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  • An online php debugger/code editor

    - by Zirak
    It's a simple deal: I'm sometimes in places where I don't have my laptop, and find myself with spare time and an idea for a project. But unfortunately, I can't do anything about it. I tried a variety of solutions, which include running IDEs (like phpstorm or Aptana) on a disc-on-key or cd (very slow and unappealing), trying several online solutions (like http://phpanywhere.net) and found that all of them are either buggy, overloaded or underloaded with features, just difficult to use, require FTP etc etc. All that is required here is a syntax highlighting and debugging alerts; no actual running of code. So the question is split into two: 1)Do you know of a good online php editor that you've used and enjoyed? 2)If no, then how would you go about making one? The second one seems a bit general, so I'll try and expand...It might be a good idea; if you can't find one, make one. The question is about the concept of making a syntax highlighter (shouldn't be too difficult), and the difficult part of catching php errors WITHOUT executing any php code. Thank you in advance.

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  • node.js beginner tutorials?

    - by TreyK
    Hey all, I'm working on creating my first real node.js http server, and I'm sort of drowning in it. As a good teacher of mine always said, "I'll just shove you in the water for now, and then I'll show you how to swim." Fortunately, she wasn't a swimming instructor, but it's a good analogy nonetheless. I feel like I've jumped into node.js and I've only found a ping pong ball to help, that is to say, most of the tutorials I've read stop shortly after the "Hello World" example and I've mostly been trying to make sense of copied and pasted code (or they assume I have knowledge of lower level HTTP and webserver concepts that have been done for me as an Apache/PHP developer). I have experience in both client-side Javascript and PHP, but node seems to be a beast all of its own. I don't quite have the low-level knowledge that seems necessary for creating a node server, and connect, which seems to be a nice module for simplifying things, seems quite sparsely explained, even in the docs on its Git. Where could I find some tutorials to help me in this situation? TL;DR - Are there any tutorials for node.js that go beyond "Hello World" but don't require much low-level knowledge? Or any tutorials that explain lower-level HTTP and webserver concepts that I would need to effectively create a node HTTP server? Thanks for any help. -Trey

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  • Document management, SCM ?

    - by tsunade
    Hello, This might not be a hard core programming question, but it's related to some of the tools used by programmers I suspect. So we're a bunch of people each with a bunch of documents and a bunch of different computers on a bunch of operating systems (well, only 2, linux and windows). The best way these documents can be stored/managed is if they were available offline (the laptop might not always be online) but also synchronized between all the machines. Having a server with extra reliable storage be a "base repository" seems like a good idea to me. Using a SCM comes to my mind and I've tried Subversion, and it seems to be a good thing that it uses a centralized repository - but: When checking out the total size of the checkout is roughly double the original size. Big files or big repositories seem to slow it down. Also I've tried rsync, which might work - but it's a bit rough when it comes to the potential conflict. Finally I've tried Unison (which is a wrapping of rsync, I think) and while it works it becomes horribly slow for the big directories we have here since it has to scan everything. So the question is - is there a SCM tool out there that is actually practial to use for a big bunch of both small and big files? If thats a NO - does anyone know other tools that do this job? Thanks for reading :)

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  • What's the next steps for moving from appengine to full django?

