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  • I can write code...but can't design well. Any suggestions?

    - by user396089
    I feel that I am good at writing code in bits and pieces, but my designs really suck. The question is how do I improve my designs (in order to become a better designer). I think schools and colleges do a good job of teaching people as to how to become good at mathematical problem solving, but lets admit the fact that most programs taught at school are generally around 1000 - 2000 lines long, which means that it is mostly an academic exercise and no way reflects the complexity of real world software (a few hundred thousand to millions of lines of code). This is where I believe that even projects like topcoder/project euler also won't be of much help, they might sharpen your mathematical problem solving ability - but you might become a theoretician programmer; someone who is more interested in the nice, clean stuff, and someone who is utterly un-interested in the day to day mundane and hairy stuff that most application programmers deal with. So my question is how do I improve my design skills? That is the ability to design small/medium scale applications that will go into a few thousand of lines of code? How can I learn design skills that would help me build a better html editor kit, or some graphics program like gimp?

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  • Observing MVC, can/should the Model be instantiated in the ViewController? Or where?

    - by user19410
    I'm writing an experimental iPhone app to learn about the MVC paradigm. I instantiate my Model class in the ViewController class. Is this stupid? I'm asking because storing the id of the Model class, and using it works where it's initialized, but referring to it later (in response to an interface action) crashes. Seemingly, the pointer address of my Model class instance changes, but how can that be? The code in question: @interface Soundcheck_Tone_GeneratorViewController : UIViewController { IBOutlet UIPickerView * frequencyWheel; @public Sinewave_Generation * sineGenerator; } @property(nonatomic,retain) Sinewave_Generation * sineGenerator; @end @implementation Soundcheck_Tone_GeneratorViewController @synthesize sineGenerator; - (void)viewDidLoad { [super viewDidLoad]; [self setSineGenerator:[[Sinewave_Generation alloc] initWithFrequency:20.0]]; // using reference -> fine } // pickerView handling is omitted here... - (void)pickerView:(UIPickerView *)thePickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component { [[self sineGenerator] setFrequency:20.0]; // using reference -> crash } @end // the Sinewave_Generation class... only to be thorough. Works fine so far. @interface Sinewave_Generation : NSObject { AudioComponentInstance toneUnit; @public double frequency,theta; } @property double frequency; - (Sinewave_Generation *) initWithFrequency: (int) f; @end @implementation Sinewave_Generation @synthesize frequency; - (Sinewave_Generation *) initWithFrequency: (int) f { self = [super init]; if ( self ) { [self setFrequency: f]; } return self; } @end

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  • how to create multiple pages in Xcode iphone apps

    - by al7r
    Hi there, i am starting my experience with iphone sdk. and i have a question, which is i am trying to create two pages to the app but i don't know how to link them or design them. like when i start the Xcode i find one page named View to design in it, i want to make that page a welcoming page then the user choose one of the three choices he see in that page. Once he clicked on one of them the program take him to the next page or the page he chose. thank you

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  • Proper Way to Create Standards-Compliant Webpage Structure

    - by Sakamoto Kazuma
    I have been working through projects involving packages that do all the web design stuff for me for the past few years. I will admit that I have not been able to focus any on actual web design. I was wondering what the standard is these days for website layouts. Are layout-tables looked down upon now? Or are all layouts done with div tags and controlled through CSS? Are frames even used anymore? Note I am not talking about chart-table tables when I say layout tables.

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  • DataMapper and Codeigniter - how to fully manage a many-to-many relationship

    - by user252160
    I have the following relationship CType has many Field Field has many Ctype and of course the tables used are fields, ctypes, and ctypes_fields. Normally, the ctypes_fields table should contain only ids referencing the other two tables. However, i'd like to put there a "options" field that will contain some content for the concrete instance only. I walked through all DataMapper tuts but I could'n find relevant info on how I could extract these specific values (the ones in the relation table) Should I create a separate model for this relation table or there is a clever way to do this ?

