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• As a newbie, where should I go if I want to create a small GUI program?

  - by jimbmk

  Hello, I'm a newbie with a little experience writing in BASIC, Python and, of all things, a smidgeon of assembler (as part of a videogame ROM hack). I wanted to create small tool for modifying the hex values at particular points, in a particular file, that would have a GUI interface. What I'm looking for is the ability to create small GUI program, that I can distribute as an EXE (or, at least a standalone directory). I'm not keen on the idea of the .NET languages, because I don't want to force people to download a massive .NET framework package. I currently have Python with IDLE and Boa Constructor set up, and the application runs there. I've tried looking up information on compiling a python app that relies on Wxwidgets, but the search results and the information I've found has been confusing, or just completely incomprehensible. My questions are: Is python a good language to use for this sort of project? If I use Py2Exe, will WxWidgets already be included? Or will my users have to somehow install WxWidgets on their machines? Am I right in thinking at Py2Exe just produces a standalone directory, 'dist', that has the necessary files for the user to just double click and run the application? If the program just relies upon Tkinter for GUI stuff, will that be included in the EXE Py2Exe produces? If so, are their any 'visual' GUI builders / IDEs for Python with only Tkinter? Thankyou for your time, JBMK

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• Problem installing mysql gem on Snow Leopard: uninitialized constant MysqlCompat::MysqlRes

  - by emson

  Hi All I've got a problem trying to install the Ruby mysql gem driver. I recently upgraded to Snow Leopard and did the Hivelogic manual install of MySQL. This all seems to work fine as I can access mysql from the command line and make changes to the database. My problem is that if I now use rake db:migrate I get: rake aborted! uninitialized constant MysqlCompat::MysqlRes (See full trace by running task with --trace) Now it appears that my mysql gem isn't working correctly as I can access MySQL fine from Python using the Python driver (which I compiled to). I therefore tried to rebuild the gem using the following command from this site: http://techliberty.blogspot.com/, (incidentally I am using a recent Intel MacBook Pro): sudo env ARCHFLAGS="-arch x86_64" gem install mysql -- --with-mysql-config=/usr/local/mysql/bin/mysql_config This compiles although I get No definition for the documentation: Building native extensions. This could take a while... Successfully installed mysql-2.8.1 1 gem installed Installing ri documentation for mysql-2.8.1... No definition for next_result No definition for field_name ... I'm a little stumped as my mysql_config is located in the correct place: /usr/local/mysql/bin/mysql_config And I have removed all other instances of the mysql gem, from my system. Any suggestions would be greatly appreciated. Many thanks. PS I saw this previous post http://stackoverflow.com/questions/1332207/uninitialized-constant-mysqlcompatmysqlres-using-mms2r-gem but it doesn't seem applicable for my version.

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• How to pass parameters to manage_shared_memory.construct() in Boost.Interprocess

  - by recipriversexclusion

  I've stared at the Boost.Interprocess documentation for hours but still haven't been able to figure this out. In the doc, they have an example of creating a vector in shared memory like so: //Define an STL compatible allocator of ints that allocates from the managed_shared_memory. //This allocator will allow placing containers in the segment typedef allocator<int, managed_shared_memory::segment_manager> ShmemAllocator; //Alias a vector that uses the previous STL-like allocator so that allocates //its values from the segment typedef vector<int, ShmemAllocator> MyVector; int main(int argc, char *argv[]) { //Create a new segment with given name and size managed_shared_memory segment(create_only, "MySharedMemory", 65536); //Initialize shared memory STL-compatible allocator const ShmemAllocator alloc_inst (segment.get_segment_manager()); //Construct a vector named "MyVector" in shared memory with argument alloc_inst MyVector *myvector = segment.construct<MyVector>("MyVector")(alloc_inst); Now, I understand this. What I'm stuck is how to pass a second parameter to segment.construct() to specify the number of elements. The interprocess document gives the prototype for construct() as MyType *ptr = managed_memory_segment.construct<MyType>("Name") (par1, par2...); but when I try MyVector *myvector = segment.construct<MyVector>("MyVector")(100, alloc_inst); I get compilation errors. My questions are: Who actually gets passed the parameters par1, par2 from segment.construct, the constructor of the object, e.g. vector? My understanding is that the template allocator parameter is being passed. Is that correct? How can I add another parameter, in addition to alloc_inst that is required by the constructor of the object being created in shared memory? There's very little information other than the terse Boost docs on this.