    - by tomcritchlow
    Hey guys, I'm super new to programming and I've been using appengine to help me learn python and general coding. I'm getting better quickly and I'm loving it all the way :) Appengine was awesome for allowing me to just dive into writing my app and getting something live that works (see http://www.7bks.com/). But I'm realising that the longer I continue to learn on appengine the more I'm constraining myself and locking myself into a single system. I'd like to move to developing on full django (since django looks super cool!). What are my next steps? To give you a feel for my level of knowledge: I'm not a unix user I'm not familiar with command line controls (I still use appengine/python completely via the appengine SDK) I've never programmed in anything other than python, anywhere other than appengine I know the word SQL, but don't know what MySQL is really or how to use it. So, specifically: What are the skills I need to learn to get up and running with full django/python? If I'm going to host somewhere else I suppose I'll need to learn some sysadmin type skills (maybe even unix?). Is there anywhere that offers easy hosting (like appengine) but that supports django? I hear such great things about heroku I'm considering switching to RoR and going there I appreciate that I'm likely not quite ready to move away from appengine just yet but I'm a fiercely passionate learner (http://www.7bks.com/blog/179001) and would love it if I knew all the steps I needed to learn so I could set about learning them. At the moment, I don't even know what the steps are I need to learn! Thank you very much. Sorry this isn't a specific programming question but I've looked around and haven't found a good how-to for someone of my level of experience and I think others would appreciate a good roadmap for the things we need to learn to get up and running. Thanks, Tom PS - if anyone is in London and fancies showing me the ropes in person that would be super awesome :)

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  • Testing InlineFormset clean methods

    - by Rory
    I have a Django project, with 2 models, a Structure and Bracket, the Bracket has a ForeignKey to a Structure (i.e. one-to-many, one Structure has many Brackets). I created a TabularInline for the admin site, so that there would be a table of Brackets on the Structure. I added a custom formset with some a custom clean method to do some extra validation, you can't have a Bracket that conflicts with another Bracket on the same Structure etc. The admin looks like this: class BracketInline(admin.TabularInline): model = Bracket formset = BracketInlineFormset class StructureAdmin(admin.ModelAdmin): inlines = [ BracketInline ] admin.site.register(Structure, StructureAdmin) That all works, and the validation works. However now I want to write some unittest to test my complex formset validation logic. My first attempt to validate known-good values is: data = {'form-TOTAL_FORMS': '1', 'form-INITIAL_FORMS': '0', 'form-MAX_NUM_FORMS': '', 'form-0-field1':'good-value', … } formset = BracketInlineFormset(data) self.assertTrue(formset.is_valid()) However that doesn't work and raises the exception: ====================================================================== ERROR: testValid (appname.tests.StructureTestCase) ---------------------------------------------------------------------- Traceback (most recent call last): File "/paht/to/project/tests.py", line 494, in testValid formset = BracketInlineFormset(data) File "/path/to/django/forms/models.py", line 672, in __init__ self.instance = self.fk.rel.to() AttributeError: 'BracketInlineFormset' object has no attribute 'fk' ---------------------------------------------------------------------- The Django documentation (for formset validation) implies one can do this. How come this isn't working? How do I test the custom clean()/validation for my inline formset?

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  • MVC2 Modelbinder for List of derived objects

    - by user250773
    I want a list of different (derived) object types working with the Default Modelbinder in Asp.net MVC 2. I have the following ViewModel: public class ItemFormModel { [Required(ErrorMessage = "Required Field")] public string Name { get; set; } public string Description { get; set; } [ScaffoldColumn(true)] //public List<Core.Object> Objects { get; set; } public ArrayList Objects { get; set; } } And the list contains objects of diffent derived types, e.g. public class TextObject : Core.Object { public string Text { get; set; } } public class BoolObject : Core.Object { public bool Value { get; set; } } It doesn't matter if I use the List or the ArrayList implementation, everything get's nicely scaffolded in the form, but the modelbinder doesn't resolve the derived object type properties for me when posting back to the ActionResult. What could be a good solution for the Viewmodel structure to get a list of different object types handled? Having an extra list for every object type (e.g. List, List etc.) seems to be not a good solution for me, since this is a lot of overhead both in building the viewmodel and mapping it back to the domain model. Thinking about the other approach of binding all properties in a custom model binder, how can I make use the data annotations approach here (validating required attributes etc.) without a lot of overhead?