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  • ModelBinding to and EntitySet (MVC2 & LinqToSQL)

    - by Myster
    Hi all There seems to be an issue with the default model binder when binding to an EntitySet causes the EntitySet to be empty. The problem is described here and here: Microsoft's response is: ... We have now fixed this and the fix will be included in .NET Framework 4.0. With the new behavior, if the EntitySet passed into Assign is the same object as the one its being assigned to, no action will occur. With a work around being to edit the code generated like so: public override EntitySet<Thing> Things { get { return this._Things; } set { //CORRECTION: _Things= new EntitySet<Thing>(); _Things.Assign(value); //WAS: this._Things.Assign(value); } } As you can imagine this is not ideal as you have to re-add the code every time, does anyone have a better solution?

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  • Is it possible to set a claimType to be required and have a certain value in WIF?

    - by Nissan Fan
    <claimTypeRequired> <claimType type="http://www.stackoverflow.com/claims/canwalkthedog" optional="false" /> </claimTypeRequired> Is it possible in WIF apps to setup the web.config to use constraints. E.g. Say that a particular claim is required and must contain a value such as 1 or 'Y'? I want to create a situation where the framework dispermits access to an application if a claim doesn't meet a certain criteria, rather than to code it out implicitly.

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  • Product table, many kinds of product, each product has many parameters

    - by StoneHeart
    Hi, i'm have not much experience in table design. My goal is a product table(s), it must design to fix some requirement below: Support many kind of products (TV, Phone, PC, ...). Each kind of product has different set of parameters like: Phone will have Color, Size, Weight, OS... PC will have CPU, HDD, RAM... Set of parameters must be dynamic. You can add or edit any parameter you like. I don't want make a table for each kind of product. So I need help to find a correct solution. Thanks.

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  • Creating custom IP-STS for sharepoint foundation 2010 without ADFS

    - by user252229
    I plan to create very simple custom IP-STS for SharePoint foundation 2010 without ADFS server so anyone can integrate Windows Live ID to SharePoint foundation 2010 simply without ADFS, I can't use ADFS server because it could not install on Windows Web Server 2008 (Web Edition), also I found many article use LDAP provider but it does not exists in SharePoint Foundation too (it requires Sharepoint Server Edition). After too much searching I just found the following article and find all technique except one problem. 1) Creating Custom Claim Provider: blogs.technet.com/b/speschka/archive/2010/03/13/writing-a-custom-claims-provider-for-sharepoint-2010-part-1.aspx 2) Creating Custom STS Provider: http://blogs.msdn.com/b/chunliu/archive/2010/04/02/how-to-make-use-of-a-custom-ip-sts-with-sharepoint-2010-part-1.aspx Only one step remains: I got following error after enter username in STS site and redirect to localhost/_trust/default.aspx , ( I leave EncryptingCertificateName empty). Operation is not valid due to the current state of the object I expect to get access denied error instead of that error. 1.Is it possible anyway? 2.Can anyone help me where can I find working article to create custom IP-STS without ADFS server Any idea will help me Thanks

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  • Querying a Cassandra column family for rows that have not been updated in X days

    - by knorv
    I'm moving an existing MySQL based application over to Cassandra. So far finding the equivalent Cassandra data model has been quite easy, but I've stumbled on the following problem for which I'd appreciate some input: Consider a MySQL table holding millions of entities: CREATE TABLE entities ( id INT AUTO_INCREMENT NOT NULL, entity_information VARCHAR(...), entity_last_updated DATETIME, PRIMARY KEY (id), KEY (entity_last_updated) ); The table is regularly queried for entities that need to be updated: SELECT id FROM entities WHERE entity_last_updated IS NULL OR entity_last_updated < DATE_ADD(NOW(), INTERVAL -7*24 HOUR) ORDER BY entity_last_updated ASC; The entities returned by this queries are then updated using the following query: UPDATE entities SET entity_information = ?, entity_last_updated = NOW() WHERE id = ?; What would be the corresponding Cassandra data model that would allow me to store the given information and effectively query the entities table for entities that need to be updated (that is: entities that have not been updated in the last seven days)?

