP uses UDP for communication, I would think it would be relatively easy for a command to be drowned out if traffic was high for a short period of time. However, I have no idea how common this is. We have a small network with a single cisco router and there are less than a dozen SNMP controlled devices on that network. In addition to the SNMP traffic, there are some status web pages being loaded from the various devices. In case it makes a difference, I believe we are using the AdventNet SNMP API version 4.0.4 for Java. Does it sound reasonable that there will be some SET commands dropped occasionally, or should we be looking for other causes?

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Django + GAE (Google App Engine) : most convenient path for a beginner?

- by mac

Some background info first: Goal: a medium-level complexity web app that I will need to maintain and possibly extend for a few years. Experience: good knowledge of python, some experience of MVC frameworks (in PHP). Desiderata: using django and google app engine. I read extensively about the compatibility issues between GAE and Django, and I am aware of the GAE patch, the norel project, and other similar pieces of code. I have also understood that the SDK provides some of the features of django "out of the box". Yet, given that I have no previous experience with neither Django nor GAE, I am unable to evaluate to which extent using a patched version of Django will strip away important features, or how far the framework provided in the SDK is compatible with Django. So I am rather confused on what would be the best way to proceed in my situation: Should I simply use a patched version of Django as the differences with the original Django are so minor that I would hardly notice them? Should I write my app completely in "regular django" and try to port it to GAE only afterwards, when I will have got a grasp on Django internals and philosophy? Should I write my app using the framework provided with the SDK and port it to django only afterwards? Should I... ? Thank you in advance for your time and advice.

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Setting iphone to vibrate and setting iphone back to sound via app.

- by Cadu

Folks, I need your knowledge here. Think about the following sittuation - my app need to set my iphone to vibrate mode on a certain time and get it back to playing sounds mode (for call receiving, sms, email, all common sound notifications) some minutes later. I've already googled that, and didn't find a good, apple accetable way of doing that: http://stackoverflow.com/questions/736047/possible-to-programmatically-open-settings-app-from-iphone http://stackoverflow.com/questions/702319/is-it-possible-to-dynamically-alter-an-iphone-apps-settings-page-in-the-settings http://stackoverflow.com/questions/1141391/display-iphone-application-settings-within-your-application http://stackoverflow.com/questions/335965/how-do-i-launch-my-settings-bundle-from-my-application [This one here is interesting, as fas I as find a way to know what is the key for the settings I'm interested in] http://stackoverflow.com/questions/335965/how-do-i-launch-my-settings-bundle-from-my-application [It mentions I can do that, but does not give an idea of how =(] http://stackoverflow.com/questions/702319/is-it-possible-to-dynamically-alter-an-iphone-apps-settings-page-in-the-settings [If this is true, I wouldn't be able to do what I want...] Does anyone there has an idea of how do I do that via app? Many thanks in advance.

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Looking for a good C++/.net book

- by Michael Minerva

I have recently started to feel that I need to greatly improve my C++ skills especially in the realm of .net. I graduated from a good four year university with a degree in computer science about 9 months ago and I have since been doing full time contract work for a small software company in my local area. Most of my work has been done using Java/lisp/cocoa/XML and before that most of my programming in my senior year was in java/C#. I did a decent amount of C++ in my Sophomore year and in my free time before that but I feel that my general knowledge of C++/.net is very lacking for the opportunities that are now coming my way. Can anyone recommend a good book that could help me get up too speed? I feel I do not need a very basic introduction to C++ but something that covers the fundamentals of .net would be good for me. So basically what I need is a book or books that would be good for a .net novice and a C++ developer who is just beyond novice. Also, a book that would help bein an interview by giving me a conversional understanding of C++ would be great. Thanks a lot!.

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How best to make a link submit a form.