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  • Serializing Configurations for a Dependency Injection / Inversion of Control

    - by Joshua Starner
    I've been researching Dependency Injection and Inversion of Control practices lately in an effort to improve the architecture of our application framework and I can't seem to find a good answer to this question. It's very likely that I have my terminology confused, mixed up, or that I'm just naive to the concept right now, so any links or clarification would be appreciated. Many examples of DI and IoC containers don't illustrate how the container will connect things together when you have a "library" of possible "plugins", or how to "serialize" a given configuration. (From what I've read about MEF, having multiple declarations of [Export] for the same type will not work if your object only requires 1 [Import]). Maybe that's a different pattern or I'm blinded by my current way of thinking. Here's some code for an example reference: public abstract class Engine { } public class FastEngine : Engine { } public class MediumEngine : Engine { } public class SlowEngine : Engine { } public class Car { public Car(Engine e) { engine = e; } private Engine engine; } This post talks about "Fine-grained context" where 2 instances of the same object need different implementations of the "Engine" class: http://stackoverflow.com/questions/2176833/ioc-resolve-vs-constructor-injection Is there a good framework that helps you configure or serialize a configuration to achieve something like this without hard coding it or hand-rolling the code to do this? public class Application { public void Go() { Car c1 = new Car(new FastEngine()); Car c2 = new Car(new SlowEngine()); } } Sample XML: <XML> <Cars> <Car name="c1" engine="FastEngine" /> <Car name="c2" engine="SlowEngine" /> </Cars> </XML>

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  • Fast, Unicode-capable, cross-platform programmer's text editor that shows invisibles like ZWSP?

    - by Roger_S
    Our publishing workflow includes Windows and Linux machines (there are some Macs too, but not in the critical-path workflow). Many texts include both English and Khmer and are marked-up in XML. XML Copy Editor is the best cross-platform open-source XML editor I've discovered. It utilizes the Scintilla editing component, which is generally good with Unicode but which does not enable non-printing or invisible characters like U+200B (zero-width space) and U+200C (zero-width non-joiner) to be displayed. Khmer does not separate words with a space character as Western languages do, so ZWSP is used in electronic texts to enable applications to break lines easily. Ideally I'd edit the markup and the content in a single editor, but XML awareness is less important at times than being able to display invisibles. (OpenOffice.org Writer and Microsoft Word are the only two apps I know that will display ZWSP. They are not suitable for the markup and text manipulations that need to be done to prepare manuscripts for publication, unfortunately, although I guess they're fine for authoring.) I tried out a promising editor last week, but a search-and-replace regex operation that took under a second in TextPad 4.7.3 lasted over twenty seconds. So I want to mention that speed and the ability to handle large (up to 150mb) files is also a concern. Is there a good, fast, free or not too expensive text editor, with versions on Windows and Linux and maybe mac too, Unicode-aware and capable of displaying invisibles like ZWSP? That has syntax highlighting, can handle large files and is customizable enough that I won't tear my hair out in frustration? Thanks, Roger_S

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  • Project Euler #14 and memoization in Clojure

    - by dbyrne
    As a neophyte clojurian, it was recommended to me that I go through the Project Euler problems as a way to learn the language. Its definitely a great way to improve your skills and gain confidence. I just finished up my answer to problem #14. It works fine, but to get it running efficiently I had to implement some memoization. I couldn't use the prepackaged memoize function because of the way my code was structured, and I think it was a good experience to roll my own anyways. My question is if there is a good way to encapsulate my cache within the function itself, or if I have to define an external cache like I have done. Also, any tips to make my code more idiomatic would be appreciated. (use 'clojure.test) (def mem (atom {})) (with-test (defn chain-length ([x] (chain-length x x 0)) ([start-val x c] (if-let [e (last(find @mem x))] (let [ret (+ c e)] (swap! mem assoc start-val ret) ret) (if (<= x 1) (let [ret (+ c 1)] (swap! mem assoc start-val ret) ret) (if (even? x) (recur start-val (/ x 2) (+ c 1)) (recur start-val (+ 1 (* x 3)) (+ c 1))))))) (is (= 10 (chain-length 13)))) (with-test (defn longest-chain ([] (longest-chain 2 0 0)) ([c max start-num] (if (>= c 1000000) start-num (let [l (chain-length c)] (if (> l max) (recur (+ 1 c) l c) (recur (+ 1 c) max start-num)))))) (is (= 837799 (longest-chain))))