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  • Howto UML: sub methods / calls / operations / procedures

    - by hsmit
    How would you guys model this in UML (in a sequence diagram)? .. car1.drive(); .. ... in Car class: .. drive(){ this.startEngine(); } startEngine(){ this.getKey(); this.insertKey(); } .. a small begin: objx car1 ---- ---- | | | drive() | |-------->| startEngine() | |------------. | | | | |<-----------. | | But where comes the getKey() method? Must this be communicated via another sequence diagram? Or is there a way to include sub procedures?

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  • Singleton: How should it be used

    - by Loki Astari
    Edit: From another question I provided an answer that has links to a lot of questions/answers about singeltons: More info about singletons here: So I have read the thread Singletons: good design or a crutch? And the argument still rages. I see Singletons as a Design Pattern (good and bad). The problem with Singleton is not the Pattern but rather the users (sorry everybody). Everybody and their father thinks they can implement one correctly (and from the many interviews I have done, most people can't). Also because everybody thinks they can implement a correct Singleton they abuse the Pattern and use it in situations that are not appropriate (replacing global variables with Singletons!). So the main questions that need to be answered are: When should you use a Singleton How do you implement a Singleton correctly My hope for this article is that we can collect together in a single place (rather than having to google and search multiple sites) an authoritative source of when (and then how) to use a Singleton correctly. Also appropriate would be a list of Anti-Usages and common bad implementations explaining why they fail to work and for good implementations their weaknesses. So get the ball rolling: I will hold my hand up and say this is what I use but probably has problems. I like "Scott Myers" handling of the subject in his books "Effective C++" Good Situations to use Singletons (not many): Logging frameworks Thread recycling pools /* * C++ Singleton * Limitation: Single Threaded Design * See: http://www.aristeia.com/Papers/DDJ_Jul_Aug_2004_revised.pdf * For problems associated with locking in multi threaded applications * * Limitation: * If you use this Singleton (A) within a destructor of another Singleton (B) * This Singleton (A) must be fully constructed before the constructor of (B) * is called. */ class MySingleton { private: // Private Constructor MySingleton(); // Stop the compiler generating methods of copy the object MySingleton(MySingleton const& copy); // Not Implemented MySingleton& operator=(MySingleton const& copy); // Not Implemented public: static MySingleton& getInstance() { // The only instance // Guaranteed to be lazy initialized // Guaranteed that it will be destroyed correctly static MySingleton instance; return instance; } }; OK. Lets get some criticism and other implementations together. :-)

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  • What makes MVVM uniquely suited to WPF?

    - by Reed Copsey
    The Model-View-ViewModel is very popular with WPF and Silverlight. I've been using this for my most recent projects, and am a very large fan. I understand that it's a refinement of MVP. However, I am wondering exactly what unique characteristics of WPF (and Silverlight) allow MVVM to work, and prevent (or at least make difficult) this pattern from working using other frameworks or technologies. I know MVVM has a strong dependency on the powerful data binding technology within WPF. This is the one feature which many articles and blogs seem to mention as being the key to WPF providing the means of the strong separation of View from ViewModel. However, data binding exists in many forms in other UI frameworks. There are even projects like Truss that provide WPF-style databinding to POCO in .NET. What features, other than data binding, make WPF and Silverlight uniquely suited to Model-View-ViewModel?

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  • Rails polymorphic associations, two assoc types in one class

    - by snitko
    Consider a class: class Link < ActiveRecord::Base has_many :link_votes, :as => :vote_subject, :class_name => 'Vote' has_many :spam_votes, :as => :vote_subject, :class_name => 'Vote' end The problem is, when I'm adding a new vote with @link.link_votes << Vote.new the vote_subject_type is 'Link', while I wish it could be 'link_votes' or something like that. Is this an AR limitation or is there a way to workaround this thing? I've actually found one related answer, but I'm not quite sure about what it says: http://stackoverflow.com/questions/1168047/polymorphic-association-with-multiple-associations-on-the-same-model/1764117#1764117

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  • Where can I find free WPF controls and control templates?

    - by Geoffrey Chetwood
    Duplicate: Where can I find free WPF controls and control templates? I am looking for some recommendations on good places to find libraries of controls/templates/styles for WPF. I know about the usual places like Infragistics, but it seems to me that there should be some kind of community effort by now to share nice, clean, well written controls for WPF controls. I am not big on the design side, and it would be nice to fill out my personal libraries with some nice examples from people who are better at design. Any ideas/recommendations?