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• How to access device settings on a Sony Ericsson mobile phone?

  - by TheRHCP

  Edited on April 29th Hello everyone, I recently bought a Sony Ericsson mobile phone which embeds Symbian S60 and I would like to add a missing feature myself. In fact I cannot actually disable Internet connection in an easy way when roaming, which cost me a lot of money last time I moved away ... So I would like to develop a little application that would just replace the actual Internet configuration with a fake configuration to avoid auto-connections. So what I would like to know is how can I access programmatically to my phone settings? I believe that this is possible but I do not really have a clue where to start. I know that Sony Ericsson provides a SDK to run Java applications on its customised JVM but Symbian is also providing a SDK to develop applications for S60 devices in many languages. The real questions is which SDK will provide an API able to access phone settings. This is not well documented so I am asking this question with the hope that someone here already had experience with development for Sony Ericsson/Symbian devices. Thanks. EDIT: It seems that I was totally wrong concerning my phone. This not based on any Symbian OS at all. This is pure Sony Ericsson so the only solution would be to look if Sony Ericsson extended J2ME functionality in their own JVM. I am gonna investigate on this.

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• PHP syntax for referencing self with late static binding

  - by Chris

  When I learned PHP it was pretty much in procedural form, more recently I've been trying to adapt to the OOP way of doing things. Hoever the tutorials I've been following were produced before PHP 5.3 when late static binding was introduced. What I want to know is how do I reference self when calling a function from a parent class. For example these two methods were written for a User class which is a child of DatabaseObject. Right now they're sitting inside the User class, but, as they're used in other child classes of DatabaseObject I'd like to promote them to be included inside DatabaseObject. public static function find_all() { global $database; $result_set = self::find_by_sql("select * from ".self::$table_name); return $result_set; } and: protected function cleaned_attributes() { global $database; $clean_attributes = array(); foreach($this->attributes() as $key => $value) { $clean_attributes[$key] = $database->escape_value($value); } return $clean_attributes; } So I have three questions: 1) How do I change the self:: reference when I move it to the parent. Is it static:: or something similar? 2) When calling the function from my code do I call it in the same way, as a function of the child class eg User::find_all() or is there a change there also? 3) Is there anything else I need to know before I start chopping bits up?

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• Detecting a Dispose() from an exception inside using block

  - by Augusto Radtke

  I have the following code in my application: using (var database = new Database()) { var poll = // Some database query code. foreach (Question question in poll.Questions) { foreach (Answer answer in question.Answers) { database.Remove(answer); } // This is a sample line that simulate an error. throw new Exception("deu pau"); database.Remove(question); } database.Remove(poll); } This code triggers the Database class Dispose() method as usual, and this method automatically commits the transaction to the database, but this leaves my database in an inconsistent state as the answers are erased but the question and the poll are not. There is any way that I can detect in the Dispose() method that it being called because of an exception instead of regular end of the closing block, so I can automate the rollback? I don´t want to manually add a try ... catch block, my objective is to use the using block as a logical safe transaction manager, so it commits to the database if the execution was clean or rollbacks if any exception occured. Do you have some thoughts on that?

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• why unsigned int 0xFFFFFFFF is equal to int -1?

  - by conejoroy

  perhaps it's a very stupid question but I'm having a hard time figuring this out =) in C or C++ it is said that the maximum number a size_t (an unsigned int data type) can hold is the same as casting -1 to that data type. for example see http://stackoverflow.com/questions/1420982/invalid-value-for-sizet Why?? I'm confused.. I mean, (talking about 32 bit ints) AFAIK the most significant bit holds the sign in a signed data type (that is, bit 0x80000000 to form a negative number). then, 1 is 0x00000001.. 0x7FFFFFFFF is the greatest positive number a int data type can hold. then, AFAIK the binary representation of -1 int should be 0x80000001 (perhaps I'm wrong). why/how this binary value is converted to anything completely different (0xFFFFFFFF) when casting ints to unsigned?? or.. how is it possible to form a binary -1 out of 0xFFFFFFFF? I have no doubt that in C: ((unsigned int)-1) == 0xFFFFFFFF or ((int)0xFFFFFFFF) == -1 is equally true than 1 + 1 == 2, I'm just wondering why. thanks!