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  • Entity Framework 4 + POCO with custom classes and WCF contracts (serialization problem)

    - by eman
    Yesterday I worked on a project where I upgraded to Entity Framework 4 with the Repository pattern. In one post, I have read that it is necessary to turn off the custom tool generator classes and then write classes (same like entites) by hand. That I can do it, I used the POCO Entity Generator and then deleted the new generated files .tt and all subordinate .cs classes. Then I wrote the "entity classes" by myself. I added the repository pattern and implemented it in the business layer and then implemented a WCF layer, which should call the methods from the business layer. By calling an Insert (Add) method from the presentation layer and everything is OK. But if I call any method that should return some class, then I get an error like (the connection was interrupted by the server). I suppose there is a problem with the serialization or am I wrong? How can by this problem solved? I'm using Visual Studio S2010, Entity Framework 4, C#. UPDATE: I have uploaded the project and hope somebody can help me! link text UPDATE 2: My questions: Why is POCO good (pros/cons)? When should POCO be used? Is POCO + the repository pattern a good choice? Should POCO classes by written by myself or could I use auto generated POCO classes?

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  • This is a great job opportunity!!! [closed]

    - by Stuart Gordon
    ASP.NET MVC Web Developer / London / £450pd / £25-£50,000pa / Interested contact [email protected] ! As a web developer within the engineering department, you will work with a team of enthusiastic developers building a new ASP.NET MVC platform for online products utilising exciting cutting edge technologies and methodologies (elements of Agile, Scrum, Lean, Kanban and XP) as well as developing new stand-alone web products that conform to W3C standards. Key Responsibilities and Objectives: Develop ASP.NET MVC websites utilising Frameworks and enterprise search technology. Develop and expand content management and delivery solutions. Help maintain and extend existing products. Formulate ideas and visions for new products and services. Be a proactive part of the development team and provide support and assistance to others when required. Qualification/Experience Required: The ideal candidate will have a web development background and be educated to degree level in a Computer Science/IT related course plus ASP.NET MVC experience. The successful candidate needs to be able to demonstrate commercial experience in all or most of the following skills: Essential: ASP.NET MVC with C# (Visual Studio), Castle, nHibernate, XHTML and JavaScript. Experience of Test Driven Development (TDD) using tools such as NUnit. Preferable: Experience of Continuous Integration (TeamCity and MSBuild), SQL Server (T-SQL), experience of source control such as Subversion (plus TortioseSVN), JQuery. Learn: Fluent NHibernate, S#arp Architecture, Spark (View engine), Behaviour Driven Design (BDD) using MSpec. Furthermore, you will possess good working knowledge of W3C web standards, web usability, web accessibility and understand the basics of search engine optimisation (SEO). You will also be a quick learner, have good communication skills and be a self-motivated and organised individual.

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  • Static Vs Non-Static Method Performance C#

    - by dotnetguts
    Hello All, I have few global methods declared in public class in my asp.net web application. I have habbit of declaring all global methods in public class in following format public static string MethodName(parameters) { } I want to know how it would impact on performance point of view? 1) Which one is Better? Static Method or Non-Static Method? 2) Reason why it is better? Following link shows Non-Static methods are good because, static methods are using locks to be Thread-safe. The always do internally a Monitor.Enter() and Monitor.exit() to ensure Thread-safety. http://bytes.com/topic/c-sharp/answers/231701-static-vs-non-static-function-performance And Following link shows Static Methods are good static methods are normally faster to invoke on the call stack than instance methods. There are several reasons for this in the C# programming language. Instance methods actually use the 'this' instance pointer as the first parameter, so an instance method will always have that overhead. Instance methods are also implemented with the callvirt instruction in the intermediate language, which imposes a slight overhead. Please note that changing your methods to static methods is unlikely to help much on ambitious performance goals, but it can help a tiny bit and possibly lead to further reductions. http://dotnetperls.com/static-method I am little confuse which one to use? Thanks

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  • Flash CS 4 / AS 2 + Dynamic Text + Html + Embedded fonts...