- by nickf

What's the best way to get a regular anchor (<a href="...">) to submit the form it is embedded in when clicked? <form> <ul> <li> <p> The link could be <span>embedded <a href="" onclick="?">at any level</a></span> in the form, so "this.parentNode.parentNode..." is no good. :( </p> </li> </ul> </form> I know that the easiest way using jQuery would be $('#myLink').click(function() { $(this).parents('form:first').submit(); }); ...but I'm trying to find a way to do this without using a library. Edit: I'm really trying to find a method which doesn't require knowledge of the form (eg: its name, id, etc). This would be similar to how you could put this on an input element: <input onclick="this.form.submit()" />

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Cannot access objects in associative arrays using jQuery

- by Sixfoot Studio

I am trying to create and array of objects so that I can access them in a for loop in jQuery and I know that this works in Actionscript so what I am trying to do is convert my current knowledge to jQuery that will work. Please have a look at this and tell me why I cannot access divToShow Thanks guys var homeImages = new Array(); homeImages[0] = { hoverImage: ".leftColImage1", divToShow: ".image1", rollOverImg: "img-family-over.jpg" }; homeImages[1] = { hoverImage: ".leftColImage2", divToShow: ".image2", rollOverImg: "img-students-over.jpg" }; homeImages[2] = { hoverImage: ".leftColImage3", divToShow: ".image3", rollOverImg: "img-pros-over.jpg" }; homeImages[3] = { hoverImage: ".leftColImage4", divToShow: ".image4", rollOverImg: "img-retired-over.jpg" }; var hoverImage; var activeDiv; var mainContent = ".mainContent"; for (k = 0; k < homeImages.length; k++) { homeImages[k].id = k; $(homeImages[k].hoverImage).mouseover(function() { //alert("divToShow : " + homeImages[this.id].divToShow); alert("this : " + this.id); activeDiv = homeImages[k].divToShow; $(".leftColImage1 img").attr("src", "/App_Themes/MyChoice2010/Images/" + homeImages[k].rollOverImg); $(mainContent).hide(); $(homeImages[k].divToShow).slideDown("slow"); }).mouseout(function() { $(".leftColImage1 img").attr("src", "/App_Themes/MyChoice2010/Images/img-family.jpg"); $(".image1").hide(); $(mainContent).slideDown("slow"); }); }

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Getting the type of an array of T, without specifying T - Type.GetType("T[]")

- by Merlyn Morgan-Graham

I am trying to create a type that refers to an array of a generic type, without specifying the generic type. That is, I would like to do the equivalent of Type.GetType("T[]"). I already know how to do this with a non-array type. E.g. Type.GetType("System.Collections.Generic.IEnumerable`1") // or typeof(IEnumerable<>) Here's some sample code that reproduces the problem. using System; using System.Collections.Generic; public class Program { public static void SomeFunc<T>(IEnumerable<T> collection) { } public static void SomeArrayFunc<T>(T[] collection) { } static void Main(string[] args) { Action<Type> printType = t => Console.WriteLine(t != null ? t.ToString() : "(null)"); Action<string> printFirstParameterType = methodName => printType( typeof(Program).GetMethod(methodName).GetParameters()[0].ParameterType ); printFirstParameterType("SomeFunc"); printFirstParameterType("SomeArrayFunc"); var iEnumerableT = Type.GetType("System.Collections.Generic.IEnumerable`1"); printType(iEnumerableT); var iEnumerableTFromTypeof = typeof(IEnumerable<>); printType(iEnumerableTFromTypeof); var arrayOfT = Type.GetType("T[]"); printType(arrayOfT); // Prints "(null)" // ... not even sure where to start for typeof(T[]) } } The output is: System.Collections.Generic.IEnumerable`1[T] T[] System.Collections.Generic.IEnumerable`1[T] System.Collections.Generic.IEnumerable`1[T] (null) I'd like to correct that last "(null)". This will be used to get an overload of a function via reflections by specifying the method signature: var someMethod = someType.GetMethod("MethodName", new[] { typeOfArrayOfT }); // ... call someMethod.MakeGenericMethod some time later I've already gotten my code mostly working by filtering the result of GetMethods(), so this is more of an exercise in knowledge and understanding.