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• Will the following NHibernate interface mapping work?

  - by Ben Aston

  I'd like to program against interfaces when working with NHibernate due to type dependency issues within the solution I am working with. SO questions such as this indicate it is possible. I have an ILocation interface and a concrete Location type. Will the following work? HBM mapping: <class name="ILocation" abstract="true" table="ILocation"> <id name="Id" type="System.Guid" unsaved-value="00000000-0000-0000-0000-000000000000"> <column name="LocationId" /> <generator class="guid" /> </id> <union-subclass table="Location" name="Location"> <property name="Name" type="System.String"/> </union-subclass> </class> Detached criteria usage using the interface: var criteria = DetachedCriteria.For<ILocation>().Add(Restrictions.Eq("Name", "blah")); var locations = criteria.GetExecutableCriteria(UoW.Session).List<ILocation>(); Are there any issues with not using the hilo ID generator and/or with this approach in general?

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• Windows Batch file to echo a specific line number

  - by Lee

  So for the second part of my current dilemma, I have a list of folders in c:\file_list.txt. I need to be able to extract them (well, echo them with some mods) based on the line number because this batch script is being called by an iterative macro process. I'm passing the line number as a parameter. @echo off setlocal enabledelayedexpansion set /a counter=0 set /a %%a = "" for /f "usebackq delims=" %%a in (c:\file_list.txt) do ( if "!counter!"=="%1" goto :printme & set /a counter+=1 ) :printme echo %%a which gives me an output of %a. Doh! So, I've tried echoing !a! (result: ECHO is off.); I've tried echoing %a (result: a) I figured the easy thing to do would be to modify the head.bat code found here: http://stackoverflow.com/questions/130116/dos-batch-commands-to-read-first-line-from-text-file except rather than echoing every line - I'd just echo the last line found. Not as simple as one might think. I've noticed that my counter is staying at zero for some reason; I'm wondering if the set /a counter+=1 is doing what I think it's doing.

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• Use auto_ptr in VC6 dll cause crash

  - by Yan Cheng CHEOK

  // dll #include <memory> __declspec(dllexport) std::auto_ptr<int> get(); __declspec(dllexport) std::auto_ptr<int> get() { return std::auto_ptr<int>(new int()); } // exe #include <iostream> #include <memory> __declspec(dllimport) std::auto_ptr<int> get(); int main() { { std::auto_ptr<int> x = get(); } std::cout << "done\n"; getchar(); } The following code run perfectly OK under VC9. However, under VC6, I will experience an immediate crash with the following message. Debug Assertion Failed! Program: C:\Projects\use_dynamic_link\Debug\use_dynamic_link.exe File: dbgheap.c Line: 1044 Expression: _CrtIsValidHeapPointer(pUserData) Is it exporting auto_ptr under VC6 is not allowed? It is a known problem that exporting STL collection classes through DLL. http://stackoverflow.com/questions/2451714/access-violation-when-accessing-an-stl-object-through-a-pointer-or-reference-in-a However, I Google around and do not see anything mention for std::auto_ptr. Any workaround?

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• How to perform spatial partitioning in n-dimensions?

  - by kevin42

  I'm trying to design an implementation of Vector Quantization as a c++ template class that can handle different types and dimensions of vectors (e.g. 16 dimension vectors of bytes, or 4d vectors of doubles, etc). I've been reading up on the algorithms, and I understand most of it: here and here I want to implement the Linde-Buzo-Gray (LBG) Algorithm, but I'm having difficulty figuring out the general algorithm for partitioning the clusters. I think I need to define a plane (hyperplane?) that splits the vectors in a cluster so there is an equal number on each side of the plane. [edit to add more info] This is an iterative process, but I think I start by finding the centroid of all the vectors, then use that centroid to define the splitting plane, get the centroid of each of the sides of the plane, continuing until I have the number of clusters needed for the VQ algorithm (iterating to optimize for less distortion along the way). The animation in the first link above shows it nicely. My questions are: What is an algorithm to find the plane once I have the centroid? How can I test a vector to see if it is on either side of that plane?

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• Setting up ehcache replication - what multicast settings do I need?