    - by AndreMiranda
    I have this scenario: 1) I have a dynamic text that receives its data from a XML. 2) The texts showed get theirs style from a CSS file. 3) My dynamic text has a html 'span' tag and it's formatted according to the CSS class that it's passed via the XML file. Ok... so far so good. It's something like: _root.txt.txtDica = "<span class='"+ node.childNodes[_global.auxCont].attributes.myStyle +"'>" + node.childNodes[_global.auxCont].attributes.myText+ "</span>"; The problem is that the swf has a poor quality text. So, I've been looking around, found some things about embedded fonts, Flash TextField() and etc. But, nothing seems to work. Does anyone know how can I generate this html tag in a dynamic text with a good quality? It's worth to say that I'm using regular fonts, such as Verdana and Arial. Thanks a lot!

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  • Just 2 free months 2 learn or improve my skills

    - by microspino
    On the 30 of June I will leave my every day work to start as freelance developer. I'd like to set a period of 2 months apart to improve my dev skills. At work I code in C# and during my spare time I enjoyed building Ruby on Rails web applications and creating some Arduino prototypes. I'm something more than junior but I don't feel really a senior developer because I never had a big corporate project built and designed by me with help of other juniors (although I don't think this is really a good definiton of a "senior", It helps describing my feelings). Using a scale from 0 (ignorant) to 10 (proficient like a "samurai") the list below describes my skills that I would like to improve with just 2 months. I've already bought some nice and updated books on all the subjects hereunder: The order doesn't matter C = 1 C# & .Net = 6 Arduino & Processing = 2 Ruby = 5 Rails = 5 HTML/XHTML/CSS = 9 Javascript = 6 Objective-C/iPhone dev = 2 Python = 4 Django = 4 Desing Patterns = 3 Algorythms = 3 Git = 5 I haven't included SQL or Databases in general nor Networking because I spent 10 years working in the past with them and I feel pretty solid for now. As an aside, I've made up some interest in Redis, Node.js, HTML5 reading about them on the web. After two months, since I have to pay my bills, I could go searching for some new job. If learning and developing were really good maybe I could also invest on something I gave birth during them. Can You give me some piece of advice on which you think It's better to improve or develop a learning project on (something like a "summer of code" thing)? The all point Is to see my weeknesses and work on them.

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  • changing the serialization procedure for a graph of objects (.net framework)

    - by pierusch
    Hello I'm developing a scientific application using .net framework. The application depends heavily upon a large data structure (a tree like structure) that has been serialized using a standard binaryformatter object. The graph structure looks like this: <serializable()>Public class BigObjet inherits list(of smallObject) end class <serializable()>public class smallObject inherits list(of otherSmallerObjects) end class ... The binaryFormatter object does a nice job but it's not optimized at all and the entire data structure reaches around 100Mb on my filesystem. Deserialization works too but it's pretty slow (around 30seconds on my quad core). I've found a nice .dll on codeproject (see "optimizing serialization...") so I wrote a modified version of the classes above overriding the default serialization/deserialization procedure reaching very good results. The problem is this: I can't lose the data previosly serialized with the old version and I'd like to be able to use the new serialization/deserialization method. I have some ideas but I'm pretty sure someone will be able to give me a proper and better advice ! use an "helper" graph of objects who takes care of the entire serialization/deserialization procedure reading data from the old format and converting them into the classes I nedd. This could work but the binaryformatter "needs" to know the types being serialized so........ :( modify the "old" graph to include a modified version of serialization procedure...so I'll be able to deserialize old file and save them with the new format......this doesn't sound too good imho. well any help will be higly highly appreciated :)

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  • Why are (almost) all the on-line games written in ActionScript (Flash) not Java?