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  • Is it easy to switch from relational to non-relational databases with Rails?

    - by Tam
    Good day, I have been using Rails/Mysql for the past while but I have been hearing about Cassandra, MongoDB, CouchDB and other document-store DB/Non-relational databases. I'm planning to explore them later as they might be better alternative for scalability. I'm planning to start an application soon. Will it make a different with Rails design if I move from relational to non-relational database? I know Rails migrations are database-agnostic but wasn't sure if moving to non-relational will make difference with design or not.

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  • Normalize or Denormalize in high traffic websites

    - by Inam Jameel
    what is the best practice for database design for high traffic websites like this one stackoverflow? should one must use normalize database for record keeping or normalized technique or combination of both? is it sensible to design normalize database as main database for record keeping to reduce redundancy and at the same time maintain another denormalized form of database for fast searching? or main database should be denormalize and one can make normalized views in the application level for fast database operations? or beside above mentioned approach? what is the best practice of designing high traffic websites???

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  • Yii: Saving date and time in DB

    - by FaisalKhan
    I am having trouble saving the date in DB through Model. In my controller, if I dump the date in log that I receive from $_POST , I get the date in this format "10/Nov/2012 07:30". If I use: $AccountAppointment->start_date=Yii::app()->dateFormatter->format($_POST['AccountAppointment']['start_date'], 'dd/M/yyyy HH:mm'); I get the error: Invalid datetime format: 1292 Incorrect datetime value: '10/NoGMT+5/2012 07:30' for column 'start_date' Changing the format in dateFormatter to 'dd/M/yyyy HH:mm' or 'dd/MM/yyyy HH:mm' or 'dd/MMM/yyyy HH:mm' throws the same error. Db is MySQL 5.0, Yii version 1.1.12. Any help would be greatly appreciated, I am almost stuck....thanks....

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  • Best way to fetch data from a single database table with multiple threads?

    - by Ravi Bhatt
    Hi, we have a system where we collect data every second on user activity on multiple web sites. we dump that data into a database X (say MS SQL Server). we now need to fetch data from this single table from daatbase X and insert into database Y (say mySql). we want to fetch time based data from database X through multiple threads so that we fetch as fast as we can. Once fetched and stored in database Y, we will delete data from database X. Are there any best practices on this sort of design? any specific things to take care on table design like sharing or something? Are there any other things that we need to take care to make sure we fetch it as fast as we can from threads running on multiple machines? Thanks in advance! Ravi

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  • Overriding as_json has no effect?

    - by Ola Tuvesson
    I'm trying to override as_json in one of my models, partly to include data from another model, partly to strip out some unnecessary fields. From what I've read this is the preferred approach in Rails 3. To keep it simple, let's say I've got something like: class Country < ActiveRecord::Base def as_json(options={}) super( :only => [:id,:name] ) end end and in my controller simply def show respond_to do |format| format.json { render :json => @country } end end Yet whatever i try, the output always contains the full data, the fields are not filtered by the ":only" clause. Basically, my override doesn't seem to kick in, though if I change it to, say... class Country < ActiveRecord::Base def as_json(options={}) {foo: "bar"} end end ...I do indeed get the expected JSON output. Have I simply got the syntax wrong?

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  • Debian Package Control file Question.

    - by AJ
    Hello, I need to create a debian package for a java application. In my package there a .jar file which is executable , a script which will run this jar file and a .so file for fmod. I read the tutorial provided at http://tldp.org/HOWTO/html_single/Debian-Binary-Package-Building-HOWTO/ My question is in control file there is a Depends field which basically mentions the packages that need to installed in order to install my application. How do i find which packages are required for my application. I followed the instructions provided in the link for one of the .so and did ~/Desktop/PennTotalRecall/native/fmod/lib/linux64$ dpkg -S libfmodex64-4.28.09.so dpkg: libfmodex64-4.28.09.so not found. It gives above result. Also my application requires java 1.5 to be installed in order for it to run. How do I specify in my debian package. Thanks, AJ

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