  - by Darren Greaves

  I am trying to set up ehcache replication as documented here: http://ehcache.sourceforge.net/EhcacheUserGuide.html#id.s22.2 This is on a Windows machine but will ultimately run on Solaris in production. The instructions say to set up a provider as follows: <cacheManagerPeerProviderFactory class="net.sf.ehcache.distribution.RMICacheManagerPeerProviderFactory" properties="peerDiscovery=automatic, multicastGroupAddress=230.0.0.1, multicastGroupPort=4446, timeToLive=32"/> And a listener like this: <cacheManagerPeerListenerFactory class="net.sf.ehcache.distribution.RMICacheManagerPeerListenerFactory" properties="hostName=localhost, port=40001, socketTimeoutMillis=2000"/> My questions are: Are the multicast IP address and port arbitrary (I know the address has to live within a specific range but do they have to be specific numbers)? Do they need to be set up in some way by our system administrator (I am on an office network)? I want to test it locally so am running two separate tomcat instances with the above config. What do I need to change in each one? I know both the listeners can't listen on the same port - but what about the provider? Also, are the listener ports arbitrary too? I've tried setting it up as above but in my testing the caches don't appear to be replicated - the value added in one tomcat's cache is not present in the other cache. Is there anything I can do to debug this situation (other than packet sniffing)? Thanks in advance for any help, been tearing my hair out over this one!

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• Dojo dialog, the iPad and the virtual keyboard issue

  - by Chris Butler

  Recently, I have been working on a project where the interface should work for desktop and tablets (in particular the iPad). One issue I am coming across is with a Dojo dialog on the iPad when text entry is taking place. Basically here is what happens: Load Dojo interface with buttons on iPad - OK Press button (touch) to show dialog (90% height and width) - OK Click on text box (touch) like DateTextBox or TimeTextBox - OK, the virtual keyboard is opened Click the date or time I want in the UI (touch) - OK, but I can't see all of the options since it is longer than the screen size... Try to scroll down (swipe up with two fingers or click 'next' in the keyboard) - not OK and the dialog repositions itself to have it's top at the top of the viewport area. Basically, the issue is that the dialog keeps trying to reposition itself. Am I able to stop dialog resizing and positioning if I catch the window onResize events? Does anyone else have this issue with the iPad and Dojo dialogs? Also, I found this StackOverflow topic on detecting the virtual keyboard, but it wasn't much help in this case... http://stackoverflow.com/questions/2593139/ipad-web-app-detect-virtual-keyboard-using-javascript-in-safari Thanks!

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• strict aliasing and alignment

  - by cooky451

  I need a safe way to alias between arbitrary POD types, conforming to ISO-C++11 explicitly considering 3.10/10 and 3.11 of n3242 or later. There are a lot of questions about strict aliasing here, most of them regarding C and not C++. I found a "solution" for C which uses unions, probably using this section union type that includes one of the aforementioned types among its elements or nonstatic data members From that I built this. #include <iostream> template <typename T, typename U> T& access_as(U* p) { union dummy_union { U dummy; T destination; }; dummy_union* u = (dummy_union*)p; return u->destination; } struct test { short s; int i; }; int main() { int buf[2]; static_assert(sizeof(buf) >= sizeof(double), ""); static_assert(sizeof(buf) >= sizeof(test), ""); access_as<double>(buf) = 42.1337; std::cout << access_as<double>(buf) << '\n'; access_as<test>(buf).s = 42; access_as<test>(buf).i = 1234; std::cout << access_as<test>(buf).s << '\n'; std::cout << access_as<test>(buf).i << '\n'; } My question is, just to be sure, is this program legal according to the standard?* It doesn't give any warnings whatsoever and works fine when compiling with MinGW/GCC 4.6.2 using: g++ -std=c++0x -Wall -Wextra -O3 -fstrict-aliasing -o alias.exe alias.cpp * Edit: And if not, how could one modify this to be legal?