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SQL: find entries in 1:n relation that don't comply with condition spanning multiple rows

- by milianw

I'm trying to optimize SQL queries in Akonadi and came across the following problem that is apparently not easy to solve with SQL, at least for me: Assume the following table structure (should work in SQLite, PostgreSQL, MySQL): CREATE TABLE a ( a_id INT PRIMARY KEY ); INSERT INTO a (a_id) VALUES (1), (2), (3), (4); CREATE TABLE b ( b_id INT PRIMARY KEY, a_id INT, name VARCHAR(255) NOT NULL ); INSERT INTO b (b_id, a_id, name) VALUES (1, 1, 'foo'), (2, 1, 'bar'), (3, 1, 'asdf'), (4, 2, 'foo'), (5, 2, 'bar'), (6, 3, 'foo'); Now my problem is to find entries in a that are missing name entries in table b. E.g. I need to make sure each entry in a has at least the name entries "foo" and "bar" in table b. Hence the query should return something similar to: a_id = 3 is missing name "bar" a_id = 4 is missing name "foo" and "bar" Since both tables are potentially huge in Akonadi, performance is of utmost importance. One solution in MySQL would be: SELECT a.a_id, CONCAT('|', GROUP_CONCAT(name ORDER BY NAME ASC SEPARATOR '|'), '|') as names FROM a LEFT JOIN b USING( a_id ) GROUP BY a.a_id HAVING names IS NULL OR names NOT LIKE '%|bar|foo|%'; I have yet to measure the performance tomorrow, but severly doubt it's any fast for tens of thousand of entries in a and thrice as many in b. Furthermore we want to support SQLite and PostgreSQL where to my knowledge the GROUP_CONCAT function is not available. Thanks, good night.

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Which is the best license for Open Source project?

- by coderex

Hi friends, I am a web developer, and i don't have enough knowledge in software licenses. I wish to publish some of my works. and i need to apply a licenses for that. My software/product is free of cost. But I have some restrictions on the distribution/Modification. Its free of cost.(but donations are acceptable ;-)) Source Code is freely available; that you can use, customize or edit/remove(but don't deviate the basic nature of the software). You don't have any permission to change the product name. There are some lib or class are and which is put into a folder caller "myname", you don't have the permission to rename "myname". You can contribute any additions modifications to my project, to the original source repository. (The contributors name/email/site link will be listed on the credit file). Don't remove the original author's name from the license. Put the license file or license code any where is in the project file or folder. You can redistribute this code as free or commercial. :) What you this, all these kinda restrictions are valid or ... ? For this, which license i want to use.

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Why would 1.000 subforms in a db be a bad idea?

- by KlaymenDK

Warm-up I'm trying to come up with a good way to implement customized document forms. It's for a tool to request access to applications; each application will want to ask its own specific questions. The thing is, we have one kind of (common) user who needs to fill in and submit documents based on templates, and another kind of (super) user who needs to be able to define what each template needs to contain. One implementation option would be to use a form (with the basic mandatory stuff), and have that form dynamically include a subform appropriate to the specific task at hand. The gist of the matter is that we could (=will!) quite easily end up having many hundreds of different subforms! (NB. These subforms will be maintained in an automated manner, but that is another topic that may be considered outside the scope of this Question.) Question It's common knowledge that having a lot of views in a Notes database is Bad Thing. But has anyone tried pushing the number of forms or subforms and made any experiences regarding performance?