    - by MasterPeter
    I absolutely love good defender games (e.g. Gemcraft, Protector: reclaiming the throne) as they can be intellectually quite challenging; it's like playing chess but a little less thinking a bit more action. Sadly, there are not that many good ones out there and I thought I would create one myself and share it with the rest of the world by making it available on-line. I have never worked with ActionScript but when it comes to on-line games, this is the main choice. I have tried to find a decent 2D game in the form of a Java applet but to no avail. Why is this so? I could write the game, most comfortably, in Delphi for Win32 but then people would need to download the executable, which could deter some form downloading it, and also it would only work on Windows. I am also familiar with Java, having worked with Java for the last four years or so. Although I don't have much experience with games programming. Should I note be deterred by the fact that all online games are written for in Flash and create my defender game as a Java applet, or should I consider learning ActionScript and games development for the ActionScript Virtual Machine (AS3 looks very much like Java... but still, it's an entirely new technology to me and I might never use it professionally.) Could you, please, just answer the the question in the title? Why Flash, not Java applets? Is it only 'politics'?

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  • Atomic operations on several transactionless external systems

    - by simendsjo
    Say you have an application connecting 3 different external systems. You need to update something in all 3. In case of a failure, you need to roll back the operations. This is not a hard thing to implement, but say operation 3 fails, and when rolling back, the rollback for operation 1 fails! Now the first external system is in an invalid state... I'm thinking a possible solution is to shut down the application and forcing a manual fix of the external system, but then again... It might already have used this information (and perhaps that's why it failed), or we might not have sufficient access. Or it might not even be a good way to rollback the action! Are there some good ways of handling such cases? EDIT: Some application details.. It's a multi user web application. Most of the work is done with scheduled jobs (through Quartz.Net), so most operations is run in it's own thread. Some user actions should trigger jobs that update several systems though. The external systems are somewhat unstable. I Was thinking of changing the application to use the Command and Unit Of Work pattern

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  • Applying correct bindings to WPF datatemplate to maximize reusability

    - by johncatfish
    Hi. I have a WPF application. I want to apply that datatemplate to a Listbox filled with records from Table02. Then, for each listboxitem I need to bind the combobox to the same database table (Table01), but for each listboxitem the selected item will vary. It will be a foreign key to Table01. <DataTemplate x:Key="Table01DataTemplate"> <Grid> <ComboBox ItemsSource="{Binding Model.IQueryable_Table01, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}}" SelectedValue="{Binding Table01_ForeignKey}" DisplayMemberPath="name" SelectedValuePath="id" /> <!-- Other stuff --> </Grid> </DataTemplate> <ListBox x:Name="lbTest" ItemTemplate="{StaticResource Table01DataTemplate}" /> <!-- In .cs file lbTest.DataContext = this; --> Notes: Model.IQueryable_Table01 is a property which encapsulates a Linq-to-sql call returning a IQueryable. lbTest will be filled by setting ItemsSource with a Linq-to-sql call. Is this a good way to do the bindings in a data template for a maximum reusability? I also thought of replacing AncestorType={x:Type Window} with lbTest.DataContext = this; AncestorType={x:Type Application} and lbTest.DataContext = App.Current; But it didn't work (Exception on loading) and I don't know if there's any caveats or down-sides to this approach. Is this good? Any suggestions or improvements? Thanks.

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  • Structuring the UI code of a single-page EXTjs Web app using Rails?