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• Valueurl Binding On Large Arrays Causes Sluggish User Interface

  - by Hooligancat

  I have a large data set (some 3500 objects) that returns from a remote server via HTTP. Currently the data is being presented in an NSCollectionView. One aspect of the data is a path pack to the server for a small image that represents the data (think thumbnail for simplicity). Bindings works fantastically for the data that is already returned, and binding the image via a valueurl binding is easy to do. However, the user interface is very sluggish when scrolling through the data set - which makes me think that the NSCollectionView is retrieving all the image data instead of just the image data used to display the currently viewable images. I was under the impression that Cocoa controls were smart enough to only retrieve data for the information that is actually being output to the user interface through lazy loading. This certainly seems to be the case with NSTableView - but I could be misguided on this thought. Should valueurl binding act lazily and, moreover, should it act lazily in an NSCollectionView? I could create a caching mechanism (in fact I already have such a thing in place for another application - see my post here if you are interested http://stackoverflow.com/questions/1740209/populating-nsimage-with-data-from-an-asynchronous-nsurlconnection) but I really don't want to go this route if I don't have to for this specific implementation as the user could potentially change data sets often and may only want small sub-sets of the data. Any suggested approaches? Thanks!

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• Code golf: combining multiple sorted lists into a single sorted list

  - by Alabaster Codify

  Implement an algorithm to merge an arbitrary number of sorted lists into one sorted list. The aim is to create the smallest working programme, in whatever language you like. For example: input: ((1, 4, 7), (2, 5, 8), (3, 6, 9)) output: (1, 2, 3, 4, 5, 6, 7, 8, 9) input: ((1, 10), (), (2, 5, 6, 7)) output: (1, 2, 5, 6, 7, 10) Note: solutions which concatenate the input lists then use a language-provided sort function are not in-keeping with the spirit of golf, and will not be accepted: sorted(sum(lists,[])) # cheating: out of bounds! Apart from anything else, your algorithm should be (but doesn't have to be) a lot faster! Clearly state the language, any foibles and the character count. Only include meaningful characters in the count, but feel free to add whitespace to the code for artistic / readability purposes. To keep things tidy, suggest improvement in comments or by editing answers where appropriate, rather than creating a new answer for each "revision". EDIT: if I was submitting this question again, I would expand on the "no language provided sort" rule to be "don't concatenate all the lists then sort the result". Existing entries which do concatenate-then-sort are actually very interesting and compact, so I won't retro-actively introduce a rule they break, but feel free to work to the more restrictive spec in new submissions. Inspired by http://stackoverflow.com/questions/464342/combining-two-sorted-lists-in-python

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• Reading a large file into Perl array of arrays and manipulating the output for different purposes

  - by Brian D.

  Hello, I am relatively new to Perl and have only used it for converting small files into different formats and feeding data between programs. Now, I need to step it up a little. I have a file of DNA data that is 5,905 lines long, with 32 fields per line. The fields are not delimited by anything and vary in length within the line, but each field is the same size on all 5905 lines. I need each line fed into a separate array from the file, and each field within the line stored as its own variable. I am having no problems storing one line, but I am having difficulties storing each line successively through the entire file. This is how I separate the first line of the full array into individual variables: my $SampleID = substr("@HorseArray", 0, 7); my $PopulationID = substr("@HorseArray", 9, 4); my $Allele1A = substr("@HorseArray", 14, 3); my $Allele1B = substr("@HorseArray", 17, 3); my $Allele2A = substr("@HorseArray", 21, 3); my $Allele2B = substr("@HorseArray", 24, 3); ...etc. My issues are: 1) I need to store each of the 5905 lines as a separate array. 2) I need to be able to reference each line based on the sample ID, or a group of lines based on population ID and sort them. I can sort and manipulate the data fine once it is defined in variables, I am just having trouble constructing a multidimensional array with each of these fields so I can reference each line at will. Any help or direction is much appreciated. I've poured over the Q&A sections on here, but have not found the answer to my questions yet. Thanks!! -Brian

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• How to make a small flash swf with ComboBox in Actionscript 3?