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Planning a programming project by example (C# or C++)

- by Lunan

I am in the last year of undergraduate degree and i am stumped by the lack of example in c++ and c# large project in my university. All the mini project and assignment are based on text based database, which is so inefficient, and console display and command, which is frustrating. I want to develop a complete prototype of corporate software which deals in Inventory, Sales, Marketing, etc. Everything you would usually find in SAP. I am grateful if any of you could direct me to a books or article or sample program. Some of the question are : How to plan for this kind of programming? should i use the concept of 1 object(such as inventory) have its own process and program and have an integrator sit for all the program, or should i integrate it in 1 big program? How to build and address a database? i have little bit knowledge in database and i know SQL but i never address database in a program before. Database are table, and how do you suppose to represent a table in a OOP way? For development type, which is better PHP and C++ or C# and ASP.NET? I am planning to use Web Interface to set form and information, but using a background program to handle the compute. .NET is very much integrated and coding should be much faster, but i really wonder about performance if compared to PHP and C++ package thank you for the info

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Creating a timesheet for work using PHP MySQL

- by Justin

I am trying to create a time-sheet for my work. I don't know if getting myself into a lot of work by doing this as I am quiet new to PHP and MYSQL but I do have a good understanding/knowledge of the two. I want the below fields in my database. Job weekPeriod ------A list of weeks Monday Sunday dateWorked ------List Of dates in the form coming from a database e.g. 1/1/2011 startTime ------List of times from 12:00am11:00pm 30 min intervals e.g. 11:30-12:30 endTime ------List of times from 12:00am11:00pm 30 min intervals e.g. 11:30-12:30 totalHours ------Automated amount ------Automated based on dayWorked comments ------Any messages here I want to be able to fill in some drop down boxes through a form that will then submit all information to my database. I want the script to know that if the date worked is on a Weekday Mon-Fri e.g. my rate of pay is 30.00ph On a sat it is 35.00ph and on a Sunday it is 40ph I then want to create a page where i select a particular week and see how many hours i worked and how much i earn and so on. Please let me know if there is such a program already established or if this is something that requires a bit of time and if I could do it being new to PHP and MYSQL

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Regex to GENERATE thumbnails!?!?! (but that's crazy!)

- by CryptoMonkey

Hello everyone! So here is my situation, and the solution that I've come up with to solve the problem. I have created an application that includes TinyMCE to allow users to create HTML content for publishing. The user can include images in their markup, and drag/resize those images effecting the final Width/Height attributes in the IMG tag. This is all great, the users can include images and resize/relocate them to their desired appearance. But one big problem is that I am now sending a (possibly) much larger image to the client, only to have the browser resize the image into the requested Width/Height attributes. All that bandwidth and lost load time.... So my solution is to pre-process my users markup content, scanning all of the IMG tags and parsing out the Height/Width/Src attributes. Then set each img's SRC tag to a phpThumb request with the parsed Height/Width passed into the thumbnails URL. This will create my reduced size image (optimising bandwidth at the expense of CPU and caching). What do you think about this solution? I've seen other posts where people were using mod_rewrite to do something similar, but I want to effect the content on the page service and not manipulate the image requests as they're being received. .... Any thoughts about this design? I need some help with the fine details as my regex skills need some work, but I'm very short on time and promise to pay my technical knowledge debt soon. To make the regex's easier, I can be sure of some things. Only img tags that need this processing will have an existing width="" height="" attributes (with the double quotes, and lower cased text, but I suppose matching the text case insensitive would be better if TinyMCE changes) So a regex to match only the necessary Img tags, and maybe another three regex's to extract the src, the width, and the height? Thanks everyone.