    - by Daniel Beardsley
    I’m in the process of creating a large single-page web-app using ext-js for the UI components with Rails on the backend. I’ve come to good solutions for transferring data using Whorm gem and Rails support of RESTful Resources. What I haven’t come to a conclusion on is how to structure the UI and business logic aspects of the application. I’ve had a look at a few options, including Netzke but haven’t seen anything that I really think fits my needs. How should a web-application that uses ext-js components, layouts, and controls in the browser and Rails on the server best implement UI component re-use, good organization, and maintainability while maintaining a flexible layout design. Specifically I’m looking for best-practice suggestions for structuring the code that creates and configures UI components (many UI config options will be based on user data) Should EXT classes be extended in static JS for often re-used customizations and then instantiated with various configuration options by generated JS within html partials? Should partials create javascript blocks that instantiate EXT components? Should partials call helpers that return ruby hashes for EXT component config which is then dumped to Json? Something else entirely? There are many options and I'd love to hear from people who've been down this road and found some methodology that worked for them.

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  • How do you tell that your unit tests are correct?

    - by Jacob Adams
    I've only done minor unit testing at various points in my career. Whenever I start diving into it again, it always troubles me how to prove that my tests are correct. How can I tell that there isn't a bug in my unit test? Usually I end up running the app, proving it works, then using the unit test as a sort of regression test. What is the recommended approach and/or what is the approach you take to this problem? Edit: I also realize that you could write small, granular unit tests that would be easy to understand. However, if you assume that small, granular code is flawless and bulletproof, you could just write small, granular programs and not need unit testing. Edit2: For the arguments "unit testing is for making sure your changes don't break anything" and "this will only happen if the test has the exact same flaw as the code", what if the test overfits? It's possible to pass both good and bad code with a bad test. My main question is what good is unit testing since if your tests can be flawed you can't really improve your confidence in your code, can't really prove your refactoring worked, and can't really prove that you met the specification?

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  • DB Design to store custom fields for a table

    - by Fazal
    Hi All, this question came up based on the responses I got for the question http://stackoverflow.com/questions/2785033/getting-wierd-issue-with-to-number-function-in-oracle As everyone suggested that storing Numeric values in VARCHAR2 columns is not a good practice (which I totally agree with), I am wondering about a basic Design choice our team has made and whether there are better way to design. Problem Statement : We Have many tables where we want to give certain number of custom fields. The number of required custom fields is known, but what kind of attribute is mapped to the column is available to the user E.g. I am putting down a hypothetical scenario below Say you have a laptop which stores 50 attribute values for every laptop record. Each laptop attributes are created by the some admin who creates the laptop. A user created a laptop product lets say lap1 with attributes String, String, numeric, numeric, String Second user created laptop lap2 with attributes String,numeric,String,String,numeric Currently there data in our design gets persisted as following Laptop Table Id Name field1 field2 field3 field4 field5 1 lap1 lappy lappy 12 13 lappy 2 lap2 lappy2 13 lappy2 lapp2 12 This example kind of simulates our requirement and our design Now here if somebody is lookinup records for lap2 table doing a comparison on field2, We need to apply TO_NUMBER. select * from laptop where name='lap2' and TO_NUMBER(field2) < 15 TO_NUMBER fails in some cases when query plan decides to first apply to_number instead of the other filter. QUESTION Is this a valid design? What are the other alternative ways to solve this problem One of our team mates suggested creating tables on the fly for such cases. Is that a good idea How do popular ORM tools give custom fields or flex fields handling? I hope I was able to make sense in the question. Sorry for such a long text.. This causes us to use TO_NUMBER when queryio

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  • WPF or Silverlight Learning Resources for Business Applications

    - by Refracted Paladin
    I am the only developer at a non-profit organization(~200 employees) where we are a M$ shop and 90% of the things I develop are specific to our company and are internal only. I am given a lot of latitude on how I accomplish my goals so using new technologies is in my best interest. So far I have developed all winform & asp.net applications. I would now like to focus on XAML driven development(WPF & Silverlight) and would like your help. I am subscribed to numerous Silverlight blogs and I have went through a few good tutorials however, I would really appreciate a GOOD SOLID book in my hands going forward. I prefer learning books versus reference books and I REALLY would like one from a Business standpoint as well. Shameless, self-promoting is welcomed if you happen to be an author or reviewer for one that meets my criteria. I would, however, prefer that recomendations were based on first-hand experience(no, 'my friend as this awesome book he told me about', please). Though, I don't mind un-released books if say they are an updated version of an existing. disclaimer -- I know there are an insane amount of Book posts here(SO) but none I believe for my specific need. If there is and I missed it I apologize.