  - by Sint

  I have a pure Actionscript 3 project, using flash.* libraries, compiles down to about 6k (using mxmlc). Program handles about 1k shapes, a few sprites, a sockets connection, works great (tastes less filling). Now, how would I add a ComboBox control without incurring excessive bloat? More specificially, I would like to keep the size under 100k. So far I have tried: Adobe mx.controls ComboBoxexample - simple mxml example compiles to 200+k both on my main Linux Box using mxmlc and in Windows using Flash Builder 4 Yahoo Astra - uses mx libraries underneath(so as bloated as Adobe?), plus does not contain exact ComboBox Keith Peter's MinimalComps - seems small, but far from providing ComboBox functionality SPAS (Swing Package for Actionscript) - compiles to 130k, but alpha version of ComboBox does not let me adjust height... asuilib - compiles to 40k, unfortunately this ComboBox does not provide for scrolling items...if it does not fit on screen no way to scroll to it Now my questions: Is there a way to lower size for projects importing mx.controls ? Maybe there is a way to fix SPAS or asuilib ComboBoxes? Perhaps, there are some other libraries which provide a ComboBox(or DropList)?

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• Need variable width negative lookbehind replacement

  - by Technoh

  I have looked at many questions here (and many more websites) and some provided hints but none gave me a definitive answer. I know regular expressions but I am far from being a guru. This particular question deals with regex in PHP. I need to locate words in a text that are not surrounded by a hyperlink of a given class. For example, I might have This <a href="blabblah" class="no_check">elephant</a> is green and this elephant is blue while this <a href="blahblah">elephant</a> is red. I would need to match against the second and third elephants but not the first (identified by test class "no_check"). Note that there could more attributes than just href and class within hyperlinks. I came up with ((?<!<a .*class="no_check".*>)\belephant\b) which works beautifully in regex test software but not in PHP. Any help is greatly appreciated. If you cannot provide a regular expression but can find some sort of PHP code logic that would circumvent the need for it, I would be equally grateful.

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• Advice on designing and building distributed application to track vehicles

  - by dario-g

  I'm working on application for tracking vehicles. There will be about 10k or more vehicles. Each will be sending ~250bytes in each minute. Data contains gps location and everything from CAN Bus (every data that we can read from vehicle computer and dashboard). Data are sent by GSM/GPRS (using UDP protocol). Estimated rows with this data per day is ~2000k. I see there 3 main blocks. 1. Multithreaded Socket Server (MSS) - I have it. MSS stores received data to the queue (using NServiceBus). 2. Rule Processor Server (RPS) - this is core of this system. This block is responsible for parsing received data, storing in the database, processing rules, sending messages to Notifier Server (this will be sending e-mails/sms texts). Rule example. As I said between received bytes there will be information about current speed. When speed will be above 120 then: show alert in web application for specified users, send e-mail, send sms text. (There can be more than one instance of RPS). 3. Web application - allows reporting and defining rules by users, monitoring alerts, etc. I'm looking for advice how to design communication between RPS and Web application. Some questions: - Should Web application and RPS have separated databases or one central database will be enough? I have one domain model in web application. If there will be one central database then can I use the same model (objects) on RPS? So, how to send changed rules to RPS? I try to decouple this blocks as much as possible. I'm planning to create different instance of application for each client (each client will have separated database). One client will be have 10k vehicles, others only 100 vehicles.

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• How to call stored proc from ASP.Net MVC stack via the ORM & return them in json?

  - by melaos

  Hi guys, i'm a total newbie with asp.net mvc and here's my jam: i have a 3 level list box which selection on box A shows options on box B and selection on box B will show the options for box C. I'm trying to do the whole thing in asp.net MVC and what i see is that the nerd dinner tutorial uses the ORM method. so i created a dbml to the database and drag the stored proc inside. i create a datacontext object but i don't quite know how to connect the result from the stored proce which should be multiple rows of data and make it into a json. so i can keep all the json data inside the html page and using jquery i could make the selection process faster. i don't expect the data inside the three boxes to change so often thus i think this method should be quite viable. Questions: So how do i get the stored proc part to return the data as json? i've noticed some tutorial online that the json return result part is at the controller and not at the model end. Why is that?

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• Find all cycles in graph, redux

  - by Shadow

  Hi, I know there are a quite some answers existing on this question. However, I found none of them really bringing it to the point. Some argue that a cycle is (almost) the same as a strongly connected components (s. http://stackoverflow.com/questions/546655/finding-all-cycles-in-graph/549402#549402) , so one could use algorithms designed for that goal. Some argue that finding a cycle can be done via DFS and checking for back-edges (s. boost graph documentation on file dependencies). I now would like to have some suggestions on whether all cycles in a graph can be detected via DFS and checking for back-edges? My opinion is that it indeed could work that way as DFS-VISIT (s. pseudocode of DFS) freshly enters each node that was not yet visited. In that sense, each vertex exhibits a potential start of a cycle. Additionally, as DFS visits each edge once, each edge leading to the starting point of a cycle is also covered. Thus, by using DFS and back-edge checking it should indeed be possible to detect all cycles in a graph. Note that, if cycles with different numbers of participant nodes exist (e.g. triangles, rectangles etc.), additional work has to be done to discriminate the acutal "shape" of each cycle.