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c++ simple conditional logging

- by Sunny

Disclaimer: I'm not a c++ developer, I can only do basic things. (I understand pointers, just my knowledge is so rusty, I haven't touch c/c++ for about 20 years :) ) The setup: I have an Outlook addin, written in C#/.Net 1.1. It uses a c++ shim to load. Usually, this works pretty well, and I use in my c# code nlog for logging purposes. But sometimes, the addin fails to load, i.t. it does not hit the managed code at all for me to be able to investigate the problem from the log files. So, I need to hook some basic logging into the c++ shim - just writing in a file. I need to make it as simple as possible for our users to enable. Actually I would prefer not to ship it by default. I was thinking about something, which will check if a specific dll is present (the logging dll), and if so, to use it. Otherwise, it will just not log anything. That way, when I have a user with such a problems, I can send him only the logging dll, the user will save it in the runtime directory, and I'll have the file. I guess this have to be done with some form a factory solution, which returns either a dummy logger, or if the dll is found, a real one. Another option would be to make some simple logger, and rebuild the shim with or w/o using it, based on directives. This is not the desirable approach, because the shim needs to be signed, and I have to instruct the user to make a backup copy of the "real" one, then restore when done, etc., instead of just saving and deleting a dll. I'd appreciate any good suggestion how to approach it, together with links or sample code how to go after this. Cheers

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Exposing a C++ API to C#

- by Siyfion

So what I have is a C++ API contained within a *.dll and I want to use a C# application to call methods within the API. So far I have created a C++ / CLR project that includes the native C++ API and managed to create a "bridge" class that looks a bit like the following: ManagedBridge.h namespace ManagedAPIWrapper { public ref class Bridge { public: int bridge_test(void); int bridge_test2(api_struct* temp); } } ManagedBridge.cpp int Bridge::bridge_test(void) { return test(); } int Bridge::bridge_test2(api_struct* temp) { return test2(temp); } I also have a C# application that has a reference to the C++/CLR "Bridge.dll" and then uses the methods contained within. I have a number of problems with this: I can't figure out how to call bridge_test2 within the C# program, as it has no knowledge of what a api_struct actually is. I know that I need to marshal the object somewhere, but do I do it in the C# program or the C++/CLR bridge? This seems like a very long-winded way of exposing all of the methods in the API, is there not an easier way that I'm missing out? (That doesn't use P/Invoke!)

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Why would JSP tags appear in HTML source code?

- by Michael

I'm a front-end web developer at a company using Java on their server. As a front-end developer, I'm concerned with the HTML structure that the server produces, but I don't have control over anything our back-end team produces. Rather than ask someone on that team, I would like to gather knowledge from the Stackoverflow community so I can communicate intelligently with the back-end team. So, I am curious as to what would cause certain JSP tags to appear in the rendered HTML that is sent to the browser. We have tags in our HTML source such as: <flow:fileRef id="vfileColor" fileId="vfile.color"/> <flow:fileRef id="StyleDir" fileId="StyleDir"/> <flow:fileRef id="vfileStylesheet" fileId="vfile.stylesheet"/> I am more interested in knowing why these appear, not as much about what they do. Is there a server setting for Tomcat/Apache/etc. that would hide these tags from the browser? Any information would be helpful. Thanks in advance.

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What choices do I have for a future in software development?

- by user354892

After graduating from college with a degree in mathematics and a minor in computer science, I took over a year to find my first programming job. I very much enjoy my work environment, but sometimes I feel like I'm not developing professionally as quickly as I am capable of. My company does mostly web programming. The project that I work on is basically a front-end for a SQL database. The entire project is (AFAIK) coded is VB.NET. I've been working on the back-end logic of the program. After some time on the job, we decided that designing web pages is not my cup of tea. It seems like the thing that I spend more time on than anything else is searching the web and SO for information about poorly documented .net and web APIs. This does not make me happy; is this normal for a programming job; I don't think it is. It really hit me the other day when i saw a question about math asked here and I didn't know the answer; I feel like my knowledge is going stale! I was previously almost hired by another company where they design graphic-intensive battle simulations for the military. I sometimes wonder what my life might be like if I had that job. I feel like my math and problem solving skills might have been a better fit at this other company. Within the wide field of software development, there are a number of directions in which to go as evidenced by the huge variety of topics discussed here on StackOverflow. I would like to feel like I'm going in the direction where I will make the most of my skills and have a satisfying career. Let me word this question as clearly as possible: given the wide breadth of the field of software development, how does it break down into sub-fields and what are the considerations for developing a software development career. I do not want to manage my career by default.