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  • Loading Dimension Tables - Methodologies

    - by Nev_Rahd
    Hello, Recently I been working on project, where need to populated Dim Tables from EDW Tables. EDW Tables are of type II which does maintain historical data. When comes to load Dim Table, for which source may be multiple EDW Tables or would be single table with multi level pivoting (on attributes). Mean: There would be 10 records - one for each attribute which need to be pivoted on domain_code to make a single row in Dim. Out of these 10 records there would be some attributes with same domain_code but with different sub_domain_code, which needs further pivoting on subdomain code. Ex: if i got domain code: 01,02, 03 = which are straight pivot on domain code I would also have domain code: 10 with subdomain code / version as 2006,2007,2008,2009 That means I need to split my source table with above attributes into two = one for domain code and other for domain_code + version. so far so good. When it comes to load Dim Table: As per design specs for Dimensions (originally written by third party), what they want is: for every single change in EDW (attribute), it should assemble all the related records (for that NK) mean new one with other attribute values which are current = process them to create a new dim record and insert it. That mean if a single extract contains 100 records updated (one for each NK), it should assemble 100 + (100*9) records to insert / update dim table. How good is this approach. Other way I tried to do is just do a lookup into dim table for that NK get the value's of recent records (attributes which not changed) and insert it and update the current one. What would be the better approach assembling records at source side for one attribute change or looking into dim table's recent record and process it. If this doesn't make sense, would like to elaborate it further. Thanks

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  • How to efficiently store and update binary data in Mongodb?

    - by Rocketman
    I am storing a large binary array within a document. I wish to continually add bytes to this array and sometimes change the value of existing bytes. I was looking for some $append_bytes and $replace_bytes type of modifiers but it appears that the best I can do is $push for arrays. It seems like this would be doable by performing seek-write type operations if I had access somehow to the underlying bson on disk, but it does not appear to me that there is anyway to do this in mongodb (and probably for good reason). If I were instead to just query this binary array, edit or add to it, and then update the document by rewriting the entire field, how costly will this be? Each binary array will be on the order of 1-2MB, and updates occur once every 5 minutes and across 1000s of documents. Worse, yet there is no easy way to spread these out (in time) and they will usually be happening close to one another on the 5 minute intervals. Does anyone have a good feel for how disastrous this will be? Seems like it would be problematic. An alternative would be to store this binary data as separate files on disk, implement a thread pool to efficiently manipulate the files on disk, and reference the filename from my mongodb document. (I'm using python and pymongo so I was looking at pytables). I'd prefer to avoid this though if possible. Is there any other alternative that I am overlooking here? Thanks in advnace.

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  • Will a Ph. D. in Computer Science help?

    - by Francisco Garcia
    I am close to my 30s and still learning about programming and software engineering. Like most people who like their profession I truly believe that I should aim to improve and keep updated. One of the things I do is reading technical papers from professional publications (IEEE and ACM) but I admit there are very good bloggers out there too. Lately I started to think (should I say realize?) that Ph. D people actually are expected to expand constantly their knowledge, but little is expected from lower classes once they know enough This made me think that maybe having a Ph. D will help to have more... respect? but I also believe that I am already getting old for that. Futhermore I see many master and doctor programs that does not seem to add any value over hard experience and self learning. I belive that a degree in computer science, althought not necessary, can lay out a good base for programming work. However: What can a Ph. D. degree give you that you cannot learn on your own? (if you are not into something VERY specific and want to work in a non academic environment)

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