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• Entity Framework 4 / POCO - Where to start?

  - by Basiclife

  Hi, I've been programming for a while and have used LINQ-To-SQL and LINQ-To-Entities before (although when using entities it has been on a Entity/Table 1-1 relationship - ie not much different than L2SQL) I've been doing a lot of reading about Inversion of Control, Unit of Work, POCO and repository patterns and would like to use this methodology in my new applications. Where I'm struggling is finding a clear, concise beginners guide for EF4 which doesn't assume knowledge of EF1. The specific questions I need answered are: Code first / model first? Pros/cons in regards to EF4 (ie what happens if I do code first, change the code at a later date and need to regenerate my DB model - Does the data get preserved and transformed or dropped?) Assuming I'm going code-first (I'd like to see how EF4 converts that to a DB schema) how do I actually get started? Quite often I've seen articles with entity diagrams stating "So this is my entity model, now I'm going to ..." - Unfortunately, I'm unclear if they're created the model in the designer, saved it to generate code then stopped any further auto-code generation -or- They've coded (POCO)? classes and the somehow imported them into the deisgner view? I suppose what I really need is an understanding of where the "magic" comes from and how to add it myself if I'm not just generating an EF model directly from a DB. I'm aware the question is a little vague but I don't know what I don't know - So any input / correction / clarification appreciated. Needless to say, I don't expect anyone to sit here and teach me EF - I'd just like some good tutorials/forums/blogs/etc. for complete entity newbies Many thanks in advance

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• How to properly develop and deploy features for existing asp.net applications on IIS

  - by Tomh

  My question actually consists of multiple questions. I'm frequently reading about companies who deploy a small subset of features for a select amount of customers using the live "database". Ruby on Rails and its ecosystem have deployment tools and database migrations to deploy or rollback such features in a live production or staging environment. My question, how is this done for an asp.net (mvc in particular) application? How do you test your newly released features against live data? Do you have any tools to modify the existing database and roll back changes if necessary? Do you make backups before deployment? Update Maybe I should point out that my question is not really clear, getting more answers here will help me phrase the question better. To make it easier I will describe a situation I'm commonly seeing with some of my clients. My clients have large deployments of popular web applications. They do not have staging/QA/testing servers. (yes this is not optimal). The data their apps consist of are images, xml files, user uploads and data in Sql Server. Having a few records, of their production database and a couple of dummy files is not a substitute of testing against real data in my opinion. How would you design a workflow that can create a acceptable environment to mimic a production environment before going live?

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• Replace System.Net.Mail.MailMessage with manually created message and send it

  - by DEH

  I am trying to send emails that will bounce to a known mailbox. I plan to use VERP. Unfortunately the System.Net.Mail.MailMessage object does not allow me to precisely set the From: and Sender: headers within my email - it forces the values so that the resulting email contains the phrase 'on behalf of', and does not allow me fine control over the relevant mime headers. I therefore plan to manually write mime email messages directly to the pickup directory so that I can independently control the From and Sender headers. My dev box is a Vista box and therefore does not have an SMTP server. I would like to configure the dev box so that I have an SMTP server running on it. I can then turn off the SMTP server, write messages to the pickup dir, then turn on the SMPT server and see how the individual emails that I have written will behave (some delivered, some bounced to a bounce handler on a different email domain, as dictated by the Sender). Two questions: 1. Can anyone recommend an SMTP server that will monitor a pickup directory? 2. If I set headers as follows; From:[email protected]; Sender:[email protected] then the recipient will see the email as having come from [email protected] ( and won't see any reference to [email protected]), but if the mail bounces then the NDR will be sent to [email protected]). It's a real pain to have to do this, but I can't see any way of using System.Net.Mail.MailMessage without it messing up my headers.

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