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How do I sort an activerecord result set on a i18n translated column?

- by PlanetMaster

Hi, I have the following line in a view: <%= f.select(:province_id, options_from_collection_for_select(Province.find(:all, :conditions => { :country_id => @property.country_id }, :order => "provinces.name ASC"), :id, :name) %> In the province model I have the following: def name I18n.t(super) end Problem is that the :name field is translated (through the province model) and that the ordering is done by activerecord on the english name. The non-english result set can be wrongly sorted this way. We have a province in Belgium called 'Oost-Vlaanderen'. In english that is 'East-Flanders". Not good for sorting:) I need something like this, but it does not work: <%= f.select(:province_id, options_from_collection_for_select(Province.find(:all, :conditions => { :country_id => @property.country_id }, :order => "provinces.I18n.t(name) ASC"), :id, :name) %> What would be the best approach to solve this? As you may have noticed, my coding knowledge is very limited, sorry for that.

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Which of the following Java coding fragments is better?

- by Simon

This isn't meant to be subjective, I am looking for reasons based on resource utilisation, compiler performance, GC performance etc. rather than elegance. Oh, and the position of brackets doesn't count, so no stylistic comments please. Take the following loop; Integer total = new Integer(0); Integer i; for (String str : string_list) { i = Integer.parse(str); total += i; } versus... Integer total = 0; for (String str : string_list) { Integer i = Integer.parse(str); total += i; } In the first one i is function scoped whereas in the second it is scoped in the loop. I have always thought (believed) that the first one would be more efficient because it just references an existing variable already allocated on the stack, whereas the second one would be pushing and popping i each iteration of the loop. There are quite a lot of other cases where I tend to scope variables more broadly than perhaps necessary so I thought I would ask here to clear up a gap in my knowledge. Also notice that assignment of the variable on initialisation either involving the new operator or not. Do any of these sorts of semi-stylistic semi-optimisations make any difference at all?

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C++: Case statement within while loop?

- by Jason

I just started C++ but have some prior knowledge to other languages (vb awhile back unfortunately), but have an odd predicament. I disliked using so many IF statements and wanted to use switch/cases as it seemed cleaner, and I wanted to get in the practice.. But.. Lets say I have the following scenario (theorietical code): while(1) { //Loop can be conditional or 1, I use it alot, for example in my game char something; std::cout << "Enter something\n -->"; std::cin >> something; //Switch to read "something" switch(something) { case 'a': cout << "You entered A, which is correct"; break; case 'b': cout << "..."; break; } } And that's my problem. Lets say I wanted to exit the WHILE loop, It'd require two break statements? This obviously looks wrong: case 'a': cout << "You entered A, which is correct"; break; break; So can I only do an IF statement on the 'a' to use break;? Am I missing something really simple? This would solve a lot of my problems that I have right now.

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Database solution for 200million writes/day, monthly summarization queries

- by sb

Hello. I'm looking for help deciding on which database system to use. (I've been googling and reading for the past few hours; it now seems worthwhile to ask for help from someone with firsthand knowledge.) I need to log around 200 million rows (or more) per 8 hour workday to a database, then perform weekly/monthly/yearly summary queries on that data. The summary queries would be for collecting data for things like billing statements, eg. "How many transactions of type A did each user run this month?" (could be more complex, but that's the general idea). I can spread the database amongst several machines, as necessary, but I don't think I can take old data offline. I'll definitely need to be able to query a month's worth of data, maybe a year. These queries would be for my own use, and wouldn't need to be generated in real-time for an end-user (they could run overnight, if needed). Does anyone have any suggestions as to which databases would be a good fit? P.S. Cassandra looks like it would have no problem handling the writes, but what about the huge monthly table scans? Is anyone familiar with Cassandra/Hadoop MapReduce performance?

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